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

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index eaa7eab729498ecb75673326c935e7de35609570..b740f41eb7a656fac47ef05e46f6342135d4d3fa 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -190,6 +190,8 @@ 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;
@@ -773,7 +775,7 @@ bool WebViewImpl::handleGestureEvent(const WebGestureEvent& event)
     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.
@@ -1134,7 +1136,9 @@ void WebViewImpl::computeScaleAndScrollForHitRect(const WebRect& hitRect, AutoZo
     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.
@@ -1274,30 +1278,41 @@ void WebViewImpl::enableTapHighlight(const PlatformGestureEvent& tapEvent)
     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)