Bug 729528 - Add a DisplayPortMetrics to track the requested display resolution along with the area. r=Cwiiis

mobile/android/base/GeckoEvent.java

@@ -37,8 +37,8 @@
 
 package org.mozilla.gecko;
 
+import org.mozilla.gecko.gfx.DisplayPortMetrics;
 import org.mozilla.gecko.gfx.IntSize;
-import org.mozilla.gecko.gfx.RectUtils;
 import org.mozilla.gecko.gfx.ViewportMetrics;
 import android.os.*;
 import android.app.*;
@@ -418,7 +418,7 @@ public class GeckoEvent {
         return event;
     }
 
-    public static GeckoEvent createViewportEvent(ViewportMetrics viewport, RectF displayPort) {
+    public static GeckoEvent createViewportEvent(ViewportMetrics viewport, DisplayPortMetrics displayPort) {
         GeckoEvent event = new GeckoEvent(VIEWPORT);
         event.mCharacters = "Viewport:Change";
         PointF origin = viewport.getOrigin();
@@ -426,7 +426,7 @@ public class GeckoEvent {
         sb.append("{ \"x\" : ").append(origin.x)
           .append(", \"y\" : ").append(origin.y)
           .append(", \"zoom\" : ").append(viewport.getZoomFactor())
-          .append(", \"displayPort\" :").append(RectUtils.toJSON(displayPort))
+          .append(", \"displayPort\" :").append(displayPort.toJSON())
           .append('}');
         event.mCharactersExtra = sb.toString();
         return event;

mobile/android/base/Makefile.in

@@ -120,6 +120,7 @@ FENNEC_JAVA_FILES = \
   gfx/CairoImage.java \
   gfx/CairoUtils.java \
   gfx/CheckerboardImage.java \
+  gfx/DisplayPortMetrics.java \
   gfx/FlexibleGLSurfaceView.java \
   gfx/FloatSize.java \
   gfx/GeckoLayerClient.java \

mobile/android/base/gfx/DisplayPortMetrics.java

@@ -0,0 +1,51 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * 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.mozilla.gecko.gfx;
+
+import android.graphics.RectF;
+
+/*
+ * This class keeps track of the area we request Gecko to paint, as well
+ * as the resolution of the paint. The area may be different from the visible
+ * area of the page, and the resolution may be different from the resolution
+ * used in the compositor to render the page. This is so that we can ask Gecko
+ * to paint a much larger area without using extra memory, and then render some
+ * subsection of that with compositor scaling.
+ */
+public final class DisplayPortMetrics {
+    private final RectF mPosition;
+    private final float mResolution;
+
+    public DisplayPortMetrics() {
+        this(0, 0, 0, 0, 1);
+    }
+
+    public DisplayPortMetrics(float left, float top, float right, float bottom, float resolution) {
+        mPosition = new RectF(left, top, right, bottom);
+        mResolution = resolution;
+    }
+
+    public boolean contains(RectF rect) {
+        return mPosition.contains(rect);
+    }
+
+    public String toJSON() {
+        StringBuffer sb = new StringBuffer(256);
+        sb.append("{ \"left\": ").append(mPosition.left)
+          .append(", \"top\": ").append(mPosition.top)
+          .append(", \"right\": ").append(mPosition.right)
+          .append(", \"bottom\": ").append(mPosition.bottom)
+          .append(", \"resolution\": ").append(mResolution)
+          .append('}');
+        return sb.toString();
+    }
+
+    public String toString() {
+        return "DisplayPortMetrics(" + mPosition.left + ","
+                + mPosition.top + "," + mPosition.right + ","
+                + mPosition.bottom + "," + mResolution + ")";
+    }
+}

mobile/android/base/gfx/GeckoLayerClient.java

@@ -68,8 +68,8 @@ public class GeckoLayerClient implements GeckoEventResponder,
 
     private IntSize mScreenSize;
     private IntSize mWindowSize;
-    private RectF mDisplayPort;
-    private RectF mReturnDisplayPort;
+    private DisplayPortMetrics mDisplayPort;
+    private DisplayPortMetrics mReturnDisplayPort;
 
     private VirtualLayer mRootLayer;
 
@@ -95,7 +95,7 @@ public class GeckoLayerClient implements GeckoEventResponder,
         // to before being read
         mScreenSize = new IntSize(0, 0);
         mWindowSize = new IntSize(0, 0);
-        mDisplayPort = new RectF();
+        mDisplayPort = new DisplayPortMetrics();
         mCurrentViewTransform = new ViewTransform(0, 0, 1);
     }
 
@@ -120,7 +120,7 @@ public class GeckoLayerClient implements GeckoEventResponder,
         sendResizeEventIfNecessary(true);
     }
 
-    RectF getDisplayPort() {
+    DisplayPortMetrics getDisplayPort() {
         return mDisplayPort;
     }
 
@@ -171,7 +171,7 @@ public class GeckoLayerClient implements GeckoEventResponder,
         GeckoAppShell.viewSizeChanged();
     }
 
-    private static RectF calculateDisplayPort(ImmutableViewportMetrics metrics) {
+    private static DisplayPortMetrics calculateDisplayPort(ImmutableViewportMetrics metrics) {
         float desiredXMargins = 2 * DEFAULT_DISPLAY_PORT_MARGIN;
         float desiredYMargins = 2 * DEFAULT_DISPLAY_PORT_MARGIN;
 
@@ -226,10 +226,11 @@ public class GeckoLayerClient implements GeckoEventResponder,
         // content changes or zooming), the size of the display port should remain constant. this
         // is intentional to avoid re-creating textures and all sorts of other reallocations in the
         // draw and composition code.
-        return new RectF(metrics.viewportRectLeft - leftMargin,
-                         metrics.viewportRectTop - topMargin,
-                         metrics.viewportRectRight + rightMargin,
-                         metrics.viewportRectBottom + bottomMargin);
+        return new DisplayPortMetrics(metrics.viewportRectLeft - leftMargin,
+                metrics.viewportRectTop - topMargin,
+                metrics.viewportRectRight + rightMargin,
+                metrics.viewportRectBottom + bottomMargin,
+                metrics.zoomFactor);
     }
 
     private void adjustViewport() {
@@ -320,7 +321,7 @@ public class GeckoLayerClient implements GeckoEventResponder,
             return "";
         }
         try {
-            return RectUtils.toJSON(mReturnDisplayPort);
+            return mReturnDisplayPort.toJSON();
         } finally {
             mReturnDisplayPort = null;
         }

mobile/android/base/gfx/LayerController.java

@@ -345,7 +345,7 @@ public class LayerController implements Tabs.OnTabsChangedListener {
         if (adjustedViewport.right > pageSize.width) adjustedViewport.right = pageSize.width;
         if (adjustedViewport.bottom > pageSize.height) adjustedViewport.bottom = pageSize.height;
 
-        RectF displayPort = (mLayerClient == null ? new RectF() : mLayerClient.getDisplayPort());
+        DisplayPortMetrics displayPort = (mLayerClient == null ? new DisplayPortMetrics() : mLayerClient.getDisplayPort());
         return !displayPort.contains(adjustedViewport);
     }
 

mobile/android/chrome/content/browser.js

@@ -1605,7 +1605,7 @@ Tab.prototype = {
       return this.browser.docShellIsActive;
   },
 
-  setDisplayPort: function(aViewportX, aViewportY, aDisplayPortRect) {
+  setDisplayPort: function(aViewportX, aViewportY, aDisplayPort) {
     let zoom = this._zoom;
     if (zoom <= 0)
       return;
@@ -1615,10 +1615,10 @@ Tab.prototype = {
       return;
 
     let cwu = window.top.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(Ci.nsIDOMWindowUtils);
-    cwu.setDisplayPortForElement((aDisplayPortRect.left - aViewportX) / zoom,
-                                 (aDisplayPortRect.top - aViewportY) / zoom,
-                                 (aDisplayPortRect.right - aDisplayPortRect.left) / zoom,
-                                 (aDisplayPortRect.bottom - aDisplayPortRect.top) / zoom,
+    cwu.setDisplayPortForElement((aDisplayPort.left - aViewportX) / zoom,
+                                 (aDisplayPort.top - aViewportY) / zoom,
+                                 (aDisplayPort.right - aDisplayPort.left) / zoom,
+                                 (aDisplayPort.bottom - aDisplayPort.top) / zoom,
                                  element);
   },