Merge FrameView and ScrollView.

Source/core/frame/FrameView.h

Index: Source/core/frame/FrameView.h
diff --git a/Source/core/frame/FrameView.h b/Source/core/frame/FrameView.h
index 7aa2629e8b7958744cc6537022f0a081cd2e0b87..7a8ec3ae446a75ac6236e5534ff42c39bbb75683 100644
--- a/Source/core/frame/FrameView.h
+++ b/Source/core/frame/FrameView.h
@@ -28,11 +28,17 @@
 #include "core/frame/FrameViewAutoSizeInfo.h"
 #include "core/rendering/PaintPhase.h"
 #include "platform/RuntimeEnabledFeatures.h"
+#include "platform/Widget.h"
+#include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/Color.h"
-#include "platform/scroll/ScrollView.h"
+#include "platform/scroll/ScrollTypes.h"
+#include "platform/scroll/ScrollableArea.h"
+#include "platform/scroll/Scrollbar.h"
 #include "wtf/Forward.h"
+#include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
+#include "wtf/TemporaryChange.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
@@ -58,7 +64,7 @@ struct CompositedSelectionBound;
 typedef unsigned long long DOMTimeStamp;
 
 // FIXME: Oilpan: move Widget (and thereby FrameView) to the heap.
-class FrameView final : public ScrollView {
+class FrameView final : public Widget, public ScrollableArea {
 public:
     friend class RenderView;
     friend class Internals;
@@ -68,8 +74,6 @@ public:
 
     virtual ~FrameView();
 
-    virtual HostWindow* hostWindow() const override;
-
     virtual void invalidateRect(const IntRect&) override;
     virtual void setFrameRect(const IntRect&) override;
 
@@ -83,11 +87,11 @@ public:
 
     RenderView* renderView() const;
 
-    virtual void setCanHaveScrollbars(bool) override;
+    void setCanHaveScrollbars(bool);
 
-    virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation) override;
+    PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
 
-    virtual void setContentsSize(const IntSize&) override;
+    void setContentsSize(const IntSize&);
     IntPoint clampOffsetAtScale(const IntPoint& offset, float scale) const;
 
     void layout(bool allowSubtree = true);
@@ -145,19 +149,18 @@ public:
 
     void adjustViewSize();
 
-    virtual IntRect windowClipRect(IncludeScrollbarsInRect = ExcludeScrollbars) const override;
     IntRect windowClipRectForFrameOwner(const HTMLFrameOwnerElement*) const;
 
-    virtual IntRect windowResizerRect() const override;
+    IntRect windowResizerRect() const;
 
-    virtual float visibleContentScaleFactor() const override { return m_visibleContentScaleFactor; }
+    float visibleContentScaleFactor() const { return m_visibleContentScaleFactor; }
     void setVisibleContentScaleFactor(float);
 
-    virtual float inputEventsScaleFactor() const override;
-    virtual IntSize inputEventsOffsetForEmulation() const override;
+    float inputEventsScaleFactor() const;
+    IntSize inputEventsOffsetForEmulation() const;
     void setInputEventsTransformForEmulation(const IntSize&, float);
 
-    virtual void setScrollPosition(const DoublePoint&, ScrollBehavior = ScrollBehaviorInstant) override;
+    void setScrollPosition(const DoublePoint&, ScrollBehavior = ScrollBehaviorInstant);
     virtual bool isRubberBandInProgress() const override;
     void setScrollPositionNonProgrammatically(const IntPoint&);
 
@@ -201,16 +204,16 @@ public:
 
     void addWidgetToUpdate(RenderEmbeddedObject&);
 
-    virtual void paintContents(GraphicsContext*, const IntRect& damageRect) override;
+    void paintContents(GraphicsContext*, const IntRect& damageRect);
     void setPaintBehavior(PaintBehavior);
     PaintBehavior paintBehavior() const;
     bool isPainting() const;
     bool hasEverPainted() const { return m_lastPaintTime; }
     void setNodeToDraw(Node*);
 
-    virtual void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect) override;
-    virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect) override;
-    virtual void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&) override;
+    void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
+    void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
+    void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&);
 
     Color documentBackgroundColor() const;
 
@@ -284,7 +287,7 @@ public:
     const ResizerAreaSet* resizerAreas() const { return m_resizerAreas.get(); }
 
     virtual void setParent(Widget*) override;
-    virtual void removeChild(Widget*) override;
+    void removeChild(Widget*);
 
     // This function exists for ports that need to handle wheel events manually.
     // On Mac WebKit1 the underlying NSScrollView just does the scrolling, but on most other platforms
@@ -323,7 +326,7 @@ public:
     // ScrollableArea interface
     virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) override;
     virtual void getTickmarks(Vector<IntRect>&) const override;
-    virtual void scrollTo(const DoublePoint&) override;
+    void scrollTo(const DoublePoint&);
     virtual IntRect scrollableAreaBoundingBox() const override;
     virtual bool scrollAnimatorEnabled() const override;
     virtual bool usesCompositedScrolling() const override;
@@ -332,16 +335,274 @@ public:
     virtual GraphicsLayer* layerForVerticalScrollbar() const override;
     virtual GraphicsLayer* layerForScrollCorner() const override;
 
+    // --- ScrollView ---
+    virtual int scrollSize(ScrollbarOrientation) const override;
+    virtual void setScrollOffset(const IntPoint&) override;
+    virtual void setScrollOffset(const DoublePoint&) override;
+    virtual bool isScrollCornerVisible() const override;
+    void scrollbarStyleChangedInternal();
+    virtual bool userInputScrollable(ScrollbarOrientation) const override;
+    virtual bool shouldPlaceVerticalScrollbarOnLeft() const override;
+
+    void notifyPageThatContentAreaWillPaintInternal() const;
+
+    // The window that hosts the ScrollView. The ScrollView will communicate scrolls and repaints to the
+    // host window in the window's coordinate space.
+    HostWindow* hostWindow() const;
+
+    // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
+    IntRect windowClipRect(IncludeScrollbarsInRect = ExcludeScrollbars) const;
+
+    // Functions for child manipulation and inspection.
+    const HashSet<RefPtr<Widget> >* children() const { return &m_children; }
+    void addChild(PassRefPtr<Widget>);
+    void removeChildInternal(Widget*);
+
+    // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars. These functions
+    // can be used to obtain those scrollbars.
+    virtual Scrollbar* horizontalScrollbar() const override { return m_horizontalScrollbar.get(); }
+    virtual Scrollbar* verticalScrollbar() const override { return m_verticalScrollbar.get(); }
+    virtual bool isScrollViewScrollbar(const Widget* child) const override { return horizontalScrollbar() == child || verticalScrollbar() == child; }
+
+    void positionScrollbarLayers();
+
+    // Functions for setting and retrieving the scrolling mode in each axis (horizontal/vertical). The mode has values of
+    // AlwaysOff, AlwaysOn, and Auto. AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
+    // Auto means show a scrollbar only when one is needed.
+    // Note that for platforms with native widgets, these modes are considered advisory. In other words the underlying native
+    // widget may choose not to honor the requested modes.
+    void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode, bool horizontalLock = false, bool verticalLock = false);
+    void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }
+    void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };
+    void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
+    ScrollbarMode horizontalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
+    ScrollbarMode verticalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
+
+    void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }
+    bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }
+    void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }
+    bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }
+
+    void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }
+
+    void setCanHaveScrollbarsInternal(bool);
+    bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
+
+    // By default, paint events are clipped to the visible area.  If set to
+    // false, paint events are no longer clipped.
+    bool clipsPaintInvalidations() const { return m_clipsRepaints; }
+    void setClipsRepaints(bool);
+
+    // Overridden by FrameView to create custom CSS scrollbars if applicable.
+    PassRefPtr<Scrollbar> createScrollbarInternal(ScrollbarOrientation);
+
+    // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
+    // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
+    // included.
+    virtual IntRect visibleContentRect(IncludeScrollbarsInRect = ExcludeScrollbars) const override;
+    IntSize visibleSize() const { return visibleContentRect().size(); }
+
+    // visibleContentRect().size() is computed from unscaledVisibleContentSize() divided by the value of visibleContentScaleFactor.
+    // For the main frame, visibleContentScaleFactor is equal to the page's pageScaleFactor; it's 1 otherwise.
+    IntSize unscaledVisibleContentSize(IncludeScrollbarsInRect = ExcludeScrollbars) const;
+    float visibleContentScaleFactorInternal() const { return 1; }
+
+    // Offset used to convert incoming input events while emulating device metics.
+    IntSize inputEventsOffsetForEmulationInternal() const { return IntSize(); }
+
+    // Scale used to convert incoming input events. Usually the same as visibleContentScaleFactor(), unless specifically changed.
+    float inputEventsScaleFactorInternal() const { return visibleContentScaleFactor(); }
+
+    // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
+    // values).
+    virtual IntSize contentsSize() const override; // Always at least as big as the visibleWidth()/visibleHeight().
+    int contentsWidth() const { return contentsSize().width(); }
+    int contentsHeight() const { return contentsSize().height(); }
+    void setContentsSizeInternal(const IntSize&);
+
+    // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
+    // FIXME: Remove the IntPoint version. crbug.com/414283.
+    virtual IntPoint scrollPosition() const override { return visibleContentRect().location(); }
+    virtual DoublePoint scrollPositionDouble() const override { return m_scrollPosition; }
+    // FIXME: Remove scrollOffset(). crbug.com/414283.
+    IntSize scrollOffset() const { return toIntSize(visibleContentRect().location()); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.
+    DoubleSize scrollOffsetDouble() const { return DoubleSize(m_scrollPosition.x(), m_scrollPosition.y()); }
+    DoubleSize pendingScrollDelta() const { return m_pendingScrollDelta; }
+    virtual IntPoint minimumScrollPosition() const override; // The minimum position we can be scrolled to.
+    // Adjust the passed in scroll position to keep it between the minimum and maximum positions.
+    IntPoint adjustScrollPositionWithinRange(const IntPoint&) const;
+    DoublePoint adjustScrollPositionWithinRange(const DoublePoint&) const;
+    double scrollX() const { return scrollPositionDouble().x(); }
+    double scrollY() const { return scrollPositionDouble().y(); }
+
+    virtual IntSize overhangAmount() const override;
+
+    void cacheCurrentScrollPosition() { m_cachedScrollPosition = scrollPositionDouble(); }
+    DoublePoint cachedScrollPosition() const { return m_cachedScrollPosition; }
+
+    // Functions for scrolling the view.
+    void setScrollPositionInternal(const DoublePoint&, ScrollBehavior = ScrollBehaviorInstant);
+    void scrollBy(const DoubleSize& s, ScrollBehavior behavior = ScrollBehaviorInstant)
+    {
+        return setScrollPosition(scrollPositionDouble() + s, behavior);
+    }
+
+    bool scroll(ScrollDirection, ScrollGranularity);
+
+    // Scroll the actual contents of the view (either blitting or invalidating as needed).
+    void scrollContents(const IntSize& scrollDelta);
+
+    // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
+    void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
+    bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
+
+    IntPoint rootViewToContents(const IntPoint&) const;
+    IntPoint contentsToRootView(const IntPoint&) const;
+    IntRect rootViewToContents(const IntRect&) const;
+    IntRect contentsToRootView(const IntRect&) const;
+
+    // Event coordinates are assumed to be in the coordinate space of a window that contains
+    // the entire widget hierarchy. It is up to the platform to decide what the precise definition
+    // of containing window is. (For example on Mac it is the containing NSWindow.)
+    IntPoint windowToContents(const IntPoint&) const;
+    FloatPoint windowToContents(const FloatPoint&) const;
+    IntPoint contentsToWindow(const IntPoint&) const;
+    IntRect windowToContents(const IntRect&) const;
+    IntRect contentsToWindow(const IntRect&) const;
+
+    // Functions for converting to screen coordinates.
+    IntRect contentsToScreen(const IntRect&) const;
+
+    // These functions are used to enable scrollbars to avoid window resizer controls that overlap the scroll view. This happens on Mac
+    // for example.
+    IntRect windowResizerRectInternal() const { return IntRect(); }
+    bool containsScrollbarsAvoidingResizer() const;
+    void adjustScrollbarsAvoidingResizerCount(int overlapDelta);
+    void windowResizerRectChanged();
+
+    void setParentInternal(Widget*); // Updates the overlapping scrollbar count.
+
+    // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
+    void frameRectsChangedInternal();
+
+    // Updates our scrollbars and notifies our contents of the resize.
+    void setFrameRectInternal(const IntRect&);
+
+    // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
+    Scrollbar* scrollbarAtWindowPoint(const IntPoint& windowPoint);
+    Scrollbar* scrollbarAtViewPoint(const IntPoint& viewPoint);
+
+    virtual IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const override
+    {
+        IntPoint newPoint = point;
+        if (!isScrollViewScrollbar(child))
+            newPoint = point - scrollOffset();
+        newPoint.moveBy(child->location());
+        return newPoint;
+    }
+
+    virtual IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const override
+    {
+        IntPoint newPoint = point;
+        if (!isScrollViewScrollbar(child))
+            newPoint = point + scrollOffset();
+        newPoint.moveBy(-child->location());
+        return newPoint;
+    }
+
+    // Widget override. Handles painting of the contents of the view as well as the scrollbars.
+    virtual void paint(GraphicsContext*, const IntRect&) override;
+    void paintScrollbars(GraphicsContext*, const IntRect&);
+
+    // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
+    virtual void show() override;
+    virtual void hide() override;
+    virtual void setParentVisible(bool) override;
+
+    // Pan scrolling.
+    static const int noPanScrollRadius = 15;
+    void addPanScrollIcon(const IntPoint&);
+    void removePanScrollIcon();
+    void paintPanScrollIcon(GraphicsContext*);
+
+    bool isPointInScrollbarCorner(const IntPoint&);
+    bool scrollbarCornerPresent() const;
+    virtual IntRect scrollCornerRect() const override;
+    void paintScrollCornerInternal(GraphicsContext*, const IntRect& cornerRect);
+    void paintScrollbarInternal(GraphicsContext*, Scrollbar*, const IntRect&);
+
+    virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const override;
+    virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const override;
+    virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const override;
+    virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const override;
+
+    void calculateAndPaintOverhangAreas(GraphicsContext*, const IntRect& dirtyRect);
+    void calculateAndPaintOverhangBackground(GraphicsContext*, const IntRect& dirtyRect);
+
+    virtual bool isScrollView() const override final { return true; }
+    virtual bool isFrameView() const override { return true; }
+
 protected:
-    virtual bool scrollContentsFastPath(const IntSize& scrollDelta) override;
-    virtual void scrollContentsSlowPath(const IntRect& updateRect) override;
+    bool scrollContentsFastPath(const IntSize& scrollDelta);
+    void scrollContentsSlowPath(const IntRect& updateRect);
 
-    virtual bool isVerticalDocument() const override;
-    virtual bool isFlippedDocument() const override;
+    bool isVerticalDocument() const;
+    bool isFlippedDocument() const;
 
     // Prevents creation of scrollbars. Used to prevent drawing two sets of
     // overlay scrollbars in the case of the pinch viewport.
-    virtual bool scrollbarsDisabled() const override;
+    bool scrollbarsDisabled() const;
+
+    // --- ScrollView ---
+    // NOTE: This should only be called by the overriden setScrollOffset from ScrollableArea.
+    void scrollToInternal(const DoublePoint& newPosition);
+
+    void contentRectangleForPaintInvalidationInternal(const IntRect&);
+
+    void paintOverhangAreasInternal(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
+
+    // These functions are used to create/destroy scrollbars.
+    void setHasHorizontalScrollbar(bool);
+    void setHasVerticalScrollbar(bool);
+
+    void updateScrollCornerInternal();
+    virtual void invalidateScrollCornerRect(const IntRect&) override;
+
+    void scrollContentsIfNeeded();
+    // Scroll the content by via the compositor.
+    bool scrollContentsFastPathInternal(const IntSize& scrollDelta) { return true; }
+    // Scroll the content by invalidating everything.
+    void scrollContentsSlowPathInternal(const IntRect& updateRect);
+
+    void setScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
+
+    // Subclassed by FrameView to check the writing-mode of the document.
+    bool isVerticalDocumentInternal() const { return true; }
+    bool isFlippedDocumentInternal() const { return false; }
+
+    enum ComputeScrollbarExistenceOption {
+        FirstPass,
+        Incremental
+    };
+    void computeScrollbarExistence(bool& newHasHorizontalScrollbar, bool& newHasVerticalScrollbar, const IntSize& docSize, ComputeScrollbarExistenceOption = FirstPass) const;
+    void updateScrollbarGeometry();
+    IntRect adjustScrollbarRectForResizer(const IntRect&, Scrollbar*);
+
+    // Called to update the scrollbars to accurately reflect the state of the view.
+    void updateScrollbars(const DoubleSize& desiredOffset);
+
+    IntSize excludeScrollbars(const IntSize&) const;
+
+    class InUpdateScrollbarsScope {
+    public:
+        explicit InUpdateScrollbarsScope(FrameView* view)
+            : m_scope(view->m_inUpdateScrollbars, true)
+        { }
+    private:
+        TemporaryChange<bool> m_scope;
+    };
+
+    bool scrollbarsDisabledInternal() const { return false; }
 
 private:
     explicit FrameView(LocalFrame*);
@@ -350,7 +611,6 @@ private:
     void init();
 
     virtual void frameRectsChanged() override;
-    virtual bool isFrameView() const override { return true; }
 
     friend class RenderWidget;
 
@@ -372,11 +632,11 @@ private:
 
     DocumentLifecycle& lifecycle() const;
 
-    virtual void contentRectangleForPaintInvalidation(const IntRect&) override;
+    void contentRectangleForPaintInvalidation(const IntRect&);
     virtual void contentsResized() override;
-    virtual void scrollbarExistenceDidChange() override;
+    void scrollbarExistenceDidChange();
 
-    // Override ScrollView methods to do point conversion via renderers, in order to
+    // Override Widget methods to do point conversion via renderers, in order to
     // take transforms into account.
     virtual IntRect convertToContainingView(const IntRect&) const override;
     virtual IntRect convertFromContainingView(const IntRect&) const override;
@@ -390,7 +650,7 @@ private:
 
     void updateScrollableAreaSet();
 
-    virtual void notifyPageThatContentAreaWillPaint() const override;
+    void notifyPageThatContentAreaWillPaint() const;
 
     void scheduleUpdateWidgetsIfNecessary();
     void updateWidgetsTimerFired(Timer<FrameView>*);
@@ -408,7 +668,7 @@ private:
     bool hasCustomScrollbars() const;
     bool shouldUseCustomScrollbars(Element*& customScrollbarElement, LocalFrame*& customScrollbarFrame);
 
-    virtual void updateScrollCorner() override;
+    void updateScrollCorner();
 
     FrameView* parentFrameView() const;
 
@@ -514,6 +774,44 @@ private:
 
     bool m_needsUpdateWidgetPositions;
     float m_topControlsViewportAdjustment;
+
+    // --- ScrollView ---
+    bool adjustScrollbarExistence(ComputeScrollbarExistenceOption = FirstPass);
+    void adjustScrollbarOpacity();
+    // FIXME(bokan): setScrollOffset, setScrollPosition, scrollTo, scrollToOffsetWithoutAnimation,
+    // notifyScrollPositionChanged...there's too many ways to scroll this class. This needs
+    // some cleanup.
+    void setScrollOffsetFromUpdateScrollbars(const DoubleSize&);
+
+    RefPtr<Scrollbar> m_horizontalScrollbar;
+    RefPtr<Scrollbar> m_verticalScrollbar;
+    ScrollbarMode m_horizontalScrollbarMode;
+    ScrollbarMode m_verticalScrollbarMode;
+
+    bool m_horizontalScrollbarLock;
+    bool m_verticalScrollbarLock;
+
+    HashSet<RefPtr<Widget> > m_children;
+
+    DoubleSize m_pendingScrollDelta;
+    DoublePoint m_scrollPosition;
+    DoublePoint m_cachedScrollPosition;
+    IntSize m_contentsSize;
+
+    int m_scrollbarsAvoidingResizer;
+    bool m_scrollbarsSuppressed;
+
+    bool m_inUpdateScrollbars;
+
+    IntPoint m_panScrollIconPoint;
+    bool m_drawPanScrollIcon;
+
+    bool m_clipsRepaints;
+
+    IntRect rectToCopyOnScroll() const;
+
+    void calculateOverhangAreasForPainting(IntRect& horizontalOverhangRect, IntRect& verticalOverhangRect);
+    void updateOverhangAreas();
 };
 
 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)