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