src/com/android/launcher2/IconCache.java

/*
 * Copyright (C) 2008 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.android.launcher2;

import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;

import java.util.HashMap;

/**
 * Cache of application icons.  Icons can be made from any thread.
 */
public class IconCache {
    private static final String TAG = "Launcher.IconCache";

    private static final int INITIAL_ICON_CACHE_CAPACITY = 50;

    private static class CacheEntry {
        public Bitmap icon;
        public String title;
        public Bitmap titleBitmap;
    }

    private final Bitmap mDefaultIcon;
    private final LauncherApplication mContext;
    private final PackageManager mPackageManager;
    private final Utilities.BubbleText mBubble;
    private final HashMap<ComponentName, CacheEntry> mCache =
            new HashMap<ComponentName, CacheEntry>(INITIAL_ICON_CACHE_CAPACITY);

    public IconCache(LauncherApplication context) {
        mContext = context;
        mPackageManager = context.getPackageManager();
        mBubble = new Utilities.BubbleText(context);
        mDefaultIcon = makeDefaultIcon();
    }

    private Bitmap makeDefaultIcon() {
        Drawable d = mPackageManager.getDefaultActivityIcon();
        Bitmap b = Bitmap.createBitmap(Math.max(d.getIntrinsicWidth(), 1),
                Math.max(d.getIntrinsicHeight(), 1),
                Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        d.setBounds(0, 0, b.getWidth(), b.getHeight());
        d.draw(c);
        return b;
    }

    /**
     * Remove any records for the supplied ComponentName.
     */
    public void remove(ComponentName componentName) {
        synchronized (mCache) {
            mCache.remove(componentName);
        }
    }

    /**
     * Empty out the cache.
     */
    public void flush() {
        synchronized (mCache) {
            mCache.clear();
        }
    }

    /**
     * Fill in "application" with the icon and label for "info."
     */
    public void getTitleAndIcon(ApplicationInfo application, ResolveInfo info) {
        synchronized (mCache) {
            CacheEntry entry = cacheLocked(application.componentName, info);
            if (entry.titleBitmap == null) {
                entry.titleBitmap = mBubble.createTextBitmap(entry.title);
            }

            application.title = entry.title;
            application.titleBitmap = entry.titleBitmap;
            application.iconBitmap = entry.icon;
        }
    }

    public Bitmap getIcon(Intent intent) {
        final ResolveInfo resolveInfo = mPackageManager.resolveActivity(intent, 0);
        ComponentName component = intent.getComponent();

        if (resolveInfo == null || component == null) {
            return mDefaultIcon;
        }

        CacheEntry entry = cacheLocked(component, resolveInfo);
        return entry.icon;
    }

    public Bitmap getIcon(ComponentName component, ResolveInfo resolveInfo) {
        if (resolveInfo == null || component == null) {
            return null;
        }

        CacheEntry entry = cacheLocked(component, resolveInfo);
        return entry.icon;
    }

    private CacheEntry cacheLocked(ComponentName componentName, ResolveInfo info) {
        CacheEntry entry = mCache.get(componentName);
        if (entry == null) {
            entry = new CacheEntry();

            mCache.put(componentName, entry);

            entry.title = info.loadLabel(mPackageManager).toString();
            if (entry.title == null) {
                entry.title = info.activityInfo.name;
            }
            entry.icon = Utilities.createIconBitmap(
                    info.activityInfo.loadIcon(mPackageManager), mContext);
        }
        return entry;
    }
}