use async avatar loading in AccountAdapter

src/main/java/eu/siacs/conversations/ui/adapter/AccountAdapter.java

@@ -1,6 +1,11 @@
 package eu.siacs.conversations.ui.adapter;
 
 import android.content.Context;
+import android.content.res.Resources;
+import android.graphics.Bitmap;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
+import android.os.AsyncTask;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -9,7 +14,9 @@ import android.widget.CompoundButton;
 import android.widget.ImageView;
 import android.widget.TextView;
 
+import java.lang.ref.WeakReference;
 import java.util.List;
+import java.util.concurrent.RejectedExecutionException;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.R;
@@ -17,6 +24,7 @@ import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.ui.ManageAccountActivity;
 import eu.siacs.conversations.ui.XmppActivity;
 import eu.siacs.conversations.ui.widget.Switch;
+import eu.siacs.conversations.utils.UIHelper;
 
 public class AccountAdapter extends ArrayAdapter<Account> {
 
@@ -43,7 +51,7 @@ public class AccountAdapter extends ArrayAdapter<Account> {
 		}
 		TextView statusView = (TextView) view.findViewById(R.id.account_status);
 		ImageView imageView = (ImageView) view.findViewById(R.id.account_image);
-		imageView.setImageBitmap(activity.avatarService().get(account, activity.getPixel(48)));
+		loadAvatar(account,imageView);
 		statusView.setText(getContext().getString(account.getStatus().getReadableId()));
 		switch (account.getStatus()) {
 			case ONLINE:
@@ -70,4 +78,88 @@ public class AccountAdapter extends ArrayAdapter<Account> {
 		});
 		return view;
 	}
+
+	class BitmapWorkerTask extends AsyncTask<Account, Void, Bitmap> {
+		private final WeakReference<ImageView> imageViewReference;
+		private Account account = null;
+
+		public BitmapWorkerTask(ImageView imageView) {
+			imageViewReference = new WeakReference<>(imageView);
+		}
+
+		@Override
+		protected Bitmap doInBackground(Account... params) {
+			return activity.avatarService().get(params[0], activity.getPixel(48), isCancelled());
+		}
+
+		@Override
+		protected void onPostExecute(Bitmap bitmap) {
+			if (bitmap != null && !isCancelled()) {
+				final ImageView imageView = imageViewReference.get();
+				if (imageView != null) {
+					imageView.setImageBitmap(bitmap);
+					imageView.setBackgroundColor(0x00000000);
+				}
+			}
+		}
+	}
+
+	public void loadAvatar(Account account, ImageView imageView) {
+		if (cancelPotentialWork(account, imageView)) {
+			final Bitmap bm = activity.avatarService().get(account,activity.getPixel(48),true);
+			if (bm != null) {
+				cancelPotentialWork(account, imageView);
+				imageView.setImageBitmap(bm);
+				imageView.setBackgroundColor(0x00000000);
+			} else {
+				imageView.setBackgroundColor(UIHelper.getColorForName(account.getDisplayName()));
+				imageView.setImageDrawable(null);
+				final BitmapWorkerTask task = new BitmapWorkerTask(imageView);
+				final AsyncDrawable asyncDrawable = new AsyncDrawable(activity.getResources(), null, task);
+				imageView.setImageDrawable(asyncDrawable);
+				try {
+					task.execute(account);
+				} catch (final RejectedExecutionException ignored) {
+				}
+			}
+		}
+	}
+
+	public static boolean cancelPotentialWork(Account account, ImageView imageView) {
+		final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
+
+		if (bitmapWorkerTask != null) {
+			final Account oldAccount = bitmapWorkerTask.account;
+			if (oldAccount == null || account != oldAccount) {
+				bitmapWorkerTask.cancel(true);
+			} else {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
+		if (imageView != null) {
+			final Drawable drawable = imageView.getDrawable();
+			if (drawable instanceof AsyncDrawable) {
+				final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;
+				return asyncDrawable.getBitmapWorkerTask();
+			}
+		}
+		return null;
+	}
+
+	static class AsyncDrawable extends BitmapDrawable {
+		private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
+
+		public AsyncDrawable(Resources res, Bitmap bitmap, BitmapWorkerTask bitmapWorkerTask) {
+			super(res, bitmap);
+			bitmapWorkerTaskReference = new WeakReference<>(bitmapWorkerTask);
+		}
+
+		public BitmapWorkerTask getBitmapWorkerTask() {
+			return bitmapWorkerTaskReference.get();
+		}
+	}
 }