android: do tile reevaluation in LOKitThread

Currently the tile reevaluation was done in UI thread which could
cause UI stutters as reevaluation is not a simple task. The
result was also a lot of tile rendering requests to LOKitThread.
This changes turns this around and the tile reevaluation is done
in LOKitThread instead. Now the UI thread just sends a LOEvent
when the reevaluation should be done. This should also reduce
the amount of messages that are queued in LOKitThread, however
an execution time should increase.

Change-Id: I01ce911226a71607c06da6100de323ca555db474

android/experimental/LOAndroid3/src/java/org/libreoffice/LOEvent.java

@@ -16,7 +16,7 @@ public class LOEvent implements Comparable<LOEvent> {
     public static final int LOAD = 4;
     public static final int CLOSE = 5;
     public static final int REDRAW = 6;
-    public static final int TILE_REQUEST = 7;
+    public static final int TILE_REEVALUATION_REQUEST = 7;
     public static final int THUMBNAIL = 8;
     public static final int TILE_INVALIDATION = 9;
     public static final int TOUCH = 10;
@@ -29,7 +29,6 @@ public class LOEvent implements Comparable<LOEvent> {
     public String mTypeString;
     public int mPartIndex;
     public String mFilename;
-    public SubTile mTile;
     public ComposedTileLayer mComposedTileLayer;
     public String mTouchType;
     public MotionEvent mMotionEvent;
@@ -47,11 +46,10 @@ public class LOEvent implements Comparable<LOEvent> {
         mTypeString = "Size Changed: " + widthPixels + " " + heightPixels;
     }
 
-    public LOEvent(int type, ComposedTileLayer composedTileLayer, SubTile tile) {
+    public LOEvent(int type, ComposedTileLayer composedTileLayer) {
         mType = type;
-        mTypeString = "Tile Request";
+        mTypeString = "Tile Reevaluation";
         mComposedTileLayer = composedTileLayer;
-        mTile = tile;
     }
 
     public LOEvent(int type, String filename) {

android/experimental/LOAndroid3/src/java/org/libreoffice/LOKitShell.java

@@ -123,9 +123,7 @@ public class LOKitShell {
         LOKitShell.sendEvent(new LOEvent(LOEvent.REDRAW));
     }
 
-    public static void sendTileRequestEvent(ComposedTileLayer composedTileLayer, SubTile tile, boolean forceRedraw, int priority) {
-        LOEvent event = new LOEvent(LOEvent.TILE_REQUEST, composedTileLayer, tile);
-        LOKitShell.sendEvent(event);
+    public static void sendTileReevaluationRequest(ComposedTileLayer composedTileLayer) {
+        LOKitShell.sendEvent(new LOEvent(LOEvent.TILE_REEVALUATION_REQUEST, composedTileLayer));
     }
-
 }

android/experimental/LOAndroid3/src/java/org/libreoffice/LOKitThread.java

@@ -44,23 +44,36 @@ public class LOKitThread extends Thread implements TileProvider.TileInvalidation
         }
     }
 
-    private void tileRequest(ComposedTileLayer composedTileLayer, SubTile tile) {
+    /* Viewport changed, recheck if tiles need to be added / removed */
+    private void tileReevaluationRequest(ComposedTileLayer composedTileLayer) {
         if (mTileProvider == null) {
             return;
         }
+        List<SubTile> tiles = new ArrayList<SubTile>();
+
+        mLayerClient.beginDrawing();
+        composedTileLayer.addNewTiles(tiles);
+        mLayerClient.endDrawing();
 
-        if (composedTileLayer.isStillValid(tile.id)) {
+        for (SubTile tile : tiles) {
             TileIdentifier tileId = tile.id;
             CairoImage image = mTileProvider.createTile(tileId.x, tileId.y, tileId.size, tileId.zoom);
+            mLayerClient.beginDrawing();
             if (image != null) {
-                mLayerClient.beginDrawing();
                 tile.setImage(image);
-                mLayerClient.endDrawing();
-                mLayerClient.forceRender();
             }
+            mLayerClient.endDrawing();
+            mLayerClient.forceRender();
         }
+
+        mLayerClient.beginDrawing();
+        composedTileLayer.markTiles();
+        composedTileLayer.clearMarkedTiles();
+        mLayerClient.endDrawing();
+        mLayerClient.forceRender();
     }
 
+    /* Invalidate tiles that intersect the input rect */
     private void tileInvalidation(RectF rect) {
         if (mLayerClient == null || mTileProvider == null) {
             return;
@@ -171,9 +184,6 @@ public class LOKitThread extends Thread implements TileProvider.TileInvalidation
             case LOEvent.CHANGE_PART:
                 changePart(event.mPartIndex);
                 break;
-            case LOEvent.TILE_REQUEST:
-                tileRequest(event.mComposedTileLayer, event.mTile);
-                break;
             case LOEvent.TILE_INVALIDATION:
                 tileInvalidation(event.mInvalidationRect);
                 break;
@@ -186,6 +196,9 @@ public class LOKitThread extends Thread implements TileProvider.TileInvalidation
             case LOEvent.KEY_EVENT:
                 keyEvent(event.mKeyEventType, event.mKeyEvent);
                 break;
+            case LOEvent.TILE_REEVALUATION_REQUEST:
+                tileReevaluationRequest(event.mComposedTileLayer);
+                break;
         }
     }
 

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/ComposedTileLayer.java

@@ -29,7 +29,10 @@ public abstract class ComposedTileLayer extends Layer implements ComponentCallba
     private final Lock tilesWriteLock = tilesReadWriteLock.writeLock();
 
     protected RectF currentViewport = new RectF();
-    protected float currentZoom;
+    protected float currentZoom = 1.0f;
+    protected RectF currentPageRect = new RectF();
+
+    private long reevaluationNanoTime = 0;
 
     public ComposedTileLayer(Context context) {
         context.registerComponentCallbacks(this);
@@ -149,12 +152,16 @@ public abstract class ComposedTileLayer extends Layer implements ComponentCallba
         if (currentViewport.equals(newViewPort) && FloatUtils.fuzzyEquals(currentZoom, newZoom)) {
             return;
         }
+
         currentViewport = newViewPort;
         currentZoom = newZoom;
+        currentPageRect = viewportMetrics.getPageRect();
 
-        clearMarkedTiles();
-        addNewTiles(viewportMetrics.getPageRect());
-        markTiles();
+        long currentReevaluationNanoTime = System.nanoTime();
+        if ((currentReevaluationNanoTime - reevaluationNanoTime) > 25 * 1000000) {
+            reevaluationNanoTime = currentReevaluationNanoTime;
+            LOKitShell.sendTileReevaluationRequest(this);
+        }
     }
 
     protected abstract RectF getViewPort(ImmutableViewportMetrics viewportMetrics);
@@ -177,27 +184,25 @@ public abstract class ComposedTileLayer extends Layer implements ComponentCallba
         }
     }
 
-    private void addNewTiles(RectF pageRect) {
-        beginTransaction();
+    public void addNewTiles(List<SubTile> newTiles) {
         for (float y = currentViewport.top; y < currentViewport.bottom; y += tileSize.height) {
-            if (y > pageRect.height()) {
+            if (y > currentPageRect.height()) {
                 continue;
             }
             for (float x = currentViewport.left; x < currentViewport.right; x += tileSize.width) {
-                if (x > pageRect.width()) {
+                if (x > currentPageRect.width()) {
                     continue;
                 }
                 if (!containsTilesMatching(x, y, currentZoom)) {
                     TileIdentifier tileId = new TileIdentifier((int) x, (int) y, currentZoom, tileSize);
                     SubTile tile = createNewTile(tileId);
-                    LOKitShell.sendTileRequestEvent(this, tile, true, getTilePriority());
+                    newTiles.add(tile);
                 }
             }
         }
-        endTransaction();
     }
 
-    private void clearMarkedTiles() {
+    public void clearMarkedTiles() {
         tilesWriteLock.lock();
         Iterator<SubTile> iterator = tiles.iterator();
         while (iterator.hasNext()) {
@@ -210,7 +215,7 @@ public abstract class ComposedTileLayer extends Layer implements ComponentCallba
         tilesWriteLock.unlock();
     }
 
-    private void markTiles() {
+    public void markTiles() {
         tilesReadLock.lock();
         for (SubTile tile : tiles) {
             if (FloatUtils.fuzzyEquals(tile.id.zoom, currentZoom)) {