#ifndef RenderMultiColumnSet_h
#define RenderMultiColumnSet_h
-#include "core/rendering/RenderRegionSet.h"
+#include "core/rendering/RenderMultiColumnFlowThread.h"
+#include "core/rendering/RenderRegion.h"
#include "wtf/Vector.h"
namespace WebCore {
-// RenderMultiColumnSet represents a set of columns that all have the same width and height. By combining runs of same-size columns into a single
-// object, we significantly reduce the number of unique RenderObjects required to represent columns.
+// RenderMultiColumnSet represents a set of columns that all have the same width and height. By
+// combining runs of same-size columns into a single object, we significantly reduce the number of
+// unique RenderObjects required to represent columns.
//
-// A simple multi-column block will have exactly one RenderMultiColumnSet child. A simple paginated multi-column block will have three
-// RenderMultiColumnSet children: one for the content at the bottom of the first page (whose columns will have a shorter height), one
-// for the 2nd to n-1 pages, and then one last column set that will hold the shorter columns on the final page (that may have to be balanced
-// as well).
+// Column sets are inserted as anonymous children of the actual multicol container (i.e. the
+// renderer whose style computes to non-auto column-count and/or column-width).
//
-// Column spans result in the creation of new column sets as well, since a spanning region has to be placed in between the column sets that
-// come before and after the span.
-class RenderMultiColumnSet FINAL : public RenderRegionSet {
+// Being a "region", a column set has no children on its own, but is merely used to slice a portion
+// of the tall "single-column" flow thread into actual columns visually, to convert from flow thread
+// coordinates to visual ones. It is in charge of both positioning columns correctly relatively to
+// the parent multicol container, and to calculate the correct translation for each column's
+// contents, and to paint any rules between them. RenderMultiColumnSet objects are used for
+// painting, hit testing, and any other type of operation that requires mapping from flow thread
+// coordinates to visual coordinates.
+//
+// Column spans result in the creation of new column sets, since a spanning renderer has to be
+// placed in between the column sets that come before and after the span.
+class RenderMultiColumnSet FINAL : public RenderRegion {
public:
- static RenderMultiColumnSet* createAnonymous(RenderFlowThread*);
+ static RenderMultiColumnSet* createAnonymous(RenderFlowThread*, RenderStyle* parentStyle);
virtual bool isRenderMultiColumnSet() const OVERRIDE { return true; }
RenderBlockFlow* multiColumnBlockFlow() const { return toRenderBlockFlow(parent()); }
- RenderMultiColumnFlowThread* multiColumnFlowThread() const { return multiColumnBlockFlow()->multiColumnFlowThread(); }
+ RenderMultiColumnFlowThread* multiColumnFlowThread() const
+ {
+ ASSERT_WITH_SECURITY_IMPLICATION(!flowThread() || flowThread()->isRenderMultiColumnFlowThread());
+ return static_cast<RenderMultiColumnFlowThread*>(flowThread());
+ }
+
+ RenderMultiColumnSet* nextSiblingMultiColumnSet() const;
+
+ LayoutUnit logicalBottomInFlowThread() const { return isHorizontalWritingMode() ? flowThreadPortionRect().maxY() : flowThreadPortionRect().maxX(); }
+
unsigned computedColumnCount() const { return m_computedColumnCount; }
LayoutUnit computedColumnWidth() const { return m_computedColumnWidth; }
LayoutUnit computedColumnHeight() const { return m_computedColumnHeight; }
m_computedColumnCount = count;
}
+ // Find the column that contains the given block offset, and return the translation needed to
+ // get from flow thread coordinates to visual coordinates.
+ LayoutSize flowThreadTranslationAtOffset(LayoutUnit) const;
+
LayoutUnit heightAdjustedForSetOffset(LayoutUnit height) const;
void updateMinimumColumnHeight(LayoutUnit height) { m_minimumColumnHeight = std::max(height, m_minimumColumnHeight); }
void clearForcedBreaks();
void addForcedBreak(LayoutUnit offsetFromFirstPage);
- // (Re-)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 recalculateBalancedHeight(bool initial);
+ // (Re-)calculate the column height if it's auto. 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 recalculateColumnHeight(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
void prepareForLayout();
+ // Expand this set's flow thread portion rectangle to contain all trailing flow thread
+ // overflow. Only to be called on the last set.
+ void expandToEncompassFlowThreadContentsIfNeeded();
+
private:
RenderMultiColumnSet(RenderFlowThread*);
// and store the results. This is needed in order to balance the columns.
void distributeImplicitBreaks();
- LayoutUnit calculateBalancedHeight(bool initial) const;
+ LayoutUnit calculateColumnHeight(bool initial) const;
unsigned m_computedColumnCount; // Used column count (the resulting 'N' from the pseudo-algorithm in the multicol spec)
LayoutUnit m_computedColumnWidth; // Used column width (the resulting 'W' from the pseudo-algorithm in the multicol spec)
projects / platform / framework / web / crosswalk.git / blobdiff