[Android] Move zoom controls management into WebView

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index 20b30d8f89db3f086671e52db70fc0f1a5a24208..3b9fe6371ecbbe451c254a4b23a34990fd1915cf 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -181,6 +181,24 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         void onPinchGestureEnd();
     }
 
+    /**
+     * An interface for controlling visibility and state of embedder-provided zoom controls.
+     */
+    public static interface ZoomControlsDelegate {

[joth, 2013/05/03 19:32:43]

nit: I think static is spurious here? (didn't know you could say this, in fact)

[mnaganov (inactive), 2013/05/07 09:55:44]

I've copied it from the two interfaces above. According to Stack Overflow, this
is indeed redundant, so removing from this interface and the two above.

+        /**
+         * Called when it's reasonable to show zoom controls.
+         */
+        void invokeZoomPicker();
+        /**
+         * Called when zoom controls need to be hidden (e.g. when the view hides).
+         */
+        void dismissZoomPicker();
+        /**
+         * Called when page scale has been changed, so the controls can update their state.
+         */
+        void updateZoomControls();
+    }
+
     private VSyncManager.Provider mVSyncProvider;
     private VSyncManager.Listener mVSyncListener;
     private int mVSyncSubscriberCount;
@@ -276,6 +294,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
     private ContentViewGestureHandler mContentViewGestureHandler;
     private PinchGestureStateListener mPinchGestureStateListener;
     private ZoomManager mZoomManager;
+    private ZoomControlsDelegate mZoomControlsDelegate;
 
     private PopupZoomer mPopupZoomer;
 
@@ -655,8 +674,15 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
 
         mZoomManager = new ZoomManager(mContext, this);
-        mZoomManager.updateMultiTouchSupport();
         mContentViewGestureHandler = new ContentViewGestureHandler(mContext, this, mZoomManager);
+        mZoomControlsDelegate = new ZoomControlsDelegate() {

[benm (inactive), 2013/05/03 16:01:12]

nit: maybe just add a comment to say that by default ContentViewCore doesn't
support zoom controls.

[mnaganov (inactive), 2013/05/03 16:09:52]

I think, it is more correct say that Chrome for Android doesn't provide zoom
controls, but telling about Chrome in the content layer doesn't make much sense.
Also, the comment on the interface says "embedder-provided zoom controls", so
it's natural to assume that ContentViewCore doesn't provide its own.

So I suppose that the comment isn't really needed.

+            @Override
+            public void invokeZoomPicker() {}
+            @Override
+            public void dismissZoomPicker() {}
+            @Override
+            public void updateZoomControls() {}
+        };
 
         mRenderCoordinates.reset();
 
@@ -1367,9 +1393,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
         setAccessibilityState(false);
         hidePopupDialog();
-        if (mContentSettings != null && mContentSettings.supportZoom()) {
-            mZoomManager.dismissZoomPicker();
-        }
+        mZoomControlsDelegate.dismissZoomPicker();
     }
 
     /**
@@ -1377,9 +1401,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      */
     public void onVisibilityChanged(View changedView, int visibility) {
       if (visibility != View.VISIBLE) {
-          if (mContentSettings.supportZoom()) {
-              mZoomManager.dismissZoomPicker();
-          }
+          mZoomControlsDelegate.dismissZoomPicker();
       }
     }
 
@@ -1781,12 +1803,12 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
         }
     }
 
-    void updateMultiTouchZoomSupport() {
-        mZoomManager.updateMultiTouchSupport();
+    public void setZoomControlsDelegate(ZoomControlsDelegate zoomControlsDelegate) {
+        mZoomControlsDelegate = zoomControlsDelegate;
     }
 
-    public boolean isMultiTouchZoomSupported() {
-        return mZoomManager.isMultiTouchZoomSupported();
+    public void updateMultiTouchZoomSupport(boolean supportsMultiTouchZoom) {
+        mZoomManager.updateMultiTouchSupport(supportsMultiTouchZoom);
     }
 
     public void selectPopupMenuItems(int[] indices) {
@@ -2160,7 +2182,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
                 contentOffsetYPix);
 
         if (needTemporarilyHideHandles) temporarilyHideTextHandles();
-        if (needUpdateZoomControls) mZoomManager.updateZoomControls();
+        if (needUpdateZoomControls) mZoomControlsDelegate.updateZoomControls();
         if (contentOffsetChanged) updateHandleScreenPositions();
 
         // Update offsets for fullscreen.
@@ -2445,15 +2467,7 @@ public class ContentViewCore implements MotionEventDelegate, NavigationClient {
      */
     @Override
     public void invokeZoomPicker() {
-        if (mContentSettings != null && mContentSettings.supportZoom()) {
-            mZoomManager.invokeZoomPicker();
-        }
-    }
-
-    // Unlike legacy WebView getZoomControls which returns external zoom controls,
-    // this method returns built-in zoom controls. This method is used in tests.
-    public View getZoomControlsForTest() {
-        return mZoomManager.getZoomControlsViewForTest();
+        mZoomControlsDelegate.invokeZoomPicker();

[joth, 2013/05/03 19:32:43]

feels like pulling at a bit of string here, but..
this method is only called from onScrolled and by AwContents. AwContents already
knows when we scrolled, so could do invokeZoomPicker itself.
But then... what about the other ZoomControlsDelegate methods. window
attach/detatch and visibility change are all known in AwContents. so it just
leaves updateFrameInfo(). And you know what.. with the synchronous compositor
that's easier to route to aw/browser view renderer than it is to get it into
ContentViewCore. (We already receive a distilled version of this call in 
BrowserViewRendererImpl::OnFrameInfoUpdated() anyway.
(ContentViewClient.onPageScaleChanged might also be an appropriate hook for
this)

So in fact, it'd be an option to entirely remove this stuff from CVC if we
wanted to.

[mnaganov (inactive), 2013/05/07 09:55:44]

Yes, I was also considering that. Decided to keep as is for now, but will take a
look later.

     }
 
     /**