Create Pinch Virtual Viewport scrollbar layers in Blink.

Source/web/PinchViewports.cpp

 /*
  * Copyright (C) 2013 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 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "PinchViewports.h"
 
 #include "WebSettingsImpl.h"
 #include "WebViewImpl.h"
 #include "core/page/Frame.h"
 #include "core/page/FrameView.h"
+#include "core/page/scrolling/ScrollingCoordinator.h"
+#include "core/platform/Scrollbar.h"
 #include "core/platform/graphics/FloatSize.h"
 #include "core/platform/graphics/GraphicsLayer.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCompositorSupport.h"
+#include "public/platform/WebLayer.h"
 #include "public/platform/WebLayerTreeView.h"
 #include "public/platform/WebScrollbarLayer.h"
 
 using WebCore::GraphicsLayer;
 
 namespace WebKit {
 
 PassOwnPtr<PinchViewports> PinchViewports::create(WebViewImpl* owner)
 {
     return adoptPtr(new PinchViewports(owner));
 }
 
 PinchViewports::PinchViewports(WebViewImpl* owner)
     : m_owner(owner)
     , m_innerViewportContainerLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
     , m_pageScaleLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
     , m_innerViewportScrollLayer(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
     , m_overlayScrollbarHorizontal(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
     , m_overlayScrollbarVertical(GraphicsLayer::create(m_owner->graphicsLayerFactory(), this))
 {
     m_innerViewportContainerLayer->platformLayer()->setIsContainerForFixedPositionLayers(true);
     // No need for the inner viewport to clip, since the compositing
     // surface takes care of it -- and clipping here would interfere with
     // dynamically-sized viewports on Android.
     m_innerViewportContainerLayer->setMasksToBounds(false);
 
     m_innerViewportScrollLayer->platformLayer()->setScrollable(true);
-
+    m_innerViewportScrollLayer->platformLayer()->setScrollClipLayer(m_innerViewportContainerLayer->platformLayer());
 
     m_innerViewportContainerLayer->addChild(m_pageScaleLayer.get());
     m_pageScaleLayer->addChild(m_innerViewportScrollLayer.get());
     m_innerViewportContainerLayer->addChild(m_overlayScrollbarHorizontal.get());
     m_innerViewportContainerLayer->addChild(m_overlayScrollbarVertical.get());
 
     // Setup the inner viewport overlay scrollbars.
     setupScrollbar(WebScrollbar::Horizontal);
     setupScrollbar(WebScrollbar::Vertical);
 }
@@ skipping 48 matching lines @@
         scrollbar->setDrawsContent(!page->mainFrame()->view()->hasOverlayScrollbars());
     if (GraphicsLayer* scrollbar = m_owner->compositor()->layerForVerticalScrollbar())
         scrollbar->setDrawsContent(!page->mainFrame()->view()->hasOverlayScrollbars());
 }
 
 void PinchViewports::setupScrollbar(WebScrollbar::Orientation orientation)
 {
     bool isHorizontal = orientation == WebScrollbar::Horizontal;
     GraphicsLayer* scrollbarGraphicsLayer = isHorizontal ?
         m_overlayScrollbarHorizontal.get() : m_overlayScrollbarVertical.get();
+    OwnPtr<WebScrollbarLayer>& webScrollbarLayer = isHorizontal ?
+        m_webOverlayScrollbarHorizontal : m_webOverlayScrollbarVertical;
 
     const int overlayScrollbarThickness = m_owner->settingsImpl()->pinchOverlayScrollbarThickness();
 
+    if (!webScrollbarLayer) {
+        WebCore::ScrollingCoordinator* coordinator = m_owner->page()->scrollingCoordinator();
+        ASSERT(coordinator);
+        WebCore::ScrollbarOrientation webcoreOrientation = isHorizontal ? WebCore::HorizontalScrollbar : WebCore::VerticalScrollbar;
+        webScrollbarLayer = coordinator->createSolidColorScrollbarLayer(webcoreOrientation, overlayScrollbarThickness);
+
+        webScrollbarLayer->setScrollLayer(m_innerViewportScrollLayer->platformLayer());
+        scrollbarGraphicsLayer->setContentsToPlatformLayer(webScrollbarLayer->layer());
+        scrollbarGraphicsLayer->setDrawsContent(false);
+    }
+
     int xPosition = isHorizontal ? 0 : m_innerViewportContainerLayer->size().width() - overlayScrollbarThickness;
     int yPosition = isHorizontal ? m_innerViewportContainerLayer->size().height() - overlayScrollbarThickness : 0;
     int width = isHorizontal ? m_innerViewportContainerLayer->size().width() - overlayScrollbarThickness : overlayScrollbarThickness;
     int height = isHorizontal ? overlayScrollbarThickness : m_innerViewportContainerLayer->size().height() - overlayScrollbarThickness;
 
     scrollbarGraphicsLayer->setPosition(WebCore::IntPoint(xPosition, yPosition));
     scrollbarGraphicsLayer->setSize(WebCore::IntSize(width, height));
 }
 
 void PinchViewports::registerViewportLayersWithTreeView(WebLayerTreeView* layerTreeView) const
 {
-    if (!layerTreeView)
-        return;
+    ASSERT(layerTreeView);
 
     WebCore::RenderLayerCompositor* compositor = m_owner->compositor();
+    GraphicsLayer* scrollLayer = compositor->scrollLayer();
+    GraphicsLayer* clipLayer = compositor->rootGraphicsLayer();
+    scrollLayer->platformLayer()->setScrollClipLayer(clipLayer->platformLayer());
+
     ASSERT(compositor);
-    layerTreeView->registerPinchViewportLayers(
-        m_innerViewportContainerLayer->platformLayer(),
+    layerTreeView->registerViewportLayers(
         m_pageScaleLayer->platformLayer(),
         m_innerViewportScrollLayer->platformLayer(),
-        compositor->scrollLayer()->platformLayer(),
-        m_overlayScrollbarHorizontal->platformLayer(),
-        m_overlayScrollbarVertical->platformLayer());
+        scrollLayer->platformLayer());
 }
 
 void PinchViewports::clearViewportLayersForTreeView(WebLayerTreeView* layerTreeView) const
 {
-    if (!layerTreeView)
-        return;
+    ASSERT(layerTreeView);
 
-    layerTreeView->clearPinchViewportLayers();
+    layerTreeView->clearViewportLayers();
 }
 
 void PinchViewports::notifyAnimationStarted(const GraphicsLayer*, double time)
 {
 }
 
 void PinchViewports::paintContents(const GraphicsLayer*, WebCore::GraphicsContext&, WebCore::GraphicsLayerPaintingPhase, const WebCore::IntRect& inClip)
 {
 }
 
@@ skipping 11 matching lines @@
     } else if (graphicsLayer == m_overlayScrollbarVertical.get()) {
         name =  "Overlay Scrollbar Vertical Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebKit