[blink] Support (semi-)transparent background colors in WebView/Frame.

third_party/WebKit/Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 343 matching lines @@
       m_maximumLegibleScale(1),
       m_doubleTapZoomPageScaleFactor(0),
       m_doubleTapZoomPending(false),
       m_enableFakePageScaleAnimationForTesting(false),
       m_fakePageScaleAnimationPageScaleFactor(0),
       m_fakePageScaleAnimationUseAnchor(false),
       m_compositorDeviceScaleFactorOverride(0),
       m_suppressNextKeypressEvent(false),
       m_imeAcceptEvents(true),
       m_devToolsEmulator(nullptr),
-      m_isTransparent(false),
       m_tabsToLinks(false),
       m_layerTreeView(nullptr),
       m_rootLayer(nullptr),
       m_rootGraphicsLayer(nullptr),
       m_visualViewportContainerLayer(nullptr),
       m_matchesHeuristicsForGpuRasterization(false),
       m_flingModifier(0),
       m_flingSourceDevice(WebGestureDeviceUninitialized),
       m_fullscreenController(FullscreenController::create(this)),
       m_baseBackgroundColor(Color::white),
       m_baseBackgroundColorOverrideEnabled(false),
       m_baseBackgroundColorOverride(Color::transparent),
+      m_backgroundColorOverrideEnabled(false),
       m_backgroundColorOverride(Color::transparent),
       m_zoomFactorOverride(0),
       m_userGestureObserved(false),
       m_shouldDispatchFirstVisuallyNonEmptyLayout(false),
       m_shouldDispatchFirstLayoutAfterFinishedParsing(false),
       m_shouldDispatchFirstLayoutAfterFinishedLoading(false),
       m_displayMode(WebDisplayModeBrowser),
       m_elasticOverscroll(FloatSize()),
       m_mutator(nullptr),
       m_scheduler(WTF::wrapUnique(Platform::current()
@@ skipping 2052 matching lines @@
 
   FrameSelection& selection = frame->selection();
   if (!selection.isAvailable()) {
     // plugins/mouse-capture-inside-shadow.html reaches here.
     return false;
   }
   return selection.computeVisibleSelectionInDOMTreeDeprecated().isBaseFirst();
 }
 
 WebColor WebViewImpl::backgroundColor() const {
-  if (isTransparent())
-    return Color::transparent;
+  if (m_backgroundColorOverrideEnabled)
+    return m_backgroundColorOverride;
   if (!m_page)
     return baseBackgroundColor().rgb();
   if (!m_page->mainFrame())
     return baseBackgroundColor().rgb();
   if (!m_page->mainFrame()->isLocalFrame())
     return baseBackgroundColor().rgb();
   FrameView* view = m_page->deprecatedLocalMainFrame()->view();
+  if (!view)
+    return baseBackgroundColor().rgb();
   return view->documentBackgroundColor().rgb();
 }
 
 WebPagePopup* WebViewImpl::pagePopup() const {
   return m_pagePopup.get();
 }
 
 // TODO(ekaramad):This method is almost duplicated in WebFrameWidgetImpl as
 // well. This code needs to be refactored  (http://crbug.com/629721).
 WebRange WebViewImpl::caretOrSelectionRange() {
@@ skipping 1042 matching lines @@
 void WebViewImpl::didCloseContextMenu() {
   LocalFrame* frame = m_page->focusController().focusedFrame();
   if (frame)
     frame->selection().setCaretBlinkingSuspended(false);
 }
 
 void WebViewImpl::hidePopups() {
   cancelPagePopup();
 }
 
-void WebViewImpl::setIsTransparent(bool isTransparent) {
-  // Set any existing frames to be transparent.
-  Frame* frame = m_page->mainFrame();
-  while (frame) {
-    if (frame->isLocalFrame())
-      toLocalFrame(frame)->view()->setTransparent(isTransparent);
-    frame = frame->tree().traverseNext();
-  }
-
-  // Future frames check this to know whether to be transparent.
-  m_isTransparent = isTransparent;
-
-  if (m_layerTreeView)
-    m_layerTreeView->setHasTransparentBackground(this->isTransparent());
-}
-
-bool WebViewImpl::isTransparent() const {
-  return m_isTransparent;
-}
-
 WebInputMethodControllerImpl* WebViewImpl::getActiveWebInputMethodController()
     const {
   return WebInputMethodControllerImpl::fromFrame(focusedLocalFrameInWidget());
 }
 
 Color WebViewImpl::baseBackgroundColor() const {
   return m_baseBackgroundColorOverrideEnabled ? m_baseBackgroundColorOverride
                                               : m_baseBackgroundColor;
 }
 
@@ skipping 27 matching lines @@
     mainFrameImpl()
         ->frame()
         ->view()
         ->updateLifecycleToCompositingCleanPlusScrolling();
   }
   updateBaseBackgroundColor();
 }
 
 void WebViewImpl::updateBaseBackgroundColor() {
   Color color = baseBackgroundColor();
-  if (m_page->mainFrame() && m_page->mainFrame()->isLocalFrame())
-    m_page->deprecatedLocalMainFrame()->view()->setBaseBackgroundColor(color);
+  if (m_page->mainFrame() && m_page->mainFrame()->isLocalFrame()) {
+    FrameView* view = m_page->deprecatedLocalMainFrame()->view();
+    view->setBaseBackgroundColor(color);
+    view->updateBaseBackgroundColorRecursively(color);
+  }
 }
 
 void WebViewImpl::setIsActive(bool active) {
   if (page())
     page()->focusController().setActive(active);
 }
 
 bool WebViewImpl::isActive() const {
   return page() ? page()->focusController().isActive() : false;
 }
@@ skipping 105 matching lines @@
 
 void WebViewImpl::mainFrameScrollOffsetChanged() {
   m_devToolsEmulator->mainFrameScrollOrScaleChanged();
 }
 
 bool WebViewImpl::useExternalPopupMenus() {
   return shouldUseExternalPopupMenus;
 }
 
 void WebViewImpl::setBackgroundColorOverride(WebColor color) {
+  m_backgroundColorOverrideEnabled = true;
   m_backgroundColorOverride = color;
   updateLayerTreeBackgroundColor();
 }
 
+void WebViewImpl::clearBackgroundColorOverride() {
+  m_backgroundColorOverrideEnabled = false;
+  updateLayerTreeBackgroundColor();
+}
+
 void WebViewImpl::setZoomFactorOverride(float zoomFactor) {
   m_zoomFactorOverride = zoomFactor;
   setZoomLevel(zoomLevel());
 }
 
 void WebViewImpl::setPageOverlayColor(WebColor color) {
   if (m_pageColorOverlay)
     m_pageColorOverlay.reset();
 
   if (color == Color::transparent)
@@ skipping 289 matching lines @@
   if (!page() || !m_layerTreeView)
     return;
 
   m_layerTreeView->setPageScaleFactorAndLimits(
       pageScaleFactor(), minimumPageScaleFactor(), maximumPageScaleFactor());
 }
 
 void WebViewImpl::updateLayerTreeBackgroundColor() {
   if (!m_layerTreeView)
     return;
-
-  m_layerTreeView->setBackgroundColor(alphaChannel(m_backgroundColorOverride)
-                                          ? m_backgroundColorOverride
-                                          : backgroundColor());
+  m_layerTreeView->setBackgroundColor(backgroundColor());
 }
 
 void WebViewImpl::updateLayerTreeDeviceScaleFactor() {
   DCHECK(page());
   DCHECK(m_layerTreeView);
 
   float deviceScaleFactor = m_compositorDeviceScaleFactorOverride
                                 ? m_compositorDeviceScaleFactorOverride
                                 : page()->deviceScaleFactorDeprecated();
   m_layerTreeView->setDeviceScaleFactor(deviceScaleFactor);
@@ skipping 133 matching lines @@
   if (focusedFrame->localFrameRoot() != mainFrameImpl()->frame())
     return nullptr;
   return focusedFrame;
 }
 
 LocalFrame* WebViewImpl::focusedLocalFrameAvailableForIme() const {
   return m_imeAcceptEvents ? focusedLocalFrameInWidget() : nullptr;
 }
 
 }  // namespace blink