Made double-tap zoom work in pinch virtual viewport mode. (Blink-side)

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 2871 matching lines @@
 {
     return m_pageScaleConstraintsSet.finalConstraints().clampToConstraints(scaleFactor);
 }
 
 IntPoint WebViewImpl::clampOffsetAtScale(const IntPoint& offset, float scale)
 {
     FrameView* view = mainFrameImpl()->frameView();
     if (!view)
         return offset;
 
-    return view->clampOffsetAtScale(offset, scale);
+    if (!pinchVirtualViewportEnabled())
+        return view->clampOffsetAtScale(offset, scale);
+
+    return page()->frameHost().pinchViewport().clampDocumentOffsetAtScale(offset, scale);
 }
 
 bool WebViewImpl::pinchVirtualViewportEnabled() const
 {
     ASSERT(page());
     return page()->settings().pinchVirtualViewportEnabled();
 }
 
 void WebViewImpl::setPinchViewportOffset(const WebFloatPoint& offset)
 {
@@ skipping 28 matching lines @@
     if (!pinchVirtualViewportEnabled()) {
         IntPoint scrollOffset(mainFrame()->scrollOffset().width, mainFrame()->scrollOffset().height);
         setPageScaleFactor(scaleFactor, scrollOffset);
         return;
     }
 
     page()->frameHost().pinchViewport().setScale(scaleFactor);
     deviceOrPageScaleFactorChanged();
 }
 
+void WebViewImpl::setPageScaleFactorFromImpl(float scaleFactor)
+{
+    ASSERT(page());
+    ASSERT(pinchVirtualViewportEnabled());
+
+    scaleFactor = clampPageScaleFactorToLimits(scaleFactor);
+    if (scaleFactor == pageScaleFactor())
+        return;
+
+    page()->frameHost().pinchViewport().setScaleWithoutClampingViewportOffset(scaleFactor);
+    deviceOrPageScaleFactorChanged();
+}
+
 void WebViewImpl::setMainFrameScrollOffset(const WebPoint& origin)
 {
     updateMainFrameScrollPosition(origin, false);
 }
 
 void WebViewImpl::setPageScaleFactor(float scaleFactor, const WebPoint& origin)
 {
     if (!page())
         return;
 
@@ skipping 1188 matching lines @@
 
 void WebViewImpl::applyViewportDeltas(const WebSize& scrollDelta, float pageScaleDelta, float topControlsDelta)
 {
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return;
 
     setTopControlsContentOffset(m_topControlsContentOffset + topControlsDelta);
 
     if (pinchVirtualViewportEnabled()) {
         if (pageScaleDelta != 1) {
-            // When the virtual viewport is enabled, offsets are already set for us.
-            setPageScaleFactor(pageScaleFactor() * pageScaleDelta);
+            // When the virtual viewport is enabled, offsets are already set for us. Don't clamp

[aelias_OOO_until_Jul13, 2014/09/19 22:39:21]

We've so far always been able to avoid "don't clamp" methods and I'd prefer to
keep it that way; that kind of approach ends up having subtle assumptions about
the order that things are called in.  It's better to fix these by sending all
parameters that cross-clamp as arguments to one method.  Can we change the Blink
API to pass the scroll offsets for the inner and outer viewport to this method
as well?

+            // the viewport offset when setting page scale here, it will be clamped when the
+            // compositor sets the viewport offset immediately following this.
+            setPageScaleFactorFromImpl(pageScaleFactor() * pageScaleDelta);
             m_doubleTapZoomPending = false;
         }
 
         return;
     }
 
     // TODO(bokan): Old pinch path only - virtual viewport pinch scrolls are automatically updated via GraphicsLayer::DidScroll.
     // this should be removed once old pinch is removed.
     if (pageScaleDelta == 1) {
         TRACE_EVENT_INSTANT2("blink", "WebViewImpl::applyScrollAndScale::scrollBy", "x", scrollDelta.width, "y", scrollDelta.height);
@@ skipping 156 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink