Added pinch viewport offset to history item.

Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 32 matching lines @@
 #include "core/dom/Element.h"
 #include "core/dom/ViewportDescription.h"
 #include "core/editing/Editor.h"
 #include "core/editing/UndoStack.h"
 #include "core/events/Event.h"
 #include "core/events/PageTransitionEvent.h"
 #include "core/fetch/FetchContext.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/ResourceLoader.h"
 #include "core/frame/DOMWindow.h"
+#include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
+#include "core/frame/PinchViewport.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/inspector/InspectorController.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/loader/DocumentLoadTiming.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/loader/FormState.h"
 #include "core/loader/FormSubmission.h"
@@ skipping 112 matching lines @@
 void FrameLoader::saveScrollState()
 {
     if (!m_currentItem || !m_frame->view())
         return;
 
     // Shouldn't clobber anything if we might still restore later.
     if (needsHistoryItemRestore(m_loadType) && !m_frame->view()->wasScrolledByUser())
         return;
 
     m_currentItem->setScrollPoint(m_frame->view()->scrollPosition());
+
+    if (m_frame->settings()->pinchVirtualViewportEnabled())
+        m_currentItem->setPinchViewportScrollPoint(m_frame->host()->pinchViewport().visibleRect().location());
+    else
+        m_currentItem->setPinchViewportScrollPoint(FloatPoint(-1, -1));
+
     if (m_frame->isMainFrame() && !m_frame->page()->inspectorController().deviceEmulationEnabled())
         m_currentItem->setPageScaleFactor(m_frame->page()->pageScaleFactor());
 
     m_client->didUpdateCurrentHistoryItem();
 }
 
 void FrameLoader::clearScrollPositionAndViewState()
 {
     ASSERT(m_frame->isMainFrame());
     if (!m_currentItem)
@@ skipping 788 matching lines @@
         return;
 
     if (!needsHistoryItemRestore(m_loadType))
         return;
 
     // This tries to balance 1. restoring as soon as possible, 2. detecting
     // clamping to avoid repeatedly popping the scroll position down as the
     // page height increases, 3. ignore clamp detection after load completes
     // because that may be because the page will never reach its previous
     // height.
-    bool canRestoreWithoutClamping = view->clampOffsetAtScale(m_currentItem->scrollPoint(), m_currentItem->pageScaleFactor()) == m_currentItem->scrollPoint();
+    float mainFrameScale = m_frame->settings()->pinchVirtualViewportEnabled() ? 1 : m_currentItem->pageScaleFactor();
+    bool canRestoreWithoutClamping = view->clampOffsetAtScale(m_currentItem->scrollPoint(), mainFrameScale) == m_currentItem->scrollPoint();
     bool canRestoreWithoutAnnoyingUser = !view->wasScrolledByUser() && (canRestoreWithoutClamping || m_state == FrameStateComplete);
     if (!canRestoreWithoutAnnoyingUser)
         return;
 
-    if (m_frame->isMainFrame() && m_currentItem->pageScaleFactor())
-        m_frame->page()->setPageScaleFactor(m_currentItem->pageScaleFactor(), m_currentItem->scrollPoint());
-    else
+    if (m_frame->isMainFrame() && m_currentItem->pageScaleFactor()) {
+        FloatPoint pinchViewportOffset(m_currentItem->pinchViewportScrollPoint());
+        IntPoint frameScrollOffset(m_currentItem->scrollPoint());
+
+        m_frame->page()->setPageScaleFactor(m_currentItem->pageScaleFactor(), frameScrollOffset);
+
+        if (m_frame->document()->settings()->pinchVirtualViewportEnabled()) {
+            // If the pinch viewport's offset is (-1, -1) it means the history item
+            // is an old version of HistoryItem so distribute the scroll between
+            // the main frame and the pinch viewport as best as we can.
+            // FIXME(bokan): This legacy distribution can be removed once the virtual viewport
+            // pinch path is enabled on all platforms for at least one release.
+            if (pinchViewportOffset.x() == -1 && pinchViewportOffset.y() == -1)
+                pinchViewportOffset = FloatPoint(frameScrollOffset - view->scrollPosition());
+
+            m_frame->host()->pinchViewport().setLocation(pinchViewportOffset);
+        }
+    } else {
         view->setScrollPositionNonProgrammatically(m_currentItem->scrollPoint());
+    }
 
     if (m_frame->isMainFrame()) {
         if (ScrollingCoordinator* scrollingCoordinator = m_frame->page()->scrollingCoordinator())
             scrollingCoordinator->frameViewRootLayerDidChange(view);
     }
 }
 
 void FrameLoader::detachChildren()
 {
     typedef Vector<RefPtr<LocalFrame> > FrameVector;
@@ skipping 391 matching lines @@
 {
     SandboxFlags flags = m_forcedSandboxFlags;
     if (LocalFrame* parentFrame = m_frame->tree().parent())
         flags |= parentFrame->document()->sandboxFlags();
     if (HTMLFrameOwnerElement* ownerElement = m_frame->ownerElement())
         flags |= ownerElement->sandboxFlags();
     return flags;
 }
 
 } // namespace WebCore