Bug 775722 - Reposition the text selection handles during pan/zoom operations. r=blassey

mobile/android/base/TextSelection.java

@@ -6,14 +6,21 @@ package org.mozilla.gecko;
 
 import android.util.Log;
 import android.view.View;
+import org.mozilla.gecko.gfx.Layer;
+import org.mozilla.gecko.gfx.Layer.RenderContext;
+import org.mozilla.gecko.gfx.LayerController;
 import org.json.JSONObject;
 
-class TextSelection implements GeckoEventListener {
+class TextSelection extends Layer implements GeckoEventListener {
     private static final String LOGTAG = "GeckoTextSelection";
 
     private final TextSelectionHandle mStartHandle;
     private final TextSelectionHandle mEndHandle;
 
+    private float mViewLeft;
+    private float mViewTop;
+    private float mViewZoom;
+
     TextSelection(TextSelectionHandle startHandle, TextSelectionHandle endHandle) {
         mStartHandle = startHandle;
         mEndHandle = endHandle;
@@ -41,11 +48,24 @@ class TextSelection implements GeckoEventListener {
                     public void run() {
                         mStartHandle.setVisibility(View.VISIBLE);
                         mEndHandle.setVisibility(View.VISIBLE);
+
+                        mViewLeft = 0.0f;
+                        mViewTop = 0.0f;
+                        mViewZoom = 0.0f;
+                        LayerController layerController = GeckoApp.mAppContext.getLayerController();
+                        if (layerController != null) {
+                            layerController.getView().addLayer(TextSelection.this);
+                        }
                     }
                 });
             } else if (event.equals("TextSelection:HideHandles")) {
                 GeckoApp.mAppContext.mMainHandler.post(new Runnable() {
                     public void run() {
+                        LayerController layerController = GeckoApp.mAppContext.getLayerController();
+                        if (layerController != null) {
+                            layerController.getView().removeLayer(TextSelection.this);
+                        }
+
                         mStartHandle.setVisibility(View.GONE);
                         mEndHandle.setVisibility(View.GONE);
                     }
@@ -67,4 +87,26 @@ class TextSelection implements GeckoEventListener {
             Log.e(LOGTAG, "Exception handling message \"" + event + "\":", e);
         }
     }
+
+    @Override
+    public void draw(final RenderContext context) {
+        // cache the relevant values from the context and bail out if they are the same. we do this
+        // because this draw function gets called a lot (once per compositor frame) and we want to
+        // avoid doing a lot of extra work in cases where it's not needed.
+        if (FloatUtils.fuzzyEquals(mViewLeft, context.viewport.left)
+                && FloatUtils.fuzzyEquals(mViewTop, context.viewport.top)
+                && FloatUtils.fuzzyEquals(mViewZoom, context.zoomFactor)) {
+            return;
+        }
+        mViewLeft = context.viewport.left;
+        mViewTop = context.viewport.top;
+        mViewZoom = context.zoomFactor;
+
+        GeckoApp.mAppContext.mMainHandler.post(new Runnable() {
+            public void run() {
+                mStartHandle.repositionWithViewport(context.viewport.left, context.viewport.top, context.zoomFactor);
+                mEndHandle.repositionWithViewport(context.viewport.left, context.viewport.top, context.zoomFactor);
+            }
+        });
+    }
 }

mobile/android/base/TextSelectionHandle.java

@@ -13,6 +13,7 @@ import android.view.MotionEvent;
 import android.view.View;
 import android.widget.RelativeLayout;
 import android.widget.ImageView;
+import org.mozilla.gecko.gfx.ImmutableViewportMetrics;
 import org.mozilla.gecko.gfx.LayerController;
 import org.json.JSONObject;
 
@@ -28,6 +29,7 @@ class TextSelectionHandle extends ImageView implements View.OnTouchListener {
 
     private int mLeft;
     private int mTop;
+    private PointF mGeckoPoint;
     private int mTouchStartX;
     private int mTouchStartY;
 
@@ -108,11 +110,18 @@ class TextSelectionHandle extends ImageView implements View.OnTouchListener {
             Log.e(LOGTAG, "Can't position handle because layerController is null");
             return;
         }
-        PointF geckoPoint = new PointF((float) left, (float) top);
-        geckoPoint = layerController.convertLayerPointToViewPoint(geckoPoint);
 
-        mLeft = Math.round(geckoPoint.x) - (mHandleType.equals(HandleType.START) ? mWidth - mShadow : mShadow);
-        mTop = Math.round(geckoPoint.y);
+        mGeckoPoint = new PointF((float) left, (float) top);
+        ImmutableViewportMetrics metrics = layerController.getViewportMetrics();
+        repositionWithViewport(metrics.viewportRectLeft, metrics.viewportRectTop, metrics.zoomFactor);
+    }
+
+    void repositionWithViewport(float x, float y, float zoom) {
+        PointF viewPoint = new PointF((mGeckoPoint.x * zoom) - x,
+                                      (mGeckoPoint.y * zoom) - y);
+
+        mLeft = Math.round(viewPoint.x) - (mHandleType.equals(HandleType.START) ? mWidth - mShadow : mShadow);
+        mTop = Math.round(viewPoint.y);
 
         setLayoutPosition();
     }

mobile/android/base/gfx/LayerController.java

@@ -300,28 +300,6 @@ public class LayerController {
         return layerPoint;
     }
 
-    /**
-     * Does the opposite of convertViewPointToLayerPoint.
-     */
-    public PointF convertLayerPointToViewPoint(PointF layerPoint) {
-        if (mLayerClient == null) {
-            return null;
-        }
-
-        ImmutableViewportMetrics viewportMetrics = mViewportMetrics;
-        PointF origin = viewportMetrics.getOrigin();
-        float zoom = viewportMetrics.zoomFactor;
-        ViewportMetrics geckoViewport = mLayerClient.getGeckoViewportMetrics();
-        PointF geckoOrigin = geckoViewport.getOrigin();
-        float geckoZoom = geckoViewport.getZoomFactor();
-
-        PointF viewPoint = new PointF(
-                ((layerPoint.x + (geckoOrigin.x / geckoZoom)) * zoom - origin.x),
-                ((layerPoint.y + (geckoOrigin.y / geckoZoom)) * zoom - origin.y));
-
-        return viewPoint;
-    }
-
     /** Retrieves whether we should show checkerboard checks or not. */
     public boolean checkerboardShouldShowChecks() {
         return mCheckerboardShouldShowChecks;

mobile/android/chrome/content/browser.js

@@ -1565,10 +1565,8 @@ var SelectionHandler = {
         break;
       }
       case "after-viewport-change": {
-        // Update the cache and reposition the handles after the viewport
-        // changes (e.g. panning, zooming).
+        // Update the cache after the viewport changes (e.g. panning, zooming).
         this.updateCacheForSelection();
-        this.positionHandles();
         break;
       }
       case "TextSelection:Move": {
@@ -1871,13 +1869,15 @@ var SelectionHandler = {
     // Translate coordinates to account for selections in sub-frames. We can't cache
     // this because the top-level page may have scrolled since selection started.
     let offset = this._getViewOffset();
+    let scrollX = {}, scrollY = {};
+    this._view.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils).getScrollXY(false, scrollX, scrollY);
     sendMessageToJava({
       gecko: {
         type: "TextSelection:PositionHandles",
-        startLeft: this.cache.start.x + offset.x,
-        startTop: this.cache.start.y + offset.y,
-        endLeft: this.cache.end.x + offset.x,
-        endTop: this.cache.end.y + offset.y
+        startLeft: this.cache.start.x + offset.x + scrollX.value,
+        startTop: this.cache.start.y + offset.y + scrollY.value,
+        endLeft: this.cache.end.x + offset.x + scrollX.value,
+        endTop: this.cache.end.y + offset.y + scrollY.value
       }
     });
   },