Import Qt5x2 branch of QtWebkit for Qt 5.2

Importing a new snapshot of webkit.

Change-Id: I2d01ad12cdc8af8cb015387641120a9d7ea5f10c
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

1 files changed, 55 insertions, 15 deletions

diff --git a/Source/WebCore/rendering/RenderMultiColumnSet.h b/Source/WebCore/rendering/RenderMultiColumnSet.h
index 88653035c..5f597f7ee 100644
--- a/Source/WebCore/rendering/RenderMultiColumnSet.h
+++ b/Source/WebCore/rendering/RenderMultiColumnSet.h
@@ -43,8 +43,8 @@ namespace WebCore {
 // come before and after the span.
 class RenderMultiColumnSet : public RenderRegionSet {
 public:
-    RenderMultiColumnSet(Node*, RenderFlowThread*);
-    
+    static RenderMultiColumnSet* createAnonymous(RenderFlowThread*);
+
     virtual bool isRenderMultiColumnSet() const OVERRIDE { return true; }
 
     unsigned computedColumnCount() const { return m_computedColumnCount; }
@@ -56,10 +56,8 @@ public:
         m_computedColumnWidth = width;
         m_computedColumnCount = count;
     }
-    void setComputedColumnHeight(LayoutUnit height)
-    {
-        m_computedColumnHeight = height;
-    }
+
+    LayoutUnit heightAdjustedForSetOffset(LayoutUnit height) const;
 
     void updateMinimumColumnHeight(LayoutUnit height) { m_minimumColumnHeight = std::max(height, m_minimumColumnHeight); }
     LayoutUnit minimumColumnHeight() const { return m_minimumColumnHeight; }
@@ -84,13 +82,27 @@ public:
         m_forcedBreakOffset = offsetFromFirstPage;
     }
 
-private:
+    // Calculate the column height when contents are supposed to be balanced. If 'initial' is set,
+    // guess an initial column height; otherwise, stretch the column height a tad. Return true if
+    // column height changed and another layout pass is required.
+    bool calculateBalancedHeight(bool initial);
+
+    // Record space shortage (the amount of space that would have been enough to prevent some
+    // element from being moved to the next column) at a column break. The smallest amount of space
+    // shortage we find is the amount with which we will stretch the column height, if it turns out
+    // after layout that the columns weren't tall enough.
+    void recordSpaceShortage(LayoutUnit spaceShortage);
+
     virtual void updateLogicalWidth() OVERRIDE;
-    virtual void updateLogicalHeight() OVERRIDE;
+
+    void prepareForLayout();
+
+private:
+    RenderMultiColumnSet(RenderFlowThread*);
+
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const OVERRIDE;
 
-    virtual void paintReplaced(PaintInfo&, const LayoutPoint& paintOffset) OVERRIDE;
-    virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation&, const LayoutPoint& accumulatedOffset, HitTestAction) OVERRIDE;
+    virtual void paintObject(PaintInfo&, const LayoutPoint& paintOffset) OVERRIDE;
 
     virtual LayoutUnit pageLogicalWidth() const OVERRIDE { return m_computedColumnWidth; }
     virtual LayoutUnit pageLogicalHeight() const OVERRIDE { return m_computedColumnHeight; }
@@ -99,34 +111,62 @@ private:
     
     // FIXME: This will change once we have column sets constrained by enclosing pages, etc.
     virtual LayoutUnit logicalHeightOfAllFlowThreadContent() const OVERRIDE { return m_computedColumnHeight; }
+
+    // FIXME: For now we return false, but it's likely we will leverage the auto height region code to do column
+    // balancing. That's why we have an override of this function that is distinct from RenderRegionSet's override.
+    virtual bool shouldHaveAutoLogicalHeight() const OVERRIDE { return false; }
     
     virtual void repaintFlowThreadContent(const LayoutRect& repaintRect, bool immediate) const OVERRIDE;
 
+    virtual void collectLayerFragments(LayerFragments&, const LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect) OVERRIDE;
+
     virtual const char* renderName() const;
     
     void paintColumnRules(PaintInfo&, const LayoutPoint& paintOffset);
-    void paintColumnContents(PaintInfo&, const LayoutPoint& paintOffset);
 
     LayoutUnit columnGap() const;
     LayoutRect columnRectAt(unsigned index) const;
     unsigned columnCount() const;
 
     LayoutRect flowThreadPortionRectAt(unsigned index) const;
-    LayoutRect flowThreadPortionOverflowRect(const LayoutRect& flowThreadPortion, unsigned index, unsigned colCount, int colGap) const;
-    
-    unsigned columnIndexAtOffset(LayoutUnit) const;
-    
+    LayoutRect flowThreadPortionOverflowRect(const LayoutRect& flowThreadPortion, unsigned index, unsigned colCount, LayoutUnit colGap) const;
+
+    enum ColumnIndexCalculationMode {
+        ClampToExistingColumns, // Stay within the range of already existing columns.
+        AssumeNewColumns // Allow column indices outside the range of already existing columns.
+    };
+    unsigned columnIndexAtOffset(LayoutUnit, ColumnIndexCalculationMode = ClampToExistingColumns) const;
+
+    void setAndConstrainColumnHeight(LayoutUnit);
+
     unsigned m_computedColumnCount;
     LayoutUnit m_computedColumnWidth;
     LayoutUnit m_computedColumnHeight;
     
     // The following variables are used when balancing the column set.
+    LayoutUnit m_maxColumnHeight; // Maximum column height allowed.
+    LayoutUnit m_minSpaceShortage; // The smallest amout of space shortage that caused a column break.
     LayoutUnit m_minimumColumnHeight;
     unsigned m_forcedBreaksCount; // FIXME: We will ultimately need to cache more information to balance around forced breaks properly.
     LayoutUnit m_maximumDistanceBetweenForcedBreaks;
     LayoutUnit m_forcedBreakOffset;
 };
 
+inline RenderMultiColumnSet* toRenderMultiColumnSet(RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderMultiColumnSet());
+    return static_cast<RenderMultiColumnSet*>(object);
+}
+
+inline const RenderMultiColumnSet* toRenderMultiColumnSet(const RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderMultiColumnSet());
+    return static_cast<const RenderMultiColumnSet*>(object);
+}
+
+// This will catch anyone doing an unnecessary cast.
+void toRenderMultiColumnSet(const RenderMultiColumnSet*);
+
 } // namespace WebCore
 
 #endif // RenderMultiColumnSet_h