/**
* Pre caches the given set of image urls. We recommend using this method to warm the image cache
* before calling {@link CustomEventNativeListener#onNativeAdLoaded}. Doing so will force images
* to cache before displaying the ad.
*/
static void preCacheImages(
@NonNull final Context context,
@NonNull final List<String> imageUrls,
@NonNull final ImageListener imageListener) {
final ImageLoader imageLoader = Networking.getImageLoader(context);
// These Atomics are only accessed on the main thread.
// We use Atomics here so we can change their values while keeping a reference for the inner
// class.
final AtomicInteger imageCounter = new AtomicInteger(imageUrls.size());
final AtomicBoolean anyFailures = new AtomicBoolean(false);
ImageLoader.ImageListener volleyImageListener =
new ImageLoader.ImageListener() {
@Override
public void onResponse(
final ImageLoader.ImageContainer imageContainer, final boolean isImmediate) {
// Image Loader returns a "default" response immediately. We want to ignore this
// unless the image is already cached.
if (imageContainer.getBitmap() != null) {
final int count = imageCounter.decrementAndGet();
if (count == 0 && !anyFailures.get()) {
imageListener.onImagesCached();
}
}
}
@Override
public void onErrorResponse(final VolleyError volleyError) {
MoPubLog.d("Failed to download a native ads image:", volleyError);
boolean anyPreviousErrors = anyFailures.getAndSet(true);
imageCounter.decrementAndGet();
if (!anyPreviousErrors) {
imageListener.onImagesFailedToCache(NativeErrorCode.IMAGE_DOWNLOAD_FAILURE);
}
}
};
for (String url : imageUrls) {
if (TextUtils.isEmpty(url)) {
anyFailures.set(true);
imageListener.onImagesFailedToCache(NativeErrorCode.IMAGE_DOWNLOAD_FAILURE);
return;
}
imageLoader.get(url, volleyImageListener);
}
}
