Expand tap highlight to allow multiple highlights for touch disambiguation.

Source/core/platform/graphics/GraphicsLayer.cpp

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 113 matching lines @@
     , m_showRepaintCounter(false)
     , m_paintingPhase(GraphicsLayerPaintAllWithOverflowClip)
     , m_contentsOrientation(CompositingCoordinatesTopDown)
     , m_parent(0)
     , m_maskLayer(0)
     , m_replicaLayer(0)
     , m_replicatedLayer(0)
     , m_repaintCount(0)
     , m_contentsLayer(0)
     , m_contentsLayerId(0)
-    , m_linkHighlight(0)
     , m_contentsLayerPurpose(NoContentsLayer)
     , m_scrollableArea(0)
 {
 #ifndef NDEBUG
     if (m_client)
         m_client->verifyNotPainting();
 #endif
 
     m_opaqueRectTrackingContentLayerDelegate = adoptPtr(new OpaqueRectTrackingContentLayerDelegate(this));
     m_layer = adoptPtr(Platform::current()->compositorSupport()->createContentLayer(m_opaqueRectTrackingContentLayerDelegate.get()));
     m_layer->layer()->setDrawsContent(m_drawsContent && m_contentsVisible);
     m_layer->layer()->setScrollClient(this);
     m_layer->setAutomaticallyComputeRasterScale(true);
 }
 
 GraphicsLayer::~GraphicsLayer()
 {
-    if (m_linkHighlight) {
-        m_linkHighlight->clearCurrentGraphicsLayer();
-        m_linkHighlight = 0;
-    }
+    for (size_t i = 0; i < m_linkHighlights.size(); i++)
+        m_linkHighlights[i]->clearCurrentGraphicsLayer();
+    m_linkHighlights.clear();
 
 #ifndef NDEBUG
     if (m_client)
         m_client->verifyNotPainting();
 #endif
 
     if (m_replicaLayer)
         m_replicaLayer->setReplicatedLayer(0);
 
     if (m_replicatedLayer)
@@ skipping 391 matching lines @@
 
 void GraphicsLayer::updateNames()
 {
     String debugName = "Layer for " + m_nameBase;
     m_layer->layer()->setDebugName(debugName);
 
     if (WebLayer* contentsLayer = contentsLayerIfRegistered()) {
         String debugName = "ContentsLayer for " + m_nameBase;
         contentsLayer->setDebugName(debugName);
     }
-    if (m_linkHighlight) {
+    for (size_t i = 0; i < m_linkHighlights.size(); i++) {
         String debugName = "LinkHighlight for " + m_nameBase;
-        m_linkHighlight->layer()->setDebugName(debugName);
+        m_linkHighlights[i]->layer()->setDebugName(debugName);

[wjmaclean, 2013/06/12 15:09:06]

It may be slightly confusing having multiple link highlight layers all with the
same name ... can they at least be numbered or something to indicate that it's
ok for there to be more than one?

     }
 }
 
 void GraphicsLayer::updateChildList()
 {
     WebLayer* childHost = m_layer->layer();
     childHost->removeAllChildren();
 
     clearContentsLayerIfUnregistered();
 
     if (m_contentsLayer) {
         // FIXME: add the contents layer in the correct order with negative z-order children.
         // This does not cause visible rendering issues because currently contents layers are only used
         // for replaced elements that don't have children.
         childHost->addChild(m_contentsLayer);
     }
 
     const Vector<GraphicsLayer*>& childLayers = children();
     size_t numChildren = childLayers.size();
     for (size_t i = 0; i < numChildren; ++i) {
         GraphicsLayer* curChild = childLayers[i];
 
         childHost->addChild(curChild->platformLayer());
     }
 
-    if (m_linkHighlight)
-        childHost->addChild(m_linkHighlight->layer());
+    for (size_t i = 0; i < m_linkHighlights.size(); i++)
+        childHost->addChild(m_linkHighlights[i]->layer());
 }
 
 void GraphicsLayer::updateLayerIsDrawable()
 {
     // For the rest of the accelerated compositor code, there is no reason to make a
     // distinction between drawsContent and contentsVisible. So, for m_layer->layer(), these two
     // flags are combined here. m_contentsLayer shouldn't receive the drawsContent flag
     // so it is only given contentsVisible.
 
     m_layer->layer()->setDrawsContent(m_drawsContent && m_contentsVisible);
     if (WebLayer* contentsLayer = contentsLayerIfRegistered())
         contentsLayer->setDrawsContent(m_contentsVisible);
 
     if (m_drawsContent) {
         m_layer->layer()->invalidate();
-        if (m_linkHighlight)
-            m_linkHighlight->invalidate();
+        for (size_t i = 0; i < m_linkHighlights.size(); i++)
+            m_linkHighlights[i]->invalidate();
     }
 }
 
 void GraphicsLayer::updateContentsRect()
 {
     WebLayer* contentsLayer = contentsLayerIfRegistered();
     if (!contentsLayer)
         return;
 
     contentsLayer->setPosition(FloatPoint(m_contentsRect.x(), m_contentsRect.y()));
@@ skipping 311 matching lines @@
     info.addMember(m_parent, "parent");
     info.addMember(m_maskLayer, "maskLayer");
     info.addMember(m_replicaLayer, "replicaLayer");
     info.addMember(m_replicatedLayer, "replicatedLayer");
     info.ignoreMember(m_client);
     info.addMember(m_name, "name");
     info.addMember(m_nameBase, "nameBase");
     info.addMember(m_layer, "layer");
     info.addMember(m_imageLayer, "imageLayer");
     info.addMember(m_contentsLayer, "contentsLayer");
-    info.addMember(m_linkHighlight, "linkHighlight");
+    for (size_t i = 0; i < m_linkHighlights.size(); i++) {
+        info.addMember(m_linkHighlights[i], "linkHighlights");
+    }
     info.addMember(m_opaqueRectTrackingContentLayerDelegate, "opaqueRectTrackingContentLayerDelegate");
     info.addMember(m_animationIdMap, "animationIdMap");
     info.addMember(m_scrollableArea, "scrollableArea");
 }
 
 void GraphicsLayer::setName(const String& name)
 {
     m_nameBase = name;
     m_name = String::format("GraphicsLayer(%p) ", this) + name;
     updateNames();
@@ skipping 135 matching lines @@
         contentsLayer->invalidate();
         addRepaintRect(contentsRect());
     }
 }
 
 void GraphicsLayer::setNeedsDisplay()
 {
     if (drawsContent()) {
         m_layer->layer()->invalidate();
         addRepaintRect(FloatRect(FloatPoint(), m_size));
-        if (m_linkHighlight)
-            m_linkHighlight->invalidate();
+        for (size_t i = 0; i < m_linkHighlights.size(); i++)
+            m_linkHighlights[i]->invalidate();
     }
 }
 
 void GraphicsLayer::setNeedsDisplayInRect(const FloatRect& rect)
 {
     if (drawsContent()) {
         m_layer->layer()->invalidateRect(rect);
         addRepaintRect(rect);
-        if (m_linkHighlight)
-            m_linkHighlight->invalidate();
+        for (size_t i = 0; i < m_linkHighlights.size(); i++)
+            m_linkHighlights[i]->invalidate();
     }
 }
 
 void GraphicsLayer::setContentsRect(const IntRect& rect)
 {
     if (rect == m_contentsRect)
         return;
 
     m_contentsRect = rect;
     updateContentsRect();
@@ skipping 201 matching lines @@
 }
 
 void GraphicsLayer::setBackgroundFilters(const FilterOperations& filters)
 {
     WebFilterOperations webFilters;
     if (!copyWebCoreFilterOperationsToWebFilterOperations(filters, webFilters))
         return;
     m_layer->layer()->setBackgroundFilters(webFilters);
 }
 
-void GraphicsLayer::setLinkHighlight(LinkHighlightClient* linkHighlight)
+void GraphicsLayer::addLinkHighlight(LinkHighlightClient* linkHighlight)
 {
-    m_linkHighlight = linkHighlight;
+    ASSERT(linkHighlight);
+    m_linkHighlights.append(linkHighlight);
     updateChildList();
 }
 
+void GraphicsLayer::removeLinkHighlight(
+    LinkHighlightClient* linkHighlight)
+{
+    m_linkHighlights.remove(m_linkHighlights.find(linkHighlight));
+    ASSERT(!m_linkHighlights.contains(linkHighlight));
+    updateChildList();
+}
+
 void GraphicsLayer::paint(GraphicsContext& context, const IntRect& clip)
 {
     paintGraphicsLayerContents(context, clip);
 }
 
 
 void GraphicsLayer::notifyAnimationStarted(double startTime)
 {
     if (m_client)
         m_client->notifyAnimationStarted(this, startTime);
@@ skipping 15 matching lines @@
 #ifndef NDEBUG
 void showGraphicsLayerTree(const WebCore::GraphicsLayer* layer)
 {
     if (!layer)
         return;
 
     String output = layer->layerTreeAsText(LayerTreeAsTextDebug | LayerTreeAsTextIncludeVisibleRects);
     fprintf(stderr, "%s\n", output.utf8().data());
 }
 #endif