Update WebView visibility during attach/detach

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

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.android_webview;
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.ComponentCallbacks2;
 import android.content.Context;
@@ skipping 954 matching lines @@
         mContentViewCore = createAndInitializeContentViewCore(mContainerView, mContext,
                 mInternalAccessAdapter, webContents, new AwGestureStateListener(),
                 mContentViewClient, mZoomControls, mWindowAndroid.getWindowAndroid());
         nativeSetJavaPeers(mNativeAwContents, this, mWebContentsDelegate, mContentsClientBridge,
                 mIoThreadClient, mInterceptNavigationDelegate);
         mWebContents = mContentViewCore.getWebContents();
         mNavigationController = mWebContents.getNavigationController();
         installWebContentsObserver();
         mSettings.setWebContents(webContents);
         nativeSetDipScale(mNativeAwContents, (float) mDIPScale);
-        updateContentViewCoreVisibility();
+        postUpdateContentViewCoreVisibility();
 
         // The native side object has been bound to this java instance, so now is the time to
         // bind all the native->java relationships.
         mCleanupReference =
                 new CleanupReference(this, new DestroyRunnable(mNativeAwContents));
     }
 
     private void installWebContentsObserver() {
         if (mWebContentsObserver != null) {
             mWebContentsObserver.destroy();
@@ skipping 805 matching lines @@
     }
 
     /**
      * @see android.webkit.WebView#onPause()
      */
     public void onPause() {
         if (TRACE) Log.d(TAG, "onPause");
         if (mIsPaused || isDestroyed(NO_WARN)) return;
         mIsPaused = true;
         nativeSetIsPaused(mNativeAwContents, mIsPaused);
-        updateContentViewCoreVisibility();
+        postUpdateContentViewCoreVisibility();
     }
 
     /**
      * @see android.webkit.WebView#onResume()
      */
     public void onResume() {
         if (TRACE) Log.d(TAG, "onResume");
         if (!mIsPaused || isDestroyed(NO_WARN)) return;
         mIsPaused = false;
         nativeSetIsPaused(mNativeAwContents, mIsPaused);
-        updateContentViewCoreVisibility();
+        postUpdateContentViewCoreVisibility();
     }
 
     /**
      * @see android.webkit.WebView#isPaused()
      */
     public boolean isPaused() {
         return isDestroyed(WARN) ? false : mIsPaused;
     }
 
     /**
@@ skipping 518 matching lines @@
     /**
      * @see android.view.View#onWindowVisibilityChanged()
      */
     public void onWindowVisibilityChanged(int visibility) {
         mAwViewMethods.onWindowVisibilityChanged(visibility);
     }
 
     private void setViewVisibilityInternal(boolean visible) {
         mIsViewVisible = visible;
         if (!isDestroyed(NO_WARN)) nativeSetViewVisibility(mNativeAwContents, mIsViewVisible);
-        updateContentViewCoreVisibility();
+        postUpdateContentViewCoreVisibility();
     }
 
     private void setWindowVisibilityInternal(boolean visible) {
         mInvalidateRootViewOnNextDraw |= Build.VERSION.SDK_INT <= Build.VERSION_CODES.LOLLIPOP
                 && visible && !mIsWindowVisible;
         mIsWindowVisible = visible;
         if (!isDestroyed(NO_WARN)) nativeSetWindowVisibility(mNativeAwContents, mIsWindowVisible);
-        updateContentViewCoreVisibility();
+        postUpdateContentViewCoreVisibility();
+    }
+
+    private void postUpdateContentViewCoreVisibility() {
+        // When WebView is attached to a visible window, WebView will be
+        // attached to a window whose visibility is initially invisible, then
+        // the window visibility will be updated to true. This means CVC
+        // visibility will be set to false then true immediately, in the same
+        // function call of View#dispatchAttachedToWindow. To prevent this flip
+        // of CVC visibility, post the task to update CVC visibility.
+        mHandler.post(new Runnable() {

[boliu, 2015/11/03 22:05:46]

Can you not post more than you need to?

Also don't re-allocate new runnable every time. Save it in an instance variable,
and maybe allocate it lazily. (To avoid gc churn)

+            @Override
+            public void run() {
+                updateContentViewCoreVisibility();
+            }
+        });
     }
 
     private void updateContentViewCoreVisibility() {
         if (isDestroyed(NO_WARN)) return;
         boolean contentViewCoreVisible = nativeIsVisible(mNativeAwContents);
 
         if (contentViewCoreVisible && !mIsContentViewCoreVisible) {
             mContentViewCore.onShow();
         } else if (!contentViewCoreVisible && mIsContentViewCoreVisible) {
             mContentViewCore.onHide();
@@ skipping 628 matching lines @@
             if (mIsAttachedToWindow) {
                 Log.w(TAG, "onAttachedToWindow called when already attached. Ignoring");
                 return;
             }
             mIsAttachedToWindow = true;
 
             mContentViewCore.onAttachedToWindow();
             nativeOnAttachedToWindow(mNativeAwContents, mContainerView.getWidth(),
                     mContainerView.getHeight());
             updateHardwareAcceleratedFeaturesToggle();
+            postUpdateContentViewCoreVisibility();
 
             setLocale(LocaleUtils.getDefaultLocale());
 
             if (mComponentCallbacks != null) return;
             mComponentCallbacks = new AwComponentCallbacks();
             mContext.registerComponentCallbacks(mComponentCallbacks);
         }
 
         @Override
         public void onDetachedFromWindow() {
             if (isDestroyed(NO_WARN)) return;
             if (!mIsAttachedToWindow) {
                 Log.w(TAG, "onDetachedFromWindow called when already detached. Ignoring");
                 return;
             }
             mIsAttachedToWindow = false;
             hideAutofillPopup();
             nativeOnDetachedFromWindow(mNativeAwContents);
 
             mContentViewCore.onDetachedFromWindow();
             updateHardwareAcceleratedFeaturesToggle();
+            postUpdateContentViewCoreVisibility();
 
             if (mComponentCallbacks != null) {
                 mContext.unregisterComponentCallbacks(mComponentCallbacks);
                 mComponentCallbacks = null;
             }
 
             mScrollAccessibilityHelper.removePostedCallbacks();
         }
 
         @Override
@@ skipping 190 matching lines @@
     private native void nativePreauthorizePermission(long nativeAwContents, String origin,
             long resources);
 
     private native void nativePostMessageToFrame(long nativeAwContents, String frameId,
             String message, String targetOrigin, int[] msgPorts);
 
     private native void nativeCreateMessageChannel(long nativeAwContents, AwMessagePort[] ports);
 
     private native void nativeGrantFileSchemeAccesstoChildProcess(long nativeAwContents);
 }