Expand tap highlight to allow multiple highlights for touch disambiguation.

Source/WebKit/chromium/src/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 675 matching lines @@
 
     PlatformGestureEventBuilder platformEvent(mainFrameImpl()->frameView(), event);
 
     // Handle link highlighting outside the main switch to avoid getting lost in the
     // complicated set of cases handled below.
     switch (event.type) {
     case WebInputEvent::GestureTapDown:
         // Queue a highlight animation, then hand off to regular handler.
 #if OS(LINUX)
         if (settingsImpl()->gestureTapHighlightEnabled())
-            enableTapHighlight(platformEvent);
+            enableTapHighlightAtPoint(platformEvent);
 #endif
         break;
     case WebInputEvent::GestureTapCancel:
     case WebInputEvent::GestureTap:
     case WebInputEvent::GestureLongPress:
-        if (m_linkHighlight)
-            m_linkHighlight->startHighlightAnimationIfNeeded();
+        for (size_t i = 0; i < m_linkHighlights.size(); i++)
+            m_linkHighlights[i]->startHighlightAnimationIfNeeded();
         break;
     default:
         break;
     }
 
     switch (event.type) {
     case WebInputEvent::GestureTap: {
         m_client->cancelScheduledContentIntents();
         if (detectContentOnTouch(platformEvent.position())) {
             eventSwallowed = true;
@@ skipping 10 matching lines @@
         if (event.data.tap.width > 0 && !shouldDisableDesktopWorkarounds()) {
             // FIXME: didTapMultipleTargets should just take a rect instead of
             // an event.
             WebGestureEvent scaledEvent = event;
             scaledEvent.x = event.x / pageScaleFactor();
             scaledEvent.y = event.y / pageScaleFactor();
             scaledEvent.data.tap.width = event.data.tap.width / pageScaleFactor();
             scaledEvent.data.tap.height = event.data.tap.height / pageScaleFactor();
             IntRect boundingBox(scaledEvent.x - scaledEvent.data.tap.width / 2, scaledEvent.y - scaledEvent.data.tap.height / 2, scaledEvent.data.tap.width, scaledEvent.data.tap.height);
             Vector<IntRect> goodTargets;
-            findGoodTouchTargets(boundingBox, mainFrameImpl()->frame(), goodTargets);
+            Vector<Node*> highlightNodes;
+            findGoodTouchTargets(boundingBox, mainFrameImpl()->frame(), goodTargets, highlightNodes);
             // FIXME: replace touch adjustment code when numberOfGoodTargets == 1?
             // Single candidate case is currently handled by: https://bugs.webkit.org/show_bug.cgi?id=85101
             if (goodTargets.size() >= 2 && m_client && m_client->didTapMultipleTargets(scaledEvent, goodTargets)) {
+                if (settingsImpl()->gestureTapHighlightEnabled())
+                    enableTapHighlights(highlightNodes);
                 eventSwallowed = true;
                 eventCancelled = true;
                 break;
             }
         }
 
         eventSwallowed = mainFrameImpl()->frame()->eventHandler()->handleGestureEvent(platformEvent);
 
         if (m_selectPopup && m_selectPopup == selectPopup) {
             // That tap triggered a select popup which is the same as the one that
@@ skipping 494 matching lines @@
     while (bestTouchNode && !invokesHandCursor(bestTouchNode, false, m_page->mainFrame()))
         bestTouchNode = bestTouchNode->parentNode();
 
     // We should pick the largest enclosing node with hand cursor set.
     while (bestTouchNode && bestTouchNode->parentNode() && invokesHandCursor(bestTouchNode->parentNode(), false, m_page->mainFrame()))
         bestTouchNode = bestTouchNode->parentNode();
 
     return bestTouchNode;
 }
 
-void WebViewImpl::enableTapHighlight(const PlatformGestureEvent& tapEvent)
+void WebViewImpl::enableTapHighlightAtPoint(const PlatformGestureEvent& tapEvent)
 {
-    // Always clear any existing highlight when this is invoked, even if we don't get a new target to highlight.
-    m_linkHighlight.clear();
-
     Node* touchNode = bestTapNode(tapEvent);
 
-    if (!touchNode || !touchNode->renderer() || !touchNode->renderer()->enclosingLayer())
-        return;
+    Vector<Node*> highlightNodes;
+    highlightNodes.append(touchNode);
 
-    Color highlightColor = touchNode->renderer()->style()->tapHighlightColor();
-    // Safari documentation for -webkit-tap-highlight-color says if the specified color has 0 alpha,
-    // then tap highlighting is disabled.
-    // http://developer.apple.com/library/safari/#documentation/appleapplications/reference/safaricssref/articles/standardcssproperties.html
-    if (!highlightColor.alpha())
-        return;
+    enableTapHighlights(highlightNodes);
+}
 
-    m_linkHighlight = LinkHighlight::create(touchNode, this);
+void WebViewImpl::enableTapHighlights(Vector<Node*>& highlightNodes)
+{
+    // Always clear any existing highlight when this is invoked, even if we
+    // don't get a new target to highlight.
+    m_linkHighlights.clear();
+
+    for (size_t i = 0; i < highlightNodes.size(); i++) {
+        Node* node = highlightNodes[i];
+
+        if (!node || !node->renderer() || !node->renderer()->enclosingLayer())
+            return;
+
+        Color highlightColor = node->renderer()->style()->tapHighlightColor();
+        // Safari documentation for -webkit-tap-highlight-color says if the
+        // specified color has 0 alpha, then tap highlighting is disabled.
+        // http://developer.apple.com/library/safari/#documentation/appleapplications/reference/safaricssref/articles/standardcssproperties.html
+        if (!highlightColor.alpha())
+            continue;
+
+        m_linkHighlights.append(LinkHighlight::create(node, this));
+    }
 }
 
 void WebViewImpl::animateZoomAroundPoint(const IntPoint& point, AutoZoomType zoomType)
 {
     if (!mainFrameImpl())
         return;
 
     float scale;
     WebPoint scroll;
     bool isAnchor;
@@ skipping 462 matching lines @@
     }
 }
 
 void WebViewImpl::layout()
 {
     TRACE_EVENT0("webkit", "WebViewImpl::layout");
     PageWidgetDelegate::layout(m_page.get());
     if (m_layerTreeView)
         m_layerTreeView->setBackgroundColor(backgroundColor());
 
-    if (m_linkHighlight)
-        m_linkHighlight->updateGeometry();
+    for (size_t i = 0; i < m_linkHighlights.size(); i++)
+        m_linkHighlights[i]->updateGeometry();
 }
 
 void WebViewImpl::enterForceCompositingMode(bool enter)
 {
     if (page()->settings()->forceCompositingMode() == enter)
         return;
 
     TRACE_EVENT1("webkit", "WebViewImpl::enterForceCompositingMode", "enter", enter);
     settingsImpl()->setForceCompositingMode(enter);
     if (enter) {
@@ skipping 1827 matching lines @@
 #ifndef NDEBUG
     ASSERT(!m_observedNewNavigation
         || m_page->mainFrame()->loader()->documentLoader() == m_newNavigationLoader);
     m_newNavigationLoader = 0;
 #endif
     m_observedNewNavigation = false;
     if (*isNewNavigation && !isNavigationWithinPage)
         m_pageScaleConstraintsSet.setNeedsReset(true);
 
     // Make sure link highlight from previous page is cleared.
-    m_linkHighlight.clear();
+    m_linkHighlights.clear();
     m_gestureAnimation.clear();
     if (m_layerTreeView)
         m_layerTreeView->didStopFlinging();
     resetSavedScrollAndScaleState();
 }
 
 void WebViewImpl::layoutUpdated(WebFrameImpl* webframe)
 {
     if (!m_client || webframe != mainFrameImpl())
         return;
@@ skipping 475 matching lines @@
 }
 
 bool WebViewImpl::shouldDisableDesktopWorkarounds()
 {
     ViewportArguments arguments = mainFrameImpl()->frame()->document()->viewportArguments();
     return arguments.width == ViewportArguments::ValueDeviceWidth || !arguments.userZoom
         || (arguments.minZoom == arguments.maxZoom && arguments.minZoom != ViewportArguments::ValueAuto);
 }
 
 } // namespace WebKit