private static Handler defineHandler(DisplayImageOptions options) {
Handler handler = options.getHandler();
if (options.isSyncLoading()) {
handler = null;
} else if (handler == null && Looper.myLooper() == Looper.getMainLooper()) {
handler = new Handler();
}
return handler;
}
/**
* Adds display image task to execution pool. Image will be set to ImageView when it's turn.<br>
* <b>NOTE:</b> {@link #init(ImageLoaderConfiguration)} method must be called before this method
* call
*
* @param uri Image URI (i.e. "http://site.com/image.png", "file:///mnt/sdcard/image.png")
* @param imageView {@link ImageView} which should display image
* @param options {@linkplain DisplayImageOptions Display image options} for image displaying. If
* <b>null</b> - default display image options {@linkplain
* ImageLoaderConfiguration.Builder#defaultDisplayImageOptions(DisplayImageOptions) from
* configuration} will be used.
* @param listener {@linkplain ImageLoadingListener Listener} for image loading process. Listener
* fires events on UI thread.
* @throws IllegalStateException if {@link #init(ImageLoaderConfiguration)} method wasn't called
* before
* @throws IllegalArgumentException if passed <b>imageView</b> is null
*/
public void displayImage(
String uri, ImageView imageView, DisplayImageOptions options, ImageLoadingListener listener) {
checkConfiguration();
if (imageView == null) {
throw new IllegalArgumentException(ERROR_WRONG_ARGUMENTS);
}
if (listener == null) {
listener = emptyListener;
}
if (options == null) {
options = configuration.defaultDisplayImageOptions;
}
if (TextUtils.isEmpty(uri)) {
engine.cancelDisplayTaskFor(imageView);
listener.onLoadingStarted(uri, imageView);
if (options.shouldShowImageResForEmptyUri()) {
imageView.setImageResource(options.getImageResForEmptyUri());
} else if (options.shouldShowImageForEmptyUri()) {
imageView.setImageDrawable(options.getImageForEmptyUri());
} else {
imageView.setImageDrawable(null);
}
listener.onLoadingComplete(uri, imageView, null);
return;
}
ImageSize targetSize =
ImageSizeUtils.defineTargetSizeForView(
imageView,
configuration.maxImageWidthForMemoryCache,
configuration.maxImageHeightForMemoryCache);
String memoryCacheKey = MemoryCacheUtil.generateKey(uri, targetSize);
engine.prepareDisplayTaskFor(imageView, memoryCacheKey);
listener.onLoadingStarted(uri, imageView);
Bitmap bmp = configuration.memoryCache.get(memoryCacheKey);
if (bmp != null && !bmp.isRecycled()) {
if (configuration.writeLogs) {
L.d(LOG_LOAD_IMAGE_FROM_MEMORY_CACHE, memoryCacheKey);
}
if (options.shouldPostProcess()) {
ImageLoadingInfo imageLoadingInfo =
new ImageLoadingInfo(
uri,
imageView,
targetSize,
memoryCacheKey,
options,
listener,
engine.getLockForUri(uri));
ProcessAndDisplayImageTask displayTask =
new ProcessAndDisplayImageTask(engine, bmp, imageLoadingInfo, options.getHandler());
engine.submit(displayTask);
} else {
options.getDisplayer().display(bmp, imageView, LoadedFrom.MEMORY_CACHE);
listener.onLoadingComplete(uri, imageView, bmp);
}
} else {
if (options.shouldShowImageResOnLoading()) {
imageView.setImageResource(options.getImageResOnLoading());
} else if (options.shouldShowImageOnLoading()) {
imageView.setImageDrawable(options.getImageOnLoading());
} else {
if (options.isResetViewBeforeLoading()) {
imageView.setImageDrawable(null);
}
}
ImageLoadingInfo imageLoadingInfo =
new ImageLoadingInfo(
uri,
imageView,
targetSize,
memoryCacheKey,
options,
listener,
engine.getLockForUri(uri));
LoadAndDisplayImageTask displayTask =
new LoadAndDisplayImageTask(engine, imageLoadingInfo, options.getHandler());
engine.submit(displayTask);
}
}