Allow zoom-in to a target rect when tapping multiple targets.

Source/web/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 172 matching lines @@
 // (such as due to a double tap gesture or find in page etc.). These are
 // experimentally determined.
 static const int touchPointPadding = 32;
 static const int nonUserInitiatedPointPadding = 11;
 static const float minScaleDifference = 0.01f;
 static const float doubleTapZoomContentDefaultMargin = 5;
 static const float doubleTapZoomContentMinimumMargin = 2;
 static const double doubleTapZoomAnimationDurationInSeconds = 0.25;
 static const float doubleTapZoomAlreadyLegibleRatio = 1.2f;
 
+static const double multipleTargetsZoomAnimationDurationInSeconds = 0.25;
+
 // Constants for viewport anchoring on resize.
 static const float viewportAnchorXCoord = 0.5f;
 static const float viewportAnchorYCoord = 0;
 
 // Constants for zooming in on a focused text field.
 static const double scrollAndScaleAnimationDurationInSeconds = 0.2;
 static const int minReadableCaretHeight = 18;
 static const float minScaleChangeToTriggerZoom = 1.05f;
 static const float leftBoxRatio = 0.3f;
 static const int caretPadding = 10;
@@ skipping 563 matching lines @@
         break;
     }
     case WebInputEvent::GestureTapDown: {
         m_client->cancelScheduledContentIntents();
         eventSwallowed = mainFrameImpl()->frame()->eventHandler()->handleGestureEvent(platformEvent);
         break;
     }
     case WebInputEvent::GestureDoubleTap:
         if (m_webSettings->doubleTapToZoomEnabled() && minimumPageScaleFactor() != maximumPageScaleFactor()) {
             m_client->cancelScheduledContentIntents();
-            animateZoomAroundPoint(platformEvent.position(), DoubleTap);
+            animateZoomToRect(WebRect(platformEvent.position().x(), platformEvent.position().y(), 0, 0), DoubleTap);
         }
         // GestureDoubleTap is currently only used by Android for zooming. For WebCore,
         // GestureTap with tap count = 2 is used instead. So we drop GestureDoubleTap here.
         eventSwallowed = true;
         break;
     case WebInputEvent::GestureScrollBegin:
     case WebInputEvent::GesturePinchBegin:
         m_client->cancelScheduledContentIntents();
     case WebInputEvent::GestureScrollEnd:
     case WebInputEvent::GestureScrollUpdate:
@@ skipping 340 matching lines @@
 
 void WebViewImpl::computeScaleAndScrollForHitRect(const WebRect& hitRect, AutoZoomType zoomType, float& scale, WebPoint& scroll, bool& isAnchor)
 {
     scale = pageScaleFactor();
     scroll.x = scroll.y = 0;
     WebRect targetRect = hitRect;
     // Padding only depends on page scale when triggered by manually tapping
     int padding = (zoomType == DoubleTap) ? touchPointPadding : nonUserInitiatedPointPadding;
     if (targetRect.isEmpty())
         targetRect.width = targetRect.height = padding;
-    WebRect rect = computeBlockBounds(targetRect, zoomType);
+    WebRect rect = targetRect;
+    if (zoomType != MultipleTargets)
+        rect = computeBlockBounds(targetRect, zoomType);
     if (zoomType == FindInPage && rect.isEmpty()) {
         // Keep current scale (no need to scroll as x,y will normally already
         // be visible). FIXME: Revisit this if it isn't always true.
         return;
     }
 
     bool scaleUnchanged = true;
     if (!rect.isEmpty()) {
         // Pages should be as legible as on desktop when at dpi scale, so no
         // need to zoom in further when automatically determining zoom level
@@ skipping 119 matching lines @@
     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;
 
     m_linkHighlight = LinkHighlight::create(touchNode, this);
 }
 
-void WebViewImpl::animateZoomAroundPoint(const IntPoint& point, AutoZoomType zoomType)
+bool WebViewImpl::animateZoomToRect(const IntRect& rect, AutoZoomType zoomType)
 {
     if (!mainFrameImpl())
-        return;
+        return false;
 
     float scale;
     WebPoint scroll;
     bool isAnchor;
-    WebPoint webPoint = point;
-    computeScaleAndScrollForHitRect(WebRect(webPoint.x, webPoint.y, 0, 0), zoomType, scale, scroll, isAnchor);
+    WebRect webRect = rect;
+    computeScaleAndScrollForHitRect(webRect, zoomType, scale, scroll, isAnchor);
+
+    if (zoomType == MultipleTargets && scale <= pageScaleFactor())
+        return false;
 
     bool isDoubleTap = (zoomType == DoubleTap);
-    double durationInSeconds = isDoubleTap ? doubleTapZoomAnimationDurationInSeconds : 0;
+    double durationInSeconds = isDoubleTap ? doubleTapZoomAnimationDurationInSeconds :
+        zoomType == MultipleTargets ? multipleTargetsZoomAnimationDurationInSeconds : 0;
+
     bool isAnimating = startPageScaleAnimation(scroll, isAnchor, scale, durationInSeconds);
 
     if (isDoubleTap && isAnimating) {
         m_doubleTapZoomPageScaleFactor = scale;
         m_doubleTapZoomPending = true;
     }
+    return true;
 }
 
 void WebViewImpl::zoomToFindInPageRect(const WebRect& rect)
 {
-    animateZoomAroundPoint(IntRect(rect).center(), FindInPage);
+    animateZoomToRect(rect, FindInPage);

[jochen (gone - plz use gerrit), 2013/07/16 10:05:24]

this is a slight change in behavior, no? Is this intentional?

+}
+
+bool WebViewImpl::zoomToMultipleTargetsRect(const WebRect& rect)
+{
+    return animateZoomToRect(rect, MultipleTargets);
 }
 
 void WebViewImpl::numberOfWheelEventHandlersChanged(unsigned numberOfWheelHandlers)
 {
     if (m_client)
         m_client->numberOfWheelEventHandlersChanged(numberOfWheelHandlers);
 }
 
 void WebViewImpl::hasTouchEventHandlers(bool hasTouchHandlers)
 {
@@ skipping 2848 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