home.java

android first home screen

/*
 * Copyright (C) 2007 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 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.ContentResolver;
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.content.res.Resources;
import android.database.ContentObserver;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PaintFlagsDrawFilter;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.PaintDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
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 android.net.Uri;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

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";

	// 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 Handler mHandler = new Handler();

	private final BroadcastReceiver mWallpaperReceiver = new WallpaperIntentReceiver();
	private final BroadcastReceiver mApplicationsReceiver = new ApplicationsIntentReceiver();
	private final ContentObserver mObserver = new FavoritesChangeObserver();

	private GridView mGrid;

	private LayoutAnimationController mShowLayoutAnimation;
	private LayoutAnimationController mHideLayoutAnimation;

	private boolean mBlockAnimation;

	private View mShowApplications;
	private CheckBox mShowApplicationsCheck;

	private ApplicationsStackLayout mApplicationsStack;

	private Animation mGridEntry;
	private Animation mGridExit;
	
	private Paint bubblePaint;

	@Override
	public void onCreate(Bundle icicle)
	{
		super.onCreate(icicle);

		setDefaultKeyMode(DEFAULT_KEYS_SEARCH_LOCAL);

		setContentView(R.layout.home);

		registerIntentReceivers();
		registerContentObservers();

		setDefaultWallpaper();

		loadApplications(true);

		bindApplications();
		bindFavorites(true);
		bindRecents();
		bindButtons();
		
		bubblePaint = new Paint();
		bubblePaint.setColor(Color.WHITE);
		
		bubblePaint.setAntiAlias(true);

		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);
		}

		getContentResolver().unregisterContentObserver(mObserver);
		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);
	}

	/**
	 * Registers various content observers. The current implementation registers only a favorites observer to keep track of the favorites applications.
	 */
	private void registerContentObservers()
	{
		ContentResolver resolver = getContentResolver();
		resolver.registerContentObserver(Uri.parse("content://" + android.provider.Settings.AUTHORITY + "/favorites?notify=true"),
		true, mObserver);
	}

	/**
	 * 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(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)
		{
			final Cursor c = getContentResolver().query(
			Uri.parse("content://" + android.provider.Settings.AUTHORITY + "/favorites?notify=true"), null, null, null, "cellX");

			final int intentIndex = c.getColumnIndexOrThrow("intent");
			final int titleIndex = c.getColumnIndexOrThrow("title");
			final int typeIndex = c.getColumnIndexOrThrow("itemType");

			final PackageManager manager = getPackageManager();

			ApplicationInfo info;
			String intentDescription;

			if (mFavorites == null)
			{
				mFavorites = new LinkedList<ApplicationInfo>();
			}
			else
			{
				mFavorites.clear();
			}

			while (c.moveToNext())
			{
				final int itemType = c.getInt(typeIndex);

				if (itemType == 0 || // 0 == application
				itemType == 1)
				{ // 1 == shortcut

					intentDescription = c.getString(intentIndex);
					if (intentDescription == null)
					{
						continue;
					}

					Intent intent;
					try
					{
						intent = Intent.getIntent(intentDescription);
					}
					catch (java.net.URISyntaxException e)
					{
						continue;
					}
					info = getApplicationInfo(manager, intent);
					if (info != null)
					{
						info.title = c.getString(titleIndex);
						info.intent = intent;
						mFavorites.addFirst(info);
					}
				}
			}

			c.close();
		}

		mApplicationsStack.setFavorites(mFavorites);
	}

	/**
	 * 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)