Load bitmaps in background in chat in order to make UI smoother

src/org/linphone/ChatFragment.java

@@ -283,7 +283,7 @@ public class ChatFragment extends Fragment implements OnClickListener, LinphoneC
 			topBar.setVisibility(View.GONE);
 		}
 		contactPicture.setVisibility(View.GONE);
-		scrollToEnd();
+		//scrollToEnd();
 	}
 
 	public void hideKeyboardVisibleMode() {
@@ -292,7 +292,7 @@ public class ChatFragment extends Fragment implements OnClickListener, LinphoneC
 		if (isOrientationLandscape && topBar != null) {
 			topBar.setVisibility(View.VISIBLE);
 		}
-		scrollToEnd();
+		//scrollToEnd();
 	}
 
 	class ChatMessageAdapter extends BaseAdapter {

src/org/linphone/ui/BubbleChat.java

@@ -19,6 +19,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.lang.ref.WeakReference;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import java.util.HashMap;
@@ -33,9 +34,13 @@ import org.linphone.mediastream.Log;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
+import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.Drawable;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.provider.MediaStore;
 import android.text.Html;
 import android.text.Spannable;
@@ -95,7 +100,8 @@ public class BubbleChat {
 	private ImageView statusView;
 	private LinphoneChatMessage nativeMessage;
 	private LinphoneChatMessage.LinphoneChatMessageListener fileTransferListener;
-	private static final int SIZE_MAX = 2048;
+	private Context mContext;
+	private static final int SIZE_MAX = 512;
 	
 	@SuppressLint("InflateParams") 
 	public BubbleChat(final Context context, LinphoneChatMessage message, LinphoneChatMessage.LinphoneChatMessageListener listener) {
@@ -104,6 +110,7 @@ public class BubbleChat {
 		}
 		nativeMessage = message;
 		fileTransferListener = listener;
+		mContext = context;
 		
 		view = new RelativeLayout(context);
 		LayoutParams layoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
@@ -160,40 +167,7 @@ public class BubbleChat {
 				});
     		} else {
     	    	imageView.setVisibility(View.VISIBLE);
-    	    	
+    	    	loadBitmap(appData, imageView);
-    	    	Bitmap bm = null;
-    	    	if (appData.startsWith("content")) {
-    	    		try {
-						bm = MediaStore.Images.Media.getBitmap(context.getContentResolver(), Uri.parse(appData));
-					} catch (FileNotFoundException e) {
-						Log.e(e);
-					} catch (IOException e) {
-						Log.e(e);
-					}
-    	    	} else {
-    	    		bm = BitmapFactory.decodeFile(appData);
-    	    		appData = "file://" + appData;
-    	    	}
-    	    	
-    	    	if (bm != null) {
-					if (bm.getWidth() > bm.getHeight() && bm.getWidth() > SIZE_MAX) {
-						bm = Bitmap.createScaledBitmap(bm, SIZE_MAX, (SIZE_MAX * bm.getHeight()) / bm.getWidth(), false);
-					} else if (bm.getHeight() > bm.getWidth() && bm.getHeight() > SIZE_MAX) {
-
-						bm = Bitmap.createScaledBitmap(bm, (SIZE_MAX * bm.getWidth()) / bm.getHeight(), SIZE_MAX, false);
-					}
-
-			    	imageView.setImageBitmap(bm);
-			    	imageView.setTag(appData);
-			    	imageView.setOnClickListener(new OnClickListener() {
-		    			@Override
-		    			public void onClick(View v) {
-		    				Intent intent = new Intent(Intent.ACTION_VIEW);
-		    				intent.setDataAndType(Uri.parse((String)v.getTag()), "image/*");
-		    				context.startActivity(intent);
-		    			}
-		    		});
-    	    	}
     		}
     	} else {
 	    	TextView msgView = (TextView) layout.findViewById(R.id.message);
@@ -340,4 +314,121 @@ public class BubbleChat {
 	public int getId() {
 		return nativeMessage.getStorageId();
 	}
+	
+	public void loadBitmap(String path, ImageView imageView) {
+		if (cancelPotentialWork(path, imageView)) {
+			BitmapWorkerTask task = new BitmapWorkerTask(imageView);
+			Bitmap defaultBitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.chat_photo_default);
+			final AsyncBitmap asyncBitmap = new AsyncBitmap(mContext.getResources(), defaultBitmap, task);
+			imageView.setImageDrawable(asyncBitmap);
+			task.execute(path);
+		}
+    }
+	
+	private class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
+	    private final WeakReference<ImageView> imageViewReference;
+	    public String path;
+
+	    public BitmapWorkerTask(ImageView imageView) {
+	    	path = null;
+	        // Use a WeakReference to ensure the ImageView can be garbage collected
+	        imageViewReference = new WeakReference<ImageView>(imageView);
+	    }
+
+	    // Decode image in background.
+	    @Override
+	    protected Bitmap doInBackground(String... params) {
+	    	path = params[0];
+	    	Bitmap bm = null;
+	    	
+	    	if (path.startsWith("content")) {
+	    		try {
+					bm = MediaStore.Images.Media.getBitmap(mContext.getContentResolver(), Uri.parse(path));
+				} catch (FileNotFoundException e) {
+					Log.e(e);
+				} catch (IOException e) {
+					Log.e(e);
+				}
+	    	} else {
+	    		bm = BitmapFactory.decodeFile(path);
+	    		path = "file://" + path;
+	    	}
+	    	
+	    	if (bm != null) {
+	    		if (bm.getWidth() >= bm.getHeight() && bm.getWidth() > SIZE_MAX) {
+					bm = Bitmap.createScaledBitmap(bm, SIZE_MAX, (SIZE_MAX * bm.getHeight()) / bm.getWidth(), false);
+				} else if (bm.getHeight() >= bm.getWidth() && bm.getHeight() > SIZE_MAX) {
+					bm = Bitmap.createScaledBitmap(bm, (SIZE_MAX * bm.getWidth()) / bm.getHeight(), SIZE_MAX, false);
+				}
+	    	}
+	    	return bm;
+	    }
+
+	    // Once complete, see if ImageView is still around and set bitmap.
+	    @Override
+	    protected void onPostExecute(Bitmap bitmap) {
+	    	if (isCancelled()) {
+	            bitmap = null;
+	        }
+
+	        if (imageViewReference != null && bitmap != null) {
+	            final ImageView imageView = imageViewReference.get();
+	            final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
+	            if (this == bitmapWorkerTask && imageView != null) {
+	                imageView.setImageBitmap(bitmap);
+	                imageView.setTag(path);
+			    	imageView.setOnClickListener(new OnClickListener() {
+		    			@Override
+		    			public void onClick(View v) {
+		    				Intent intent = new Intent(Intent.ACTION_VIEW);
+		    				intent.setDataAndType(Uri.parse((String)v.getTag()), "image/*");
+		    				mContext.startActivity(intent);
+		    			}
+		    		});
+	            }
+		    }
+	    }
+	}
+	
+	static class AsyncBitmap extends BitmapDrawable {
+	    private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
+
+	    public AsyncBitmap(Resources res, Bitmap bitmap, BitmapWorkerTask bitmapWorkerTask) {
+	        super(res, bitmap);
+	        bitmapWorkerTaskReference = new WeakReference<BitmapWorkerTask>(bitmapWorkerTask);
+	    }
+
+	    public BitmapWorkerTask getBitmapWorkerTask() {
+	        return bitmapWorkerTaskReference.get();
+	    }
+	}
+	
+	public static boolean cancelPotentialWork(String path, ImageView imageView) {
+	    final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
+
+	    if (bitmapWorkerTask != null) {
+	        final String bitmapData = bitmapWorkerTask.path;
+	        // If bitmapData is not yet set or it differs from the new data
+	        if (bitmapData == null || bitmapData != path) {
+	            // Cancel previous task
+	            bitmapWorkerTask.cancel(true);
+	        } else {
+	            // The same work is already in progress
+	            return false;
+	        }
+	    }
+	    // No task associated with the ImageView, or an existing task was cancelled
+	    return true;
+	}
+	
+	private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
+	   if (imageView != null) {
+	       final Drawable drawable = imageView.getDrawable();
+	       if (drawable instanceof AsyncBitmap) {
+	           final AsyncBitmap asyncDrawable = (AsyncBitmap) drawable;
+	           return asyncDrawable.getBitmapWorkerTask();
+	       }
+	    }
+	    return null;
+	}
 }