core/page/FrameView.h

/*
   Copyright (C) 1997 Martin Jones (mjones (at) kde.org)
             (C) 1998 Waldo Bastian (bastian (at) kde.org)
             (C) 1998, 1999 Torben Weis (weis (at) kde.org)
             (C) 1999 Lars Knoll (knoll (at) kde.org)
             (C) 1999 Antti Koivisto (koivisto (at) kde.org)
   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#ifndef FrameView_h
#define FrameView_h

#include "core/page/AdjustViewSizeOrNot.h"
#include "core/page/Frame.h"
#include "core/platform/ScrollView.h"
#include "core/platform/graphics/Color.h"
#include "core/platform/graphics/LayoutRect.h"
#include "core/rendering/Pagination.h"
#include "core/rendering/PaintPhase.h"
#include "wtf/Forward.h"
#include "wtf/OwnPtr.h"
#include "wtf/text/WTFString.h"

namespace WebCore {

class Element;
class Event;
class FloatSize;
class FrameActionScheduler;
class KURL;
class Node;
class Page;
class RenderBox;
class RenderEmbeddedObject;
class RenderLayer;
class RenderObject;
class RenderScrollbarPart;
class RenderStyle;

Pagination::Mode paginationModeForRenderStyle(RenderStyle*);

typedef unsigned long long DOMTimeStamp;

class FrameView : public ScrollView {
public:
    friend class RenderView;
    friend class Internals;

    static PassRefPtr<FrameView> create(Frame*);
    static PassRefPtr<FrameView> create(Frame*, const IntSize& initialSize);

    virtual ~FrameView();

    virtual HostWindow* hostWindow() const;

    virtual void invalidateRect(const IntRect&);
    virtual void setFrameRect(const IntRect&);

    virtual bool scheduleAnimation();

    Frame* frame() const { return m_frame.get(); }
    void clearFrame();

    RenderView* renderView() const { return m_frame ? m_frame->contentRenderer() : 0; }

    int mapFromLayoutToCSSUnits(LayoutUnit);
    LayoutUnit mapFromCSSToLayoutUnits(int);

    LayoutUnit marginWidth() const { return m_margins.width(); } // -1 means default
    LayoutUnit marginHeight() const { return m_margins.height(); } // -1 means default
    void setMarginWidth(LayoutUnit);
    void setMarginHeight(LayoutUnit);

    virtual void setCanHaveScrollbars(bool);
    void updateCanHaveScrollbars();

    virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);

    virtual void setContentsSize(const IntSize&);

    void layout(bool allowSubtree = true);
    bool didFirstLayout() const;
    void layoutTimerFired(Timer<FrameView>*);
    void scheduleRelayout();
    void scheduleRelayoutOfSubtree(RenderObject*);
    void unscheduleRelayout();
    bool layoutPending() const;
    bool isInLayout() const { return m_inLayout; }

    void layoutLazyBlocks();

    RenderObject* layoutRoot(bool onlyDuringLayout = false) const;
    void clearLayoutRoot() { m_layoutRoot = 0; }
    int layoutCount() const { return m_layoutCount; }

    bool needsLayout() const;
    void setNeedsLayout();
    void setViewportConstrainedObjectsNeedLayout();

    bool needsFullRepaint() const { return m_doFullRepaint; }

    void serviceScriptedAnimations(double monotonicAnimationStartTime);

    void updateCompositingLayersAfterStyleChange();
    void updateCompositingLayersAfterLayout();

    bool hasCompositedContent() const;
    bool isEnclosedInCompositingLayer() const;

    // Returns true when a paint with the PaintBehaviorFlattenCompositingLayers flag set gives
    // a faithful representation of the content.
    bool isSoftwareRenderable() const;

    void resetScrollbars();
    void prepareForDetach();
    void detachCustomScrollbars();
    virtual void recalculateScrollbarOverlayStyle();

    void clear();

    bool isTransparent() const;
    void setTransparent(bool isTransparent);

    // True if the FrameView is not transparent, and the base background color is opaque.
    bool hasOpaqueBackground() const;

    Color baseBackgroundColor() const;
    void setBaseBackgroundColor(const StyleColor&);
    void updateBackgroundRecursively(const StyleColor&, bool);

    bool shouldUpdateWhileOffscreen() const;
    void setShouldUpdateWhileOffscreen(bool);
    bool shouldUpdate() const;

    void adjustViewSize();

    virtual IntRect windowClipRect(bool clipToContents = true) const;
    IntRect windowClipRectForFrameOwner(const HTMLFrameOwnerElement*, bool clipToLayerContents) const;

    virtual IntRect windowResizerRect() const;

    virtual float visibleContentScaleFactor() const OVERRIDE { return m_visibleContentScaleFactor; }
    void setVisibleContentScaleFactor(float);

    virtual void setScrollPosition(const IntPoint&) OVERRIDE;
    virtual void repaintFixedElementsAfterScrolling();
    virtual void updateFixedElementsAfterScrolling();
    virtual bool shouldRubberBandInDirection(ScrollDirection) const;
    virtual bool requestScrollPositionUpdate(const IntPoint&) OVERRIDE;
    virtual bool isRubberBandInProgress() const OVERRIDE;
    void setScrollPositionNonProgrammatically(const IntPoint&);

    // This is different than visibleContentRect() in that it ignores negative (or overly positive)
    // offsets from rubber-banding, and it takes zooming into account.
    LayoutRect viewportConstrainedVisibleContentRect() const;

    AtomicString mediaType() const;
    void setMediaType(const AtomicString&);
    void adjustMediaTypeForPrinting(bool printing);

    void setCannotBlitToWindow();
    void setIsOverlapped(bool);
    bool isOverlapped() const { return m_isOverlapped; }
    bool isOverlappedIncludingAncestors() const;
    void setContentIsOpaque(bool);

    void addSlowRepaintObject();
    void removeSlowRepaintObject();
    bool hasSlowRepaintObjects() const { return m_slowRepaintObjectCount; }

    // Includes fixed- and sticky-position objects.
    typedef HashSet<RenderObject*> ViewportConstrainedObjectSet;
    void addViewportConstrainedObject(RenderObject*);
    void removeViewportConstrainedObject(RenderObject*);
    const ViewportConstrainedObjectSet* viewportConstrainedObjects() const { return m_viewportConstrainedObjects.get(); }
    bool hasViewportConstrainedObjects() const { return m_viewportConstrainedObjects && m_viewportConstrainedObjects->size() > 0; }

    void beginDeferredRepaints();
    void endDeferredRepaints();
    void handleLoadCompleted();
    void flushDeferredRepaints();
    void startDeferredRepaintTimer(double delay);
    void resetDeferredRepaintDelay();

    void beginDisableRepaints();
    void endDisableRepaints();
    bool repaintsDisabled() { return m_disableRepaints > 0; }

    void updateAnnotatedRegions();
    void updateControlTints();

    void restoreScrollbar();

    void scheduleEvent(PassRefPtr<Event>, PassRefPtr<Node>);
    void pauseScheduledEvents();
    void resumeScheduledEvents();
    void postLayoutTimerFired(Timer<FrameView>*);

    bool wasScrolledByUser() const;
    void setWasScrolledByUser(bool);

    bool safeToPropagateScrollToParent() const { return m_safeToPropagateScrollToParent; }
    void setSafeToPropagateScrollToParent(bool isSafe) { m_safeToPropagateScrollToParent = isSafe; }

    void addWidgetToUpdate(RenderObject*);
    void removeWidgetToUpdate(RenderObject*);

    virtual void paintContents(GraphicsContext*, const IntRect& damageRect);
    void setPaintBehavior(PaintBehavior);
    PaintBehavior paintBehavior() const;
    bool isPainting() const;
    bool hasEverPainted() const { return m_lastPaintTime; }
    void setLastPaintTime(double lastPaintTime) { m_lastPaintTime = lastPaintTime; }
    void setNodeToDraw(Node*);

    virtual void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
    virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
    virtual void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&) OVERRIDE;

    StyleColor documentBackgroundColor() const;

    static double currentPaintTimeStamp() { return sCurrentPaintTimeStamp; } // returns 0 if not painting

    void updateLayoutAndStyleIfNeededRecursive();

    void incrementVisuallyNonEmptyCharacterCount(unsigned);
    void incrementVisuallyNonEmptyPixelCount(const IntSize&);
    void setIsVisuallyNonEmpty() { m_isVisuallyNonEmpty = true; }
    bool isVisuallyNonEmpty() const { return m_isVisuallyNonEmpty; }
    void enableAutoSizeMode(bool enable, const IntSize& minSize, const IntSize& maxSize);

    void forceLayout(bool allowSubtree = false);
    void forceLayoutForPagination(const FloatSize& pageSize, const FloatSize& originalPageSize, float maximumShrinkFactor, AdjustViewSizeOrNot);

    bool scrollToFragment(const KURL&);
    bool scrollToAnchor(const String&);
    void maintainScrollPositionAtAnchor(Node*);
    void scrollElementToRect(Element*, const IntRect&);

    // Methods to convert points and rects between the coordinate space of the renderer, and this view.
    virtual IntRect convertFromRenderer(const RenderObject*, const IntRect&) const;
    virtual IntRect convertToRenderer(const RenderObject*, const IntRect&) const;
    virtual IntPoint convertFromRenderer(const RenderObject*, const IntPoint&) const;
    virtual IntPoint convertToRenderer(const RenderObject*, const IntPoint&) const;

    bool isFrameViewScrollCorner(RenderScrollbarPart* scrollCorner) const { return m_scrollCorner == scrollCorner; }

    bool isScrollable();

    enum ScrollbarModesCalculationStrategy { RulesFromWebContentOnly, AnyRule };
    void calculateScrollbarModesForLayout(ScrollbarMode& hMode, ScrollbarMode& vMode, ScrollbarModesCalculationStrategy = AnyRule);

    // Normal delay
    static void setRepaintThrottlingDeferredRepaintDelay(double p);
    // Negative value would mean that first few repaints happen without a delay
    static void setRepaintThrottlingnInitialDeferredRepaintDelayDuringLoading(double p);
    // The delay grows on each repaint to this maximum value
    static void setRepaintThrottlingMaxDeferredRepaintDelayDuringLoading(double p);
    // On each repaint the delay increses by this amount
    static void setRepaintThrottlingDeferredRepaintDelayIncrementDuringLoading(double p);

    virtual IntPoint lastKnownMousePosition() const;

    virtual bool scrollbarsCanBeActive() const OVERRIDE;

    // FIXME: Remove this method once plugin loading is decoupled from layout.
    void flushAnyPendingPostLayoutTasks();

    virtual bool shouldSuspendScrollAnimations() const;
    virtual void scrollbarStyleChanged(int newStyle, bool forceUpdate);

    void setAnimatorsAreActive();

    RenderBox* embeddedContentBox() const;

    void setTracksRepaints(bool);
    bool isTrackingRepaints() const { return m_isTrackingRepaints; }
    void resetTrackedRepaints();
    const Vector<IntRect>& trackedRepaintRects() const { return m_trackedRepaintRects; }
    String trackedRepaintRectsAsText() const;

    typedef HashSet<ScrollableArea*> ScrollableAreaSet;
    // Returns whether the scrollable area has just been newly added.
    bool addScrollableArea(ScrollableArea*);
    // Returns whether the scrollable area has just been removed.
    bool removeScrollableArea(ScrollableArea*);
    bool containsScrollableArea(ScrollableArea*) const;
    const ScrollableAreaSet* scrollableAreas() const { return m_scrollableAreas.get(); }

    // With CSS style "resize:" enabled, a little resizer handle will appear at the bottom
    // right of the object. We keep track of these resizer areas for checking if touches
    // (implemented using Scroll gesture) are targeting the resizer.
    typedef HashSet<RenderLayer*> ResizerAreaSet;
    void addResizerArea(RenderLayer*);
    void removeResizerArea(RenderLayer*);
    const ResizerAreaSet* resizerAreas() const { return m_resizerAreas.get(); }

    virtual void removeChild(Widget*) OVERRIDE;

    // 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
    // we need this function in order to do the scroll ourselves.
    bool wheelEvent(const PlatformWheelEvent&);

    // Page and FrameView both store a Pagination value. Page::pagination() is set only by API,
    // and FrameView::pagination() is set only by CSS. Page::pagination() will affect all
    // FrameViews in the page cache, but FrameView::pagination() only affects the current
    // FrameView. FrameView::pagination() will return m_pagination if it has been set. Otherwise,
    // it will return Page::pagination() since currently there are no callers that need to
    // distinguish between the two.
    const Pagination& pagination() const;
    void setPagination(const Pagination&);

    bool inProgrammaticScroll() const { return m_inProgrammaticScroll; }
    void setInProgrammaticScroll(bool programmaticScroll) { m_inProgrammaticScroll = programmaticScroll; }

    void setHasSoftwareFilters(bool hasSoftwareFilters) { m_hasSoftwareFilters = hasSoftwareFilters; }
    bool hasSoftwareFilters() const { return m_hasSoftwareFilters; }

    virtual bool isActive() const OVERRIDE;

    // DEPRECATED: Use viewportConstrainedVisibleContentRect() instead.
    IntSize scrollOffsetForFixedPosition() const;

protected:
    virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect);
    virtual void scrollContentsSlowPath(const IntRect& updateRect);

    virtual bool isVerticalDocument() const;
    virtual bool isFlippedDocument() const;

private:
    explicit FrameView(Frame*);

    void reset();
    void init();

    virtual bool isFrameView() const OVERRIDE { return true; }

    friend class RenderWidget;
    bool useSlowRepaints(bool considerOverlap = true) const;
    bool useSlowRepaintsIfNotOverlapped() const;
    void updateCanBlitOnScrollRecursively();
    bool contentsInCompositedLayer() const;

    void applyOverflowToViewport(RenderObject*, ScrollbarMode& hMode, ScrollbarMode& vMode);
    void applyPaginationToViewport();

    void updateOverflowStatus(bool horizontalOverflow, bool verticalOverflow);

    void paintControlTints();

    void forceLayoutParentViewIfNeeded();
    void performPostLayoutTasks();
    void autoSizeIfEnabled();

    virtual void repaintContentRectangle(const IntRect&);
    virtual void contentsResized() OVERRIDE;
    virtual void visibleContentsResized();

    // Override ScrollView 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;
    virtual IntPoint convertToContainingView(const IntPoint&) const OVERRIDE;
    virtual IntPoint convertFromContainingView(const IntPoint&) const OVERRIDE;

    // ScrollableArea interface
    virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) OVERRIDE;
    virtual void getTickmarks(Vector<IntRect>&) const OVERRIDE;
    virtual void scrollTo(const IntSize&) OVERRIDE;
    virtual ScrollableArea* enclosingScrollableArea() const OVERRIDE;
    virtual IntRect scrollableAreaBoundingBox() const OVERRIDE;
    virtual bool scrollAnimatorEnabled() const OVERRIDE;
    virtual bool usesCompositedScrolling() const OVERRIDE;
    virtual GraphicsLayer* layerForScrolling() const OVERRIDE;
    virtual GraphicsLayer* layerForHorizontalScrollbar() const OVERRIDE;
    virtual GraphicsLayer* layerForVerticalScrollbar() const OVERRIDE;
    virtual GraphicsLayer* layerForScrollCorner() const OVERRIDE;
#if ENABLE(RUBBER_BANDING)
    virtual GraphicsLayer* layerForOverhangAreas() const OVERRIDE;
#endif

    void updateScrollableAreaSet();

    virtual void notifyPageThatContentAreaWillPaint() const;

    bool shouldUseLoadTimeDeferredRepaintDelay() const;
    void deferredRepaintTimerFired(Timer<FrameView>*);
    void doDeferredRepaints();
    void updateDeferredRepaintDelayAfterRepaint();
    double adjustedDeferredRepaintDelay() const;

    bool updateWidgets();
    void updateWidget(RenderObject*);
    void scrollToAnchor();
    void scrollPositionChanged();

    bool hasCustomScrollbars() const;

    virtual void updateScrollCorner();

    FrameView* parentFrameView() const;

    virtual AXObjectCache* axObjectCache() const;
    void removeFromAXObjectCache();

    static double sCurrentPaintTimeStamp; // used for detecting decoded resource thrash in the cache

    LayoutSize m_size;
    LayoutSize m_margins;

    typedef HashSet<RenderObject*> RenderObjectSet;
    OwnPtr<RenderObjectSet> m_widgetUpdateSet;
    RefPtr<Frame> m_frame;

    bool m_doFullRepaint;

    bool m_canHaveScrollbars;
    bool m_cannotBlitToWindow;
    bool m_isOverlapped;
    bool m_contentIsOpaque;
    unsigned m_slowRepaintObjectCount;
    int m_borderX;
    int m_borderY;

    Timer<FrameView> m_layoutTimer;
    bool m_delayedLayout;
    RenderObject* m_layoutRoot;

    bool m_layoutSchedulingEnabled;
    bool m_inLayout;
    bool m_doingPreLayoutStyleUpdate;
    bool m_inSynchronousPostLayout;
    int m_layoutCount;
    unsigned m_nestedLayoutCount;
    Timer<FrameView> m_postLayoutTasksTimer;
    bool m_firstLayoutCallbackPending;

    bool m_firstLayout;
    bool m_isTransparent;
    Color m_baseBackgroundColor;
    IntSize m_lastViewportSize;
    float m_lastZoomFactor;

    AtomicString m_mediaType;
    AtomicString m_mediaTypeWhenNotPrinting;

    OwnPtr<FrameActionScheduler> m_actionScheduler;

    bool m_overflowStatusDirty;
    bool m_horizontalOverflow;
    bool m_verticalOverflow;
    RenderObject* m_viewportRenderer;

    Pagination m_pagination;

    bool m_wasScrolledByUser;
    bool m_inProgrammaticScroll;
    bool m_safeToPropagateScrollToParent;

    unsigned m_deferringRepaints;
    unsigned m_repaintCount;
    Vector<LayoutRect> m_repaintRects;
    Timer<FrameView> m_deferredRepaintTimer;
    double m_deferredRepaintDelay;
    double m_lastPaintTime;

    unsigned m_disableRepaints;

    bool m_isTrackingRepaints; // Used for testing.
    Vector<IntRect> m_trackedRepaintRects;

    bool m_shouldUpdateWhileOffscreen;

    unsigned m_deferSetNeedsLayouts;
    bool m_setNeedsLayoutWasDeferred;

    RefPtr<Node> m_nodeToDraw;
    PaintBehavior m_paintBehavior;
    bool m_isPainting;

    unsigned m_visuallyNonEmptyCharacterCount;
    unsigned m_visuallyNonEmptyPixelCount;
    bool m_isVisuallyNonEmpty;
    bool m_firstVisuallyNonEmptyLayoutCallbackPending;

    RefPtr<Node> m_maintainScrollPositionAnchor;

    // Renderer to hold our custom scroll corner.
    RenderScrollbarPart* m_scrollCorner;

    // If true, automatically resize the frame view around its content.
    bool m_shouldAutoSize;
    bool m_inAutoSize;
    // True if autosize has been run since m_shouldAutoSize was set.
    bool m_didRunAutosize;
    // The lower bound on the size when autosizing.
    IntSize m_minAutoSize;
    // The upper bound on the size when autosizing.
    IntSize m_maxAutoSize;

    OwnPtr<ScrollableAreaSet> m_scrollableAreas;
    OwnPtr<ResizerAreaSet> m_resizerAreas;
    OwnPtr<ViewportConstrainedObjectSet> m_viewportConstrainedObjects;

    static double s_normalDeferredRepaintDelay;
    static double s_initialDeferredRepaintDelayDuringLoading;
    static double s_maxDeferredRepaintDelayDuringLoading;
    static double s_deferredRepaintDelayIncrementDuringLoading;

    bool m_hasSoftwareFilters;

    float m_visibleContentScaleFactor;
};

inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)
{
    if (m_isVisuallyNonEmpty)
        return;
    m_visuallyNonEmptyCharacterCount += count;
    // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout.
    // The first few hundred characters rarely contain the interesting content of the page.
    static const unsigned visualCharacterThreshold = 200;
    if (m_visuallyNonEmptyCharacterCount > visualCharacterThreshold)
        setIsVisuallyNonEmpty();
}

inline void FrameView::incrementVisuallyNonEmptyPixelCount(const IntSize& size)
{
    if (m_isVisuallyNonEmpty)
        return;
    m_visuallyNonEmptyPixelCount += size.width() * size.height();
    // Use a threshold value to prevent very small amounts of visible content from triggering didFirstVisuallyNonEmptyLayout
    static const unsigned visualPixelThreshold = 32 * 32;
    if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
        setIsVisuallyNonEmpty();
}

inline int FrameView::mapFromLayoutToCSSUnits(LayoutUnit value)
{
    return value / m_frame->pageZoomFactor();
}

inline LayoutUnit FrameView::mapFromCSSToLayoutUnits(int value)
{
    return value * m_frame->pageZoomFactor();
}

inline FrameView* toFrameView(Widget* widget)
{
    ASSERT(!widget || widget->isFrameView());
    return static_cast<FrameView*>(widget);
}

inline const FrameView* toFrameView(const Widget* widget)
{
    ASSERT(!widget || widget->isFrameView());
    return static_cast<const FrameView*>(widget);
}

// This will catch anyone doing an unnecessary cast.
void toFrameView(const FrameView*);

} // namespace WebCore

#endif // FrameView_h