The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/*
* Copyright (C) 2007 The Android开源工程
*
* 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 com.example.android.home;
import android.app.Activity;
import android.app.ActivityManager;
import android.app.SearchManager;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PaintFlagsDrawFilter;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.ColorFilter;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.PaintDrawable;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.util.Xml;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.LayoutAnimationController;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.TextView;
import java.io.IOException;
import java.io.FileReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
public class Home extends Activity {
/**
* Tag used for logging errors.
*/
private static final String LOG_TAG = "Home";
/**
* Keys during freeze/thaw.
*/
private static final String KEY_SAVE_GRID_OPENED = "grid.opened";
private static final String DEFAULT_FAVORITES_PATH = "etc/favorites.xml";
private static final String TAG_FAVORITES = "favorites";
private static final String TAG_FAVORITE = "favorite";
private static final String TAG_PACKAGE = "package";
private static final String TAG_CLASS = "class";
// Identifiers for option menu items
private static final int MENU_WALLPAPER_SETTINGS = Menu.FIRST + 1;
private static final int MENU_SEARCH = MENU_WALLPAPER_SETTINGS + 1;
private static final int MENU_SETTINGS = MENU_SEARCH + 1;
/**
* Maximum number of recent tasks to query.
*/
private static final int MAX_RECENT_TASKS = 20;
private static boolean mWallpaperChecked;
private static ArrayList<ApplicationInfo> mApplications;
private static LinkedList<ApplicationInfo> mFavorites;
private final BroadcastReceiver mWallpaperReceiver = new WallpaperIntentReceiver();
private final BroadcastReceiver mApplicationsReceiver = new ApplicationsIntentReceiver();
private GridView mGrid;
private LayoutAnimationController mShowLayoutAnimation;
private LayoutAnimationController mHideLayoutAnimation;
private boolean mBlockAnimation;
private boolean mHomeDown;
private boolean mBackDown;
private View mShowApplications;
private CheckBox mShowApplicationsCheck;
private ApplicationsStackLayout mApplicationsStack;
private Animation mGridEntry;
private Animation mGridExit;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setDefaultKeyMode(DEFAULT_KEYS_SEARCH_LOCAL);
setContentView(R.layout.home);
registerIntentReceivers();
setDefaultWallpaper();
loadApplications(true);
bindApplications();
bindFavorites(true);
bindRecents();
bindButtons();
mGridEntry = AnimationUtils.loadAnimation(this, R.anim.grid_entry);
mGridExit = AnimationUtils.loadAnimation(this, R.anim.grid_exit);
}
@Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
// Close the menu
if (Intent.ACTION_MAIN.equals(intent.getAction())) {
getWindow().closeAllPanels();
}
}
@Override
public void onDestroy() {
super.onDestroy();
// Remove the callback for the cached drawables or we leak
// the previous Home screen on orientation change
final int count = mApplications.size();
for (int i = 0; i < count; i++) {
mApplications.get(i).icon.setCallback(null);
}
unregisterReceiver(mWallpaperReceiver);
unregisterReceiver(mApplicationsReceiver);
}
@Override
protected void onResume() {
super.onResume();
bindRecents();
}
@Override
protected void onRestoreInstanceState(Bundle state) {
super.onRestoreInstanceState(state);
final boolean opened = state.getBoolean(KEY_SAVE_GRID_OPENED, false);
if (opened) {
showApplications(false);
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean(KEY_SAVE_GRID_OPENED, mGrid.getVisibility() == View.VISIBLE);
}
/**
* Registers various intent receivers. The current implementation registers
* only a wallpaper intent receiver to let other applications change the
* wallpaper.
*/
private void registerIntentReceivers() {
IntentFilter filter = new IntentFilter(Intent.ACTION_WALLPAPER_CHANGED);
registerReceiver(mWallpaperReceiver, filter);
filter = new IntentFilter(Intent.ACTION_PACKAGE_ADDED);
filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
filter.addDataScheme("package");
registerReceiver(mApplicationsReceiver, filter);
}
/**
* Creates a new appplications adapter for the grid view and registers it.
*/
private void bindApplications() {
if (mGrid == null) {
mGrid = (GridView) findViewById(R.id.all_apps);
}
mGrid.setAdapter(new ApplicationsAdapter(this, mApplications));
mGrid.setSelection(0);
if (mApplicationsStack == null) {
mApplicationsStack = (ApplicationsStackLayout) findViewById(R.id.faves_and_recents);
}
}
/**
* Binds actions to the various buttons.
*/
private void bindButtons() {
mShowApplications = findViewById(R.id.show_all_apps);
mShowApplications.setOnClickListener(new ShowApplications());
mShowApplicationsCheck = (CheckBox) findViewById(R.id.show_all_apps_check);
mGrid.setOnItemClickListener(new ApplicationLauncher());
}
/**
* When no wallpaper was manually set, a default wallpaper is used instead.
*/
private void setDefaultWallpaper() {
if (!mWallpaperChecked) {
Drawable wallpaper = peekWallpaper();
if (wallpaper == null) {
try {
clearWallpaper();
} catch (IOException e) {
Log.e(LOG_TAG, "Failed to clear wallpaper " + e);
}
} else {
getWindow().setBackgroundDrawable(new ClippedDrawable(wallpaper));
}
mWallpaperChecked = true;
}
}
/**
* Refreshes the favorite applications stacked over the all apps button.
* The number of favorites depends on the user.
*/
private void bindFavorites(boolean isLaunching) {
if (!isLaunching || mFavorites == null) {
if (mFavorites == null) {
mFavorites = new LinkedList<ApplicationInfo>();
} else {
mFavorites.clear();
}
mApplicationsStack.setFavorites(mFavorites);
FileReader favReader;
// Environment.getRootDirectory() is a fancy way of saying ANDROID_ROOT or "/system".
final File favFile = new File(Environment.getRootDirectory(), DEFAULT_FAVORITES_PATH);
try {
favReader = new FileReader(favFile);
} catch (FileNotFoundException e) {
Log.e(LOG_TAG, "Couldn't find or open favorites file " + favFile);
return;
}
final Intent intent = new Intent(Intent.ACTION_MAIN, null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
final PackageManager packageManager = getPackageManager();
try {
final XmlPullParser parser = Xml.newPullParser();
parser.setInput(favReader);
beginDocument(parser, TAG_FAVORITES);
ApplicationInfo info;
while (true) {
nextElement(parser);
String name = parser.getName();
if (!TAG_FAVORITE.equals(name)) {
break;
}
final String favoritePackage = parser.getAttributeValue(null, TAG_PACKAGE);
final String favoriteClass = parser.getAttributeValue(null, TAG_CLASS);
final ComponentName cn = new ComponentName(favoritePackage, favoriteClass);
intent.setComponent(cn);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
info = getApplicationInfo(packageManager, intent);
if (info != null) {
info.intent = intent;
mFavorites.addFirst(info);
}
}
} catch (XmlPullParserException e) {
Log.w(LOG_TAG, "Got exception parsing favorites.", e);
} catch (IOException e) {
Log.w(LOG_TAG, "Got exception parsing favorites.", e);
}
}
mApplicationsStack.setFavorites(mFavorites);
}
private static void beginDocument(XmlPullParser parser, String firstElementName)
throws XmlPullParserException, IOException {
int type;
while ((type = parser.next()) != XmlPullParser.START_TAG &&
type != XmlPullParser.END_DOCUMENT) {
// Empty
}
if (type != XmlPullParser.START_TAG) {
throw new XmlPullParserException("No start tag found");
}
if (!parser.getName().equals(firstElementName)) {
throw new XmlPullParserException("Unexpected start tag: found " + parser.getName() +
", expected " + firstElementName);
}
}
private static void nextElement(XmlPullParser parser) throws XmlPullParserException, IOException {
int type;
while ((type = parser.next()) != XmlPullParser.START_TAG &&
type != XmlPullParser.END_DOCUMENT) {
// Empty
}
}
/**
* Refreshes the recently launched applications stacked over the favorites. The number
* of recents depends on how many favorites are present.
*/
private void bindRecents() {
final PackageManager manager = getPackageManager();
final ActivityManager tasksManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
final List<ActivityManager.RecentTaskInfo> recentTasks = tasksManager.getRecentTasks(
MAX_RECENT_TASKS, 0);
final int count = recentTasks.size();
final ArrayList<ApplicationInfo> recents = new ArrayList<ApplicationInfo>();
for (int i = count - 1; i >= 0; i--) {
final Intent intent = recentTasks.get(i).baseIntent;
if (Intent.ACTION_MAIN.equals(intent.getAction()) &&
!intent.hasCategory(Intent.CATEGORY_HOME)) {
ApplicationInfo info = getApplicationInfo(manager, intent);
if (info != null) {
info.intent = intent;
if (!mFavorites.contains(info)) {
recents.add(info);
}
}
}
}
mApplicationsStack.setRecents(recents);
}
private static ApplicationInfo getApplicationInfo(PackageManager manager, Intent intent) {
final ResolveInfo resolveInfo = manager.resolveActivity(intent, 0);
if (resolveInfo == null) {
return null;
}
final ApplicationInfo info = new ApplicationInfo();
final ActivityInfo activityInfo = resolveInfo.activityInfo;
info.icon = activityInfo.loadIcon(manager);
if (info.title == null || info.title.length() == 0) {
info.title = activityInfo.loadLabel(manager);
}
if (info.title == null) {
info.title = "";
}
return info;
}
@Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
if (!hasFocus) {
mBackDown = mHomeDown = false;
}
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_BACK:
mBackDown = true;
return true;
case KeyEvent.KEYCODE_HOME:
mHomeDown = true;
return true;
}
} else if (event.getAction() == KeyEvent.ACTION_UP) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_BACK:
if (!event.isCanceled()) {
// Do BACK behavior.
}
mBackDown = true;
return true;
case KeyEvent.KEYCODE_HOME:
if (!event.isCanceled()) {
// Do HOME behavior.
}
mHomeDown = true;
return true;
}
}
return super.dispatchKeyEvent(event);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, MENU_WALLPAPER_SETTINGS, 0, R.string.menu_wallpaper)
.setIcon(android.R.drawable.ic_menu_gallery)
.setAlphabeticShortcut('W');
menu.add(0, MENU_SEARCH, 0, R.string.menu_search)
.setIcon(android.R.drawable.ic_search_category_default)
.setAlphabeticShortcut(SearchManager.MENU_KEY);
menu.add(0, MENU_SETTINGS, 0, R.string.menu_settings)
.setIcon(android.R.drawable.ic_menu_preferences)
.setIntent(new Intent(android.provider.Settings.ACTION_SETTINGS));
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case MENU_WALLPAPER_SETTINGS:
startWallpaper();
return true;
case MENU_SEARCH:
onSearchRequested();
return true;
}
return super.onOptionsItemSelected(item);
}
private void startWallpaper() {
final Intent pickWallpaper = new Intent(Intent.ACTION_SET_WALLPAPER);
startActivity(Intent.createChooser(pickWallpaper, getString(R.string.menu_wallpaper)));
}
/**
* Loads the list of installed applications in mApplications.
*/
private void loadApplications(boolean isLaunching) {
if (isLaunching && mApplications != null) {
return;
}
PackageManager manager = getPackageManager();
Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
final List<ResolveInfo> apps = manager.queryIntentActivities(mainIntent, 0);
Collections.sort(apps, new ResolveInfo.DisplayNameComparator(manager));
if (apps != null) {
final int count = apps.size();
if (mApplications == null) {
mApplications = new ArrayList<ApplicationInfo>(count);
}
mApplications.clear();
for (int i = 0; i < count; i++) {
ApplicationInfo application = new ApplicationInfo();
ResolveInfo info = apps.get(i);
application.title = info.loadLabel(manager);
application.setActivity(new ComponentName(
info.activityInfo.applicationInfo.packageName,
info.activityInfo.name),
Intent.FLAG_ACTIVITY_NEW_TASK
| Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
application.icon = info.activityInfo.loadIcon(manager);
mApplications.add(application);
}
}
}
/**
* Shows all of the applications by playing an animation on the grid.
*/
private void showApplications(boolean animate) {
if (mBlockAnimation) {
return;
}
mBlockAnimation = true;
mShowApplicationsCheck.toggle();
if (mShowLayoutAnimation == null) {
mShowLayoutAnimation = AnimationUtils.loadLayoutAnimation(
this, R.anim.show_applications);
}
// This enables a layout animation; if you uncomment this code, you need to
// comment the line mGrid.startAnimation() below
// mGrid.setLayoutAnimationListener(new ShowGrid());
// mGrid.setLayoutAnimation(mShowLayoutAnimation);
// mGrid.startLayoutAnimation();
if (animate) {
mGridEntry.setAnimationListener(new ShowGrid());
mGrid.startAnimation(mGridEntry);
}
mGrid.setVisibility(View.VISIBLE);
if (!animate) {
mBlockAnimation = false;
}
// ViewDebug.startHierarchyTracing("Home", mGrid);
}
/**
* Hides all of the applications by playing an animation on the grid.
*/
private void hideApplications() {
if (mBlockAnimation) {
return;
}
mBlockAnimation = true;
mShowApplicationsCheck.toggle();
if (mHideLayoutAnimation == null) {
mHideLayoutAnimation = AnimationUtils.loadLayoutAnimation(
this, R.anim.hide_applications);
}
mGridExit.setAnimationListener(new HideGrid());
mGrid.startAnimation(mGridExit);
mGrid.setVisibility(View.INVISIBLE);
mShowApplications.requestFocus();
// This enables a layout animation; if you uncomment this code, you need to
// comment the line mGrid.startAnimation() above
// mGrid.setLayoutAnimationListener(new HideGrid());
// mGrid.setLayoutAnimation(mHideLayoutAnimation);
// mGrid.startLayoutAnimation();
}
/**
* Receives intents from other applications to change the wallpaper.
*/
private class WallpaperIntentReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
getWindow().setBackgroundDrawable(new ClippedDrawable(getWallpaper()));
}
}
/**
* Receives notifications when applications are added/removed.
*/
private class ApplicationsIntentReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
loadApplications(false);
bindApplications();
bindRecents();
bindFavorites(false);
}
}
/**
* GridView adapter to show the list of all installed applications.
*/
private class ApplicationsAdapter extends ArrayAdapter<ApplicationInfo> {
private Rect mOldBounds = new Rect();
public ApplicationsAdapter(Context context, ArrayList<ApplicationInfo> apps) {
super(context, 0, apps);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
final ApplicationInfo info = mApplications.get(position);
if (convertView == null) {
final LayoutInflater inflater = getLayoutInflater();
convertView = inflater.inflate(R.layout.application, parent, false);
}
Drawable icon = info.icon;
if (!info.filtered) {
//final Resources resources = getContext().getResources();
int width = 42;//(int) resources.getDimension(android.R.dimen.app_icon_size);
int height = 42;//(int) resources.getDimension(android.R.dimen.app_icon_size);
final int iconWidth = icon.getIntrinsicWidth();
final int iconHeight = icon.getIntrinsicHeight();
if (icon instanceof PaintDrawable) {
PaintDrawable painter = (PaintDrawable) icon;
painter.setIntrinsicWidth(width);
painter.setIntrinsicHeight(height);
}
if (width > 0 && height > 0 && (width < iconWidth || height < iconHeight)) {
final float ratio = (float) iconWidth / iconHeight;
if (iconWidth > iconHeight) {
height = (int) (width / ratio);
} else if (iconHeight > iconWidth) {
width = (int) (height * ratio);
}
final Bitmap.Config c =
icon.getOpacity() != PixelFormat.OPAQUE ?
Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
final Bitmap thumb = Bitmap.createBitmap(width, height, c);
final Canvas canvas = new Canvas(thumb);
canvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG, 0));
// Copy the old bounds to restore them later
// If we were to do oldBounds = icon.getBounds(),
// the call to setBounds() that follows would
// change the same instance and we would lose the
// old bounds
mOldBounds.set(icon.getBounds());
icon.setBounds(0, 0, width, height);
icon.draw(canvas);
icon.setBounds(mOldBounds);
icon = info.icon = new BitmapDrawable(thumb);
info.filtered = true;
}
}
final TextView textView = (TextView) convertView.findViewById(R.id.label);
textView.setCompoundDrawablesWithIntrinsicBounds(null, icon, null, null);
textView.setText(info.title);
return convertView;
}
}
/**
* Shows and hides the applications grid view.
*/
private class ShowApplications implements View.OnClickListener {
public void onClick(View v) {
if (mGrid.getVisibility() != View.VISIBLE) {
showApplications(true);
} else {
hideApplications();
}
}
}
/**
* Hides the applications grid when the layout animation is over.
*/
private class HideGrid implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
mBlockAnimation = false;
}
public void onAnimationRepeat(Animation animation) {
}
}
/**
* Shows the applications grid when the layout animation is over.
*/
private class ShowGrid implements Animation.AnimationListener {
public void onAnimationStart(Animation animation) {
}
public void onAnimationEnd(Animation animation) {
mBlockAnimation = false;
// ViewDebug.stopHierarchyTracing();
}
public void onAnimationRepeat(Animation animation) {
}
}
/**
* Starts the selected activity/application in the grid view.
*/
private class ApplicationLauncher implements AdapterView.OnItemClickListener {
public void onItemClick(AdapterView parent, View v, int position, long id) {
ApplicationInfo app = (ApplicationInfo) parent.getItemAtPosition(position);
startActivity(app.intent);
}
}
/**
* When a drawable is attached to a View, the View gives the Drawable its dimensions
* by calling Drawable.setBounds(). In this application, the View that draws the
* wallpaper has the same size as the screen. However, the wallpaper might be larger
* that the screen which means it will be automatically stretched. Because stretching
* a bitmap while drawing it is very expensive, we use a ClippedDrawable instead.
* This drawable simply draws another wallpaper but makes sure it is not stretched
* by always giving it its intrinsic dimensions. If the wallpaper is larger than the
* screen, it will simply get clipped but it won't impact performance.
*/
private class ClippedDrawable extends Drawable {
private final Drawable mWallpaper;
public ClippedDrawable(Drawable wallpaper) {
mWallpaper = wallpaper;
}
@Override
public void setBounds(int left, int top, int right, int bottom) {
super.setBounds(left, top, right, bottom);
// Ensure the wallpaper is as large as it really is, to avoid stretching it
// at drawing time
mWallpaper.setBounds(left, top, left + mWallpaper.getIntrinsicWidth(),
top + mWallpaper.getIntrinsicHeight());
}
public void draw(Canvas canvas) {
mWallpaper.draw(canvas);
}
public void setAlpha(int alpha) {
mWallpaper.setAlpha(alpha);
}
public void setColorFilter(ColorFilter cf) {
mWallpaper.setColorFilter(cf);
}
public int getOpacity() {
return mWallpaper.getOpacity();
}
}
}