Hooking up setBackgroundColor from AwContents to renderer

Final call into WebKit API ommitted as it depends on blink change https://codereview.chromium.org/19883002/

BUG=263263

Review URL: https://chromiumcodereview.appspot.com/19693016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@213255 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 46 insertions, 4 deletions

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 40075d7..c94c1ab 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -156,12 +156,15 @@ public class AwContents {
     // TODO(boliu): This should be in a global context, not per webview.
     private final double mDIPScale;
 
+    // The base background color, i.e. not accounting for any CSS body from the current page.
+    private int mBaseBackgroundColor = Color.WHITE;
+
     // Must call nativeUpdateLastHitTestData first to update this before use.
     private final HitTestData mPossiblyStaleHitTestData = new HitTestData();
 
     private DefaultVideoPosterRequestHandler mDefaultVideoPosterRequestHandler;
 
-    // Bound method for suppling Picture instances to the AwContentClient. Will be null if the
+    // Bound method for suppling Picture instances to the AwContentsClient. Will be null if the
     // picture listener API has not yet been enabled, or if it is using invalidation-only mode.
     private Callable<Picture> mPictureListenerContentProvider;
 
@@ -641,7 +644,10 @@ public class AwContents {
     private final Rect mClipBoundsTemporary = new Rect();
 
     public void onDraw(Canvas canvas) {
-        if (mNativeAwContents == 0) return;
+        if (mNativeAwContents == 0) {
+            canvas.drawColor(getEffectiveBackgroundColor());
+            return;
+        }
 
         mScrollOffsetManager.syncScrollOffsetFromOnDraw();
 
@@ -651,8 +657,7 @@ public class AwContents {
                     mClipBoundsTemporary.left, mClipBoundsTemporary.top,
                     mClipBoundsTemporary.right, mClipBoundsTemporary.bottom )) {
             Log.w(TAG, "nativeOnDraw failed; clearing to background color.");
-            int c = mContentViewCore.getBackgroundColor();
-            canvas.drawRGB(Color.red(c), Color.green(c), Color.blue(c));
+            canvas.drawColor(getEffectiveBackgroundColor());
         }
     }
 
@@ -818,6 +823,21 @@ public class AwContents {
         }
     }
 
+    public void setBackgroundColor(int color) {
+        mBaseBackgroundColor = color;
+        if (mNativeAwContents != 0) nativeSetBackgroundColor(mNativeAwContents, color);
+    }
+
+    private int getEffectiveBackgroundColor() {
+        // Do not ask the ContentViewCore for the background color, as it will always
+        // report white prior to initial navigation or post destruction,  whereas we want
+        // to use the client supplied base value in those cases.
+        if (mNativeAwContents == 0 || !mContentsClient.isCachedRendererBackgroundColorValid()) {
+            return mBaseBackgroundColor;
+        }
+        return mContentsClient.getCachedRendererBackgroundColor();
+    }
+
     public boolean isMultiTouchZoomSupported() {
         return mSettings.supportsMultiTouchZoom();
     }
@@ -1718,6 +1738,7 @@ public class AwContents {
 
     private native int nativeReleasePopupAwContents(int nativeAwContents);
     private native void nativeFocusFirstNode(int nativeAwContents);
+    private native void nativeSetBackgroundColor(int nativeAwContents, int color);
 
     private native int nativeGetAwDrawGLViewContext(int nativeAwContents);
     private native Picture nativeCapturePicture(int nativeAwContents);
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
index 7de19e5..fe42ad3 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContentsClient.java
@@ -52,6 +52,12 @@ public abstract class AwContentsClient {
 
     private double mDIPScale;
 
+    // Last background color reported from the renderer. Holds the sentinal value INVALID_COLOR
+    // if not valid.
+    private int mCachedRendererBackgroundColor = INVALID_COLOR;
+
+    private static final int INVALID_COLOR = 0;
+
     class AwWebContentsObserver extends WebContentsObserverAndroid {
         public AwWebContentsObserver(ContentViewCore contentViewCore) {
             super(contentViewCore);
@@ -90,6 +96,12 @@ public abstract class AwContentsClient {
     }
 
     private class AwContentViewClient extends ContentViewClient {
+        @Override
+        public void onBackgroundColorChanged(int color) {
+            // Avoid storing the sentinal INVALID_COLOR (note that both 0 and 1 are both
+            // fully transparent so this transpose makes no visible difference).
+            mCachedRendererBackgroundColor = color == INVALID_COLOR ? 1 : color;
+        }
 
         @Override
         public void onScaleChanged(float oldScale, float newScale) {
@@ -174,6 +186,15 @@ public abstract class AwContentsClient {
         return mContentViewClient;
     }
 
+    final int getCachedRendererBackgroundColor() {
+        assert isCachedRendererBackgroundColorValid();
+        return mCachedRendererBackgroundColor;
+    }
+
+    final boolean isCachedRendererBackgroundColorValid() {
+        return mCachedRendererBackgroundColor != INVALID_COLOR;
+    }
+
     //--------------------------------------------------------------------------------------------
     //             WebView specific methods that map directly to WebViewClient / WebChromeClient
     //--------------------------------------------------------------------------------------------