Factor out ContentViewAndroidDelegate

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index 65d815924c7e950517e8fcde222ed5a0bdff2aad..aabcc3bd8ac8fdd8dbbc71bb5fbe5ce7a5a72613 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -42,6 +42,7 @@ import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputConnection;
 import android.webkit.JavascriptInterface;
 import android.webkit.ValueCallback;
+import android.widget.FrameLayout;
 
 import org.chromium.android_webview.permission.AwGeolocationCallback;
 import org.chromium.android_webview.permission.AwPermissionRequest;
@@ -55,9 +56,11 @@ import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.SuppressFBWarnings;
 import org.chromium.components.navigation_interception.InterceptNavigationDelegate;
 import org.chromium.components.navigation_interception.NavigationParams;
+import org.chromium.content.browser.ContentViewAndroidDelegate;
 import org.chromium.content.browser.ContentViewClient;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content.browser.ContentViewStatics;
+import org.chromium.content.browser.RenderCoordinates;
 import org.chromium.content.browser.SmartClipProvider;
 import org.chromium.content.common.CleanupReference;
 import org.chromium.content_public.browser.GestureStateListener;
@@ -78,11 +81,14 @@ import org.chromium.ui.gfx.DeviceDisplayInfo;
 
 import java.io.File;
 import java.lang.annotation.Annotation;
+import java.lang.ref.WeakReference;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.WeakHashMap;
 import java.util.concurrent.Callable;
 
@@ -92,7 +98,7 @@ import java.util.concurrent.Callable;
  * primary entry point for the WebViewProvider implementation; it holds a 1:1 object
  * relationship with application WebView instances.
  * (We define this class independent of the hidden WebViewProvider interfaces, to allow
- * continuous build & test in the open source SDK-based tree).
+ * continuous build & test in the open source SDK-based tree).
  */
 @JNINamespace("android_webview")
 public class AwContents implements SmartClipProvider,
@@ -264,6 +270,7 @@ public class AwContents implements SmartClipProvider,
     private final Context mContext;
     private final int mAppTargetSdkVersion;
     private ContentViewCore mContentViewCore;
+    private AwContentViewAndroidDelegate mViewAndroidDelegate;
     private WindowAndroidWrapper mWindowAndroid;
     private WebContents mWebContents;
     private NavigationController mNavigationController;
@@ -810,7 +817,9 @@ public class AwContents implements SmartClipProvider,
             ContentViewCore.ZoomControlsDelegate zoomControlsDelegate,
             WindowAndroid windowAndroid) {
         ContentViewCore contentViewCore = new ContentViewCore(context);
-        contentViewCore.initialize(containerView, internalDispatcher, webContents,
+        AwContentViewAndroidDelegate viewDelegate = new AwContentViewAndroidDelegate(
+                containerView, contentViewCore.getRenderCoordinates());
+        contentViewCore.initialize(containerView, viewDelegate, internalDispatcher, webContents,
                 windowAndroid);
         contentViewCore.addGestureStateListener(gestureStateListener);
         contentViewCore.setContentViewClient(contentViewClient);
@@ -818,6 +827,133 @@ public class AwContents implements SmartClipProvider,
         return contentViewCore;
     }
 
+    /**
+     * Implementation of the interface {@link org.chromium.ui.base.ViewAndroidDelegate}
+     * for WebView.
+     */
+    public static class AwContentViewAndroidDelegate extends ContentViewAndroidDelegate {
+        /**
+         * The current container view. This view can be updated with
+         * {@link #updateCurrentContainerView()}. This needs to be a WeakReference
+         * because ViewAndroidDelegate is held strongly native side, which otherwise
+         * indefinitely prevents Android WebView from being garbage collected.
+         */
+        private WeakReference<ViewGroup> mContainerView;
+
+        /**
+         * List of anchor views stored in the order in which they were acquired mapped
+         * to their position.
+         */
+        private final Map<View, Position> mAnchorViews = new LinkedHashMap<>();
+
+        private final RenderCoordinates mRenderCoordinates;
+
+        /**
+         * Represents the position of an anchor view.
+         */
+        @VisibleForTesting
+        private static class Position {
+            public final float mX;
+            public final float mY;
+            public final float mWidth;
+            public final float mHeight;
+            public final int mLeftMargin;
+            public final int mTopMargin;
+
+            public Position(float x, float y, float width, float height, int leftMargin,
+                    int topMargin) {
+                mX = x;
+                mY = y;
+                mWidth = width;
+                mHeight = height;
+                mLeftMargin = leftMargin;
+                mTopMargin = topMargin;
+            }
+        }
+
+        AwContentViewAndroidDelegate(ViewGroup containerView, RenderCoordinates renderCoordinates) {
+            super(null);
+            mContainerView = new WeakReference<>(containerView);
+            mRenderCoordinates = renderCoordinates;
+        }
+
+        @Override
+        public void addView(View anchorView) {
+            ViewGroup containerView = mContainerView.get();
+            if (containerView == null) return;
+            containerView.addView(anchorView);
+            // |mAnchorViews| will be updated with the right view position in |setViewPosition|.
+            mAnchorViews.put(anchorView, null);
+        }
+
+        @Override
+        public void removeView(View anchorView) {
+            mAnchorViews.remove(anchorView);
+            ViewGroup containerView = mContainerView.get();
+            if (containerView != null) {
+                containerView.removeView(anchorView);
+            }
+        }
+
+        /**
+        * Updates the current container view to which this class delegates. Existing anchor views
+        * are transferred from the old to the new container view.
+        */
+        public void updateCurrentContainerView(ViewGroup containerView) {
+            ViewGroup oldContainerView = mContainerView.get();
+            mContainerView = new WeakReference<>(containerView);
+            for (Entry<View, Position> entry : mAnchorViews.entrySet()) {
+                View anchorView = entry.getKey();
+                Position position = entry.getValue();
+                if (oldContainerView != null) {
+                    oldContainerView.removeView(anchorView);
+                }
+                containerView.addView(anchorView);
+                if (position != null) {
+                    float scale = (float) DeviceDisplayInfo.create(containerView.getContext())
+                            .getDIPScale();
+                    setViewPosition(anchorView, position.mX, position.mY,
+                            position.mWidth, position.mHeight, scale,
+                            position.mLeftMargin, position.mTopMargin);
+                }
+            }
+        }
+
+        @SuppressWarnings("deprecation")  // AbsoluteLayout
+        @Override
+        public void setViewPosition(View anchorView, float x, float y, float width, float height,
+                float scale, int leftMargin, int topMargin) {
+            if (!mAnchorViews.containsKey(anchorView)) return;
+            mAnchorViews.put(anchorView, new Position(x, y, width, height, leftMargin, topMargin));
+
+            ViewGroup containerView = getContainerView();
+            if (containerView instanceof FrameLayout) {
+                super.setViewPosition(anchorView, x, y, width, height, scale, leftMargin,
+                        topMargin);
+                return;
+            }
+            // This fixes the offset due to a difference in
+            // scrolling model of WebView vs. Chrome.
+            // TODO(sgurun) fix this to use mContainerViewAtCreation.getScroll[X/Y]()
+            // as it naturally accounts for scroll differences between
+            // these models.
+            leftMargin += mRenderCoordinates.getScrollXPixInt();
+            topMargin += mRenderCoordinates.getScrollYPixInt();
+
+            int scaledWidth = Math.round(width * scale);
+            int scaledHeight = Math.round(height * scale);
+            android.widget.AbsoluteLayout.LayoutParams lp =
+                    new android.widget.AbsoluteLayout.LayoutParams(
+                        scaledWidth, scaledHeight, leftMargin, topMargin);
+            anchorView.setLayoutParams(lp);
+        }
+
+        @Override
+        protected ViewGroup getContainerView() {
+            return mContainerView.get();
+        }
+    }
+
     boolean isFullScreen() {
         return mFullScreenTransitionsState.isFullScreen();
     }
@@ -917,6 +1053,7 @@ public class AwContents implements SmartClipProvider,
         updateNativeAwGLFunctor();
         mContainerView.setWillNotDraw(false);
 
+        mViewAndroidDelegate.updateCurrentContainerView(mContainerView);
         mContentViewCore.setContainerView(mContainerView);
         if (mAwPdfExporter != null) {
             mAwPdfExporter.setContainerView(mContainerView);
@@ -1040,6 +1177,8 @@ public class AwContents implements SmartClipProvider,
         mContentViewCore = createAndInitializeContentViewCore(mContainerView, mContext,
                 mInternalAccessAdapter, webContents, new AwGestureStateListener(),
                 mContentViewClient, mZoomControls, mWindowAndroid.getWindowAndroid());
+        mViewAndroidDelegate = (AwContentViewAndroidDelegate)
+                mContentViewCore.getViewAndroidDelegate();
         nativeSetJavaPeers(mNativeAwContents, this, mWebContentsDelegate, mContentsClientBridge,
                 mIoThreadClient, mInterceptNavigationDelegate);
         mWebContents = mContentViewCore.getWebContents();