commit 48f5c271fa5d80c5a0a00257a0e4db4b62d631eb Author: inorichi Date: Tue Aug 14 08:57:03 2018 +0200 Initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..0cadce6 --- /dev/null +++ b/.gitignore @@ -0,0 +1,11 @@ +*.iml +.gradle +/local.properties +/.idea/libraries +/.idea/modules.xml +/.idea/workspace.xml +.DS_Store +.idea/ +/build +/captures +.externalNativeBuild diff --git a/README.md b/README.md new file mode 100644 index 0000000..49a90ce --- /dev/null +++ b/README.md @@ -0,0 +1,24 @@ +Implementation of a ViewPager that supports both vertical and horizontal swiping. +It's based on the support library 27.1.1 and uses the same package as ViewPager +in order to use its interfaces and make it compatible with adapters and listeners. + +A pager can be instantiated either from XML: + +```xml + +``` + +Or from code: + +```kt +val pager = DirectionalViewPager(context, false) // true for horizontal +``` + +The direction of the pager can be changed at runtime with: + +```kt +pager.setHorizontal(!pager.isHorizontal()); +``` diff --git a/build.gradle b/build.gradle new file mode 100644 index 0000000..077cb2f --- /dev/null +++ b/build.gradle @@ -0,0 +1,27 @@ +// Top-level build file where you can add configuration options common to all sub-projects/modules. + +buildscript { + + repositories { + google() + jcenter() + } + dependencies { + classpath 'com.android.tools.build:gradle:3.1.4' + + + // NOTE: Do not place your application dependencies here; they belong + // in the individual module build.gradle files + } +} + +allprojects { + repositories { + google() + jcenter() + } +} + +task clean(type: Delete) { + delete rootProject.buildDir +} diff --git a/demo/.gitignore b/demo/.gitignore new file mode 100644 index 0000000..796b96d --- /dev/null +++ b/demo/.gitignore @@ -0,0 +1 @@ +/build diff --git a/demo/build.gradle b/demo/build.gradle new file mode 100644 index 0000000..d36258a --- /dev/null +++ b/demo/build.gradle @@ -0,0 +1,23 @@ +apply plugin: 'com.android.application' + +android { + compileSdkVersion 27 + + defaultConfig { + applicationId "android.support.directionalviewpager.demo" + minSdkVersion 14 + targetSdkVersion 27 + versionCode 1 + versionName "1.0" + } + buildTypes { + release { + minifyEnabled false + } + } +} + +dependencies { + compile project(":library") + implementation 'com.android.support:appcompat-v7:27.1.1' +} diff --git a/demo/src/main/AndroidManifest.xml b/demo/src/main/AndroidManifest.xml new file mode 100644 index 0000000..e2a2ac3 --- /dev/null +++ b/demo/src/main/AndroidManifest.xml @@ -0,0 +1,19 @@ + + + + + + + + + + + + diff --git a/demo/src/main/java/com/demo/ViewPagerActivity.java b/demo/src/main/java/com/demo/ViewPagerActivity.java new file mode 100644 index 0000000..fc09c22 --- /dev/null +++ b/demo/src/main/java/com/demo/ViewPagerActivity.java @@ -0,0 +1,88 @@ +package com.demo; + +import android.content.res.Resources; +import android.graphics.Color; +import android.graphics.drawable.ColorDrawable; +import android.os.Bundle; +import android.support.annotation.NonNull; +import android.support.annotation.Nullable; +import android.support.directionalviewpager.demo.R; +import android.support.v4.view.DirectionalViewPager; +import android.support.v4.view.PagerAdapter; +import android.support.v7.app.AppCompatActivity; +import android.support.v7.widget.Toolbar; +import android.util.TypedValue; +import android.view.Gravity; +import android.view.Menu; +import android.view.MenuItem; +import android.view.View; +import android.view.ViewGroup; +import android.widget.TextView; + +public class ViewPagerActivity extends AppCompatActivity { + + private DirectionalViewPager pager; + + @Override + protected void onCreate(@Nullable Bundle savedInstanceState) { + super.onCreate(savedInstanceState); + setContentView(R.layout.activity_main); + + Toolbar toolbar = findViewById(R.id.toolbar); + pager = findViewById(R.id.pager); + + setSupportActionBar(toolbar); + pager.setAdapter(new Adapter()); + + Resources r = getResources(); + int margin = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 32, r.getDisplayMetrics()); + pager.setPageMargin(margin); + pager.setPageMarginDrawable(new ColorDrawable(Color.BLACK)); + } + + @Override + public boolean onCreateOptionsMenu(Menu menu) { + getMenuInflater().inflate(R.menu.main, menu); + return true; + } + + @Override + public boolean onOptionsItemSelected(MenuItem item) { + if (item.getItemId() == R.id.action_swap) { + pager.setHorizontal(!pager.isHorizontal()); + return true; + } + return false; + } + + class Adapter extends PagerAdapter { + + @Override + public int getCount() { + return 5; + } + + @NonNull + @Override + public Object instantiateItem(@NonNull ViewGroup container, int position) { + TextView text = new TextView(container.getContext()); + text.setGravity(Gravity.CENTER); + text.setTextSize(64); + text.setText("" + position); + container.addView(text); + return text; + } + + @Override + public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) { + View view = (View) object; + container.removeView(view); + } + + @Override + public boolean isViewFromObject(@NonNull View view, @NonNull Object object) { + return view == object; + } + } + +} diff --git a/demo/src/main/res/drawable-v24/ic_launcher_foreground.xml b/demo/src/main/res/drawable-v24/ic_launcher_foreground.xml new file mode 100644 index 0000000..c3903ed --- /dev/null +++ b/demo/src/main/res/drawable-v24/ic_launcher_foreground.xml @@ -0,0 +1,34 @@ + + + + + + + + + + + diff --git a/demo/src/main/res/drawable/ic_launcher_background.xml b/demo/src/main/res/drawable/ic_launcher_background.xml new file mode 100644 index 0000000..310fdaa --- /dev/null +++ b/demo/src/main/res/drawable/ic_launcher_background.xml @@ -0,0 +1,170 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + diff --git a/demo/src/main/res/layout/activity_main.xml b/demo/src/main/res/layout/activity_main.xml new file mode 100644 index 0000000..a1d54c8 --- /dev/null +++ b/demo/src/main/res/layout/activity_main.xml @@ -0,0 +1,19 @@ + + + + + + + diff --git a/demo/src/main/res/menu/main.xml b/demo/src/main/res/menu/main.xml new file mode 100644 index 0000000..9b072f7 --- /dev/null +++ b/demo/src/main/res/menu/main.xml @@ -0,0 +1,8 @@ + + + + + diff --git a/demo/src/main/res/mipmap-anydpi-v26/ic_launcher.xml b/demo/src/main/res/mipmap-anydpi-v26/ic_launcher.xml new file mode 100644 index 0000000..d378acd --- /dev/null +++ b/demo/src/main/res/mipmap-anydpi-v26/ic_launcher.xml @@ -0,0 +1,5 @@ + + + + + diff --git a/demo/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml b/demo/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml new file mode 100644 index 0000000..d378acd --- /dev/null +++ b/demo/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml @@ -0,0 +1,5 @@ + + + + + diff --git a/demo/src/main/res/mipmap-hdpi/ic_launcher.png b/demo/src/main/res/mipmap-hdpi/ic_launcher.png new file mode 100644 index 0000000..a2f5908 Binary files /dev/null and b/demo/src/main/res/mipmap-hdpi/ic_launcher.png differ diff --git a/demo/src/main/res/mipmap-hdpi/ic_launcher_round.png b/demo/src/main/res/mipmap-hdpi/ic_launcher_round.png new file mode 100644 index 0000000..1b52399 Binary files /dev/null and b/demo/src/main/res/mipmap-hdpi/ic_launcher_round.png differ diff --git a/demo/src/main/res/mipmap-mdpi/ic_launcher.png b/demo/src/main/res/mipmap-mdpi/ic_launcher.png new file mode 100644 index 0000000..ff10afd Binary files /dev/null and b/demo/src/main/res/mipmap-mdpi/ic_launcher.png differ diff --git a/demo/src/main/res/mipmap-mdpi/ic_launcher_round.png b/demo/src/main/res/mipmap-mdpi/ic_launcher_round.png new file mode 100644 index 0000000..115a4c7 Binary files /dev/null and b/demo/src/main/res/mipmap-mdpi/ic_launcher_round.png differ diff --git a/demo/src/main/res/mipmap-xhdpi/ic_launcher.png b/demo/src/main/res/mipmap-xhdpi/ic_launcher.png new file mode 100644 index 0000000..dcd3cd8 Binary files /dev/null and b/demo/src/main/res/mipmap-xhdpi/ic_launcher.png differ diff --git a/demo/src/main/res/mipmap-xhdpi/ic_launcher_round.png b/demo/src/main/res/mipmap-xhdpi/ic_launcher_round.png new file mode 100644 index 0000000..459ca60 Binary files /dev/null and b/demo/src/main/res/mipmap-xhdpi/ic_launcher_round.png differ diff --git a/demo/src/main/res/mipmap-xxhdpi/ic_launcher.png b/demo/src/main/res/mipmap-xxhdpi/ic_launcher.png new file mode 100644 index 0000000..8ca12fe Binary files /dev/null and b/demo/src/main/res/mipmap-xxhdpi/ic_launcher.png differ diff --git a/demo/src/main/res/mipmap-xxhdpi/ic_launcher_round.png b/demo/src/main/res/mipmap-xxhdpi/ic_launcher_round.png new file mode 100644 index 0000000..8e19b41 Binary files /dev/null and b/demo/src/main/res/mipmap-xxhdpi/ic_launcher_round.png differ diff --git a/demo/src/main/res/mipmap-xxxhdpi/ic_launcher.png b/demo/src/main/res/mipmap-xxxhdpi/ic_launcher.png new file mode 100644 index 0000000..b824ebd Binary files /dev/null and b/demo/src/main/res/mipmap-xxxhdpi/ic_launcher.png differ diff --git a/demo/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png b/demo/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png new file mode 100644 index 0000000..4c19a13 Binary files /dev/null and b/demo/src/main/res/mipmap-xxxhdpi/ic_launcher_round.png differ diff --git a/demo/src/main/res/values/colors.xml b/demo/src/main/res/values/colors.xml new file mode 100644 index 0000000..3ab3e9c --- /dev/null +++ b/demo/src/main/res/values/colors.xml @@ -0,0 +1,6 @@ + + + #3F51B5 + #303F9F + #FF4081 + diff --git a/demo/src/main/res/values/strings.xml b/demo/src/main/res/values/strings.xml new file mode 100644 index 0000000..6d83485 --- /dev/null +++ b/demo/src/main/res/values/strings.xml @@ -0,0 +1,3 @@ + + DirectionalViewPager + diff --git a/demo/src/main/res/values/styles.xml b/demo/src/main/res/values/styles.xml new file mode 100644 index 0000000..0eb88fe --- /dev/null +++ b/demo/src/main/res/values/styles.xml @@ -0,0 +1,11 @@ + + + + + + diff --git a/gradle.properties b/gradle.properties new file mode 100644 index 0000000..743d692 --- /dev/null +++ b/gradle.properties @@ -0,0 +1,13 @@ +# Project-wide Gradle settings. +# IDE (e.g. Android Studio) users: +# Gradle settings configured through the IDE *will override* +# any settings specified in this file. +# For more details on how to configure your build environment visit +# http://www.gradle.org/docs/current/userguide/build_environment.html +# Specifies the JVM arguments used for the daemon process. +# The setting is particularly useful for tweaking memory settings. +org.gradle.jvmargs=-Xmx1536m +# When configured, Gradle will run in incubating parallel mode. +# This option should only be used with decoupled projects. More details, visit +# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects +# org.gradle.parallel=true diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 0000000..7a3265e Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000..030edbc --- /dev/null +++ b/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,6 @@ +#Mon Aug 13 15:53:04 CEST 2018 +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists +distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip diff --git a/gradlew b/gradlew new file mode 100755 index 0000000..cccdd3d --- /dev/null +++ b/gradlew @@ -0,0 +1,172 @@ +#!/usr/bin/env sh + +############################################################################## +## +## Gradle start up script for UN*X +## +############################################################################## + +# Attempt to set APP_HOME +# Resolve links: $0 may be a link +PRG="$0" +# Need this for relative symlinks. +while [ -h "$PRG" ] ; do + ls=`ls -ld "$PRG"` + link=`expr "$ls" : '.*-> \(.*\)$'` + if expr "$link" : '/.*' > /dev/null; then + PRG="$link" + else + PRG=`dirname "$PRG"`"/$link" + fi +done +SAVED="`pwd`" +cd "`dirname \"$PRG\"`/" >/dev/null +APP_HOME="`pwd -P`" +cd "$SAVED" >/dev/null + +APP_NAME="Gradle" +APP_BASE_NAME=`basename "$0"` + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS="" + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD="maximum" + +warn () { + echo "$*" +} + +die () { + echo + echo "$*" + echo + exit 1 +} + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "`uname`" in + CYGWIN* ) + cygwin=true + ;; + Darwin* ) + darwin=true + ;; + MINGW* ) + msys=true + ;; + NONSTOP* ) + nonstop=true + ;; +esac + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD="$JAVA_HOME/jre/sh/java" + else + JAVACMD="$JAVA_HOME/bin/java" + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD="java" + which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." +fi + +# Increase the maximum file descriptors if we can. +if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then + MAX_FD_LIMIT=`ulimit -H -n` + if [ $? -eq 0 ] ; then + if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then + MAX_FD="$MAX_FD_LIMIT" + fi + ulimit -n $MAX_FD + if [ $? -ne 0 ] ; then + warn "Could not set maximum file descriptor limit: $MAX_FD" + fi + else + warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT" + fi +fi + +# For Darwin, add options to specify how the application appears in the dock +if $darwin; then + GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\"" +fi + +# For Cygwin, switch paths to Windows format before running java +if $cygwin ; then + APP_HOME=`cygpath --path --mixed "$APP_HOME"` + CLASSPATH=`cygpath --path --mixed "$CLASSPATH"` + JAVACMD=`cygpath --unix "$JAVACMD"` + + # We build the pattern for arguments to be converted via cygpath + ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null` + SEP="" + for dir in $ROOTDIRSRAW ; do + ROOTDIRS="$ROOTDIRS$SEP$dir" + SEP="|" + done + OURCYGPATTERN="(^($ROOTDIRS))" + # Add a user-defined pattern to the cygpath arguments + if [ "$GRADLE_CYGPATTERN" != "" ] ; then + OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)" + fi + # Now convert the arguments - kludge to limit ourselves to /bin/sh + i=0 + for arg in "$@" ; do + CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -` + CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option + + if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition + eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"` + else + eval `echo args$i`="\"$arg\"" + fi + i=$((i+1)) + done + case $i in + (0) set -- ;; + (1) set -- "$args0" ;; + (2) set -- "$args0" "$args1" ;; + (3) set -- "$args0" "$args1" "$args2" ;; + (4) set -- "$args0" "$args1" "$args2" "$args3" ;; + (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;; + (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;; + (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;; + (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;; + (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;; + esac +fi + +# Escape application args +save () { + for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done + echo " " +} +APP_ARGS=$(save "$@") + +# Collect all arguments for the java command, following the shell quoting and substitution rules +eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS" + +# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong +if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then + cd "$(dirname "$0")" +fi + +exec "$JAVACMD" "$@" diff --git a/gradlew.bat b/gradlew.bat new file mode 100644 index 0000000..f955316 --- /dev/null +++ b/gradlew.bat @@ -0,0 +1,84 @@ +@if "%DEBUG%" == "" @echo off +@rem ########################################################################## +@rem +@rem Gradle startup script for Windows +@rem +@rem ########################################################################## + +@rem Set local scope for the variables with windows NT shell +if "%OS%"=="Windows_NT" setlocal + +set DIRNAME=%~dp0 +if "%DIRNAME%" == "" set DIRNAME=. +set APP_BASE_NAME=%~n0 +set APP_HOME=%DIRNAME% + +@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +set DEFAULT_JVM_OPTS= + +@rem Find java.exe +if defined JAVA_HOME goto findJavaFromJavaHome + +set JAVA_EXE=java.exe +%JAVA_EXE% -version >NUL 2>&1 +if "%ERRORLEVEL%" == "0" goto init + +echo. +echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. +echo. +echo Please set the JAVA_HOME variable in your environment to match the +echo location of your Java installation. + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +set JAVA_EXE=%JAVA_HOME%/bin/java.exe + +if exist "%JAVA_EXE%" goto init + +echo. +echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% +echo. +echo Please set the JAVA_HOME variable in your environment to match the +echo location of your Java installation. + +goto fail + +:init +@rem Get command-line arguments, handling Windows variants + +if not "%OS%" == "Windows_NT" goto win9xME_args + +:win9xME_args +@rem Slurp the command line arguments. +set CMD_LINE_ARGS= +set _SKIP=2 + +:win9xME_args_slurp +if "x%~1" == "x" goto execute + +set CMD_LINE_ARGS=%* + +:execute +@rem Setup the command line + +set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar + +@rem Execute Gradle +"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS% + +:end +@rem End local scope for the variables with windows NT shell +if "%ERRORLEVEL%"=="0" goto mainEnd + +:fail +rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of +rem the _cmd.exe /c_ return code! +if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1 +exit /b 1 + +:mainEnd +if "%OS%"=="Windows_NT" endlocal + +:omega diff --git a/library/.gitignore b/library/.gitignore new file mode 100644 index 0000000..796b96d --- /dev/null +++ b/library/.gitignore @@ -0,0 +1 @@ +/build diff --git a/library/build.gradle b/library/build.gradle new file mode 100644 index 0000000..2f2464f --- /dev/null +++ b/library/build.gradle @@ -0,0 +1,22 @@ +apply plugin: 'com.android.library' + +android { + compileSdkVersion 27 + + defaultConfig { + minSdkVersion 14 + targetSdkVersion 27 + versionCode 1 + versionName "1.0" + } + + buildTypes { + release { + minifyEnabled false + } + } +} + +dependencies { + compileOnly 'com.android.support:support-core-ui:27.1.1' +} diff --git a/library/src/main/AndroidManifest.xml b/library/src/main/AndroidManifest.xml new file mode 100644 index 0000000..0a416b6 --- /dev/null +++ b/library/src/main/AndroidManifest.xml @@ -0,0 +1,2 @@ + diff --git a/library/src/main/java/android/support/v4/view/DirectionalViewPager.java b/library/src/main/java/android/support/v4/view/DirectionalViewPager.java new file mode 100644 index 0000000..d7efbbb --- /dev/null +++ b/library/src/main/java/android/support/v4/view/DirectionalViewPager.java @@ -0,0 +1,3472 @@ +/* + * Copyright (C) 2011 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package android.support.v4.view; + +import android.content.Context; +import android.content.res.Resources; +import android.content.res.TypedArray; +import android.database.DataSetObserver; +import android.graphics.Canvas; +import android.graphics.Rect; +import android.graphics.drawable.Drawable; +import android.os.Bundle; +import android.os.Parcel; +import android.os.Parcelable; +import android.os.SystemClock; +import android.support.annotation.CallSuper; +import android.support.annotation.DrawableRes; +import android.support.annotation.NonNull; +import android.support.annotation.Nullable; +import android.support.directionalviewpager.R; +import android.support.v4.content.ContextCompat; +import android.support.v4.view.accessibility.AccessibilityEventCompat; +import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat; +import android.util.AttributeSet; +import android.util.Log; +import android.view.FocusFinder; +import android.view.Gravity; +import android.view.KeyEvent; +import android.view.MotionEvent; +import android.view.SoundEffectConstants; +import android.view.VelocityTracker; +import android.view.View; +import android.view.ViewConfiguration; +import android.view.ViewGroup; +import android.view.ViewParent; +import android.view.accessibility.AccessibilityEvent; +import android.view.animation.Interpolator; +import android.widget.EdgeEffect; +import android.widget.Scroller; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; + +import static android.support.v4.view.ViewPager.OnPageChangeListener; +import static android.support.v4.view.ViewPager.PageTransformer; + +/** + * Layout manager that allows the user to flip left and right + * through pages of data. You supply an implementation of a + * {@link PagerAdapter} to generate the pages that the view shows. + * + *

ViewPager is most often used in conjunction with {@link android.app.Fragment}, + * which is a convenient way to supply and manage the lifecycle of each page. + * There are standard adapters implemented for using fragments with the ViewPager, + * which cover the most common use cases. These are + * {@link android.support.v4.app.FragmentPagerAdapter} and + * {@link android.support.v4.app.FragmentStatePagerAdapter}; each of these + * classes have simple code showing how to build a full user interface + * with them. + * + *

Views which are annotated with the {@link DecorView} annotation are treated as + * part of the view pagers 'decor'. Each decor view's position can be controlled via + * its {@code android:layout_gravity} attribute. For example: + * + * 

+ * <android.support.v4.view.ViewPager
+ *     android:layout_width="match_parent"
+ *     android:layout_height="match_parent">
+ *
+ *     <android.support.v4.view.PagerTitleStrip
+ *         android:layout_width="match_parent"
+ *         android:layout_height="wrap_content"
+ *         android:layout_gravity="top" />
+ *
+ * </android.support.v4.view.ViewPager>
+ *
+ * + *

For more information about how to use ViewPager, read Creating Swipe Views with + * Tabs.

+ * + *

You can find examples of using ViewPager in the API 4+ Support Demos and API 13+ Support Demos + * sample code. + */ +@SuppressWarnings("ALL") +public class DirectionalViewPager extends ViewGroup { + private static final String TAG = "ViewPager"; + private static final boolean DEBUG = true; + + private static final boolean USE_CACHE = false; + + private static final int DEFAULT_OFFSCREEN_PAGES = 1; + private static final int MAX_SETTLE_DURATION = 600; // ms + private static final int MIN_DISTANCE_FOR_FLING = 25; // dips + + private static final int DEFAULT_GUTTER_SIZE = 16; // dips + + private static final int MIN_FLING_VELOCITY = 400; // dips + + static final int[] LAYOUT_ATTRS = new int[] { + android.R.attr.layout_gravity + }; + + /** + * Used to track what the expected number of items in the adapter should be. + * If the app changes this when we don't expect it, we'll throw a big obnoxious exception. + */ + private int mExpectedAdapterCount; + + static class ItemInfo { + Object object; + int position; + boolean scrolling; + float widthFactor; + float offset; + } + + private static final Comparator COMPARATOR = new Comparator(){ + @Override + public int compare(ItemInfo lhs, ItemInfo rhs) { + return lhs.position - rhs.position; + } + }; + + private static final Interpolator sInterpolator = new Interpolator() { + @Override + public float getInterpolation(float t) { + t -= 1.0f; + return t * t * t * t * t + 1.0f; + } + }; + + private final ArrayList mItems = new ArrayList(); + private final ItemInfo mTempItem = new ItemInfo(); + + private final Rect mTempRect = new Rect(); + + PagerAdapter mAdapter; + int mCurItem; // Index of currently displayed page. + private int mRestoredCurItem = -1; + private Parcelable mRestoredAdapterState = null; + private ClassLoader mRestoredClassLoader = null; + + private Scroller mScroller; + private boolean mIsScrollStarted; + + private PagerObserver mObserver; + + private int mPageMargin; + private Drawable mMarginDrawable; + private int mTopPageBounds; + private int mBottomPageBounds; + private int mLeftPageBounds; + private int mRightPageBounds; + + // Offsets of the first and last items, if known. + // Set during population, used to determine if we are at the beginning + // or end of the pager data set during touch scrolling. + private float mFirstOffset = -Float.MAX_VALUE; + private float mLastOffset = Float.MAX_VALUE; + + private int mChildWidthMeasureSpec; + private int mChildHeightMeasureSpec; + private boolean mInLayout; + + private boolean mScrollingCacheEnabled; + + private boolean mPopulatePending; + private int mOffscreenPageLimit = DEFAULT_OFFSCREEN_PAGES; + + private boolean mIsBeingDragged; + private boolean mIsUnableToDrag; + private int mDefaultGutterSize; + private int mGutterSize; + private int mTouchSlop; + /** + * Position of the last motion event. + */ + private float mLastMotionX; + private float mLastMotionY; + private float mInitialMotionX; + private float mInitialMotionY; + /** + * ID of the active pointer. This is used to retain consistency during + * drags/flings if multiple pointers are used. + */ + private int mActivePointerId = INVALID_POINTER; + /** + * Sentinel value for no current active pointer. + * Used by {@link #mActivePointerId}. + */ + private static final int INVALID_POINTER = -1; + + /** + * Determines speed during touch scrolling + */ + private VelocityTracker mVelocityTracker; + private int mMinimumVelocity; + private int mMaximumVelocity; + private int mFlingDistance; + private int mCloseEnough; + + // If the pager is at least this close to its final position, complete the scroll + // on touch down and let the user interact with the content inside instead of + // "catching" the flinging pager. + private static final int CLOSE_ENOUGH = 2; // dp + + private boolean mFakeDragging; + private long mFakeDragBeginTime; + + private EdgeEffect mStartEdge; + private EdgeEffect mEndEdge; + + private boolean mFirstLayout = true; + private boolean mNeedCalculatePageOffsets = false; + private boolean mCalledSuper; + private int mDecorChildCount; + + private List mOnPageChangeListeners; + private OnPageChangeListener mOnPageChangeListener; + private OnPageChangeListener mInternalPageChangeListener; + private List mAdapterChangeListeners; + private PageTransformer mPageTransformer; + private int mPageTransformerLayerType; + + private static final int DRAW_ORDER_DEFAULT = 0; + private static final int DRAW_ORDER_FORWARD = 1; + private static final int DRAW_ORDER_REVERSE = 2; + private int mDrawingOrder; + private ArrayList mDrawingOrderedChildren; + private static final ViewPositionComparator sPositionComparator = new ViewPositionComparator(); + + private boolean isHorizontal = true; + + /** + * Indicates that the pager is in an idle, settled state. The current page + * is fully in view and no animation is in progress. + */ + public static final int SCROLL_STATE_IDLE = 0; + + /** + * Indicates that the pager is currently being dragged by the user. + */ + public static final int SCROLL_STATE_DRAGGING = 1; + + /** + * Indicates that the pager is in the process of settling to a final position. + */ + public static final int SCROLL_STATE_SETTLING = 2; + + private final Runnable mEndScrollRunnable = new Runnable() { + @Override + public void run() { + setScrollState(SCROLL_STATE_IDLE); + populate(); + } + }; + + private int mScrollState = SCROLL_STATE_IDLE; + + /** + * Callback interface for responding to adapter changes. + */ + public interface OnAdapterChangeListener { + /** + * Called when the adapter for the given view pager has changed. + * + * @param viewPager ViewPager where the adapter change has happened + * @param oldAdapter the previously set adapter + * @param newAdapter the newly set adapter + */ + void onAdapterChanged(@NonNull DirectionalViewPager viewPager, + @Nullable PagerAdapter oldAdapter, @Nullable PagerAdapter newAdapter); + } + + public DirectionalViewPager(@NonNull Context context) { + this(context, true); + } + + public DirectionalViewPager(@NonNull Context context, boolean isHorizontal) { + super(context); + this.isHorizontal = isHorizontal; + initViewPager(); + } + + public DirectionalViewPager(@NonNull Context context, @Nullable AttributeSet attrs) { + super(context, attrs); + final TypedArray a = context.getTheme().obtainStyledAttributes( + attrs, + R.styleable.DirectionalViewPager, + 0, 0); + + try { + isHorizontal = a.getInt(R.styleable.DirectionalViewPager_android_orientation,0) != 1; + initViewPager(); + } finally { + a.recycle(); + } + } + + void initViewPager() { + setWillNotDraw(false); + setDescendantFocusability(FOCUS_AFTER_DESCENDANTS); + setFocusable(true); + final Context context = getContext(); + mScroller = new Scroller(context, sInterpolator); + final ViewConfiguration configuration = ViewConfiguration.get(context); + final float density = context.getResources().getDisplayMetrics().density; + + mTouchSlop = configuration.getScaledPagingTouchSlop(); + mMinimumVelocity = (int) (MIN_FLING_VELOCITY * density); + mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); + mStartEdge = new EdgeEffect(context); + mEndEdge = new EdgeEffect(context); + + mFlingDistance = (int) (MIN_DISTANCE_FOR_FLING * density); + mCloseEnough = (int) (CLOSE_ENOUGH * density); + mDefaultGutterSize = (int) (DEFAULT_GUTTER_SIZE * density); + + ViewCompat.setAccessibilityDelegate(this, new MyAccessibilityDelegate()); + + if (ViewCompat.getImportantForAccessibility(this) + == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_AUTO) { + ViewCompat.setImportantForAccessibility(this, + ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_YES); + } + + ViewCompat.setOnApplyWindowInsetsListener(this, + new android.support.v4.view.OnApplyWindowInsetsListener() { + private final Rect mTempRect = new Rect(); + + @Override + public WindowInsetsCompat onApplyWindowInsets(final View v, + final WindowInsetsCompat originalInsets) { + // First let the ViewPager itself try and consume them... + final WindowInsetsCompat applied = + ViewCompat.onApplyWindowInsets(v, originalInsets); + if (applied.isConsumed()) { + // If the ViewPager consumed all insets, return now + return applied; + } + + // Now we'll manually dispatch the insets to our children. Since ViewPager + // children are always full-height, we do not want to use the standard + // ViewGroup dispatchApplyWindowInsets since if child 0 consumes them, + // the rest of the children will not receive any insets. To workaround this + // we manually dispatch the applied insets, not allowing children to + // consume them from each other. We do however keep track of any insets + // which are consumed, returning the union of our children's consumption + final Rect res = mTempRect; + res.left = applied.getSystemWindowInsetLeft(); + res.top = applied.getSystemWindowInsetTop(); + res.right = applied.getSystemWindowInsetRight(); + res.bottom = applied.getSystemWindowInsetBottom(); + + for (int i = 0, count = getChildCount(); i < count; i++) { + final WindowInsetsCompat childInsets = ViewCompat + .dispatchApplyWindowInsets(getChildAt(i), applied); + // Now keep track of any consumed by tracking each dimension's min + // value + res.left = Math.min(childInsets.getSystemWindowInsetLeft(), + res.left); + res.top = Math.min(childInsets.getSystemWindowInsetTop(), + res.top); + res.right = Math.min(childInsets.getSystemWindowInsetRight(), + res.right); + res.bottom = Math.min(childInsets.getSystemWindowInsetBottom(), + res.bottom); + } + + // Now return a new WindowInsets, using the consumed window insets + return applied.replaceSystemWindowInsets( + res.left, res.top, res.right, res.bottom); + } + }); + } + + @Override + protected void onDetachedFromWindow() { + removeCallbacks(mEndScrollRunnable); + // To be on the safe side, abort the scroller + if ((mScroller != null) && !mScroller.isFinished()) { + mScroller.abortAnimation(); + } + super.onDetachedFromWindow(); + } + + void setScrollState(int newState) { + if (mScrollState == newState) { + return; + } + + mScrollState = newState; + if (mPageTransformer != null) { + // PageTransformers can do complex things that benefit from hardware layers. + enableLayers(newState != SCROLL_STATE_IDLE); + } + dispatchOnScrollStateChanged(newState); + } + + /** + * Set a PagerAdapter that will supply views for this pager as needed. + * + * @param adapter Adapter to use + */ + public void setAdapter(@Nullable PagerAdapter adapter) { + if (mAdapter != null) { + mAdapter.setViewPagerObserver(null); + mAdapter.startUpdate(this); + for (int i = 0; i < mItems.size(); i++) { + final ItemInfo ii = mItems.get(i); + mAdapter.destroyItem(this, ii.position, ii.object); + } + mAdapter.finishUpdate(this); + mItems.clear(); + removeNonDecorViews(); + mCurItem = 0; + scrollTo(0, 0); + } + + final PagerAdapter oldAdapter = mAdapter; + mAdapter = adapter; + mExpectedAdapterCount = 0; + + if (mAdapter != null) { + if (mObserver == null) { + mObserver = new PagerObserver(); + } + mAdapter.setViewPagerObserver(mObserver); + mPopulatePending = false; + final boolean wasFirstLayout = mFirstLayout; + mFirstLayout = true; + mExpectedAdapterCount = mAdapter.getCount(); + if (mRestoredCurItem >= 0) { + mAdapter.restoreState(mRestoredAdapterState, mRestoredClassLoader); + setCurrentItemInternal(mRestoredCurItem, false, true); + mRestoredCurItem = -1; + mRestoredAdapterState = null; + mRestoredClassLoader = null; + } else if (!wasFirstLayout) { + populate(); + } else { + requestLayout(); + } + } + + // Dispatch the change to any listeners + if (mAdapterChangeListeners != null && !mAdapterChangeListeners.isEmpty()) { + for (int i = 0, count = mAdapterChangeListeners.size(); i < count; i++) { + mAdapterChangeListeners.get(i).onAdapterChanged(this, oldAdapter, adapter); + } + } + } + + private void removeNonDecorViews() { + for (int i = 0; i < getChildCount(); i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (!lp.isDecor) { + removeViewAt(i); + i--; + } + } + } + + /** + * Retrieve the current adapter supplying pages. + * + * @return The currently registered PagerAdapter + */ + @Nullable + public PagerAdapter getAdapter() { + return mAdapter; + } + + /** + * Add a listener that will be invoked whenever the adapter for this ViewPager changes. + * + * @param listener listener to add + */ + public void addOnAdapterChangeListener(@NonNull OnAdapterChangeListener listener) { + if (mAdapterChangeListeners == null) { + mAdapterChangeListeners = new ArrayList<>(); + } + mAdapterChangeListeners.add(listener); + } + + /** + * Remove a listener that was previously added via + * {@link #addOnAdapterChangeListener(OnAdapterChangeListener)}. + * + * @param listener listener to remove + */ + public void removeOnAdapterChangeListener(@NonNull OnAdapterChangeListener listener) { + if (mAdapterChangeListeners != null) { + mAdapterChangeListeners.remove(listener); + } + } + + private int getClientWidth() { + return getMeasuredWidth() - getPaddingLeft() - getPaddingRight(); + } + + private int getClientHeight() { + return getMeasuredHeight() - getPaddingTop() - getPaddingBottom(); + } + + private int getClientSize() { + return isHorizontal ? getClientWidth() : getClientHeight(); + } + + /** + * Set the currently selected page. If the ViewPager has already been through its first + * layout with its current adapter there will be a smooth animated transition between + * the current item and the specified item. + * + * @param item Item index to select + */ + public void setCurrentItem(int item) { + mPopulatePending = false; + setCurrentItemInternal(item, !mFirstLayout, false); + } + + /** + * Set the currently selected page. + * + * @param item Item index to select + * @param smoothScroll True to smoothly scroll to the new item, false to transition immediately + */ + public void setCurrentItem(int item, boolean smoothScroll) { + mPopulatePending = false; + setCurrentItemInternal(item, smoothScroll, false); + } + + public int getCurrentItem() { + return mCurItem; + } + + void setCurrentItemInternal(int item, boolean smoothScroll, boolean always) { + setCurrentItemInternal(item, smoothScroll, always, 0); + } + + void setCurrentItemInternal(int item, boolean smoothScroll, boolean always, int velocity) { + if (mAdapter == null || mAdapter.getCount() <= 0) { + setScrollingCacheEnabled(false); + return; + } + if (!always && mCurItem == item && mItems.size() != 0) { + setScrollingCacheEnabled(false); + return; + } + + if (item < 0) { + item = 0; + } else if (item >= mAdapter.getCount()) { + item = mAdapter.getCount() - 1; + } + final int pageLimit = mOffscreenPageLimit; + if (item > (mCurItem + pageLimit) || item < (mCurItem - pageLimit)) { + // We are doing a jump by more than one page. To avoid + // glitches, we want to keep all current pages in the view + // until the scroll ends. + for (int i = 0; i < mItems.size(); i++) { + mItems.get(i).scrolling = true; + } + } + final boolean dispatchSelected = mCurItem != item; + + if (mFirstLayout) { + // We don't have any idea how big we are yet and shouldn't have any pages either. + // Just set things up and let the pending layout handle things. + mCurItem = item; + if (dispatchSelected) { + dispatchOnPageSelected(item); + } + requestLayout(); + } else { + populate(item); + scrollToItem(item, smoothScroll, velocity, dispatchSelected); + } + } + + private void scrollToItem(int item, boolean smoothScroll, int velocity, + boolean dispatchSelected) { + final ItemInfo curInfo = infoForPosition(item); + int destX = 0; + int destY = 0; + if (curInfo != null) { + if (isHorizontal) { + destX = (int) (getClientWidth() * Math.max(mFirstOffset, + Math.min(curInfo.offset, mLastOffset))); + } else { + destY = (int) (getClientHeight() * Math.max(mFirstOffset, + Math.min(curInfo.offset, mLastOffset))); + } + } + if (smoothScroll) { + smoothScrollTo(destX, destY, velocity); + if (dispatchSelected) { + dispatchOnPageSelected(item); + } + } else { + if (dispatchSelected) { + dispatchOnPageSelected(item); + } + completeScroll(false); + scrollTo(destX, destY); + pageScrolled(destX, destY); + } + } + + /** + * Set a listener that will be invoked whenever the page changes or is incrementally + * scrolled. See {@link OnPageChangeListener}. + * + * @param listener Listener to set + * + * @deprecated Use {@link #addOnPageChangeListener(OnPageChangeListener)} + * and {@link #removeOnPageChangeListener(OnPageChangeListener)} instead. + */ + @Deprecated + public void setOnPageChangeListener(OnPageChangeListener listener) { + mOnPageChangeListener = listener; + } + + /** + * Add a listener that will be invoked whenever the page changes or is incrementally + * scrolled. See {@link OnPageChangeListener}. + * + *

Components that add a listener should take care to remove it when finished. + * Other components that take ownership of a view may call {@link #clearOnPageChangeListeners()} + * to remove all attached listeners.

+ * + * @param listener listener to add + */ + public void addOnPageChangeListener(@NonNull OnPageChangeListener listener) { + if (mOnPageChangeListeners == null) { + mOnPageChangeListeners = new ArrayList<>(); + } + mOnPageChangeListeners.add(listener); + } + + /** + * Remove a listener that was previously added via + * {@link #addOnPageChangeListener(OnPageChangeListener)}. + * + * @param listener listener to remove + */ + public void removeOnPageChangeListener(@NonNull OnPageChangeListener listener) { + if (mOnPageChangeListeners != null) { + mOnPageChangeListeners.remove(listener); + } + } + + /** + * Remove all listeners that are notified of any changes in scroll state or position. + */ + public void clearOnPageChangeListeners() { + if (mOnPageChangeListeners != null) { + mOnPageChangeListeners.clear(); + } + } + + /** + * Sets a {@link PageTransformer} that will be called for each attached page whenever + * the scroll position is changed. This allows the application to apply custom property + * transformations to each page, overriding the default sliding behavior. + * + *

Note: By default, calling this method will cause contained pages to use + * {@link View#LAYER_TYPE_HARDWARE}. This layer type allows custom alpha transformations, + * but it will cause issues if any of your pages contain a {@link android.view.SurfaceView} + * and you have not called {@link android.view.SurfaceView#setZOrderOnTop(boolean)} to put that + * {@link android.view.SurfaceView} above your app content. To disable this behavior, call + * {@link #setPageTransformer(boolean,PageTransformer,int)} and pass + * {@link View#LAYER_TYPE_NONE} for {@code pageLayerType}.

+ * + * @param reverseDrawingOrder true if the supplied PageTransformer requires page views + * to be drawn from last to first instead of first to last. + * @param transformer PageTransformer that will modify each page's animation properties + */ + public void setPageTransformer(boolean reverseDrawingOrder, + @Nullable PageTransformer transformer) { + setPageTransformer(reverseDrawingOrder, transformer, View.LAYER_TYPE_HARDWARE); + } + + /** + * Sets a {@link PageTransformer} that will be called for each attached page whenever + * the scroll position is changed. This allows the application to apply custom property + * transformations to each page, overriding the default sliding behavior. + * + * @param reverseDrawingOrder true if the supplied PageTransformer requires page views + * to be drawn from last to first instead of first to last. + * @param transformer PageTransformer that will modify each page's animation properties + * @param pageLayerType View layer type that should be used for ViewPager pages. It should be + * either {@link View#LAYER_TYPE_HARDWARE}, + * {@link View#LAYER_TYPE_SOFTWARE}, or + * {@link View#LAYER_TYPE_NONE}. + */ + public void setPageTransformer(boolean reverseDrawingOrder, + @Nullable PageTransformer transformer, int pageLayerType) { + final boolean hasTransformer = transformer != null; + final boolean needsPopulate = hasTransformer != (mPageTransformer != null); + mPageTransformer = transformer; + setChildrenDrawingOrderEnabled(hasTransformer); + if (hasTransformer) { + mDrawingOrder = reverseDrawingOrder ? DRAW_ORDER_REVERSE : DRAW_ORDER_FORWARD; + mPageTransformerLayerType = pageLayerType; + } else { + mDrawingOrder = DRAW_ORDER_DEFAULT; + } + if (needsPopulate) populate(); + } + + @Override + protected int getChildDrawingOrder(int childCount, int i) { + final int index = mDrawingOrder == DRAW_ORDER_REVERSE ? childCount - 1 - i : i; + final int result = + ((LayoutParams) mDrawingOrderedChildren.get(index).getLayoutParams()).childIndex; + return result; + } + + /** + * Set a separate OnPageChangeListener for internal use by the support library. + * + * @param listener Listener to set + * @return The old listener that was set, if any. + */ + OnPageChangeListener setInternalPageChangeListener(OnPageChangeListener listener) { + OnPageChangeListener oldListener = mInternalPageChangeListener; + mInternalPageChangeListener = listener; + return oldListener; + } + + /** + * Returns the number of pages that will be retained to either side of the + * current page in the view hierarchy in an idle state. Defaults to 1. + * + * @return How many pages will be kept offscreen on either side + * @see #setOffscreenPageLimit(int) + */ + public int getOffscreenPageLimit() { + return mOffscreenPageLimit; + } + + /** + * Set the number of pages that should be retained to either side of the + * current page in the view hierarchy in an idle state. Pages beyond this + * limit will be recreated from the adapter when needed. + * + *

This is offered as an optimization. If you know in advance the number + * of pages you will need to support or have lazy-loading mechanisms in place + * on your pages, tweaking this setting can have benefits in perceived smoothness + * of paging animations and interaction. If you have a small number of pages (3-4) + * that you can keep active all at once, less time will be spent in layout for + * newly created view subtrees as the user pages back and forth.

+ * + *

You should keep this limit low, especially if your pages have complex layouts. + * This setting defaults to 1.

+ * + * @param limit How many pages will be kept offscreen in an idle state. + */ + public void setOffscreenPageLimit(int limit) { + if (limit < DEFAULT_OFFSCREEN_PAGES) { + Log.w(TAG, "Requested offscreen page limit " + limit + " too small; defaulting to " + + DEFAULT_OFFSCREEN_PAGES); + limit = DEFAULT_OFFSCREEN_PAGES; + } + if (limit != mOffscreenPageLimit) { + mOffscreenPageLimit = limit; + populate(); + } + } + + /** + * Set the margin between pages. + * + * @param marginPixels Distance between adjacent pages in pixels + * @see #getPageMargin() + * @see #setPageMarginDrawable(Drawable) + * @see #setPageMarginDrawable(int) + */ + public void setPageMargin(int marginPixels) { + final int oldMargin = mPageMargin; + mPageMargin = marginPixels; + + final int width = getWidth(); + final int height = getHeight(); + recomputeScrollPosition(width, width, height, height, marginPixels, oldMargin); + + requestLayout(); + } + + /** + * Return the margin between pages. + * + * @return The size of the margin in pixels + */ + public int getPageMargin() { + return mPageMargin; + } + + /** + * Set a drawable that will be used to fill the margin between pages. + * + * @param d Drawable to display between pages + */ + public void setPageMarginDrawable(@Nullable Drawable d) { + mMarginDrawable = d; + if (d != null) refreshDrawableState(); + setWillNotDraw(d == null); + invalidate(); + } + + /** + * Set a drawable that will be used to fill the margin between pages. + * + * @param resId Resource ID of a drawable to display between pages + */ + public void setPageMarginDrawable(@DrawableRes int resId) { + setPageMarginDrawable(ContextCompat.getDrawable(getContext(), resId)); + } + + @Override + protected boolean verifyDrawable(Drawable who) { + return super.verifyDrawable(who) || who == mMarginDrawable; + } + + @Override + protected void drawableStateChanged() { + super.drawableStateChanged(); + final Drawable d = mMarginDrawable; + if (d != null && d.isStateful()) { + d.setState(getDrawableState()); + } + } + + // We want the duration of the page snap animation to be influenced by the distance that + // the screen has to travel, however, we don't want this duration to be effected in a + // purely linear fashion. Instead, we use this method to moderate the effect that the distance + // of travel has on the overall snap duration. + float distanceInfluenceForSnapDuration(float f) { + f -= 0.5f; // center the values about 0. + f *= 0.3f * (float) Math.PI / 2.0f; + return (float) Math.sin(f); + } + + /** + * Like {@link View#scrollBy}, but scroll smoothly instead of immediately. + * + * @param x the number of pixels to scroll by on the X axis + * @param y the number of pixels to scroll by on the Y axis + */ + void smoothScrollTo(int x, int y) { + smoothScrollTo(x, y, 0); + } + + /** + * Like {@link View#scrollBy}, but scroll smoothly instead of immediately. + * + * @param x the number of pixels to scroll by on the X axis + * @param y the number of pixels to scroll by on the Y axis + * @param velocity the velocity associated with a fling, if applicable. (0 otherwise) + */ + void smoothScrollTo(int x, int y, int velocity) { + if (getChildCount() == 0) { + // Nothing to do. + setScrollingCacheEnabled(false); + return; + } + + int sx = getScrollX(); + int sy = getScrollY(); + boolean wasScrolling = (mScroller != null) && !mScroller.isFinished(); + if (wasScrolling) { + // We're in the middle of a previously initiated scrolling. Check to see + // whether that scrolling has actually started (if we always call getStartX + // we can get a stale value from the scroller if it hadn't yet had its first + // computeScrollOffset call) to decide what is the current scrolling position. + if (isHorizontal) { + sx = mIsScrollStarted ? mScroller.getCurrX() : mScroller.getStartX(); + } else { + sy = mIsScrollStarted ? mScroller.getCurrY() : mScroller.getStartY(); + } + // And abort the current scrolling. + mScroller.abortAnimation(); + setScrollingCacheEnabled(false); + } + int dx = x - sx; + int dy = y - sy; + if (dx == 0 && dy == 0) { + completeScroll(false); + populate(); + setScrollState(SCROLL_STATE_IDLE); + return; + } + + setScrollingCacheEnabled(true); + setScrollState(SCROLL_STATE_SETTLING); + + final int directionSize; + final float distance; + final float directionDelta; + if (isHorizontal) { + directionSize = getClientWidth(); + directionDelta = dx; + } else { + directionSize = getClientHeight(); + directionDelta = dy; + } + final float distanceRatio = Math.min(1f, 1.0f * Math.abs(directionDelta) / directionSize); + final int halfDirectionSize = directionSize / 2; + distance = halfDirectionSize + halfDirectionSize + * distanceInfluenceForSnapDuration(distanceRatio); + + int duration; + velocity = Math.abs(velocity); + if (velocity > 0) { + duration = 4 * Math.round(1000 * Math.abs(distance / velocity)); + } else { + final float pageWidth = directionSize * mAdapter.getPageWidth(mCurItem); + final float pageDelta = (float) Math.abs(directionDelta) / (pageWidth + mPageMargin); + duration = (int) ((pageDelta + 1) * 100); + } + duration = Math.min(duration, MAX_SETTLE_DURATION); + + // Reset the "scroll started" flag. It will be flipped to true in all places + // where we call computeScrollOffset(). + mIsScrollStarted = false; + mScroller.startScroll(sx, sy, dx, dy, duration); + ViewCompat.postInvalidateOnAnimation(this); + } + + ItemInfo addNewItem(int position, int index) { + ItemInfo ii = new ItemInfo(); + ii.position = position; + ii.object = mAdapter.instantiateItem(this, position); + ii.widthFactor = mAdapter.getPageWidth(position); + if (index < 0 || index >= mItems.size()) { + mItems.add(ii); + } else { + mItems.add(index, ii); + } + return ii; + } + + void dataSetChanged() { + // This method only gets called if our observer is attached, so mAdapter is non-null. + + final int adapterCount = mAdapter.getCount(); + mExpectedAdapterCount = adapterCount; + boolean needPopulate = mItems.size() < mOffscreenPageLimit * 2 + 1 + && mItems.size() < adapterCount; + int newCurrItem = mCurItem; + + boolean isUpdating = false; + for (int i = 0; i < mItems.size(); i++) { + final ItemInfo ii = mItems.get(i); + final int newPos = mAdapter.getItemPosition(ii.object); + + if (newPos == PagerAdapter.POSITION_UNCHANGED) { + continue; + } + + if (newPos == PagerAdapter.POSITION_NONE) { + mItems.remove(i); + i--; + + if (!isUpdating) { + mAdapter.startUpdate(this); + isUpdating = true; + } + + mAdapter.destroyItem(this, ii.position, ii.object); + needPopulate = true; + + if (mCurItem == ii.position) { + // Keep the current item in the valid range + newCurrItem = Math.max(0, Math.min(mCurItem, adapterCount - 1)); + needPopulate = true; + } + continue; + } + + if (ii.position != newPos) { + if (ii.position == mCurItem) { + // Our current item changed position. Follow it. + newCurrItem = newPos; + } + + ii.position = newPos; + needPopulate = true; + } + } + + if (isUpdating) { + mAdapter.finishUpdate(this); + } + + Collections.sort(mItems, COMPARATOR); + + if (needPopulate) { + // Reset our known page widths; populate will recompute them. + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (!lp.isDecor) { + lp.widthFactor = 0.f; + } + } + + setCurrentItemInternal(newCurrItem, false, true); + requestLayout(); + } + } + + void populate() { + populate(mCurItem); + } + + void populate(int newCurrentItem) { + ItemInfo oldCurInfo = null; + if (mCurItem != newCurrentItem) { + oldCurInfo = infoForPosition(mCurItem); + mCurItem = newCurrentItem; + } + + if (mAdapter == null) { + sortChildDrawingOrder(); + return; + } + + // Bail now if we are waiting to populate. This is to hold off + // on creating views from the time the user releases their finger to + // fling to a new position until we have finished the scroll to + // that position, avoiding glitches from happening at that point. + if (mPopulatePending) { + if (DEBUG) Log.i(TAG, "populate is pending, skipping for now..."); + sortChildDrawingOrder(); + return; + } + + // Also, don't populate until we are attached to a window. This is to + // avoid trying to populate before we have restored our view hierarchy + // state and conflicting with what is restored. + if (getWindowToken() == null) { + return; + } + + mAdapter.startUpdate(this); + + final int pageLimit = mOffscreenPageLimit; + final int startPos = Math.max(0, mCurItem - pageLimit); + final int N = mAdapter.getCount(); + final int endPos = Math.min(N - 1, mCurItem + pageLimit); + + if (N != mExpectedAdapterCount) { + String resName; + try { + resName = getResources().getResourceName(getId()); + } catch (Resources.NotFoundException e) { + resName = Integer.toHexString(getId()); + } + throw new IllegalStateException("The application's PagerAdapter changed the adapter's" + + " contents without calling PagerAdapter#notifyDataSetChanged!" + + " Expected adapter item count: " + mExpectedAdapterCount + ", found: " + N + + " Pager id: " + resName + + " Pager class: " + getClass() + + " Problematic adapter: " + mAdapter.getClass()); + } + + // Locate the currently focused item or add it if needed. + int curIndex = -1; + ItemInfo curItem = null; + for (curIndex = 0; curIndex < mItems.size(); curIndex++) { + final ItemInfo ii = mItems.get(curIndex); + if (ii.position >= mCurItem) { + if (ii.position == mCurItem) curItem = ii; + break; + } + } + + if (curItem == null && N > 0) { + curItem = addNewItem(mCurItem, curIndex); + } + + // Fill 3x the available width or up to the number of offscreen + // pages requested to either side, whichever is larger. + // If we have no current item we have no work to do. + if (curItem != null) { + float extraWidthStart = 0.f; + int itemIndex = curIndex - 1; + ItemInfo ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; + final int clientSize; + final float startPadding; + final float endPadding; + if (isHorizontal) { + clientSize = getClientWidth(); + startPadding = getPaddingLeft(); + endPadding = getPaddingRight(); + } else { + clientSize = getClientHeight(); + startPadding = getPaddingTop(); + endPadding = getPaddingBottom(); + } + final float startWidthNeeded = clientSize <= 0 ? 0 : + 2.f - curItem.widthFactor + startPadding / (float) clientSize; + for (int pos = mCurItem - 1; pos >= 0; pos--) { + if (extraWidthStart >= startWidthNeeded && pos < startPos) { + if (ii == null) { + break; + } + if (pos == ii.position && !ii.scrolling) { + mItems.remove(itemIndex); + mAdapter.destroyItem(this, pos, ii.object); + if (DEBUG) { + Log.i(TAG, "populate() - destroyItem() with pos: " + pos + + " view: " + ((View) ii.object)); + } + itemIndex--; + curIndex--; + ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; + } + } else if (ii != null && pos == ii.position) { + extraWidthStart += ii.widthFactor; + itemIndex--; + ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; + } else { + ii = addNewItem(pos, itemIndex + 1); + extraWidthStart += ii.widthFactor; + curIndex++; + ii = itemIndex >= 0 ? mItems.get(itemIndex) : null; + } + } + + float extraWidthEnd = curItem.widthFactor; + itemIndex = curIndex + 1; + if (extraWidthEnd < 2.f) { + ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; + final float endWidthNeeded = clientSize <= 0 ? 0 : + endPadding / (float) clientSize + 2.f; + for (int pos = mCurItem + 1; pos < N; pos++) { + if (extraWidthEnd >= endWidthNeeded && pos > endPos) { + if (ii == null) { + break; + } + if (pos == ii.position && !ii.scrolling) { + mItems.remove(itemIndex); + mAdapter.destroyItem(this, pos, ii.object); + if (DEBUG) { + Log.i(TAG, "populate() - destroyItem() with pos: " + pos + + " view: " + ((View) ii.object)); + } + ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; + } + } else if (ii != null && pos == ii.position) { + extraWidthEnd += ii.widthFactor; + itemIndex++; + ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; + } else { + ii = addNewItem(pos, itemIndex); + itemIndex++; + extraWidthEnd += ii.widthFactor; + ii = itemIndex < mItems.size() ? mItems.get(itemIndex) : null; + } + } + } + + calculatePageOffsets(curItem, curIndex, oldCurInfo); + } + + if (DEBUG) { + Log.i(TAG, "Current page list:"); + for (int i = 0; i < mItems.size(); i++) { + Log.i(TAG, "#" + i + ": page " + mItems.get(i).position); + } + } + + mAdapter.setPrimaryItem(this, mCurItem, curItem != null ? curItem.object : null); + + mAdapter.finishUpdate(this); + + // Check width measurement of current pages and drawing sort order. + // Update LayoutParams as needed. + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + lp.childIndex = i; + if (!lp.isDecor && lp.widthFactor == 0.f) { + // 0 means requery the adapter for this, it doesn't have a valid width. + final ItemInfo ii = infoForChild(child); + if (ii != null) { + lp.widthFactor = ii.widthFactor; + lp.position = ii.position; + } + } + } + sortChildDrawingOrder(); + + if (hasFocus()) { + View currentFocused = findFocus(); + ItemInfo ii = currentFocused != null ? infoForAnyChild(currentFocused) : null; + if (ii == null || ii.position != mCurItem) { + for (int i = 0; i < getChildCount(); i++) { + View child = getChildAt(i); + ii = infoForChild(child); + if (ii != null && ii.position == mCurItem) { + if (child.requestFocus(View.FOCUS_FORWARD)) { + break; + } + } + } + } + } + } + + private void sortChildDrawingOrder() { + if (mDrawingOrder != DRAW_ORDER_DEFAULT) { + if (mDrawingOrderedChildren == null) { + mDrawingOrderedChildren = new ArrayList(); + } else { + mDrawingOrderedChildren.clear(); + } + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + mDrawingOrderedChildren.add(child); + } + Collections.sort(mDrawingOrderedChildren, sPositionComparator); + } + } + + private void calculatePageOffsets(ItemInfo curItem, int curIndex, ItemInfo oldCurInfo) { + final int N = mAdapter.getCount(); + final int clientSize = isHorizontal ? getClientWidth() : getClientHeight(); + final float marginOffset = clientSize > 0 ? (float) mPageMargin / clientSize : 0; + // Fix up offsets for later layout. + if (oldCurInfo != null) { + final int oldCurPosition = oldCurInfo.position; + // Base offsets off of oldCurInfo. + if (oldCurPosition < curItem.position) { + int itemIndex = 0; + ItemInfo ii = null; + float offset = oldCurInfo.offset + oldCurInfo.widthFactor + marginOffset; + for (int pos = oldCurPosition + 1; + pos <= curItem.position && itemIndex < mItems.size(); pos++) { + ii = mItems.get(itemIndex); + while (pos > ii.position && itemIndex < mItems.size() - 1) { + itemIndex++; + ii = mItems.get(itemIndex); + } + while (pos < ii.position) { + // We don't have an item populated for this, + // ask the adapter for an offset. + offset += mAdapter.getPageWidth(pos) + marginOffset; + pos++; + } + ii.offset = offset; + offset += ii.widthFactor + marginOffset; + } + } else if (oldCurPosition > curItem.position) { + int itemIndex = mItems.size() - 1; + ItemInfo ii = null; + float offset = oldCurInfo.offset; + for (int pos = oldCurPosition - 1; + pos >= curItem.position && itemIndex >= 0; pos--) { + ii = mItems.get(itemIndex); + while (pos < ii.position && itemIndex > 0) { + itemIndex--; + ii = mItems.get(itemIndex); + } + while (pos > ii.position) { + // We don't have an item populated for this, + // ask the adapter for an offset. + offset -= mAdapter.getPageWidth(pos) + marginOffset; + pos--; + } + offset -= ii.widthFactor + marginOffset; + ii.offset = offset; + } + } + } + + // Base all offsets off of curItem. + final int itemCount = mItems.size(); + float offset = curItem.offset; + int pos = curItem.position - 1; + mFirstOffset = curItem.position == 0 ? curItem.offset : -Float.MAX_VALUE; + mLastOffset = curItem.position == N - 1 + ? curItem.offset + curItem.widthFactor - 1 : Float.MAX_VALUE; + // Previous pages + for (int i = curIndex - 1; i >= 0; i--, pos--) { + final ItemInfo ii = mItems.get(i); + while (pos > ii.position) { + offset -= mAdapter.getPageWidth(pos--) + marginOffset; + } + offset -= ii.widthFactor + marginOffset; + ii.offset = offset; + if (ii.position == 0) mFirstOffset = offset; + } + offset = curItem.offset + curItem.widthFactor + marginOffset; + pos = curItem.position + 1; + // Next pages + for (int i = curIndex + 1; i < itemCount; i++, pos++) { + final ItemInfo ii = mItems.get(i); + while (pos < ii.position) { + offset += mAdapter.getPageWidth(pos++) + marginOffset; + } + if (ii.position == N - 1) { + mLastOffset = offset + ii.widthFactor - 1; + } + ii.offset = offset; + offset += ii.widthFactor + marginOffset; + } + + mNeedCalculatePageOffsets = false; + } + + /** + * This is the persistent state that is saved by ViewPager. Only needed + * if you are creating a sublass of ViewPager that must save its own + * state, in which case it should implement a subclass of this which + * contains that state. + */ + public static class SavedState extends AbsSavedState { + int position; + Parcelable adapterState; + ClassLoader loader; + + public SavedState(@NonNull Parcelable superState) { + super(superState); + } + + @Override + public void writeToParcel(Parcel out, int flags) { + super.writeToParcel(out, flags); + out.writeInt(position); + out.writeParcelable(adapterState, flags); + } + + @Override + public String toString() { + return "FragmentPager.SavedState{" + + Integer.toHexString(System.identityHashCode(this)) + + " position=" + position + "}"; + } + + public static final Creator CREATOR = new ClassLoaderCreator() { + @Override + public SavedState createFromParcel(Parcel in, ClassLoader loader) { + return new SavedState(in, loader); + } + + @Override + public SavedState createFromParcel(Parcel in) { + return new SavedState(in, null); + } + @Override + public SavedState[] newArray(int size) { + return new SavedState[size]; + } + }; + + SavedState(Parcel in, ClassLoader loader) { + super(in, loader); + if (loader == null) { + loader = getClass().getClassLoader(); + } + position = in.readInt(); + adapterState = in.readParcelable(loader); + this.loader = loader; + } + } + + @Override + public Parcelable onSaveInstanceState() { + Parcelable superState = super.onSaveInstanceState(); + SavedState ss = new SavedState(superState); + ss.position = mCurItem; + if (mAdapter != null) { + ss.adapterState = mAdapter.saveState(); + } + return ss; + } + + @Override + public void onRestoreInstanceState(Parcelable state) { + if (!(state instanceof SavedState)) { + super.onRestoreInstanceState(state); + return; + } + + SavedState ss = (SavedState) state; + super.onRestoreInstanceState(ss.getSuperState()); + + if (mAdapter != null) { + mAdapter.restoreState(ss.adapterState, ss.loader); + setCurrentItemInternal(ss.position, false, true); + } else { + mRestoredCurItem = ss.position; + mRestoredAdapterState = ss.adapterState; + mRestoredClassLoader = ss.loader; + } + } + + @Override + public void addView(View child, int index, ViewGroup.LayoutParams params) { + if (!checkLayoutParams(params)) { + params = generateLayoutParams(params); + } + final LayoutParams lp = (LayoutParams) params; + // Any views added via inflation should be classed as part of the decor + lp.isDecor |= isDecorView(child); + if (mInLayout) { + if (lp != null && lp.isDecor) { + throw new IllegalStateException("Cannot add pager decor view during layout"); + } + lp.needsMeasure = true; + addViewInLayout(child, index, params); + } else { + super.addView(child, index, params); + } + + if (USE_CACHE) { + if (child.getVisibility() != GONE) { + child.setDrawingCacheEnabled(mScrollingCacheEnabled); + } else { + child.setDrawingCacheEnabled(false); + } + } + } + + private static boolean isDecorView(@NonNull View view) { + Class clazz = view.getClass(); + return clazz.getAnnotation(ViewPager.DecorView.class) != null; + } + + @Override + public void removeView(View view) { + if (mInLayout) { + removeViewInLayout(view); + } else { + super.removeView(view); + } + } + + ItemInfo infoForChild(View child) { + for (int i = 0; i < mItems.size(); i++) { + ItemInfo ii = mItems.get(i); + if (mAdapter.isViewFromObject(child, ii.object)) { + return ii; + } + } + return null; + } + + ItemInfo infoForAnyChild(View child) { + ViewParent parent; + while ((parent = child.getParent()) != this) { + if (parent == null || !(parent instanceof View)) { + return null; + } + child = (View) parent; + } + return infoForChild(child); + } + + ItemInfo infoForPosition(int position) { + for (int i = 0; i < mItems.size(); i++) { + ItemInfo ii = mItems.get(i); + if (ii.position == position) { + return ii; + } + } + return null; + } + + @Override + protected void onAttachedToWindow() { + super.onAttachedToWindow(); + mFirstLayout = true; + } + + @Override + protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { + // For simple implementation, our internal size is always 0. + // We depend on the container to specify the layout size of + // our view. We can't really know what it is since we will be + // adding and removing different arbitrary views and do not + // want the layout to change as this happens. + setMeasuredDimension(getDefaultSize(0, widthMeasureSpec), + getDefaultSize(0, heightMeasureSpec)); + + final int maxGutterSize = (isHorizontal ? getMeasuredWidth() : getMeasuredHeight()) / 10; + mGutterSize = Math.min(maxGutterSize, mDefaultGutterSize); + + // Children are just made to fill our space. + int childWidthSize = getMeasuredWidth() - getPaddingLeft() - getPaddingRight(); + int childHeightSize = getMeasuredHeight() - getPaddingTop() - getPaddingBottom(); + + /* + * Make sure all children have been properly measured. Decor views first. + * Right now we cheat and make this less complicated by assuming decor + * views won't intersect. We will pin to edges based on gravity. + */ + int size = getChildCount(); + for (int i = 0; i < size; ++i) { + final View child = getChildAt(i); + if (child.getVisibility() != GONE) { + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (lp != null && lp.isDecor) { + final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; + final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK; + int widthMode = MeasureSpec.AT_MOST; + int heightMode = MeasureSpec.AT_MOST; + boolean consumeVertical = vgrav == Gravity.TOP || vgrav == Gravity.BOTTOM; + boolean consumeHorizontal = hgrav == Gravity.LEFT || hgrav == Gravity.RIGHT; + + if (consumeVertical) { + widthMode = MeasureSpec.EXACTLY; + } else if (consumeHorizontal) { + heightMode = MeasureSpec.EXACTLY; + } + + int widthSize = childWidthSize; + int heightSize = childHeightSize; + if (lp.width != LayoutParams.WRAP_CONTENT) { + widthMode = MeasureSpec.EXACTLY; + if (lp.width != LayoutParams.MATCH_PARENT) { + widthSize = lp.width; + } + } + if (lp.height != LayoutParams.WRAP_CONTENT) { + heightMode = MeasureSpec.EXACTLY; + if (lp.height != LayoutParams.MATCH_PARENT) { + heightSize = lp.height; + } + } + final int widthSpec = MeasureSpec.makeMeasureSpec(widthSize, widthMode); + final int heightSpec = MeasureSpec.makeMeasureSpec(heightSize, heightMode); + child.measure(widthSpec, heightSpec); + + if (consumeVertical) { + childHeightSize -= child.getMeasuredHeight(); + } else if (consumeHorizontal) { + childWidthSize -= child.getMeasuredWidth(); + } + } + } + } + + mChildWidthMeasureSpec = MeasureSpec.makeMeasureSpec(childWidthSize, MeasureSpec.EXACTLY); + mChildHeightMeasureSpec = MeasureSpec.makeMeasureSpec(childHeightSize, MeasureSpec.EXACTLY); + + // Make sure we have created all fragments that we need to have shown. + mInLayout = true; + populate(); + mInLayout = false; + + // Page views next. + size = getChildCount(); + for (int i = 0; i < size; ++i) { + final View child = getChildAt(i); + if (child.getVisibility() != GONE) { + if (DEBUG) { + Log.v(TAG, "Measuring #" + i + " " + child + ": " + mChildWidthMeasureSpec); + } + + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (lp == null || !lp.isDecor) { + final int widthSpec = MeasureSpec.makeMeasureSpec( + (int) (childWidthSize * lp.widthFactor), MeasureSpec.EXACTLY); + child.measure(widthSpec, mChildHeightMeasureSpec); + } + } + } + } + + @Override + protected void onSizeChanged(int w, int h, int oldw, int oldh) { + super.onSizeChanged(w, h, oldw, oldh); + + // Make sure scroll position is set correctly. + if (w != oldw || h != oldh) { + recomputeScrollPosition(w, oldw, h, oldh, mPageMargin, mPageMargin); + } + } + + private void recomputeScrollPosition(int width, int oldWidth, int height, int oldHeight, + int margin, int oldMargin) { + if (isHorizontal) { + if (oldWidth > 0 && !mItems.isEmpty()) { + if (!mScroller.isFinished()) { + mScroller.setFinalX(getCurrentItem() * getClientWidth()); + } else { + final int widthWithMargin = width - getPaddingLeft() - getPaddingRight() + margin; + final int oldWidthWithMargin = oldWidth - getPaddingLeft() - getPaddingRight() + + oldMargin; + final int xpos = getScrollX(); + final float pageOffset = (float) xpos / oldWidthWithMargin; + final int newOffsetPixels = (int) (pageOffset * widthWithMargin); + + scrollTo(newOffsetPixels, getScrollY()); + } + } else { + final ItemInfo ii = infoForPosition(mCurItem); + final float scrollOffset = ii != null ? Math.min(ii.offset, mLastOffset) : 0; + final int scrollPos = + (int) (scrollOffset * (width - getPaddingLeft() - getPaddingRight())); + if (scrollPos != getScrollX()) { + completeScroll(false); + scrollTo(scrollPos, getScrollY()); + } + } + } else { + if (oldHeight > 0 && !mItems.isEmpty()) { + if (!mScroller.isFinished()) { + mScroller.setFinalY(getCurrentItem() * getClientHeight()); + } else { + final int heightWithMargin = height - getPaddingTop() - getPaddingBottom() + + margin; + final int oldHeightWithMargin = oldHeight - getPaddingTop() - getPaddingBottom() + + oldMargin; + final int ypos = getScrollY(); + final float pageOffset = (float) ypos / oldHeightWithMargin; + final int newOffsetPixels = (int) (pageOffset * heightWithMargin); + + scrollTo(getScrollX(), newOffsetPixels); + } + } else { + final ItemInfo ii = infoForPosition(mCurItem); + final float scrollOffset = ii != null ? Math.min(ii.offset, mLastOffset) : 0; + final int scrollPos = + (int) (scrollOffset * (height - getPaddingTop() - getPaddingBottom())); + if (scrollPos != getScrollY()) { + completeScroll(false); + scrollTo(getScrollX(), scrollPos); + } + } + } + } + + @Override + protected void onLayout(boolean changed, int l, int t, int r, int b) { + final int count = getChildCount(); + int width = r - l; + int height = b - t; + int paddingLeft = getPaddingLeft(); + int paddingTop = getPaddingTop(); + int paddingRight = getPaddingRight(); + int paddingBottom = getPaddingBottom(); + final int scrollX = getScrollX(); + final int scrollY = getScrollY(); + + int decorCount = 0; + + // First pass - decor views. We need to do this in two passes so that + // we have the proper offsets for non-decor views later. + for (int i = 0; i < count; i++) { + final View child = getChildAt(i); + if (child.getVisibility() != GONE) { + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + int childLeft = 0; + int childTop = 0; + if (lp.isDecor) { + final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; + final int vgrav = lp.gravity & Gravity.VERTICAL_GRAVITY_MASK; + switch (hgrav) { + default: + childLeft = paddingLeft; + break; + case Gravity.LEFT: + childLeft = paddingLeft; + paddingLeft += child.getMeasuredWidth(); + break; + case Gravity.CENTER_HORIZONTAL: + childLeft = Math.max((width - child.getMeasuredWidth()) / 2, + paddingLeft); + break; + case Gravity.RIGHT: + childLeft = width - paddingRight - child.getMeasuredWidth(); + paddingRight += child.getMeasuredWidth(); + break; + } + switch (vgrav) { + default: + childTop = paddingTop; + break; + case Gravity.TOP: + childTop = paddingTop; + paddingTop += child.getMeasuredHeight(); + break; + case Gravity.CENTER_VERTICAL: + childTop = Math.max((height - child.getMeasuredHeight()) / 2, + paddingTop); + break; + case Gravity.BOTTOM: + childTop = height - paddingBottom - child.getMeasuredHeight(); + paddingBottom += child.getMeasuredHeight(); + break; + } + if (isHorizontal) { + childLeft += scrollX; + } else { + childTop += scrollY; + } + child.layout(childLeft, childTop, + childLeft + child.getMeasuredWidth(), + childTop + child.getMeasuredHeight()); + decorCount++; + } + } + } + + final int childWidth = width - paddingLeft - paddingRight; + final int childHeight = height - paddingTop - paddingBottom; + // Page views. Do this once we have the right padding offsets from above. + for (int i = 0; i < count; i++) { + final View child = getChildAt(i); + if (child.getVisibility() != GONE) { + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + ItemInfo ii; + if (!lp.isDecor && (ii = infoForChild(child)) != null) { + int loff; + int childLeft; + int childTop; + if (isHorizontal) { + loff = (int) (childWidth * ii.offset); + childLeft = paddingLeft + loff; + childTop = paddingTop; + } else { + loff = (int) (childHeight * ii.offset); + childLeft = paddingLeft; + childTop = paddingTop + loff; + } + if (lp.needsMeasure) { + // This was added during layout and needs measurement. + // Do it now that we know what we're working with. + lp.needsMeasure = false; + final int widthSpec = MeasureSpec.makeMeasureSpec( + (int) (childWidth * lp.widthFactor), + MeasureSpec.EXACTLY); + final int heightSpec = MeasureSpec.makeMeasureSpec( + (int) (height - paddingTop - paddingBottom), + MeasureSpec.EXACTLY); + child.measure(widthSpec, heightSpec); + } + if (DEBUG) { + Log.v(TAG, "Positioning #" + i + " " + child + " f=" + ii.object + + ":" + childLeft + "," + childTop + " " + child.getMeasuredWidth() + + "x" + child.getMeasuredHeight()); + } + child.layout(childLeft, childTop, + childLeft + child.getMeasuredWidth(), + childTop + child.getMeasuredHeight()); + } + } + } + mTopPageBounds = paddingTop; + mBottomPageBounds = height - paddingBottom; + mLeftPageBounds = paddingLeft; + mRightPageBounds = width - paddingRight; + mDecorChildCount = decorCount; + + if (mFirstLayout) { + scrollToItem(mCurItem, false, 0, false); + } + mFirstLayout = false; + } + + @Override + public void computeScroll() { + mIsScrollStarted = true; + if (!mScroller.isFinished() && mScroller.computeScrollOffset()) { + int oldX = getScrollX(); + int oldY = getScrollY(); + int x = mScroller.getCurrX(); + int y = mScroller.getCurrY(); + + if (oldX != x || oldY != y) { + scrollTo(x, y); + if (!pageScrolled(x, y)) { + mScroller.abortAnimation(); + if (isHorizontal) { + scrollTo(0, y); + } else { + scrollTo(x, 0); + } + } + } + + // Keep on drawing until the animation has finished. + ViewCompat.postInvalidateOnAnimation(this); + return; + } + + // Done with scroll, clean up state. + completeScroll(true); + } + + private boolean pageScrolled(int xpos, int ypos) { + if (mItems.size() == 0) { + if (mFirstLayout) { + // If we haven't been laid out yet, we probably just haven't been populated yet. + // Let's skip this call since it doesn't make sense in this state + return false; + } + mCalledSuper = false; + onPageScrolled(0, 0, 0); + if (!mCalledSuper) { + throw new IllegalStateException( + "onPageScrolled did not call superclass implementation"); + } + return false; + } + final ItemInfo ii = infoForCurrentScrollPosition(); + final int size = getClientSize(); + final int sizeWithMargin = size + mPageMargin; + final float marginOffset = (float) mPageMargin / size; + final int currentPage = ii.position; + final int pos = isHorizontal ? xpos : ypos; + final float pageOffset = (((float) pos / size) - ii.offset) + / (ii.widthFactor + marginOffset); + final int offsetPixels = (int) (pageOffset * sizeWithMargin); + + mCalledSuper = false; + onPageScrolled(currentPage, pageOffset, offsetPixels); + if (!mCalledSuper) { + throw new IllegalStateException( + "onPageScrolled did not call superclass implementation"); + } + return true; + } + + /** + * This method will be invoked when the current page is scrolled, either as part + * of a programmatically initiated smooth scroll or a user initiated touch scroll. + * If you override this method you must call through to the superclass implementation + * (e.g. super.onPageScrolled(position, offset, offsetPixels)) before onPageScrolled + * returns. + * + * @param position Position index of the first page currently being displayed. + * Page position+1 will be visible if positionOffset is nonzero. + * @param offset Value from [0, 1) indicating the offset from the page at position. + * @param offsetPixels Value in pixels indicating the offset from position. + */ + @CallSuper + protected void onPageScrolled(int position, float offset, int offsetPixels) { + // Offset any decor views if needed - keep them on-screen at all times. + if (mDecorChildCount > 0) { + if (isHorizontal) { + final int scrollX = getScrollX(); + int paddingLeft = getPaddingLeft(); + int paddingRight = getPaddingRight(); + final int width = getWidth(); + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (!lp.isDecor) continue; + + final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; + int childLeft = 0; + switch (hgrav) { + default: + childLeft = paddingLeft; + break; + case Gravity.LEFT: + childLeft = paddingLeft; + paddingLeft += child.getWidth(); + break; + case Gravity.CENTER_HORIZONTAL: + childLeft = Math.max((width - child.getMeasuredWidth()) / 2, + paddingLeft); + break; + case Gravity.RIGHT: + childLeft = width - paddingRight - child.getMeasuredWidth(); + paddingRight += child.getMeasuredWidth(); + break; + } + childLeft += scrollX; + + final int childOffset = childLeft - child.getLeft(); + if (childOffset != 0) { + child.offsetLeftAndRight(childOffset); + } + } + } else { + final int scrollY = getScrollY(); + int paddingTop = getPaddingTop(); + int paddingBottom = getPaddingBottom(); + final int height = getHeight(); + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + if (!lp.isDecor) continue; + + final int hgrav = lp.gravity & Gravity.HORIZONTAL_GRAVITY_MASK; + int childTop = 0; + switch (hgrav) { + default: + childTop = paddingTop; + break; + case Gravity.TOP: + childTop = paddingTop; + paddingTop += child.getHeight(); + break; + case Gravity.CENTER_VERTICAL: + childTop = Math.max((height - child.getMeasuredHeight()) / 2, + paddingTop); + break; + case Gravity.BOTTOM: + childTop = height - paddingBottom - child.getMeasuredHeight(); + paddingBottom += child.getMeasuredHeight(); + break; + } + childTop += scrollY; + + final int childOffset = childTop - child.getTop(); + if (childOffset != 0) { + child.offsetTopAndBottom(childOffset); + } + } + } + } + + dispatchOnPageScrolled(position, offset, offsetPixels); + + if (mPageTransformer != null) { + if (isHorizontal) { + final int scrollX = getScrollX(); + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + + if (lp.isDecor) continue; + final float transformPos = (float) (child.getLeft() - scrollX) / getClientWidth(); + mPageTransformer.transformPage(child, transformPos); + } + } else { + final int scrollY = getScrollY(); + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + final LayoutParams lp = (LayoutParams) child.getLayoutParams(); + + if (lp.isDecor) continue; + final float transformPos = (float) (child.getTop() - scrollY) / getClientHeight(); + mPageTransformer.transformPage(child, transformPos); + } + } + } + + mCalledSuper = true; + } + + private void dispatchOnPageScrolled(int position, float offset, int offsetPixels) { + if (mOnPageChangeListener != null) { + mOnPageChangeListener.onPageScrolled(position, offset, offsetPixels); + } + if (mOnPageChangeListeners != null) { + for (int i = 0, z = mOnPageChangeListeners.size(); i < z; i++) { + OnPageChangeListener listener = mOnPageChangeListeners.get(i); + if (listener != null) { + listener.onPageScrolled(position, offset, offsetPixels); + } + } + } + if (mInternalPageChangeListener != null) { + mInternalPageChangeListener.onPageScrolled(position, offset, offsetPixels); + } + } + + private void dispatchOnPageSelected(int position) { + if (mOnPageChangeListener != null) { + mOnPageChangeListener.onPageSelected(position); + } + if (mOnPageChangeListeners != null) { + for (int i = 0, z = mOnPageChangeListeners.size(); i < z; i++) { + OnPageChangeListener listener = mOnPageChangeListeners.get(i); + if (listener != null) { + listener.onPageSelected(position); + } + } + } + if (mInternalPageChangeListener != null) { + mInternalPageChangeListener.onPageSelected(position); + } + } + + private void dispatchOnScrollStateChanged(int state) { + if (mOnPageChangeListener != null) { + mOnPageChangeListener.onPageScrollStateChanged(state); + } + if (mOnPageChangeListeners != null) { + for (int i = 0, z = mOnPageChangeListeners.size(); i < z; i++) { + OnPageChangeListener listener = mOnPageChangeListeners.get(i); + if (listener != null) { + listener.onPageScrollStateChanged(state); + } + } + } + if (mInternalPageChangeListener != null) { + mInternalPageChangeListener.onPageScrollStateChanged(state); + } + } + + private void completeScroll(boolean postEvents) { + boolean needPopulate = mScrollState == SCROLL_STATE_SETTLING; + if (needPopulate) { + // Done with scroll, no longer want to cache view drawing. + setScrollingCacheEnabled(false); + boolean wasScrolling = !mScroller.isFinished(); + if (wasScrolling) { + mScroller.abortAnimation(); + int oldX = getScrollX(); + int oldY = getScrollY(); + int x = mScroller.getCurrX(); + int y = mScroller.getCurrY(); + if (oldX != x || oldY != y) { + scrollTo(x, y); + if (x != oldX || y != oldY) { + pageScrolled(x, y); + } + } + } + } + mPopulatePending = false; + for (int i = 0; i < mItems.size(); i++) { + ItemInfo ii = mItems.get(i); + if (ii.scrolling) { + needPopulate = true; + ii.scrolling = false; + } + } + if (needPopulate) { + if (postEvents) { + ViewCompat.postOnAnimation(this, mEndScrollRunnable); + } else { + mEndScrollRunnable.run(); + } + } + } + + private boolean isGutterDragX(float x, float dx) { + return (x < mGutterSize && dx > 0) || (x > getWidth() - mGutterSize && dx < 0); + } + + private boolean isGutterDragY(float y, float dy) { + return (y < mGutterSize && dy > 0) || (y > getHeight() - mGutterSize && dy < 0); + } + + private void enableLayers(boolean enable) { + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final int layerType = enable + ? mPageTransformerLayerType : View.LAYER_TYPE_NONE; + getChildAt(i).setLayerType(layerType, null); + } + } + + @Override + public boolean onInterceptTouchEvent(MotionEvent ev) { + /* + * This method JUST determines whether we want to intercept the motion. + * If we return true, onMotionEvent will be called and we do the actual + * scrolling there. + */ + + final int action = ev.getAction() & MotionEvent.ACTION_MASK; + + // Always take care of the touch gesture being complete. + if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) { + // Release the drag. + if (DEBUG) Log.v(TAG, "Intercept done!"); + resetTouch(); + return false; + } + + // Nothing more to do here if we have decided whether or not we + // are dragging. + if (action != MotionEvent.ACTION_DOWN) { + if (mIsBeingDragged) { + if (DEBUG) Log.v(TAG, "Intercept returning true!"); + return true; + } + if (mIsUnableToDrag) { + if (DEBUG) Log.v(TAG, "Intercept returning false!"); + return false; + } + } + + switch (action) { + case MotionEvent.ACTION_MOVE: { + /* + * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check + * whether the user has moved far enough from his original down touch. + */ + + /* + * Locally do absolute value. mLastMotionY is set to the y value + * of the down event. + */ + final int activePointerId = mActivePointerId; + if (activePointerId == INVALID_POINTER) { + // If we don't have a valid id, the touch down wasn't on content. + break; + } + + final int pointerIndex = ev.findPointerIndex(activePointerId); + final float x = ev.getX(pointerIndex); + final float y = ev.getY(pointerIndex); + + if (isHorizontal) { + final float dx = x - mLastMotionX; + final float xDiff = Math.abs(dx); + final float yDiff = Math.abs(y - mInitialMotionY); + if (DEBUG) Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff); + + if (dx != 0 && !isGutterDragX(mLastMotionX, dx) + && canScroll(this, false, (int) dx, (int) x, (int) y)) { + // Nested view has scrollable area under this point. Let it be handled there. + mLastMotionX = x; + mLastMotionY = y; + mIsUnableToDrag = true; + return false; + } + if (xDiff > mTouchSlop && xDiff * 0.5f > yDiff) { + if (DEBUG) Log.v(TAG, "Starting drag!"); + mIsBeingDragged = true; + requestParentDisallowInterceptTouchEvent(true); + setScrollState(SCROLL_STATE_DRAGGING); + mLastMotionX = dx > 0 + ? mInitialMotionX + mTouchSlop : mInitialMotionX - mTouchSlop; + mLastMotionY = y; + setScrollingCacheEnabled(true); + } else if (yDiff > mTouchSlop) { + // The finger has moved enough in the vertical + // direction to be counted as a drag... abort + // any attempt to drag horizontally, to work correctly + // with children that have scrolling containers. + if (DEBUG) Log.v(TAG, "Starting unable to drag!"); + mIsUnableToDrag = true; + } + if (mIsBeingDragged) { + // Scroll to follow the motion event + if (performDragX(x)) { + ViewCompat.postInvalidateOnAnimation(this); + } + } + break; + } else { + final float dy = y - mLastMotionY; + final float yDiff = Math.abs(dy); + final float xDiff = Math.abs(x - mInitialMotionX); + if (DEBUG) Log.v(TAG, "Moved y to " + x + "," + y + " diff=" + xDiff + "," + yDiff); + + if (dy != 0 && !isGutterDragY(mLastMotionY, dy) + && canScroll(this, false, (int) dy, (int) x, (int) y)) { + // Nested view has scrollable area under this point. Let it be handled there. + mLastMotionX = x; + mLastMotionY = y; + mIsUnableToDrag = true; + return false; + } + if (yDiff > mTouchSlop && yDiff * 0.5f > xDiff) { + if (DEBUG) Log.v(TAG, "Starting drag!"); + mIsBeingDragged = true; + requestParentDisallowInterceptTouchEvent(true); + setScrollState(SCROLL_STATE_DRAGGING); + mLastMotionY = dy > 0 + ? mInitialMotionY + mTouchSlop : mInitialMotionY - mTouchSlop; + mLastMotionX = x; + setScrollingCacheEnabled(true); + } else if (xDiff > mTouchSlop) { + // The finger has moved enough in the horizontal + // direction to be counted as a drag... abort + // any attempt to drag horizontally, to work correctly + // with children that have scrolling containers. + if (DEBUG) Log.v(TAG, "Starting unable to drag!"); + mIsUnableToDrag = true; + } + if (mIsBeingDragged) { + // Scroll to follow the motion event + if (performDragY(y)) { + ViewCompat.postInvalidateOnAnimation(this); + } + } + break; + } + } + + case MotionEvent.ACTION_DOWN: { + /* + * Remember location of down touch. + * ACTION_DOWN always refers to pointer index 0. + */ + mLastMotionX = mInitialMotionX = ev.getX(); + mLastMotionY = mInitialMotionY = ev.getY(); + mActivePointerId = ev.getPointerId(0); + mIsUnableToDrag = false; + + mIsScrollStarted = true; + mScroller.computeScrollOffset(); + if (mScrollState == SCROLL_STATE_SETTLING && ((isHorizontal && + Math.abs(mScroller.getFinalX() - mScroller.getCurrX()) > mCloseEnough) || + (!isHorizontal && + Math.abs(mScroller.getFinalY() - mScroller.getCurrY()) > mCloseEnough))) { + // Let the user 'catch' the pager as it animates. + mScroller.abortAnimation(); + mPopulatePending = false; + populate(); + mIsBeingDragged = true; + requestParentDisallowInterceptTouchEvent(true); + setScrollState(SCROLL_STATE_DRAGGING); + } else { + completeScroll(false); + mIsBeingDragged = false; + } + + if (DEBUG) { + Log.v(TAG, "Down at " + mLastMotionX + "," + mLastMotionY + + " mIsBeingDragged=" + mIsBeingDragged + + "mIsUnableToDrag=" + mIsUnableToDrag); + } + break; + } + + case MotionEvent.ACTION_POINTER_UP: + onSecondaryPointerUp(ev); + break; + } + + if (mVelocityTracker == null) { + mVelocityTracker = VelocityTracker.obtain(); + } + mVelocityTracker.addMovement(ev); + + /* + * The only time we want to intercept motion events is if we are in the + * drag mode. + */ + return mIsBeingDragged; + } + + @Override + public boolean onTouchEvent(MotionEvent ev) { + if (mFakeDragging) { + // A fake drag is in progress already, ignore this real one + // but still eat the touch events. + // (It is likely that the user is multi-touching the screen.) + return true; + } + + if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { + // Don't handle edge touches immediately -- they may actually belong to one of our + // descendants. + return false; + } + + if (mAdapter == null || mAdapter.getCount() == 0) { + // Nothing to present or scroll; nothing to touch. + return false; + } + + if (mVelocityTracker == null) { + mVelocityTracker = VelocityTracker.obtain(); + } + mVelocityTracker.addMovement(ev); + + final int action = ev.getAction(); + boolean needsInvalidate = false; + + switch (action & MotionEvent.ACTION_MASK) { + case MotionEvent.ACTION_DOWN: { + mScroller.abortAnimation(); + mPopulatePending = false; + populate(); + + // Remember where the motion event started + mLastMotionX = mInitialMotionX = ev.getX(); + mLastMotionY = mInitialMotionY = ev.getY(); + mActivePointerId = ev.getPointerId(0); + break; + } + case MotionEvent.ACTION_MOVE: + if (!mIsBeingDragged) { + final int pointerIndex = ev.findPointerIndex(mActivePointerId); + if (pointerIndex == -1) { + // A child has consumed some touch events and put us into an inconsistent + // state. + needsInvalidate = resetTouch(); + break; + } + final float x = ev.getX(pointerIndex); + final float xDiff = Math.abs(x - mLastMotionX); + final float y = ev.getY(pointerIndex); + final float yDiff = Math.abs(y - mLastMotionY); + if (DEBUG) { + Log.v(TAG, "Moved x to " + x + "," + y + " diff=" + xDiff + "," + yDiff); + } + if (isHorizontal) { + if (xDiff > mTouchSlop && xDiff > yDiff) { + if (DEBUG) Log.v(TAG, "Starting drag!"); + mIsBeingDragged = true; + requestParentDisallowInterceptTouchEvent(true); + mLastMotionX = x - mInitialMotionX > 0 ? mInitialMotionX + mTouchSlop : + mInitialMotionX - mTouchSlop; + mLastMotionY = y; + setScrollState(SCROLL_STATE_DRAGGING); + setScrollingCacheEnabled(true); + + // Disallow Parent Intercept, just in case + ViewParent parent = getParent(); + if (parent != null) { + parent.requestDisallowInterceptTouchEvent(true); + } + } + } else { + if (yDiff > mTouchSlop && yDiff > xDiff) { + if (DEBUG) Log.v(TAG, "Starting drag!"); + mIsBeingDragged = true; + requestParentDisallowInterceptTouchEvent(true); + mLastMotionY = y - mInitialMotionY > 0 ? mInitialMotionY + mTouchSlop : + mInitialMotionY - mTouchSlop; + mLastMotionX = x; + setScrollState(SCROLL_STATE_DRAGGING); + setScrollingCacheEnabled(true); + + // Disallow Parent Intercept, just in case + ViewParent parent = getParent(); + if (parent != null) { + parent.requestDisallowInterceptTouchEvent(true); + } + } + } + } + // Not else! Note that mIsBeingDragged can be set above. + if (mIsBeingDragged) { + // Scroll to follow the motion event + final int activePointerIndex = ev.findPointerIndex(mActivePointerId); + if (isHorizontal) { + final float x = ev.getX(activePointerIndex); + needsInvalidate |= performDragX(x); + } else { + final float y = ev.getY(activePointerIndex); + needsInvalidate |= performDragY(y); + } + } + break; + case MotionEvent.ACTION_UP: + if (mIsBeingDragged) { + final VelocityTracker velocityTracker = mVelocityTracker; + velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); + mPopulatePending = true; + final int activePointerIndex = ev.findPointerIndex(mActivePointerId); + final int size = getClientSize(); + final int initialVelocity; + final int scroll; + final int totalDelta; + if (isHorizontal) { + initialVelocity = (int) velocityTracker.getXVelocity(mActivePointerId); + scroll = getScrollX(); + totalDelta = (int) (ev.getX(activePointerIndex) - mInitialMotionX); + } else { + initialVelocity = (int) velocityTracker.getYVelocity(mActivePointerId); + scroll = getScrollY(); + totalDelta = (int) (ev.getY(activePointerIndex) - mInitialMotionY); + } + final ItemInfo ii = infoForCurrentScrollPosition(); + final float marginOffset = (float) mPageMargin / size; + final int currentPage = ii.position; + final float pageOffset = (((float) scroll / size) - ii.offset) + / (ii.widthFactor + marginOffset); + + int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, + totalDelta); + setCurrentItemInternal(nextPage, true, true, initialVelocity); + + needsInvalidate = resetTouch(); + } + break; + case MotionEvent.ACTION_CANCEL: + if (mIsBeingDragged) { + scrollToItem(mCurItem, true, 0, false); + needsInvalidate = resetTouch(); + } + break; + case MotionEvent.ACTION_POINTER_DOWN: { + final int index = ev.getActionIndex(); + if (isHorizontal) { + mLastMotionX = ev.getX(index); + } else { + mLastMotionY = ev.getY(index); + } + mActivePointerId = ev.getPointerId(index); + break; + } + case MotionEvent.ACTION_POINTER_UP: + onSecondaryPointerUp(ev); + if (isHorizontal) { + mLastMotionX = ev.getX(ev.findPointerIndex(mActivePointerId)); + } else { + mLastMotionY = ev.getY(ev.findPointerIndex(mActivePointerId)); + } + break; + } + if (needsInvalidate) { + ViewCompat.postInvalidateOnAnimation(this); + } + return true; + } + + private boolean resetTouch() { + boolean needsInvalidate; + mActivePointerId = INVALID_POINTER; + endDrag(); + mStartEdge.onRelease(); + mEndEdge.onRelease(); + needsInvalidate = mStartEdge.isFinished() || mEndEdge.isFinished(); + return needsInvalidate; + } + + private void requestParentDisallowInterceptTouchEvent(boolean disallowIntercept) { + final ViewParent parent = getParent(); + if (parent != null) { + parent.requestDisallowInterceptTouchEvent(disallowIntercept); + } + } + + private boolean performDragX(float x) { + boolean needsInvalidate = false; + + final float deltaX = mLastMotionX - x; + mLastMotionX = x; + + float oldScrollX = getScrollX(); + float scrollX = oldScrollX + deltaX; + final int width = getClientWidth(); + + float leftBound = width * mFirstOffset; + float rightBound = width * mLastOffset; + boolean leftAbsolute = true; + boolean rightAbsolute = true; + + final ItemInfo firstItem = mItems.get(0); + final ItemInfo lastItem = mItems.get(mItems.size() - 1); + if (firstItem.position != 0) { + leftAbsolute = false; + leftBound = firstItem.offset * width; + } + if (lastItem.position != mAdapter.getCount() - 1) { + rightAbsolute = false; + rightBound = lastItem.offset * width; + } + + if (scrollX < leftBound) { + if (leftAbsolute) { + float over = leftBound - scrollX; + mStartEdge.onPull(Math.abs(over) / width); + needsInvalidate = true; + } + scrollX = leftBound; + } else if (scrollX > rightBound) { + if (rightAbsolute) { + float over = scrollX - rightBound; + mEndEdge.onPull(Math.abs(over) / width); + needsInvalidate = true; + } + scrollX = rightBound; + } + // Don't lose the rounded component + mLastMotionX += scrollX - (int) scrollX; + scrollTo((int) scrollX, getScrollY()); + pageScrolled((int) scrollX, 0); + + return needsInvalidate; + } + + private boolean performDragY(float y) { + boolean needsInvalidate = false; + + final float deltaY = mLastMotionY - y; + mLastMotionY = y; + + float oldScrollY = getScrollY(); + float scrollY = oldScrollY + deltaY; + final int height = getClientHeight(); + + float topBound = height * mFirstOffset; + float bottomBound = height * mLastOffset; + boolean topAbsolute = true; + boolean bottomAbsolute = true; + + final ItemInfo firstItem = mItems.get(0); + final ItemInfo lastItem = mItems.get(mItems.size() - 1); + if (firstItem.position != 0) { + topAbsolute = false; + topBound = firstItem.offset * height; + } + if (lastItem.position != mAdapter.getCount() - 1) { + bottomAbsolute = false; + bottomBound = lastItem.offset * height; + } + + if (scrollY < topBound) { + if (topAbsolute) { + float over = topBound - scrollY; + mStartEdge.onPull(Math.abs(over) / height); + needsInvalidate = true; + } + scrollY = topBound; + } else if (scrollY > bottomBound) { + if (bottomAbsolute) { + float over = scrollY - bottomBound; + mEndEdge.onPull(Math.abs(over) / height); + needsInvalidate = true; + } + scrollY = bottomBound; + } + // Don't lose the rounded component + mLastMotionY += scrollY - (int) scrollY; + scrollTo(getScrollX(), (int) scrollY); + pageScrolled(0, (int) scrollY); + + return needsInvalidate; + } + + /** + * @return Info about the page at the current scroll position. + * This can be synthetic for a missing middle page; the 'object' field can be null. + */ + private ItemInfo infoForCurrentScrollPosition() { + final int size = getClientSize(); + final float scroll; + if (isHorizontal) { + scroll = getScrollX(); + } else { + scroll = getScrollY(); + } + final float scrollOffset = size > 0 ? (float) scroll / size : 0; + final float marginOffset = size > 0 ? (float) mPageMargin / size : 0; + int lastPos = -1; + float lastOffset = 0.f; + float lastSize = 0.f; + boolean first = true; + + ItemInfo lastItem = null; + for (int i = 0; i < mItems.size(); i++) { + ItemInfo ii = mItems.get(i); + float offset; + if (!first && ii.position != lastPos + 1) { + // Create a synthetic item for a missing page. + ii = mTempItem; + ii.offset = lastOffset + lastSize + marginOffset; + ii.position = lastPos + 1; + ii.widthFactor = mAdapter.getPageWidth(ii.position); + i--; + } + offset = ii.offset; + + final float startBound = offset; + final float endBound = offset + ii.widthFactor + marginOffset; + if (first || scrollOffset >= startBound) { + if (scrollOffset < endBound || i == mItems.size() - 1) { + return ii; + } + } else { + return lastItem; + } + first = false; + lastPos = ii.position; + lastOffset = offset; + lastSize = ii.widthFactor; + lastItem = ii; + } + + return lastItem; + } + + private int determineTargetPage(int currentPage, float pageOffset, int velocity, int delta) { + int targetPage; + if (Math.abs(delta) > mFlingDistance && Math.abs(velocity) > mMinimumVelocity) { + targetPage = velocity > 0 ? currentPage : currentPage + 1; + } else { + final float truncator = currentPage >= mCurItem ? 0.4f : 0.6f; + targetPage = currentPage + (int) (pageOffset + truncator); + } + + if (mItems.size() > 0) { + final ItemInfo firstItem = mItems.get(0); + final ItemInfo lastItem = mItems.get(mItems.size() - 1); + + // Only let the user target pages we have items for + targetPage = Math.max(firstItem.position, Math.min(targetPage, lastItem.position)); + } + + return targetPage; + } + + @Override + public void draw(Canvas canvas) { + super.draw(canvas); + boolean needsInvalidate = false; + + final int overScrollMode = getOverScrollMode(); + if (overScrollMode == View.OVER_SCROLL_ALWAYS + || (overScrollMode == View.OVER_SCROLL_IF_CONTENT_SCROLLS + && mAdapter != null && mAdapter.getCount() > 1)) { + if (!mStartEdge.isFinished()) { + final int restoreCount = canvas.save(); + if (isHorizontal) { + final int width = getWidth(); + final int height = getHeight() - getPaddingTop() - getPaddingBottom(); + canvas.rotate(270); + canvas.translate(-height + getPaddingTop(), mFirstOffset * width); + mStartEdge.setSize(height, width); + } else { + final int width = getWidth() - getPaddingLeft() - getPaddingRight(); + final int height = getHeight(); + canvas.rotate(0); + canvas.translate(-getPaddingTop(), mFirstOffset * height); + mStartEdge.setSize(width, height); + } + + needsInvalidate |= mStartEdge.draw(canvas); + canvas.restoreToCount(restoreCount); + } + if (!mEndEdge.isFinished()) { + final int restoreCount = canvas.save(); + if (isHorizontal) { + final int width = getWidth(); + final int height = getHeight() - getPaddingTop() - getPaddingBottom(); + canvas.rotate(90); + canvas.translate(-getPaddingTop(), -(mLastOffset + 1) * width); + mEndEdge.setSize(height, width); + } else { + final int width = getWidth() - getPaddingLeft() - getPaddingRight(); + final int height = getHeight(); + canvas.rotate(180); + canvas.translate(-width + getPaddingTop(), -(mLastOffset + 1) * height); + mEndEdge.setSize(width, height); + } + + needsInvalidate |= mEndEdge.draw(canvas); + canvas.restoreToCount(restoreCount); + } + } else { + mStartEdge.finish(); + mEndEdge.finish(); + } + + if (needsInvalidate) { + // Keep animating + ViewCompat.postInvalidateOnAnimation(this); + } + } + + @Override + protected void onDraw(Canvas canvas) { + super.onDraw(canvas); + + // Draw the margin drawable between pages if needed. + if (mPageMargin > 0 && mMarginDrawable != null && mItems.size() > 0 && mAdapter != null) { + final int scroll; + final int size; + if (isHorizontal) { + scroll = getScrollX(); + size = getWidth(); + } else { + scroll = getScrollY(); + size = getHeight(); + } + + final float marginOffset = (float) mPageMargin / size; + int itemIndex = 0; + ItemInfo ii = mItems.get(0); + float offset = ii.offset; + final int itemCount = mItems.size(); + final int firstPos = ii.position; + final int lastPos = mItems.get(itemCount - 1).position; + for (int pos = firstPos; pos < lastPos; pos++) { + while (pos > ii.position && itemIndex < itemCount) { + ii = mItems.get(++itemIndex); + } + + float drawAt; + if (pos == ii.position) { + drawAt = (ii.offset + ii.widthFactor) * size; + offset = ii.offset + ii.widthFactor + marginOffset; + } else { + float widthFactor = mAdapter.getPageWidth(pos); + drawAt = (offset + widthFactor) * size; + offset += widthFactor + marginOffset; + } + + if (drawAt + mPageMargin > scroll) { + if (isHorizontal) { + mMarginDrawable.setBounds(Math.round(drawAt), mTopPageBounds, + Math.round(drawAt + mPageMargin), mBottomPageBounds); + } else { + mMarginDrawable.setBounds(mLeftPageBounds, (int) drawAt, + mRightPageBounds, (int) (drawAt + mPageMargin)); + } + mMarginDrawable.draw(canvas); + } + if (drawAt > scroll + size) { + break; // No more visible, no sense in continuing + } + } + } + } + + /** + * Start a fake drag of the pager. + * + *

A fake drag can be useful if you want to synchronize the motion of the ViewPager + * with the touch scrolling of another view, while still letting the ViewPager + * control the snapping motion and fling behavior. (e.g. parallax-scrolling tabs.) + * Call {@link #fakeDragBy(float)} to simulate the actual drag motion. Call + * {@link #endFakeDrag()} to complete the fake drag and fling as necessary. + * + *

During a fake drag the ViewPager will ignore all touch events. If a real drag + * is already in progress, this method will return false. + * + * @return true if the fake drag began successfully, false if it could not be started. + * + * @see #fakeDragBy(float) + * @see #endFakeDrag() + */ + public boolean beginFakeDrag() { + if (mIsBeingDragged) { + return false; + } + mFakeDragging = true; + setScrollState(SCROLL_STATE_DRAGGING); + if (isHorizontal) { + mInitialMotionX = mLastMotionX = 0; + } else { + mInitialMotionY = mLastMotionY = 0; + } + if (mVelocityTracker == null) { + mVelocityTracker = VelocityTracker.obtain(); + } else { + mVelocityTracker.clear(); + } + final long time = SystemClock.uptimeMillis(); + final MotionEvent ev = MotionEvent.obtain(time, time, MotionEvent.ACTION_DOWN, 0, 0, 0); + mVelocityTracker.addMovement(ev); + ev.recycle(); + mFakeDragBeginTime = time; + return true; + } + + /** + * End a fake drag of the pager. + * + * @see #beginFakeDrag() + * @see #fakeDragBy(float) + */ + public void endFakeDrag() { + if (!mFakeDragging) { + throw new IllegalStateException("No fake drag in progress. Call beginFakeDrag first."); + } + + if (mAdapter != null) { + final VelocityTracker velocityTracker = mVelocityTracker; + velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); + mPopulatePending = true; + final int initialVelocity; + final int size = getClientWidth(); + final int scroll; + final int totalDelta; + if (isHorizontal) { + initialVelocity = (int) velocityTracker.getXVelocity(mActivePointerId); + scroll = getScrollX(); + totalDelta = (int) (mLastMotionX - mInitialMotionX); + } else { + initialVelocity = (int) velocityTracker.getYVelocity(mActivePointerId); + scroll = getScrollY(); + totalDelta = (int) (mLastMotionY - mInitialMotionY); + } + + final ItemInfo ii = infoForCurrentScrollPosition(); + final int currentPage = ii.position; + final float pageOffset = (((float) scroll / size) - ii.offset) / ii.widthFactor; + int nextPage = determineTargetPage(currentPage, pageOffset, initialVelocity, + totalDelta); + setCurrentItemInternal(nextPage, true, true, initialVelocity); + } + endDrag(); + + mFakeDragging = false; + } + + /** + * Fake drag by an offset in pixels. You must have called {@link #beginFakeDrag()} first. + * + * @param offset Offset in pixels to drag by. + * @see #beginFakeDrag() + * @see #endFakeDrag() + */ + public void fakeDragBy(float offset) { + if (!mFakeDragging) { + throw new IllegalStateException("No fake drag in progress. Call beginFakeDrag first."); + } + + if (mAdapter == null) { + return; + } + + final int size = getClientSize(); + float oldScroll; + if (isHorizontal) { + mLastMotionX += offset; + oldScroll = getScrollX(); + } else { + mLastMotionY += offset; + oldScroll = getScrollY(); + } + + float scroll = oldScroll - offset; + + float startBound = size * mFirstOffset; + float endBound = size * mLastOffset; + + final ItemInfo firstItem = mItems.get(0); + final ItemInfo lastItem = mItems.get(mItems.size() - 1); + if (firstItem.position != 0) { + startBound = firstItem.offset * size; + } + if (lastItem.position != mAdapter.getCount() - 1) { + endBound = lastItem.offset * size; + } + + if (scroll < startBound) { + scroll = startBound; + } else if (scroll > endBound) { + scroll = endBound; + } + // Don't lose the rounded component + final MotionEvent ev; + final long time = SystemClock.uptimeMillis(); + if (isHorizontal) { + mLastMotionX += scroll - (int) scroll; + scrollTo((int) scroll, getScrollY()); + pageScrolled((int) scroll, 0); + + ev = MotionEvent.obtain(mFakeDragBeginTime, time, MotionEvent.ACTION_MOVE, + mLastMotionX, 0, 0); + } else { + mLastMotionY += scroll - (int) scroll; + scrollTo(getScrollX(), (int) scroll); + pageScrolled(0, (int) scroll); + + ev = MotionEvent.obtain(mFakeDragBeginTime, time, MotionEvent.ACTION_MOVE, + 0, mLastMotionY, 0); + } + + // Synthesize an event for the VelocityTracker. + mVelocityTracker.addMovement(ev); + ev.recycle(); + } + + /** + * Returns true if a fake drag is in progress. + * + * @return true if currently in a fake drag, false otherwise. + * + * @see #beginFakeDrag() + * @see #fakeDragBy(float) + * @see #endFakeDrag() + */ + public boolean isFakeDragging() { + return mFakeDragging; + } + + private void onSecondaryPointerUp(MotionEvent ev) { + final int pointerIndex = ev.getActionIndex(); + final int pointerId = ev.getPointerId(pointerIndex); + if (pointerId == mActivePointerId) { + // This was our active pointer going up. Choose a new + // active pointer and adjust accordingly. + final int newPointerIndex = pointerIndex == 0 ? 1 : 0; + if (isHorizontal) { + mLastMotionX = ev.getX(newPointerIndex); + } else { + mLastMotionY = ev.getY(newPointerIndex); + } + mActivePointerId = ev.getPointerId(newPointerIndex); + if (mVelocityTracker != null) { + mVelocityTracker.clear(); + } + } + } + + private void endDrag() { + mIsBeingDragged = false; + mIsUnableToDrag = false; + + if (mVelocityTracker != null) { + mVelocityTracker.recycle(); + mVelocityTracker = null; + } + } + + private void setScrollingCacheEnabled(boolean enabled) { + if (mScrollingCacheEnabled != enabled) { + mScrollingCacheEnabled = enabled; + if (USE_CACHE) { + final int size = getChildCount(); + for (int i = 0; i < size; ++i) { + final View child = getChildAt(i); + if (child.getVisibility() != GONE) { + child.setDrawingCacheEnabled(enabled); + } + } + } + } + } + + /** + * Check if this ViewPager can be scrolled horizontally in a certain direction. + * + * @param direction Negative to check scrolling left, positive to check scrolling right. + * @return Whether this ViewPager can be scrolled in the specified direction. It will always + * return false if the specified direction is 0. + */ + @Override + public boolean canScrollHorizontally(int direction) { + if (mAdapter == null || !isHorizontal) { + return false; + } + + final int width = getClientWidth(); + final int scrollX = getScrollX(); + if (direction < 0) { + return (scrollX > (int) (width * mFirstOffset)); + } else if (direction > 0) { + return (scrollX < (int) (width * mLastOffset)); + } else { + return false; + } + } + + /** + * Check if this ViewPager can be scrolled vertically in a certain direction. + * + * @param direction Negative to check scrolling up, positive to check scrolling down. + * @return Whether this ViewPager can be scrolled in the specified direction. It will always + * return false if the specified direction is 0. + */ + @Override + public boolean canScrollVertically(int direction) { + if (mAdapter == null || isHorizontal) { + return false; + } + + final int width = getClientWidth(); + final int scrollX = getScrollX(); + if (direction < 0) { + return (scrollX > (int) (width * mFirstOffset)); + } else if (direction > 0) { + return (scrollX < (int) (width * mLastOffset)); + } else { + return false; + } + } + + /** + * Tests scrollability within child views of v given a delta of dx. + * + * @param v View to test for horizontal scrollability + * @param checkV Whether the view v passed should itself be checked for scrollability (true), + * or just its children (false). + * @param dx Delta scrolled in pixels + * @param x X coordinate of the active touch point + * @param y Y coordinate of the active touch point + * @return true if child views of v can be scrolled by delta of dx. + */ + protected boolean canScroll(View v, boolean checkV, int delta, int x, int y) { + if (v instanceof ViewGroup) { + final ViewGroup group = (ViewGroup) v; + final int scrollX = v.getScrollX(); + final int scrollY = v.getScrollY(); + final int count = group.getChildCount(); + // Count backwards - let topmost views consume scroll distance first. + for (int i = count - 1; i >= 0; i--) { + // TODO: Add versioned support here for transformed views. + // This will not work for transformed views in Honeycomb+ + final View child = group.getChildAt(i); + if (x + scrollX >= child.getLeft() && x + scrollX < child.getRight() + && y + scrollY >= child.getTop() && y + scrollY < child.getBottom() + && canScroll(child, true, delta, x + scrollX - child.getLeft(), + y + scrollY - child.getTop())) { + return true; + } + } + } + + return checkV && ((isHorizontal && v.canScrollHorizontally(-delta)) || + (!isHorizontal && v.canScrollVertically(-delta))); + } + + @Override + public boolean dispatchKeyEvent(KeyEvent event) { + // Let the focused view and/or our descendants get the key first + return super.dispatchKeyEvent(event) || executeKeyEvent(event); + } + + /** + * You can call this function yourself to have the scroll view perform + * scrolling from a key event, just as if the event had been dispatched to + * it by the view hierarchy. + * + * @param event The key event to execute. + * @return Return true if the event was handled, else false. + */ + public boolean executeKeyEvent(@NonNull KeyEvent event) { + boolean handled = false; + if (event.getAction() == KeyEvent.ACTION_DOWN) { + switch (event.getKeyCode()) { + case KeyEvent.KEYCODE_DPAD_LEFT: + if (event.hasModifiers(KeyEvent.META_ALT_ON)) { + handled = pageLeft(); + } else { + handled = arrowScroll(FOCUS_LEFT); + } + break; + case KeyEvent.KEYCODE_DPAD_RIGHT: + if (event.hasModifiers(KeyEvent.META_ALT_ON)) { + handled = pageRight(); + } else { + handled = arrowScroll(FOCUS_RIGHT); + } + break; + case KeyEvent.KEYCODE_TAB: + if (event.hasNoModifiers()) { + handled = arrowScroll(FOCUS_FORWARD); + } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) { + handled = arrowScroll(FOCUS_BACKWARD); + } + break; + } + } + return handled; + } + + /** + * Handle scrolling in response to a left or right arrow click. + * + * @param direction The direction corresponding to the arrow key that was pressed. It should be + * either {@link View#FOCUS_LEFT} or {@link View#FOCUS_RIGHT}. + * @return Whether the scrolling was handled successfully. + */ + public boolean arrowScroll(int direction) { + View currentFocused = findFocus(); + if (currentFocused == this) { + currentFocused = null; + } else if (currentFocused != null) { + boolean isChild = false; + for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup; + parent = parent.getParent()) { + if (parent == this) { + isChild = true; + break; + } + } + if (!isChild) { + // This would cause the focus search down below to fail in fun ways. + final StringBuilder sb = new StringBuilder(); + sb.append(currentFocused.getClass().getSimpleName()); + for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup; + parent = parent.getParent()) { + sb.append(" => ").append(parent.getClass().getSimpleName()); + } + Log.e(TAG, "arrowScroll tried to find focus based on non-child " + + "current focused view " + sb.toString()); + currentFocused = null; + } + } + + boolean handled = false; + + View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, + direction); + if (nextFocused != null && nextFocused != currentFocused) { + if (direction == View.FOCUS_LEFT) { + // If there is nothing to the left, or this is causing us to + // jump to the right, then what we really want to do is page left. + final int nextLeft = getChildRectInPagerCoordinates(mTempRect, nextFocused).left; + final int currLeft = getChildRectInPagerCoordinates(mTempRect, currentFocused).left; + if (currentFocused != null && nextLeft >= currLeft) { + handled = pageLeft(); + } else { + handled = nextFocused.requestFocus(); + } + } else if (direction == View.FOCUS_RIGHT) { + // If there is nothing to the right, or this is causing us to + // jump to the left, then what we really want to do is page right. + final int nextLeft = getChildRectInPagerCoordinates(mTempRect, nextFocused).left; + final int currLeft = getChildRectInPagerCoordinates(mTempRect, currentFocused).left; + if (currentFocused != null && nextLeft <= currLeft) { + handled = pageRight(); + } else { + handled = nextFocused.requestFocus(); + } + } + } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) { + // Trying to move left and nothing there; try to page. + handled = pageLeft(); + } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) { + // Trying to move right and nothing there; try to page. + handled = pageRight(); + } + if (handled) { + playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); + } + return handled; + } + + private Rect getChildRectInPagerCoordinates(Rect outRect, View child) { + if (outRect == null) { + outRect = new Rect(); + } + if (child == null) { + outRect.set(0, 0, 0, 0); + return outRect; + } + outRect.left = child.getLeft(); + outRect.right = child.getRight(); + outRect.top = child.getTop(); + outRect.bottom = child.getBottom(); + + ViewParent parent = child.getParent(); + while (parent instanceof ViewGroup && parent != this) { + final ViewGroup group = (ViewGroup) parent; + outRect.left += group.getLeft(); + outRect.right += group.getRight(); + outRect.top += group.getTop(); + outRect.bottom += group.getBottom(); + + parent = group.getParent(); + } + return outRect; + } + + boolean pageLeft() { + if (mCurItem > 0) { + setCurrentItem(mCurItem - 1, true); + return true; + } + return false; + } + + boolean pageRight() { + if (mAdapter != null && mCurItem < (mAdapter.getCount() - 1)) { + setCurrentItem(mCurItem + 1, true); + return true; + } + return false; + } + + /** + * We only want the current page that is being shown to be focusable. + */ + @Override + public void addFocusables(ArrayList views, int direction, int focusableMode) { + final int focusableCount = views.size(); + + final int descendantFocusability = getDescendantFocusability(); + + if (descendantFocusability != FOCUS_BLOCK_DESCENDANTS) { + for (int i = 0; i < getChildCount(); i++) { + final View child = getChildAt(i); + if (child.getVisibility() == VISIBLE) { + ItemInfo ii = infoForChild(child); + if (ii != null && ii.position == mCurItem) { + child.addFocusables(views, direction, focusableMode); + } + } + } + } + + // we add ourselves (if focusable) in all cases except for when we are + // FOCUS_AFTER_DESCENDANTS and there are some descendants focusable. this is + // to avoid the focus search finding layouts when a more precise search + // among the focusable children would be more interesting. + if (descendantFocusability != FOCUS_AFTER_DESCENDANTS + || (focusableCount == views.size())) { // No focusable descendants + // Note that we can't call the superclass here, because it will + // add all views in. So we need to do the same thing View does. + if (!isFocusable()) { + return; + } + if ((focusableMode & FOCUSABLES_TOUCH_MODE) == FOCUSABLES_TOUCH_MODE + && isInTouchMode() && !isFocusableInTouchMode()) { + return; + } + if (views != null) { + views.add(this); + } + } + } + + /** + * We only want the current page that is being shown to be touchable. + */ + @Override + public void addTouchables(ArrayList views) { + // Note that we don't call super.addTouchables(), which means that + // we don't call View.addTouchables(). This is okay because a ViewPager + // is itself not touchable. + for (int i = 0; i < getChildCount(); i++) { + final View child = getChildAt(i); + if (child.getVisibility() == VISIBLE) { + ItemInfo ii = infoForChild(child); + if (ii != null && ii.position == mCurItem) { + child.addTouchables(views); + } + } + } + } + + /** + * We only want the current page that is being shown to be focusable. + */ + @Override + protected boolean onRequestFocusInDescendants(int direction, + Rect previouslyFocusedRect) { + int index; + int increment; + int end; + int count = getChildCount(); + if ((direction & FOCUS_FORWARD) != 0) { + index = 0; + increment = 1; + end = count; + } else { + index = count - 1; + increment = -1; + end = -1; + } + for (int i = index; i != end; i += increment) { + View child = getChildAt(i); + if (child.getVisibility() == VISIBLE) { + ItemInfo ii = infoForChild(child); + if (ii != null && ii.position == mCurItem) { + if (child.requestFocus(direction, previouslyFocusedRect)) { + return true; + } + } + } + } + return false; + } + + @Override + public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { + // Dispatch scroll events from this ViewPager. + if (event.getEventType() == AccessibilityEventCompat.TYPE_VIEW_SCROLLED) { + return super.dispatchPopulateAccessibilityEvent(event); + } + + // Dispatch all other accessibility events from the current page. + final int childCount = getChildCount(); + for (int i = 0; i < childCount; i++) { + final View child = getChildAt(i); + if (child.getVisibility() == VISIBLE) { + final ItemInfo ii = infoForChild(child); + if (ii != null && ii.position == mCurItem + && child.dispatchPopulateAccessibilityEvent(event)) { + return true; + } + } + } + + return false; + } + + @Override + protected ViewGroup.LayoutParams generateDefaultLayoutParams() { + return new LayoutParams(); + } + + @Override + protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { + return generateDefaultLayoutParams(); + } + + @Override + protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { + return p instanceof LayoutParams && super.checkLayoutParams(p); + } + + @Override + public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) { + return new LayoutParams(getContext(), attrs); + } + + public boolean isHorizontal() { + return isHorizontal; + } + + public void setHorizontal(boolean isHorizontal) { + if (this.isHorizontal == isHorizontal) return; + this.isHorizontal = isHorizontal; + + // Reset values + mInitialMotionX = 0; + mInitialMotionY = 0; + mLastMotionX = 0; + mLastMotionY = 0; + if (mVelocityTracker != null) { + mVelocityTracker.clear(); + } + + scrollToItem(mCurItem, false, 0, false); + requestLayout(); + } + + class MyAccessibilityDelegate extends AccessibilityDelegateCompat { + + @Override + public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) { + super.onInitializeAccessibilityEvent(host, event); + event.setClassName(DirectionalViewPager.class.getName()); + event.setScrollable(canScroll()); + if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED && mAdapter != null) { + event.setItemCount(mAdapter.getCount()); + event.setFromIndex(mCurItem); + event.setToIndex(mCurItem); + } + } + + @Override + public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) { + super.onInitializeAccessibilityNodeInfo(host, info); + info.setClassName(DirectionalViewPager.class.getName()); + info.setScrollable(canScroll()); + if (canScrollHorizontally(1)) { + info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD); + } + if (canScrollHorizontally(-1)) { + info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD); + } + } + + @Override + public boolean performAccessibilityAction(View host, int action, Bundle args) { + if (super.performAccessibilityAction(host, action, args)) { + return true; + } + switch (action) { + case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: { + if (canScrollHorizontally(1)) { + setCurrentItem(mCurItem + 1); + return true; + } + } return false; + case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: { + if (canScrollHorizontally(-1)) { + setCurrentItem(mCurItem - 1); + return true; + } + } return false; + } + return false; + } + + private boolean canScroll() { + return (mAdapter != null) && (mAdapter.getCount() > 1); + } + } + + private class PagerObserver extends DataSetObserver { + PagerObserver() { + } + + @Override + public void onChanged() { + dataSetChanged(); + } + @Override + public void onInvalidated() { + dataSetChanged(); + } + } + + /** + * Layout parameters that should be supplied for views added to a + * ViewPager. + */ + public static class LayoutParams extends ViewGroup.LayoutParams { + /** + * true if this view is a decoration on the pager itself and not + * a view supplied by the adapter. + */ + public boolean isDecor; + + /** + * Gravity setting for use on decor views only: + * Where to position the view page within the overall ViewPager + * container; constants are defined in {@link android.view.Gravity}. + */ + public int gravity; + + /** + * Width as a 0-1 multiplier of the measured pager width + */ + float widthFactor = 0.f; + + /** + * true if this view was added during layout and needs to be measured + * before being positioned. + */ + boolean needsMeasure; + + /** + * Adapter position this view is for if !isDecor + */ + int position; + + /** + * Current child index within the ViewPager that this view occupies + */ + int childIndex; + + public LayoutParams() { + super(MATCH_PARENT, MATCH_PARENT); + } + + public LayoutParams(Context context, AttributeSet attrs) { + super(context, attrs); + + final TypedArray a = context.obtainStyledAttributes(attrs, LAYOUT_ATTRS); + gravity = a.getInteger(0, Gravity.TOP); + a.recycle(); + } + } + + static class ViewPositionComparator implements Comparator { + @Override + public int compare(View lhs, View rhs) { + final LayoutParams llp = (LayoutParams) lhs.getLayoutParams(); + final LayoutParams rlp = (LayoutParams) rhs.getLayoutParams(); + if (llp.isDecor != rlp.isDecor) { + return llp.isDecor ? 1 : -1; + } + return llp.position - rlp.position; + } + } +} diff --git a/library/src/main/res/values/attrs.xml b/library/src/main/res/values/attrs.xml new file mode 100644 index 0000000..47ccb95 --- /dev/null +++ b/library/src/main/res/values/attrs.xml @@ -0,0 +1,6 @@ + + + + + + diff --git a/settings.gradle b/settings.gradle new file mode 100644 index 0000000..462ba77 --- /dev/null +++ b/settings.gradle @@ -0,0 +1 @@ +include ':demo', ':library'