Merge pull request #379 from MisterRager/expose-bitmap-recycle

Feature Request: Expose API For Capturing Bitmaps On Tile#reset

tileview/src/main/java/com/qozix/tileview/TileView.java

@@ -19,6 +19,7 @@
 import com.qozix.tileview.detail.DetailLevelManager;
 import com.qozix.tileview.geom.CoordinateTranslater;
 import com.qozix.tileview.geom.FloatMathHelper;
+import com.qozix.tileview.graphics.BitmapRecycler;
 import com.qozix.tileview.graphics.BitmapProvider;
 import com.qozix.tileview.hotspots.HotSpot;
 import com.qozix.tileview.hotspots.HotSpotManager;
@@ -287,6 +288,18 @@ public void setBitmapProvider( BitmapProvider bitmapProvider ) {
     mTileCanvasViewGroup.setBitmapProvider( bitmapProvider );
   }
 
+  /**
+   * Sets a custom class to perform the Bitmap finalization on Tile#reset.
+   * By default, a BitmapRecycler implementation is provided that calls Bitmap#recycle, but
+   * alternative implementations could be used that recycle Bitmap instances to prevent garbage
+   * collection or do other things after the Bitmap is no longer needed for rendering.
+   *
+   * @param bitmapRecycler A class instance that implements BitmapRecycler and must define a recycleBitmap method, which accepts a Bitmap after it is no longer being used
+   */
+  public void setBitmapRecycler( BitmapRecycler bitmapRecycler ) {
+    mTileCanvasViewGroup.setBitmapRecycler( bitmapRecycler );
+  }
+
   /**
    * Defines whether tile bitmaps should be rendered using an AlphaAnimation
    *

tileview/src/main/java/com/qozix/tileview/graphics/BitmapRecycler.java

@@ -0,0 +1,13 @@
+package com.qozix.tileview.graphics;
+
+import android.graphics.Bitmap;
+
+/**
+ * This interface represents the final operations applied to a {@link Bitmap} owned by a
+ * {@link com.qozix.tileview.tiles.Tile} after it is no longer being used. Generally, this only
+ * entails a call to {@link Bitmap#recycle()}, but it also provides a place to catch {@link Bitmap}
+ * instances for reuse in a cache or an object pool.
+ */
+public interface BitmapRecycler {
+  void recycleBitmap( Bitmap bitmap );
+}

tileview/src/main/java/com/qozix/tileview/graphics/BitmapRecyclerDefault.java

@@ -0,0 +1,12 @@
+package com.qozix.tileview.graphics;
+
+import android.graphics.Bitmap;
+
+public class BitmapRecyclerDefault implements BitmapRecycler {
+  @Override
+  public void recycleBitmap( Bitmap bitmap ) {
+    if( !bitmap.isRecycled() ) {
+      bitmap.recycle();
+    }
+  }
+}

tileview/src/main/java/com/qozix/tileview/tiles/Tile.java

@@ -10,6 +10,7 @@
 import com.qozix.tileview.detail.DetailLevel;
 import com.qozix.tileview.geom.FloatMathHelper;
 import com.qozix.tileview.graphics.BitmapProvider;
+import com.qozix.tileview.graphics.BitmapRecycler;
 
 import java.lang.ref.WeakReference;
 
@@ -58,6 +59,7 @@ public enum State {
   private DetailLevel mDetailLevel;
 
   private WeakReference<TileRenderRunnable> mTileRenderRunnableWeakReference;
+  private WeakReference<BitmapRecycler> mBitmapRecyclerReference;
 
   public Tile( int column, int row, int width, int height, Object data, DetailLevel detailLevel ) {
     mRow = row;
@@ -168,12 +170,17 @@ public void setState( State state ) {
   }
 
   public void execute( TileRenderPoolExecutor tileRenderPoolExecutor ) {
+    execute( tileRenderPoolExecutor, null );
+  }
+
+  public void execute( TileRenderPoolExecutor tileRenderPoolExecutor, BitmapRecycler recycler ) {
     if(mState != State.UNASSIGNED){
       return;
     }
     mState = State.PENDING_DECODE;
     TileRenderRunnable runnable = new TileRenderRunnable();
     mTileRenderRunnableWeakReference = new WeakReference<>( runnable );
+    mBitmapRecyclerReference = new WeakReference<>( recycler );
     runnable.setTile( this );
     runnable.setTileRenderPoolExecutor( tileRenderPoolExecutor );
     tileRenderPoolExecutor.execute( runnable );
@@ -254,8 +261,11 @@ void reset() {
     }
     mState = State.UNASSIGNED;
     mRenderTimeStamp = null;
-    if( mBitmap != null && !mBitmap.isRecycled() ) {
-      mBitmap.recycle();
+    if( mBitmap != null ) {
+      BitmapRecycler recycler = mBitmapRecyclerReference.get();
+      if( recycler != null ) {
+        recycler.recycleBitmap( mBitmap );
+      }
     }
     mBitmap = null;
   }

tileview/src/main/java/com/qozix/tileview/tiles/TileCanvasViewGroup.java

@@ -10,6 +10,8 @@
 import android.view.ViewGroup;
 
 import com.qozix.tileview.detail.DetailLevel;
+import com.qozix.tileview.graphics.BitmapRecyclerDefault;
+import com.qozix.tileview.graphics.BitmapRecycler;
 import com.qozix.tileview.graphics.BitmapProvider;
 import com.qozix.tileview.graphics.BitmapProviderAssets;
 
@@ -34,6 +36,7 @@ public class TileCanvasViewGroup extends ViewGroup {
   private float mScale = 1;
 
   private BitmapProvider mBitmapProvider;
+  private BitmapRecycler mBitmapRecycler;
 
   private DetailLevel mDetailLevelToRender;
   private DetailLevel mLastRenderedDetailLevel;
@@ -112,10 +115,21 @@ public BitmapProvider getBitmapProvider() {
     return mBitmapProvider;
   }
 
+  public BitmapRecycler getBitmapRecycler() {
+    if( mBitmapRecycler == null ) {
+      mBitmapRecycler = new BitmapRecyclerDefault();
+    }
+    return mBitmapRecycler;
+  }
+
   public void setBitmapProvider( BitmapProvider bitmapProvider ) {
     mBitmapProvider = bitmapProvider;
   }
 
+  public void setBitmapRecycler( BitmapRecycler bitmapRecycler ) {
+    mBitmapRecycler = bitmapRecycler;
+  }
+
   public void setTileRenderListener( TileRenderListener tileRenderListener ) {
     mTileRenderListener = tileRenderListener;
   }

tileview/src/main/java/com/qozix/tileview/tiles/TileRenderPoolExecutor.java

@@ -51,7 +51,7 @@ public void queue( TileCanvasViewGroup tileCanvasViewGroup, Set<Tile> renderSet
       if( isShutdownOrTerminating() ) {
         return;
       }
-      tile.execute( this );
+      tile.execute( this, tileCanvasViewGroup.getBitmapRecycler() );
     }
   }