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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  * Copyright (C) 2006 Apple Computer, Inc.
      4  *
      5  * This library is free software; you can redistribute it and/or
      6  * modify it under the terms of the GNU Library General Public
      7  * License as published by the Free Software Foundation; either
      8  * version 2 of the License, or (at your option) any later version.
      9  *
     10  * This library is distributed in the hope that it will be useful,
     11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13  * Library General Public License for more details.
     14  *
     15  * You should have received a copy of the GNU Library General Public License
     16  * along with this library; see the file COPYING.LIB.  If not, write to
     17  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     18  * Boston, MA 02110-1301, USA.
     19  *
     20  */
     21 
     22 #ifndef RenderView_h
     23 #define RenderView_h
     24 
     25 #include "core/page/FrameView.h"
     26 #include "core/platform/PODFreeListArena.h"
     27 #include "core/rendering/LayoutState.h"
     28 #include "core/rendering/RenderBlock.h"
     29 #include "wtf/OwnPtr.h"
     30 
     31 namespace WebCore {
     32 
     33 class CustomFilterGlobalContext;
     34 class FlowThreadController;
     35 class RenderLayerCompositor;
     36 class RenderLazyBlock;
     37 class RenderQuote;
     38 class RenderWidget;
     39 
     40 // The root of the render tree, corresponding to the CSS initial containing block.
     41 // It's dimensions match that of the viewport, and it is always at position (0,0)
     42 // relative to the document (and so isn't necessarily in view).
     43 class RenderView FINAL : public RenderBlock {
     44 public:
     45     explicit RenderView(Document*);
     46     virtual ~RenderView();
     47 
     48     bool hitTest(const HitTestRequest&, HitTestResult&);
     49     bool hitTest(const HitTestRequest&, const HitTestLocation&, HitTestResult&);
     50 
     51     virtual const char* renderName() const OVERRIDE { return "RenderView"; }
     52 
     53     virtual bool isRenderView() const OVERRIDE { return true; }
     54 
     55     virtual bool requiresLayer() const OVERRIDE { return true; }
     56 
     57     virtual bool isChildAllowed(RenderObject*, RenderStyle*) const OVERRIDE;
     58 
     59     virtual void layout() OVERRIDE;
     60     virtual void updateLogicalWidth() OVERRIDE;
     61     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const OVERRIDE;
     62 
     63     virtual LayoutUnit availableLogicalHeight(AvailableLogicalHeightType) const OVERRIDE;
     64 
     65     // The same as the FrameView's layoutHeight/layoutWidth but with null check guards.
     66     int viewHeight() const;
     67     int viewWidth() const;
     68     int viewLogicalWidth() const { return style()->isHorizontalWritingMode() ? viewWidth() : viewHeight(); }
     69     int viewLogicalHeight() const;
     70 
     71     float zoomFactor() const;
     72 
     73     FrameView* frameView() const { return m_frameView; }
     74 
     75     virtual void computeRectForRepaint(const RenderLayerModelObject* repaintContainer, LayoutRect&, bool fixed = false) const OVERRIDE;
     76     void repaintViewRectangle(const LayoutRect&) const;
     77     // Repaint the view, and all composited layers that intersect the given absolute rectangle.
     78     // FIXME: ideally we'd never have to do this, if all repaints are container-relative.
     79     void repaintRectangleInViewAndCompositedLayers(const LayoutRect&);
     80     void repaintViewAndCompositedLayers();
     81 
     82     virtual void paint(PaintInfo&, const LayoutPoint&);
     83     virtual void paintBoxDecorations(PaintInfo&, const LayoutPoint&) OVERRIDE;
     84 
     85     enum SelectionRepaintMode { RepaintNewXOROld, RepaintNewMinusOld, RepaintNothing };
     86     void setSelection(RenderObject* start, int startPos, RenderObject* end, int endPos, SelectionRepaintMode = RepaintNewXOROld);
     87     void getSelection(RenderObject*& startRenderer, int& startOffset, RenderObject*& endRenderer, int& endOffset) const;
     88     void clearSelection();
     89     RenderObject* selectionStart() const { return m_selectionStart; }
     90     RenderObject* selectionEnd() const { return m_selectionEnd; }
     91     IntRect selectionBounds(bool clipToVisibleContent = true) const;
     92     void selectionStartEnd(int& startPos, int& endPos) const;
     93     void repaintSelection() const;
     94 
     95     bool printing() const;
     96 
     97     virtual void absoluteRects(Vector<IntRect>&, const LayoutPoint& accumulatedOffset) const;
     98     virtual void absoluteQuads(Vector<FloatQuad>&, bool* wasFixed) const;
     99 
    100     void setMaximalOutlineSize(int o);
    101     int maximalOutlineSize() const { return m_maximalOutlineSize; }
    102 
    103     virtual LayoutRect viewRect() const OVERRIDE;
    104 
    105     void updateWidgetPositions();
    106     void addWidget(RenderWidget*);
    107     void removeWidget(RenderWidget*);
    108 
    109     // layoutDelta is used transiently during layout to store how far an object has moved from its
    110     // last layout location, in order to repaint correctly.
    111     // If we're doing a full repaint m_layoutState will be 0, but in that case layoutDelta doesn't matter.
    112     LayoutSize layoutDelta() const
    113     {
    114         return m_layoutState ? m_layoutState->m_layoutDelta : LayoutSize();
    115     }
    116     void addLayoutDelta(const LayoutSize& delta)
    117     {
    118         if (m_layoutState) {
    119             m_layoutState->m_layoutDelta += delta;
    120 #if !ASSERT_DISABLED
    121             m_layoutState->m_layoutDeltaXSaturated |= m_layoutState->m_layoutDelta.width() == LayoutUnit::max() || m_layoutState->m_layoutDelta.width() == LayoutUnit::min();
    122             m_layoutState->m_layoutDeltaYSaturated |= m_layoutState->m_layoutDelta.height() == LayoutUnit::max() || m_layoutState->m_layoutDelta.height() == LayoutUnit::min();
    123 #endif
    124         }
    125     }
    126 
    127 #if !ASSERT_DISABLED
    128     bool layoutDeltaMatches(const LayoutSize& delta)
    129     {
    130         if (!m_layoutState)
    131             return false;
    132         return (delta.width() == m_layoutState->m_layoutDelta.width() || m_layoutState->m_layoutDeltaXSaturated) && (delta.height() == m_layoutState->m_layoutDelta.height() || m_layoutState->m_layoutDeltaYSaturated);
    133     }
    134 #endif
    135 
    136     bool doingFullRepaint() const { return m_frameView->needsFullRepaint(); }
    137 
    138     // Subtree push/pop
    139     void pushLayoutState(RenderObject*);
    140     void popLayoutState(RenderObject*) { return popLayoutState(); } // Just doing this to keep popLayoutState() private and to make the subtree calls symmetrical.
    141 
    142     bool shouldDisableLayoutStateForSubtree(RenderObject*) const;
    143 
    144     // Returns true if layoutState should be used for its cached offset and clip.
    145     bool layoutStateEnabled() const { return m_layoutStateDisableCount == 0 && m_layoutState; }
    146     LayoutState* layoutState() const { return m_layoutState; }
    147 
    148     virtual void updateHitTestResult(HitTestResult&, const LayoutPoint&);
    149 
    150     LayoutUnit pageLogicalHeight() const { return m_pageLogicalHeight; }
    151     void setPageLogicalHeight(LayoutUnit height)
    152     {
    153         if (m_pageLogicalHeight != height) {
    154             m_pageLogicalHeight = height;
    155             m_pageLogicalHeightChanged = true;
    156         }
    157     }
    158 
    159     // Notification that this view moved into or out of a native window.
    160     void setIsInWindow(bool);
    161 
    162     RenderLayerCompositor* compositor();
    163     bool usesCompositing() const;
    164 
    165     CustomFilterGlobalContext* customFilterGlobalContext();
    166 
    167     IntRect unscaledDocumentRect() const;
    168     LayoutRect backgroundRect(RenderBox* backgroundRenderer) const;
    169 
    170     IntRect documentRect() const;
    171 
    172     // Renderer that paints the root background has background-images which all have background-attachment: fixed.
    173     bool rootBackgroundIsEntirelyFixed() const;
    174 
    175     bool hasRenderNamedFlowThreads() const;
    176     bool checkTwoPassLayoutForAutoHeightRegions() const;
    177     FlowThreadController* flowThreadController();
    178 
    179     void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
    180 
    181     IntervalArena* intervalArena();
    182 
    183     IntSize viewportSize() const { return document()->viewportSize(); }
    184 
    185     void setRenderQuoteHead(RenderQuote* head) { m_renderQuoteHead = head; }
    186     RenderQuote* renderQuoteHead() const { return m_renderQuoteHead; }
    187 
    188     void setFirstLazyBlock(RenderLazyBlock* block) { m_firstLazyBlock = block; }
    189     RenderLazyBlock* firstLazyBlock() const { return m_firstLazyBlock; }
    190     void markLazyBlocksForLayout();
    191 
    192     // FIXME: This is a work around because the current implementation of counters
    193     // requires walking the entire tree repeatedly and most pages don't actually use either
    194     // feature so we shouldn't take the performance hit when not needed. Long term we should
    195     // rewrite the counter and quotes code.
    196     void addRenderCounter() { m_renderCounterCount++; }
    197     void removeRenderCounter() { ASSERT(m_renderCounterCount > 0); m_renderCounterCount--; }
    198     bool hasRenderCounters() { return m_renderCounterCount; }
    199 
    200     virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0) OVERRIDE;
    201 
    202     virtual bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect) const OVERRIDE FINAL;
    203 
    204 protected:
    205     virtual void mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0) const OVERRIDE;
    206     virtual const RenderObject* pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap&) const OVERRIDE;
    207     virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const;
    208     virtual bool requiresColumns(int desiredColumnCount) const OVERRIDE;
    209     virtual void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const OVERRIDE;
    210 
    211 private:
    212     bool initializeLayoutState(LayoutState&);
    213 
    214     virtual void calcColumnWidth() OVERRIDE;
    215     virtual ColumnInfo::PaginationUnit paginationUnit() const OVERRIDE;
    216 
    217     bool shouldRepaint(const LayoutRect&) const;
    218 
    219     // These functions may only be accessed by LayoutStateMaintainer.
    220     bool pushLayoutState(RenderBox* renderer, const LayoutSize& offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
    221     {
    222         // We push LayoutState even if layoutState is disabled because it stores layoutDelta too.
    223         if (!doingFullRepaint() || m_layoutState->isPaginated() || renderer->hasColumns() || renderer->flowThreadContainingBlock()
    224             || m_layoutState->lineGrid() || (renderer->style()->lineGrid() != RenderStyle::initialLineGrid() && renderer->isBlockFlow())
    225             || (renderer->isRenderBlock() && toRenderBlock(renderer)->shapeInsideInfo())
    226             || (m_layoutState->shapeInsideInfo() && renderer->isRenderBlock() && !toRenderBlock(renderer)->allowsShapeInsideInfoSharing())
    227             ) {
    228             m_layoutState = new LayoutState(m_layoutState, renderer, offset, pageHeight, pageHeightChanged, colInfo);
    229             return true;
    230         }
    231         return false;
    232     }
    233 
    234     void popLayoutState()
    235     {
    236         LayoutState* state = m_layoutState;
    237         m_layoutState = state->m_next;
    238         delete state;
    239     }
    240 
    241     // Suspends the LayoutState optimization. Used under transforms that cannot be represented by
    242     // LayoutState (common in SVG) and when manipulating the render tree during layout in ways
    243     // that can trigger repaint of a non-child (e.g. when a list item moves its list marker around).
    244     // Note that even when disabled, LayoutState is still used to store layoutDelta.
    245     // These functions may only be accessed by LayoutStateMaintainer or LayoutStateDisabler.
    246     void disableLayoutState() { m_layoutStateDisableCount++; }
    247     void enableLayoutState() { ASSERT(m_layoutStateDisableCount > 0); m_layoutStateDisableCount--; }
    248 
    249     void layoutContent(const LayoutState&);
    250     void layoutContentInAutoLogicalHeightRegions(const LayoutState&);
    251 #ifndef NDEBUG
    252     void checkLayoutState(const LayoutState&);
    253 #endif
    254 
    255     size_t getRetainedWidgets(Vector<RenderWidget*>&);
    256     void releaseWidgets(Vector<RenderWidget*>&);
    257 
    258     friend class LayoutStateMaintainer;
    259     friend class LayoutStateDisabler;
    260 
    261 protected:
    262     FrameView* m_frameView;
    263 
    264     RenderObject* m_selectionStart;
    265     RenderObject* m_selectionEnd;
    266     int m_selectionStartPos;
    267     int m_selectionEndPos;
    268 
    269     int m_maximalOutlineSize; // Used to apply a fudge factor to dirty-rect checks on blocks/tables.
    270 
    271     typedef HashSet<RenderWidget*> RenderWidgetSet;
    272     RenderWidgetSet m_widgets;
    273 
    274 private:
    275     bool shouldUsePrintingLayout() const;
    276 
    277     LayoutUnit m_pageLogicalHeight;
    278     bool m_pageLogicalHeightChanged;
    279     LayoutState* m_layoutState;
    280     unsigned m_layoutStateDisableCount;
    281     OwnPtr<RenderLayerCompositor> m_compositor;
    282     OwnPtr<CustomFilterGlobalContext> m_customFilterGlobalContext;
    283     OwnPtr<FlowThreadController> m_flowThreadController;
    284     RefPtr<IntervalArena> m_intervalArena;
    285 
    286     RenderLazyBlock* m_firstLazyBlock;
    287     RenderQuote* m_renderQuoteHead;
    288     unsigned m_renderCounterCount;
    289 };
    290 
    291 inline RenderView* toRenderView(RenderObject* object)
    292 {
    293     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderView());
    294     return static_cast<RenderView*>(object);
    295 }
    296 
    297 inline const RenderView* toRenderView(const RenderObject* object)
    298 {
    299     ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderView());
    300     return static_cast<const RenderView*>(object);
    301 }
    302 
    303 // This will catch anyone doing an unnecessary cast.
    304 void toRenderView(const RenderView*);
    305 
    306 ALWAYS_INLINE RenderView* Document::renderView() const
    307 {
    308     return toRenderView(renderer());
    309 }
    310 
    311 // Stack-based class to assist with LayoutState push/pop
    312 class LayoutStateMaintainer {
    313     WTF_MAKE_NONCOPYABLE(LayoutStateMaintainer);
    314 public:
    315     // ctor to push now
    316     LayoutStateMaintainer(RenderView* view, RenderBox* root, LayoutSize offset, bool disableState = false, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
    317         : m_view(view)
    318         , m_disabled(disableState)
    319         , m_didStart(false)
    320         , m_didEnd(false)
    321         , m_didCreateLayoutState(false)
    322     {
    323         push(root, offset, pageHeight, pageHeightChanged, colInfo);
    324     }
    325 
    326     // ctor to maybe push later
    327     LayoutStateMaintainer(RenderView* view)
    328         : m_view(view)
    329         , m_disabled(false)
    330         , m_didStart(false)
    331         , m_didEnd(false)
    332         , m_didCreateLayoutState(false)
    333     {
    334     }
    335 
    336     ~LayoutStateMaintainer()
    337     {
    338         ASSERT(m_didStart == m_didEnd);   // if this fires, it means that someone did a push(), but forgot to pop().
    339     }
    340 
    341     void push(RenderBox* root, LayoutSize offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
    342     {
    343         ASSERT(!m_didStart);
    344         // We push state even if disabled, because we still need to store layoutDelta
    345         m_didCreateLayoutState = m_view->pushLayoutState(root, offset, pageHeight, pageHeightChanged, colInfo);
    346         if (m_disabled && m_didCreateLayoutState)
    347             m_view->disableLayoutState();
    348         m_didStart = true;
    349     }
    350 
    351     void pop()
    352     {
    353         if (m_didStart) {
    354             ASSERT(!m_didEnd);
    355             if (m_didCreateLayoutState) {
    356                 m_view->popLayoutState();
    357                 if (m_disabled)
    358                     m_view->enableLayoutState();
    359             }
    360 
    361             m_didEnd = true;
    362         }
    363     }
    364 
    365     bool didPush() const { return m_didStart; }
    366 
    367 private:
    368     RenderView* m_view;
    369     bool m_disabled : 1;        // true if the offset and clip part of layoutState is disabled
    370     bool m_didStart : 1;        // true if we did a push or disable
    371     bool m_didEnd : 1;          // true if we popped or re-enabled
    372     bool m_didCreateLayoutState : 1; // true if we actually made a layout state.
    373 };
    374 
    375 class LayoutStateDisabler {
    376     WTF_MAKE_NONCOPYABLE(LayoutStateDisabler);
    377 public:
    378     LayoutStateDisabler(RenderView* view)
    379         : m_view(view)
    380     {
    381         if (m_view)
    382             m_view->disableLayoutState();
    383     }
    384 
    385     ~LayoutStateDisabler()
    386     {
    387         if (m_view)
    388             m_view->enableLayoutState();
    389     }
    390 private:
    391     RenderView* m_view;
    392 };
    393 
    394 class FragmentationDisabler {
    395     WTF_MAKE_NONCOPYABLE(FragmentationDisabler);
    396 public:
    397     FragmentationDisabler(RenderObject* root);
    398     ~FragmentationDisabler();
    399 private:
    400     RenderObject* m_root;
    401     RenderObject::FlowThreadState m_flowThreadState;
    402     bool m_fragmenting;
    403 #ifndef NDEBUG
    404     LayoutState* m_layoutState;
    405 #endif
    406 };
    407 
    408 } // namespace WebCore
    409 
    410 #endif // RenderView_h
    411