Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

cc/scrollbar_layer.cc

 // 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.
 
 #include "cc/scrollbar_layer.h"
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "cc/caching_bitmap_content_layer_updater.h"
 #include "cc/layer_painter.h"
 #include "cc/layer_tree_host.h"
 #include "cc/prioritized_resource.h"
 #include "cc/resource_update_queue.h"
 #include "cc/scrollbar_layer_impl.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebRect.h"
 #include "ui/gfx/rect_conversions.h"
 
 namespace cc {
 
+scoped_ptr<WebKit::WebScrollbarThemeGeometry> ScrollbarLayer::s_defaultGeometry;
+bool ScrollbarLayer::s_usesOverlayScrollbars = false;
+
 scoped_ptr<LayerImpl> ScrollbarLayer::createLayerImpl(LayerTreeImpl* treeImpl)
 {
     return ScrollbarLayerImpl::create(treeImpl, id(), ScrollbarGeometryFixedThumb::create(make_scoped_ptr(m_geometry->clone()))).PassAs<LayerImpl>();
 }
 
 scoped_refptr<ScrollbarLayer> ScrollbarLayer::create(
     scoped_ptr<WebKit::WebScrollbar> scrollbar,
     scoped_ptr<ScrollbarThemePainter> painter,
     scoped_ptr<WebKit::WebScrollbarThemeGeometry> geometry,
+    int scrollLayerId, bool isPinchZoomScrollbar)
+{
+    return make_scoped_refptr(new ScrollbarLayer(scrollbar.Pass(), painter.Pass(), geometry.Pass(), scrollLayerId, isPinchZoomScrollbar));
+}
+
+scoped_refptr<ScrollbarLayer> ScrollbarLayer::create(
+    scoped_ptr<WebKit::WebScrollbar> scrollbar,
+    scoped_ptr<ScrollbarThemePainter> painter,
     int scrollLayerId)
 {
-    return make_scoped_refptr(new ScrollbarLayer(scrollbar.Pass(), painter.Pass(), geometry.Pass(), scrollLayerId));
+    if (!s_defaultGeometry)
+        return make_scoped_refptr(static_cast<ScrollbarLayer*>(0));
+    return create(scrollbar.Pass(), painter.Pass(),
+        make_scoped_ptr(s_defaultGeometry->clone()).Pass(),
+        scrollLayerId, true);
+}
+
+void ScrollbarLayer::setDefaultGeometry(
+    WebKit::WebScrollbarThemeGeometry* themeGeometry)
+{
+    // We assume themeGeometry is ours to own.
+    if (themeGeometry)
+        s_defaultGeometry = make_scoped_ptr(themeGeometry);
+}
+
+WebKit::WebScrollbarThemeGeometry* ScrollbarLayer::cloneDefaultGeometry()
+{
+    if (s_defaultGeometry)
+        return s_defaultGeometry->clone();
+    return 0;
+}
+
+void ScrollbarLayer::setDefaultUsesOverlayScrollbars(bool usesOverlayScrollbars)
+{
+    s_usesOverlayScrollbars = usesOverlayScrollbars;
 }
 
 ScrollbarLayer::ScrollbarLayer(
     scoped_ptr<WebKit::WebScrollbar> scrollbar,
     scoped_ptr<ScrollbarThemePainter> painter,
     scoped_ptr<WebKit::WebScrollbarThemeGeometry> geometry,
-    int scrollLayerId)
+    int scrollLayerId, bool isPinchZoomScrollbar)
     : m_scrollbar(scrollbar.Pass())
     , m_painter(painter.Pass())
     , m_geometry(geometry.Pass())
     , m_scrollLayerId(scrollLayerId)
     , m_textureFormat(GL_INVALID_ENUM)
+    , m_isPinchZoomScrollbar(isPinchZoomScrollbar)
 {
     if (!m_scrollbar->isOverlay())
         setShouldScrollOnMainThread(true);
 }
 
 ScrollbarLayer::~ScrollbarLayer()
 {
 }
 
 void ScrollbarLayer::setScrollLayerId(int id)
@@ skipping 62 matching lines @@
 
     if (m_foreTrack && m_foreTrack->texture()->haveBackingTexture())
         scrollbarLayer->setForeTrackResourceId(m_foreTrack->texture()->resourceId());
     else
         scrollbarLayer->setForeTrackResourceId(0);
 
     if (m_thumb && m_thumb->texture()->haveBackingTexture())
         scrollbarLayer->setThumbResourceId(m_thumb->texture()->resourceId());
     else
         scrollbarLayer->setThumbResourceId(0);
+
+    scrollbarLayer->setIsPinchZoomScrollbar(m_isPinchZoomScrollbar);
 }
 
 ScrollbarLayer* ScrollbarLayer::toScrollbarLayer()
 {
     return this;
 }
 
 class ScrollbarBackgroundPainter : public LayerPainter {
 public:
     static scoped_ptr<ScrollbarBackgroundPainter> create(WebKit::WebScrollbar* scrollbar, ScrollbarThemePainter *painter, WebKit::WebScrollbarThemeGeometry* geometry, WebKit::WebScrollbar::ScrollbarPart trackPart)
@@ skipping 198 matching lines @@
     gfx::Rect thumbRect = m_geometry->thumbRect(m_scrollbar.get());
     m_thumbSize = thumbRect.size();
     gfx::Rect originThumbRect = scrollbarLayerRectToContentRect(gfx::Rect(thumbRect.size()));
     if (!originThumbRect.IsEmpty())
         updatePart(m_thumbUpdater.get(), m_thumb.get(), originThumbRect, queue, stats);
 
     m_dirtyRect = gfx::RectF();
 }
 
 }  // namespace cc