Java tutorial
/* This file is part of Subsonic. Subsonic is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Subsonic is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Subsonic. If not, see <http://www.gnu.org/licenses/>. Copyright 2009 (C) Sindre Mehus */ package github.daneren2005.dsub.util; import android.annotation.TargetApi; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.LinearGradient; import android.graphics.Paint; import android.graphics.Shader; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.TransitionDrawable; import android.media.RemoteControlClient; import android.os.Build; import android.os.Handler; import android.os.Looper; import android.util.DisplayMetrics; import android.util.Log; import android.support.v4.util.LruCache; import android.view.View; import android.widget.ImageView; import android.widget.TextView; import github.daneren2005.dsub.R; import github.daneren2005.dsub.domain.ArtistInfo; import github.daneren2005.dsub.domain.MusicDirectory; import github.daneren2005.dsub.domain.Playlist; import github.daneren2005.dsub.domain.ServerInfo; import github.daneren2005.dsub.service.MusicService; import github.daneren2005.dsub.service.MusicServiceFactory; /** * Asynchronous loading of images, with caching. * <p/> * There should normally be only one instance of this class. * * @author Sindre Mehus */ public class ImageLoader { private static final String TAG = ImageLoader.class.getSimpleName(); private Context context; private LruCache<String, Bitmap> cache; private Handler handler; private Bitmap nowPlaying; private final int imageSizeDefault; private final int imageSizeLarge; private final int avatarSizeDefault; private boolean clearingCache = false; private final static int[] COLORS = { 0xFF33B5E5, 0xFFAA66CC, 0xFF99CC00, 0xFFFFBB33, 0xFFFF4444 }; public ImageLoader(Context context) { this.context = context; handler = new Handler(Looper.getMainLooper()); final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024); final int cacheSize = maxMemory / 4; // Determine the density-dependent image sizes. imageSizeDefault = context.getResources().getDrawable(R.drawable.unknown_album).getIntrinsicHeight(); DisplayMetrics metrics = context.getResources().getDisplayMetrics(); imageSizeLarge = Math.round(Math.min(metrics.widthPixels, metrics.heightPixels)); avatarSizeDefault = context.getResources().getDrawable(R.drawable.ic_social_person).getIntrinsicHeight(); cache = new LruCache<String, Bitmap>(cacheSize) { @Override protected int sizeOf(String key, Bitmap bitmap) { return bitmap.getRowBytes() * bitmap.getHeight() / 1024; } @Override protected void entryRemoved(boolean evicted, String key, Bitmap oldBitmap, Bitmap newBitmap) { if (evicted) { if (oldBitmap != nowPlaying || clearingCache) { oldBitmap.recycle(); } else { cache.put(key, oldBitmap); } } } }; } public void clearCache() { nowPlaying = null; new SilentBackgroundTask<Void>(context) { @Override protected Void doInBackground() throws Throwable { clearingCache = true; cache.evictAll(); clearingCache = false; return null; } }.execute(); } private Bitmap getUnknownImage(MusicDirectory.Entry entry, int size) { String key; int color; if (entry == null) { key = getKey("unknown", size); color = COLORS[0]; return getUnknownImage(key, size, color, null, null); } else { key = getKey(entry.getId() + "unknown", size); String hash; if (entry.getAlbum() != null) { hash = entry.getAlbum(); } else if (entry.getArtist() != null) { hash = entry.getArtist(); } else { hash = entry.getId(); } color = COLORS[Math.abs(hash.hashCode()) % COLORS.length]; return getUnknownImage(key, size, color, entry.getAlbum(), entry.getArtist()); } } private Bitmap getUnknownImage(String key, int size, int color, String topText, String bottomText) { Bitmap bitmap = cache.get(key); if (bitmap == null) { bitmap = createUnknownImage(size, color, topText, bottomText); cache.put(key, bitmap); } return bitmap; } private Bitmap createUnknownImage(int size, int primaryColor, String topText, String bottomText) { Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); Paint color = new Paint(); color.setColor(primaryColor); canvas.drawRect(0, 0, size, size * 2.0f / 3.0f, color); color.setShader(new LinearGradient(0, 0, 0, size / 3.0f, Color.rgb(82, 82, 82), Color.BLACK, Shader.TileMode.MIRROR)); canvas.drawRect(0, size * 2.0f / 3.0f, size, size, color); if (topText != null || bottomText != null) { Paint font = new Paint(); font.setFlags(Paint.ANTI_ALIAS_FLAG); font.setColor(Color.WHITE); font.setTextSize(3.0f + size * 0.07f); if (topText != null) { canvas.drawText(topText, size * 0.05f, size * 0.6f, font); } if (bottomText != null) { canvas.drawText(bottomText, size * 0.05f, size * 0.8f, font); } } return bitmap; } public Bitmap getCachedImage(Context context, MusicDirectory.Entry entry, boolean large) { int size = large ? imageSizeLarge : imageSizeDefault; if (entry == null || entry.getCoverArt() == null) { return getUnknownImage(entry, size); } Bitmap bitmap = cache.get(getKey(entry.getCoverArt(), size)); if (bitmap == null || bitmap.isRecycled()) { bitmap = FileUtil.getAlbumArtBitmap(context, entry, size); String key = getKey(entry.getCoverArt(), size); cache.put(key, bitmap); cache.get(key); } return bitmap; } public SilentBackgroundTask loadImage(View view, MusicDirectory.Entry entry, boolean large, boolean crossfade) { int size = large ? imageSizeLarge : imageSizeDefault; return loadImage(view, entry, large, size, crossfade); } public SilentBackgroundTask loadImage(View view, MusicDirectory.Entry entry, boolean large, int size, boolean crossfade) { // TODO: If we know this a artist, try to load artist info instead if (entry != null && !entry.isAlbum() && ServerInfo.checkServerVersion(context, "1.11") && !Util.isOffline(context)) { SilentBackgroundTask task = new ArtistImageTask(view.getContext(), entry, size, imageSizeLarge, large, view, crossfade); task.execute(); return task; } else if (entry != null && entry.getCoverArt() == null && entry.isDirectory() && !Util.isOffline(context)) { // Try to lookup child cover art MusicDirectory.Entry firstChild = FileUtil.lookupChild(context, entry, true); if (firstChild != null) { entry.setCoverArt(firstChild.getCoverArt()); } } Bitmap bitmap; if (entry == null || entry.getCoverArt() == null) { bitmap = getUnknownImage(entry, size); setImage(view, Util.createDrawableFromBitmap(context, bitmap), crossfade); return null; } bitmap = cache.get(getKey(entry.getCoverArt(), size)); if (bitmap != null && !bitmap.isRecycled()) { final Drawable drawable = Util.createDrawableFromBitmap(this.context, bitmap); setImage(view, drawable, crossfade); if (large) { nowPlaying = bitmap; } return null; } if (!large) { setImage(view, null, false); } ImageTask task = new ViewImageTask(view.getContext(), entry, size, imageSizeLarge, large, view, crossfade); task.execute(); return task; } public SilentBackgroundTask<Void> loadImage(View view, String url, boolean large) { Bitmap bitmap; int size = large ? imageSizeLarge : imageSizeDefault; if (url == null) { String key = getKey(url + "unknown", size); int color = COLORS[Math.abs(key.hashCode()) % COLORS.length]; bitmap = getUnknownImage(key, size, color, null, null); setImage(view, Util.createDrawableFromBitmap(context, bitmap), true); return null; } bitmap = cache.get(getKey(url, size)); if (bitmap != null && !bitmap.isRecycled()) { final Drawable drawable = Util.createDrawableFromBitmap(this.context, bitmap); setImage(view, drawable, true); return null; } setImage(view, null, false); SilentBackgroundTask<Void> task = new ViewUrlTask(view.getContext(), view, url, size); task.execute(); return task; } public SilentBackgroundTask<Void> loadImage(Context context, RemoteControlClient remoteControl, MusicDirectory.Entry entry) { Bitmap bitmap; if (entry == null || entry.getCoverArt() == null) { bitmap = getUnknownImage(entry, imageSizeLarge); setImage(remoteControl, Util.createDrawableFromBitmap(context, bitmap)); return null; } bitmap = cache.get(getKey(entry.getCoverArt(), imageSizeLarge)); if (bitmap != null && !bitmap.isRecycled()) { Drawable drawable = Util.createDrawableFromBitmap(this.context, bitmap); setImage(remoteControl, drawable); return null; } setImage(remoteControl, Util.createDrawableFromBitmap(context, null)); ImageTask task = new RemoteControlClientImageTask(context, entry, imageSizeLarge, imageSizeLarge, false, remoteControl); task.execute(); return task; } public SilentBackgroundTask<Void> loadAvatar(Context context, ImageView view, String username) { if (username == null) { view.setImageResource(R.drawable.ic_social_person); return null; } Bitmap bitmap = cache.get(username); if (bitmap != null && !bitmap.isRecycled()) { Drawable drawable = Util.createDrawableFromBitmap(this.context, bitmap); view.setImageDrawable(drawable); return null; } view.setImageDrawable(null); SilentBackgroundTask<Void> task = new AvatarTask(context, view, username); task.execute(); return task; } public SilentBackgroundTask loadImage(View view, Playlist playlist, boolean large, boolean crossfade) { MusicDirectory.Entry entry = new MusicDirectory.Entry(); String id; if (Util.isOffline(context)) { id = "pl-" + playlist.getName(); entry.setTitle(playlist.getComment()); } else { id = "pl-" + playlist.getId(); entry.setTitle(playlist.getName()); } entry.setId(id); entry.setCoverArt(id); // So this isn't treated as a artist entry.setParent(""); return loadImage(view, entry, large, crossfade); } private String getKey(String coverArtId, int size) { return coverArtId + size; } private void setImage(View view, final Drawable drawable, boolean crossfade) { if (view instanceof TextView) { // Cross-fading is not implemented for TextView since it's not in use. It would be easy to add it, though. TextView textView = (TextView) view; textView.setCompoundDrawablesWithIntrinsicBounds(drawable, null, null, null); } else if (view instanceof ImageView) { final ImageView imageView = (ImageView) view; if (crossfade && drawable != null) { Drawable existingDrawable = imageView.getDrawable(); if (existingDrawable == null) { Bitmap emptyImage; if (drawable.getIntrinsicWidth() > 0 && drawable.getIntrinsicHeight() > 0) { emptyImage = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888); } else { emptyImage = Bitmap.createBitmap(imageSizeDefault, imageSizeDefault, Bitmap.Config.ARGB_8888); } existingDrawable = new BitmapDrawable(context.getResources(), emptyImage); } else if (existingDrawable instanceof TransitionDrawable) { // This should only ever be used if user is skipping through many songs quickly TransitionDrawable tmp = (TransitionDrawable) existingDrawable; existingDrawable = tmp.getDrawable(tmp.getNumberOfLayers() - 1); } if (existingDrawable != null && drawable != null) { Drawable[] layers = new Drawable[] { existingDrawable, drawable }; final TransitionDrawable transitionDrawable = new TransitionDrawable(layers); imageView.setImageDrawable(transitionDrawable); transitionDrawable.startTransition(250); // Get rid of transition drawable after transition occurs handler.postDelayed(new Runnable() { @Override public void run() { // Only execute if still on same transition drawable if (imageView.getDrawable() == transitionDrawable) { imageView.setImageDrawable(drawable); } } }, 500L); } else { imageView.setImageDrawable(drawable); } } else { imageView.setImageDrawable(drawable); } } } @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH) private void setImage(RemoteControlClient remoteControl, Drawable drawable) { if (remoteControl != null && drawable != null) { Bitmap origBitmap = ((BitmapDrawable) drawable).getBitmap(); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2 && origBitmap != null) { origBitmap = origBitmap.copy(origBitmap.getConfig(), false); } if (origBitmap != null && !origBitmap.isRecycled()) { remoteControl.editMetadata(false) .putBitmap(RemoteControlClient.MetadataEditor.BITMAP_KEY_ARTWORK, origBitmap).apply(); } else { if (origBitmap != null) { Log.e(TAG, "Tried to load a recycled bitmap."); } remoteControl.editMetadata(false) .putBitmap(RemoteControlClient.MetadataEditor.BITMAP_KEY_ARTWORK, null).apply(); } } } public abstract class ImageTask extends SilentBackgroundTask<Void> { private final Context mContext; private final MusicDirectory.Entry mEntry; private final int mSize; private final int mSaveSize; private final boolean mIsNowPlaying; protected Drawable mDrawable; public ImageTask(Context context, MusicDirectory.Entry entry, int size, int saveSize, boolean isNowPlaying) { super(context); mContext = context; mEntry = entry; mSize = size; mSaveSize = saveSize; mIsNowPlaying = isNowPlaying; } @Override protected Void doInBackground() throws Throwable { try { MusicService musicService = MusicServiceFactory.getMusicService(mContext); Bitmap bitmap = musicService.getCoverArt(mContext, mEntry, mSize, null, this); if (bitmap != null) { String key = getKey(mEntry.getCoverArt(), mSize); cache.put(key, bitmap); // Make sure key is the most recently "used" cache.get(key); if (mIsNowPlaying) { nowPlaying = bitmap; } } else { bitmap = getUnknownImage(mEntry, mSize); } mDrawable = Util.createDrawableFromBitmap(mContext, bitmap); } catch (Throwable x) { Log.e(TAG, "Failed to download album art.", x); cancelled.set(true); } return null; } } private class ViewImageTask extends ImageTask { protected boolean mCrossfade; private View mView; public ViewImageTask(Context context, MusicDirectory.Entry entry, int size, int saveSize, boolean isNowPlaying, View view, boolean crossfade) { super(context, entry, size, saveSize, isNowPlaying); mView = view; mCrossfade = crossfade; } @Override protected void done(Void result) { setImage(mView, mDrawable, mCrossfade); } } private class RemoteControlClientImageTask extends ImageTask { private RemoteControlClient mRemoteControl; public RemoteControlClientImageTask(Context context, MusicDirectory.Entry entry, int size, int saveSize, boolean isNowPlaying, RemoteControlClient remoteControl) { super(context, entry, size, saveSize, isNowPlaying); mRemoteControl = remoteControl; } @Override protected void done(Void result) { setImage(mRemoteControl, mDrawable); } } private class ArtistImageTask extends SilentBackgroundTask<Void> { private final Context mContext; private final MusicDirectory.Entry mEntry; private final int mSize; private final int mSaveSize; private final boolean mIsNowPlaying; private Drawable mDrawable; private boolean mCrossfade; private View mView; private SilentBackgroundTask subTask; public ArtistImageTask(Context context, MusicDirectory.Entry entry, int size, int saveSize, boolean isNowPlaying, View view, boolean crossfade) { super(context); mContext = context; mEntry = entry; mSize = size; mSaveSize = saveSize; mIsNowPlaying = isNowPlaying; mView = view; mCrossfade = crossfade; } @Override protected Void doInBackground() throws Throwable { MusicService musicService = MusicServiceFactory.getMusicService(mContext); ArtistInfo artistInfo = musicService.getArtistInfo(mEntry.getId(), false, true, mContext, null); String url = artistInfo.getImageUrl(); // Figure out whether we are going to get a artist image or the standard image if (url != null && !"".equals(url.trim())) { // If getting the artist image fails for any reason, retry for the standard version subTask = new ViewUrlTask(mContext, mView, url, mSize) { @Override protected void failedToDownload() { // Call loadImage so we can take advantage of all of it's logic checks loadImage(mView, mEntry, mSize == imageSizeLarge, mCrossfade); // Delete subTask so it doesn't get called in done subTask = null; } }; } else { if (mEntry != null && mEntry.getCoverArt() == null && mEntry.isDirectory() && !Util.isOffline(context)) { // Try to lookup child cover art MusicDirectory.Entry firstChild = FileUtil.lookupChild(context, mEntry, true); if (firstChild != null) { mEntry.setCoverArt(firstChild.getCoverArt()); } } if (mEntry != null && mEntry.getCoverArt() != null) { subTask = new ViewImageTask(mContext, mEntry, mSize, mSaveSize, mIsNowPlaying, mView, mCrossfade); } else { // If entry is null as well, we need to just set as a blank image Bitmap bitmap = getUnknownImage(mEntry, mSize); mDrawable = Util.createDrawableFromBitmap(mContext, bitmap); return null; } } // Execute whichever way we decided to go subTask.doInBackground(); return null; } @Override public void done(Void result) { if (subTask != null) { subTask.done(result); } else if (mDrawable != null) { setImage(mView, mDrawable, mCrossfade); } } } private class ViewUrlTask extends SilentBackgroundTask<Void> { private final Context mContext; private final String mUrl; private final ImageView mView; private Drawable mDrawable; private int mSize; public ViewUrlTask(Context context, View view, String url, int size) { super(context); mContext = context; mView = (ImageView) view; mUrl = url; mSize = size; } @Override protected Void doInBackground() throws Throwable { try { MusicService musicService = MusicServiceFactory.getMusicService(mContext); Bitmap bitmap = musicService.getBitmap(mUrl, mSize, mContext, null, this); if (bitmap != null) { String key = getKey(mUrl, mSize); cache.put(key, bitmap); // Make sure key is the most recently "used" cache.get(key); mDrawable = Util.createDrawableFromBitmap(mContext, bitmap); } } catch (Throwable x) { Log.e(TAG, "Failed to download from url " + mUrl, x); cancelled.set(true); } return null; } @Override protected void done(Void result) { if (mDrawable != null) { mView.setImageDrawable(mDrawable); } else { failedToDownload(); } } protected void failedToDownload() { } } private class AvatarTask extends SilentBackgroundTask<Void> { private final Context mContext; private final String mUsername; private final ImageView mView; private Drawable mDrawable; public AvatarTask(Context context, ImageView view, String username) { super(context); mContext = context; mView = view; mUsername = username; } @Override protected Void doInBackground() throws Throwable { try { MusicService musicService = MusicServiceFactory.getMusicService(mContext); Bitmap bitmap = musicService.getAvatar(mUsername, avatarSizeDefault, mContext, null, this); if (bitmap != null) { cache.put(mUsername, bitmap); // Make sure key is the most recently "used" cache.get(mUsername); mDrawable = Util.createDrawableFromBitmap(mContext, bitmap); } } catch (Throwable x) { Log.e(TAG, "Failed to download album art.", x); } return null; } @Override protected void done(Void result) { if (mDrawable != null) { mView.setImageDrawable(mDrawable); } else { mView.setImageResource(R.drawable.ic_social_person); } } } }