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

cc/layer_tree_host.cc

 // Copyright 2011 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/layer_tree_host.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "cc/animation_registrar.h"
 #include "cc/heads_up_display_layer.h"
 #include "cc/heads_up_display_layer_impl.h"
 #include "cc/layer.h"
 #include "cc/layer_animation_controller.h"
 #include "cc/layer_iterator.h"
 #include "cc/layer_tree_host_client.h"
 #include "cc/layer_tree_host_common.h"
 #include "cc/layer_tree_host_impl.h"
 #include "cc/layer_tree_impl.h"
 #include "cc/math_util.h"
 #include "cc/occlusion_tracker.h"
 #include "cc/overdraw_metrics.h"
+#include "cc/pinch_zoom_scrollbar.h"
+#include "cc/pinch_zoom_scrollbar_geometry.h"
+#include "cc/pinch_zoom_scrollbar_painter.h"
 #include "cc/prioritized_resource_manager.h"
+#include "cc/scrollbar_layer.h"
 #include "cc/single_thread_proxy.h"
 #include "cc/switches.h"
 #include "cc/thread.h"
 #include "cc/thread_proxy.h"
 #include "cc/top_controls_manager.h"
 #include "cc/tree_synchronizer.h"
 
 namespace {
 static int numLayerTreeInstances;
 }
@@ skipping 282 matching lines @@
     hostImpl->setDeviceScaleFactor(deviceScaleFactor());
     hostImpl->setDebugState(m_debugState);
 
     DCHECK(!syncTree->ViewportSizeInvalid());
 
     if (newImplTreeHasNoEvictedResources) {
         if (syncTree->ContentsTexturesPurged())
             syncTree->ResetContentsTexturesPurged();
     }
 
+    syncTree->SetPinchZoomHorizontalLayerId(
+        m_pinchZoomScrollbarHorizontal ? m_pinchZoomScrollbarHorizontal->id() : -1);
+    syncTree->SetPinchZoomVerticalLayerId(
+        m_pinchZoomScrollbarVertical ? m_pinchZoomScrollbarVertical->id() : -1);
+
     if (!m_settings.implSidePainting) {
         // If we're not in impl-side painting, the tree is immediately
         // considered active.
         syncTree->DidBecomeActive();
     }
 
     if (m_debugState.continuousPainting)
         hostImpl->savePaintTime(m_renderingStats.totalPaintTime, commitNumber());
 
     m_commitNumber++;
 }
 
+void LayerTreeHost::setPinchZoomScrollbarsBoundsAndPosition()
+{
+    if (!m_pinchZoomScrollbarHorizontal || !m_pinchZoomScrollbarVertical)
+        return;
+
+    gfx::Size size = layoutViewportSize();
+    int trackWidth = PinchZoomScrollbarGeometry::kTrackWidth;
+
+    m_pinchZoomScrollbarHorizontal->setBounds(gfx::Size(size.width() - trackWidth, trackWidth));
+    m_pinchZoomScrollbarHorizontal->setPosition(gfx::PointF(0, size.height() - trackWidth));
+    m_pinchZoomScrollbarHorizontal->setNeedsDisplay();

[enne (OOO), 2013/03/06 19:32:58]

setBounds should take care of this if anything changes.

[wjmaclean, 2013/03/06 22:36:53]

Removed.

+
+    m_pinchZoomScrollbarVertical->setBounds(gfx::Size(trackWidth, size.height() - trackWidth));
+    m_pinchZoomScrollbarVertical->setPosition(gfx::PointF(size.width() - trackWidth, 0));
+    m_pinchZoomScrollbarVertical->setNeedsDisplay();
+}
+
+static scoped_refptr<ScrollbarLayer> CreatePinchZoomScrollbar(
+    WebKit::WebScrollbar::Orientation orientation, LayerTreeHost* owner)
+{
+    scoped_refptr<ScrollbarLayer> scrollbarLayer = ScrollbarLayer::create(
+        make_scoped_ptr(
+            new PinchZoomScrollbar(orientation, owner)).PassAs<WebKit::WebScrollbar>(),
+        scoped_ptr<ScrollbarThemePainter>(new PinchZoomScrollbarPainter).Pass(),
+        scoped_ptr<WebKit::WebScrollbarThemeGeometry>(
+            new PinchZoomScrollbarGeometry).Pass(),
+        -1);
+        scrollbarLayer->setIsDrawable(true);
+        scrollbarLayer->setOpacity(0);
+        return scrollbarLayer;
+}
+
+void LayerTreeHost::createAndAddPinchZoomScrollbars()
+{
+    bool needsPropertiesUpdated = false;
+
+    if (!m_pinchZoomScrollbarHorizontal) {

[enne (OOO), 2013/03/06 19:32:58]

It's always the case that you have both pinch zoom scrollbars or neither, right?
Just asking, since this way these conditionals are structured it looks like it
could be the case that you could enter into this function having only one or the
other.

[wjmaclean, 2013/03/06 22:36:53]

If nothing is wrong, then yes, we have both or neither. I guess I was just
programming for the worst case here, but have changed the condition to re-create
both if either is missing. That way it's always clear we expect to have both.

+        m_pinchZoomScrollbarHorizontal = CreatePinchZoomScrollbar(WebKit::WebScrollbar::Horizontal, this);
+        needsPropertiesUpdated = true;
+    }
+
+    if (!m_pinchZoomScrollbarVertical) {
+        m_pinchZoomScrollbarVertical = CreatePinchZoomScrollbar( WebKit::WebScrollbar::Vertical, this);
+        needsPropertiesUpdated = true;
+    }
+
+    DCHECK(m_pinchZoomScrollbarHorizontal && m_pinchZoomScrollbarVertical);
+
+    if (!m_pinchZoomScrollbarHorizontal->parent())
+        m_rootLayer->addChild(m_pinchZoomScrollbarHorizontal);
+
+    if (!m_pinchZoomScrollbarVertical->parent())
+        m_rootLayer->addChild(m_pinchZoomScrollbarVertical);
+
+    if (needsPropertiesUpdated)
+        setPinchZoomScrollbarsBoundsAndPosition();
+}
+
 void LayerTreeHost::willCommit()
 {
     m_client->willCommit();
 }
 
 void LayerTreeHost::updateHudLayer()
 {
     if (m_debugState.showHudInfo()) {
         if (!m_hudLayer)
             m_hudLayer = HeadsUpDisplayLayer::create();
 
         if (m_rootLayer && !m_hudLayer->parent())
             m_rootLayer->addChild(m_hudLayer);
     } else if (m_hudLayer) {
         m_hudLayer->removeFromParent();
         m_hudLayer = 0;
     }
+
+    // Setup pinch-zoom scrollbars if required.

[enne (OOO), 2013/03/06 19:32:58]

This comment doesn't really add anything.

[wjmaclean, 2013/03/06 22:36:53]

Done.

It used to mean more before the last re-factor I guess.

+    if (m_settings.usePinchZoomScrollbars)
+        createAndAddPinchZoomScrollbars();
 }
 
 void LayerTreeHost::commitComplete()
 {
     m_client->didCommit();
 }
 
 scoped_ptr<OutputSurface> LayerTreeHost::createOutputSurface()
 {
     return m_client->createOutputSurface();
@@ skipping 126 matching lines @@
 }
 
 void LayerTreeHost::setViewportSize(const gfx::Size& layoutViewportSize, const gfx::Size& deviceViewportSize)
 {
     if (layoutViewportSize == m_layoutViewportSize && deviceViewportSize == m_deviceViewportSize)
         return;
 
     m_layoutViewportSize = layoutViewportSize;
     m_deviceViewportSize = deviceViewportSize;
 
+    setPinchZoomScrollbarsBoundsAndPosition();
     setNeedsCommit();
 }
 
 void LayerTreeHost::setPageScaleFactorAndLimits(float pageScaleFactor, float minPageScaleFactor, float maxPageScaleFactor)
 {
     if (pageScaleFactor == m_pageScaleFactor && minPageScaleFactor == m_minPageScaleFactor && maxPageScaleFactor == m_maxPageScaleFactor)
         return;
 
     m_pageScaleFactor = pageScaleFactor;
     m_minPageScaleFactor = minPageScaleFactor;
@@ skipping 73 matching lines @@
 
     for (size_t i = 0; i < layer->children().size(); ++i) {
         Layer* found = findFirstScrollableLayer(layer->children()[i].get());
         if (found)
             return found;
     }
 
     return 0;
 }
 
+Layer* LayerTreeHost::rootScrollLayer() const
+{
+    return findFirstScrollableLayer(m_rootLayer.get());
+}
+
 void LayerTreeHost::updateLayers(Layer* rootLayer, ResourceUpdateQueue& queue)
 {
     TRACE_EVENT0("cc", "LayerTreeHost::updateLayers");
 
     LayerList updateList;
 
     {
         Layer* rootScroll = findFirstScrollableLayer(rootLayer);
         if (rootScroll)
             rootScroll->setImplTransform(m_implTransform);
@@ skipping 273 matching lines @@
     }
 }
 
 void LayerTreeHost::setAnimationEventsRecursive(const AnimationEventsVector& events, Layer* layer, base::Time wallClockTime)
 {
     if (!layer)
         return;
 
     for (size_t eventIndex = 0; eventIndex < events.size(); ++eventIndex) {
         if (layer->id() == events[eventIndex].layerId) {
-            if (events[eventIndex].type == AnimationEvent::Started)
+            switch (events[eventIndex].type) {
+            case AnimationEvent::Started :
                 layer->notifyAnimationStarted(events[eventIndex], wallClockTime.ToDoubleT());
-            else
+                break;
+            case AnimationEvent::Finished :
                 layer->notifyAnimationFinished(wallClockTime.ToDoubleT());
+                break;
+
+            case AnimationEvent::PropertyUpdate :
+                layer->notifyAnimationPropertyUpdate(events[eventIndex]);
+                break;
+
+            default:
+                NOTREACHED();
+            }
         }
     }
 
     for (size_t childIndex = 0; childIndex < layer->children().size(); ++childIndex)
         setAnimationEventsRecursive(events, layer->children()[childIndex].get(), wallClockTime);
 }
 
 skia::RefPtr<SkPicture> LayerTreeHost::capturePicture()
 {
     return m_proxy->capturePicture();
 }
 
 }  // namespace cc