Add async slide previews loading.

* The previews storage contains bytes arrays instead of Bitmaps which
should decrease memory footprint.
* All previews processing moved to the background thread.

This change should solve out of memory errors.

Change-Id: Idd4046020c8fe8f977858f1911e04c0ec095380a

8 files changed, 235 insertions, 30 deletions

diff --git a/android/sdremote/src/org/libreoffice/impressremote/activity/SlideShowActivity.java b/android/sdremote/src/org/libreoffice/impressremote/activity/SlideShowActivity.java
index 7de2ee4049af..4b91a6af8f65 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/activity/SlideShowActivity.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/activity/SlideShowActivity.java
@@ -245,21 +245,31 @@ public class SlideShowActivity extends SherlockFragmentActivity implements Servi
     protected void onDestroy() {
         super.onDestroy();
 
+        disconnectComputer();
+
         unbindService();
     }
 
-    private void unbindService() {
+    private void disconnectComputer() {
         if (!isServiceBound()) {
             return;
         }
 
-        unbindService(this);
+        mCommunicationService.disconnect();
     }
 
     private boolean isServiceBound() {
         return mCommunicationService != null;
     }
 
+    private void unbindService() {
+        if (!isServiceBound()) {
+            return;
+        }
+
+        unbindService(this);
+    }
+
     @Override
     public void onServiceDisconnected(ComponentName aComponentName) {
         mCommunicationService = null;
diff --git a/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesGridAdapter.java b/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesGridAdapter.java
index f7f7a010b8ab..846226fa50e0 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesGridAdapter.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesGridAdapter.java
@@ -18,14 +18,17 @@ import android.widget.TextView;
 
 import org.libreoffice.impressremote.R;
 import org.libreoffice.impressremote.communication.SlideShow;
+import org.libreoffice.impressremote.util.ImageLoader;
 
 public class SlidesGridAdapter extends BaseAdapter {
     private final LayoutInflater mLayoutInflater;
+    private final ImageLoader mImageLoader;
 
     private final SlideShow mSlideShow;
 
     public SlidesGridAdapter(Context aContext, SlideShow aSlideShow) {
         mLayoutInflater = LayoutInflater.from(aContext);
+        mImageLoader = new ImageLoader(aContext.getResources(), R.drawable.slide_unknown);
 
         mSlideShow = aSlideShow;
     }
@@ -37,7 +40,7 @@ public class SlidesGridAdapter extends BaseAdapter {
 
     @Override
     public Object getItem(int aPosition) {
-        return mSlideShow.getSlidePreview(aPosition);
+        return mSlideShow.getSlidePreviewBytes(aPosition);
     }
 
     @Override
@@ -51,12 +54,12 @@ public class SlidesGridAdapter extends BaseAdapter {
         ViewHolder aSlideViewHolder = getViewHolder(aSlideView);
 
         if (isSlidePreviewAvailable(aPosition)) {
-            aSlideViewHolder.aSlidePreview.setImageBitmap(mSlideShow.getSlidePreview(aPosition));
+            setUpSlidePreview(aSlideViewHolder, aPosition);
         } else {
-            aSlideViewHolder.aSlidePreview.setImageResource(R.drawable.slide_unknown);
+            setUpUnknownSlidePreview(aSlideViewHolder);
         }
 
-        aSlideViewHolder.aSlideIndex.setText(buildSlideIndex(aPosition));
+        aSlideViewHolder.mSlideIndex.setText(buildSlideIndex(aPosition));
 
         return aSlideView;
     }
@@ -78,21 +81,31 @@ public class SlidesGridAdapter extends BaseAdapter {
     }
 
     private static final class ViewHolder {
-        public ImageView aSlidePreview;
-        public TextView aSlideIndex;
+        public ImageView mSlidePreview;
+        public TextView mSlideIndex;
     }
 
     private ViewHolder buildViewHolder(View aView) {
         ViewHolder aViewHolder = new ViewHolder();
 
-        aViewHolder.aSlidePreview = (ImageView) aView.findViewById(R.id.image_slide_preview);
-        aViewHolder.aSlideIndex = (TextView) aView.findViewById(R.id.text_slide_index);
+        aViewHolder.mSlidePreview = (ImageView) aView.findViewById(R.id.image_slide_preview);
+        aViewHolder.mSlideIndex = (TextView) aView.findViewById(R.id.text_slide_index);
 
         return aViewHolder;
     }
 
     private boolean isSlidePreviewAvailable(int aSlideIndex) {
-        return mSlideShow.getSlidePreview(aSlideIndex) != null;
+        return mSlideShow.getSlidePreviewBytes(aSlideIndex) != null;
+    }
+
+    private void setUpSlidePreview(ViewHolder aSlideViewHolder, int aPosition) {
+        byte[] aSlidePreviewBytes = mSlideShow.getSlidePreviewBytes(aPosition);
+
+        mImageLoader.loadImage(aSlideViewHolder.mSlidePreview, aSlidePreviewBytes);
+    }
+
+    private void setUpUnknownSlidePreview(ViewHolder aSlideViewHolder) {
+        aSlideViewHolder.mSlidePreview.setImageResource(R.drawable.slide_unknown);
     }
 
     private String buildSlideIndex(int aPosition) {
diff --git a/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesPagerAdapter.java b/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesPagerAdapter.java
index 352e7a89f849..02097d27a743 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesPagerAdapter.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/adapter/SlidesPagerAdapter.java
@@ -17,14 +17,17 @@ import android.widget.ImageView;
 
 import org.libreoffice.impressremote.R;
 import org.libreoffice.impressremote.communication.SlideShow;
+import org.libreoffice.impressremote.util.ImageLoader;
 
 public class SlidesPagerAdapter extends PagerAdapter {
     private final LayoutInflater mLayoutInflater;
+    private final ImageLoader mImageLoader;
 
     private final SlideShow mSlideShow;
 
     public SlidesPagerAdapter(Context aContext, SlideShow aSlideShow) {
         mLayoutInflater = LayoutInflater.from(aContext);
+        mImageLoader = new ImageLoader(aContext.getResources(), R.drawable.slide_unknown);
 
         mSlideShow = aSlideShow;
     }
@@ -39,10 +42,10 @@ public class SlidesPagerAdapter extends PagerAdapter {
         ImageView aSlideView = (ImageView) getView(aViewGroup);
 
         if (isSlidePreviewAvailable(aPosition)) {
-            aSlideView.setImageBitmap(mSlideShow.getSlidePreview(aPosition));
+            setUpSlidePreview(aSlideView, aPosition);
         }
         else {
-            aSlideView.setImageResource(R.drawable.slide_unknown);
+            setUpUnknownSlidePreview(aSlideView);
         }
 
         aViewGroup.addView(aSlideView);
@@ -55,7 +58,17 @@ public class SlidesPagerAdapter extends PagerAdapter {
     }
 
     private boolean isSlidePreviewAvailable(int aSlideIndex) {
-        return mSlideShow.getSlidePreview(aSlideIndex) != null;
+        return mSlideShow.getSlidePreviewBytes(aSlideIndex) != null;
+    }
+
+    private void setUpSlidePreview(ImageView aSlideView, int aPosition) {
+        byte[] aSlidePreviewBytes = mSlideShow.getSlidePreviewBytes(aPosition);
+
+        mImageLoader.loadImage(aSlideView, aSlidePreviewBytes);
+    }
+
+    private void setUpUnknownSlidePreview(ImageView aSlideView) {
+        aSlideView.setImageResource(R.drawable.slide_unknown);
     }
 
     @Override
diff --git a/android/sdremote/src/org/libreoffice/impressremote/communication/CommunicationService.java b/android/sdremote/src/org/libreoffice/impressremote/communication/CommunicationService.java
index 2e32813fbba0..2977921f25a9 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/communication/CommunicationService.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/communication/CommunicationService.java
@@ -264,7 +264,7 @@ public class CommunicationService extends Service implements Runnable, MessagesL
 
     @Override
     public void onSlidePreview(int aSlideIndex, byte[] aPreview) {
-        mSlideShow.setSlidePreview(aSlideIndex, aPreview);
+        mSlideShow.setSlidePreviewBytes(aSlideIndex, aPreview);
 
         Intent aIntent = Intents.buildSlidePreviewIntent(aSlideIndex);
         LocalBroadcastManager.getInstance(this).sendBroadcast(aIntent);
diff --git a/android/sdremote/src/org/libreoffice/impressremote/communication/MessagesReceiver.java b/android/sdremote/src/org/libreoffice/impressremote/communication/MessagesReceiver.java
index 4d226d868183..bb6de8fc8742 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/communication/MessagesReceiver.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/communication/MessagesReceiver.java
@@ -14,10 +14,12 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import android.text.TextUtils;
 import android.util.Base64;
+import android.util.Log;
 
 class MessagesReceiver implements Runnable {
     private final BufferedReader mMessagesReader;
diff --git a/android/sdremote/src/org/libreoffice/impressremote/communication/SlideShow.java b/android/sdremote/src/org/libreoffice/impressremote/communication/SlideShow.java
index 79852c507b68..a216dfc8f0eb 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/communication/SlideShow.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/communication/SlideShow.java
@@ -8,8 +8,6 @@
  */
 package org.libreoffice.impressremote.communication;
 
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
 import android.util.SparseArray;
 
 
@@ -17,7 +15,7 @@ public class SlideShow {
     private int mSlidesCount;
     private int mCurrentSlideIndex;
 
-    private final SparseArray<Bitmap> mSlidePreviews;
+    private final SparseArray<byte[]> mSlidePreviewsBytes;
     private final SparseArray<String> mSlideNotes;
 
     private final Timer mTimer;
@@ -26,7 +24,7 @@ public class SlideShow {
         this.mSlidesCount = 0;
         this.mCurrentSlideIndex = 0;
 
-        this.mSlidePreviews = new SparseArray<Bitmap>();
+        this.mSlidePreviewsBytes = new SparseArray<byte[]>();
         this.mSlideNotes = new SparseArray<String>();
 
         this.mTimer = new Timer();
@@ -52,15 +50,12 @@ public class SlideShow {
         return getCurrentSlideIndex() + 1;
     }
 
-    public void setSlidePreview(int aSlideIndex, byte[] aSlidePreviewBytes) {
-        Bitmap aSlidePreview = BitmapFactory
-            .decodeByteArray(aSlidePreviewBytes, 0, aSlidePreviewBytes.length);
-
-        mSlidePreviews.put(aSlideIndex, aSlidePreview);
+    public void setSlidePreviewBytes(int aSlideIndex, byte[] aSlidePreviewBytes) {
+        mSlidePreviewsBytes.put(aSlideIndex, aSlidePreviewBytes);
     }
 
-    public Bitmap getSlidePreview(int aSlideIndex) {
-        return mSlidePreviews.get(aSlideIndex);
+    public byte[] getSlidePreviewBytes(int aSlideIndex) {
+        return mSlidePreviewsBytes.get(aSlideIndex);
     }
 
     public void setSlideNotes(int aSlideIndex, String aSlideNotes) {
@@ -85,7 +80,7 @@ public class SlideShow {
         mSlidesCount = 0;
         mCurrentSlideIndex = 0;
 
-        mSlidePreviews.clear();
+        mSlidePreviewsBytes.clear();
         mSlideNotes.clear();
     }
 }
diff --git a/android/sdremote/src/org/libreoffice/impressremote/fragment/SlidesGridFragment.java b/android/sdremote/src/org/libreoffice/impressremote/fragment/SlidesGridFragment.java
index ebc9a24d02ef..25e2819a7c4c 100644
--- a/android/sdremote/src/org/libreoffice/impressremote/fragment/SlidesGridFragment.java
+++ b/android/sdremote/src/org/libreoffice/impressremote/fragment/SlidesGridFragment.java
@@ -51,14 +51,12 @@ public class SlidesGridFragment extends SherlockFragment implements ServiceConne
 
     private void bindService() {
         Intent aServiceIntent = new Intent(getActivity(), CommunicationService.class);
-
         getActivity().bindService(aServiceIntent, this, Context.BIND_AUTO_CREATE);
     }
 
     @Override
     public void onServiceConnected(ComponentName aComponentName, IBinder aBinder) {
         CommunicationService.CBinder aServiceBinder = (CommunicationService.CBinder) aBinder;
-
         mCommunicationService = aServiceBinder.getService();
 
         setUpSlidesGrid();
@@ -109,14 +107,23 @@ public class SlidesGridFragment extends SherlockFragment implements ServiceConne
 
         @Override
         public void onReceive(Context aContext, Intent aIntent) {
-            if (Intents.Actions.SLIDE_PREVIEW.equals(aIntent.getAction())) {
+            if (Intents.Actions.SLIDE_SHOW_RUNNING.equals(aIntent.getAction())) {
                 mSlidesGridFragment.refreshSlidesGrid();
+
+                return;
+            }
+
+            if (Intents.Actions.SLIDE_PREVIEW.equals(aIntent.getAction())) {
+                int aSlideIndex = aIntent.getIntExtra(Intents.Extras.SLIDE_INDEX, 0);
+
+                mSlidesGridFragment.refreshSlidePreview(aSlideIndex);
             }
         }
     }
 
     private IntentFilter buildIntentsReceiverFilter() {
         IntentFilter aIntentFilter = new IntentFilter();
+        aIntentFilter.addAction(Intents.Actions.SLIDE_SHOW_RUNNING);
         aIntentFilter.addAction(Intents.Actions.SLIDE_PREVIEW);
 
         return aIntentFilter;
@@ -132,6 +139,17 @@ public class SlidesGridFragment extends SherlockFragment implements ServiceConne
         getSlidesGrid().invalidateViews();
     }
 
+    private void refreshSlidePreview(int aSlideIndex) {
+        GridView aSlidesGrid = getSlidesGrid();
+        View aSlideView = aSlidesGrid.getChildAt(aSlideIndex);
+
+        if (aSlideView == null) {
+            return;
+        }
+
+        aSlidesGrid.getAdapter().getView(aSlideIndex, aSlideView, aSlidesGrid);
+    }
+
     @Override
     public void onPause() {
         super.onPause();
diff --git a/android/sdremote/src/org/libreoffice/impressremote/util/ImageLoader.java b/android/sdremote/src/org/libreoffice/impressremote/util/ImageLoader.java
new file mode 100644
index 000000000000..1bd2f4f326df
--- /dev/null
+++ b/android/sdremote/src/org/libreoffice/impressremote/util/ImageLoader.java
@@ -0,0 +1,154 @@
+/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package org.libreoffice.impressremote.util;
+
+import java.lang.ref.WeakReference;
+import java.util.Arrays;
+
+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.os.AsyncTask;
+import android.widget.ImageView;
+
+public final class ImageLoader {
+    private final Resources mResources;
+    private final Bitmap mLoadingImage;
+
+    public ImageLoader(Resources aResources, int aLoadingImageResourceId) {
+        mResources = aResources;
+        mLoadingImage = BitmapFactory.decodeResource(mResources, aLoadingImageResourceId);
+    }
+
+    public void loadImage(ImageView aImageView, byte[] aImageBytes) {
+        if (isSameImageLoading(aImageView, aImageBytes)) {
+            return;
+        }
+
+        if (isImageLoadingCancellationRequired(aImageView, aImageBytes)) {
+            cancelImageLoading(aImageView);
+        }
+
+        startImageLoading(aImageView, aImageBytes);
+    }
+
+    private boolean isSameImageLoading(ImageView aImageView, byte[] aImageBytes) {
+        if (!isImageLoading(aImageView)) {
+            return false;
+        }
+
+        ImageLoadingTask aImageLoadingTask = getImageLoadingTask(aImageView);
+
+        return Arrays.equals(aImageBytes, aImageLoadingTask.getImageBytes());
+    }
+
+    private boolean isImageLoading(ImageView aImageView) {
+        ImageLoadingTask aImageLoadingTask = getImageLoadingTask(aImageView);
+
+        return aImageLoadingTask != null;
+    }
+
+    private ImageLoadingTask getImageLoadingTask(ImageView aImageView) {
+        if (aImageView == null) {
+            return null;
+        }
+
+        Drawable aImageDrawable = aImageView.getDrawable();
+
+        if (!(aImageDrawable instanceof AsyncDrawable)) {
+            return null;
+        }
+
+        AsyncDrawable aAsyncImageDrawable = (AsyncDrawable) aImageDrawable;
+
+        return aAsyncImageDrawable.getImageLoadingTask();
+    }
+
+    private boolean isImageLoadingCancellationRequired(ImageView aImageView, byte[] aImageBytes) {
+        return isImageLoading(aImageView) && !isSameImageLoading(aImageView, aImageBytes);
+    }
+
+    private void cancelImageLoading(ImageView aImageView) {
+        ImageLoadingTask aImageLoadingTask = getImageLoadingTask(aImageView);
+
+        aImageLoadingTask.cancel(true);
+    }
+
+    private void startImageLoading(ImageView aImageView, byte[] aImageBytes) {
+        ImageLoadingTask aImageLoadingTask = new ImageLoadingTask(aImageView, aImageBytes);
+        AsyncDrawable aAsyncDrawable = new AsyncDrawable(mResources, mLoadingImage, aImageLoadingTask);
+
+        aImageView.setImageDrawable(aAsyncDrawable);
+        aImageLoadingTask.execute();
+    }
+
+    private static class ImageLoadingTask extends AsyncTask<Void, Void, Bitmap> {
+        private final WeakReference<ImageView> mImageViewReference;
+        private final byte[] mImageBytes;
+
+        public ImageLoadingTask(ImageView aImageView, byte[] aImageBytes) {
+            mImageViewReference = new WeakReference<ImageView>(aImageView);
+            mImageBytes = aImageBytes;
+        }
+
+        public byte[] getImageBytes() {
+            return mImageBytes;
+        }
+
+        @Override
+        protected Bitmap doInBackground(Void... aParameters) {
+            return BitmapFactory.decodeByteArray(mImageBytes, 0, mImageBytes.length);
+        }
+
+        @Override
+        protected void onPostExecute(Bitmap aBitmap) {
+            super.onPostExecute(aBitmap);
+
+            if (isCancelled()) {
+                return;
+            }
+
+            if (aBitmap == null) {
+                return;
+            }
+
+            if (mImageViewReference == null) {
+                return;
+            }
+
+            if (getImageView() == null) {
+                return;
+            }
+
+            getImageView().setImageBitmap(aBitmap);
+        }
+
+        private ImageView getImageView() {
+            return mImageViewReference.get();
+        }
+    }
+
+    private static class AsyncDrawable extends BitmapDrawable {
+        private final WeakReference<ImageLoadingTask> mImageLoadingTaskReference;
+
+        public AsyncDrawable(Resources aResources, Bitmap aBitmap, ImageLoadingTask aImageLoadingTask) {
+            super(aResources, aBitmap);
+
+            mImageLoadingTaskReference = new WeakReference<ImageLoadingTask>(aImageLoadingTask);
+        }
+
+        public ImageLoadingTask getImageLoadingTask() {
+            return mImageLoadingTaskReference.get();
+        }
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */