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      1 /*
      2  * Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef ColumnInfo_h
     27 #define ColumnInfo_h
     28 
     29 #include "core/platform/LayoutUnit.h"
     30 #include "wtf/Vector.h"
     31 
     32 namespace WebCore {
     33 
     34 class ColumnInfo {
     35     WTF_MAKE_NONCOPYABLE(ColumnInfo); WTF_MAKE_FAST_ALLOCATED;
     36 public:
     37     ColumnInfo()
     38         : m_desiredColumnWidth(0)
     39         , m_desiredColumnCount(1)
     40         , m_progressionAxis(InlineAxis)
     41         , m_progressionIsReversed(false)
     42         , m_columnCount(1)
     43         , m_columnHeight(0)
     44         , m_minimumColumnHeight(0)
     45         , m_forcedBreaks(0)
     46         , m_maximumDistanceBetweenForcedBreaks(0)
     47         , m_forcedBreakOffset(0)
     48         , m_paginationUnit(Column)
     49     {
     50     }
     51 
     52     LayoutUnit desiredColumnWidth() const { return m_desiredColumnWidth; }
     53     void setDesiredColumnWidth(LayoutUnit width) { m_desiredColumnWidth = width; }
     54 
     55     unsigned desiredColumnCount() const { return m_desiredColumnCount; }
     56     void setDesiredColumnCount(unsigned count) { m_desiredColumnCount = count; }
     57 
     58     enum Axis { InlineAxis, BlockAxis };
     59 
     60     Axis progressionAxis() const { return m_progressionAxis; }
     61     void setProgressionAxis(Axis progressionAxis) { m_progressionAxis = progressionAxis; }
     62 
     63     bool progressionIsReversed() const { return m_progressionIsReversed; }
     64     void setProgressionIsReversed(bool reversed) { m_progressionIsReversed = reversed; }
     65 
     66     unsigned columnCount() const { return m_columnCount; }
     67     LayoutUnit columnHeight() const { return m_columnHeight; }
     68 
     69     // Set our count and height.  This is enough info for a RenderBlock to compute page rects
     70     // dynamically.
     71     void setColumnCountAndHeight(int count, LayoutUnit height)
     72     {
     73         m_columnCount = count;
     74         m_columnHeight = height;
     75     }
     76     void setColumnHeight(LayoutUnit height) { m_columnHeight = height; }
     77 
     78     void updateMinimumColumnHeight(LayoutUnit height) { m_minimumColumnHeight = std::max(height, m_minimumColumnHeight); }
     79     LayoutUnit minimumColumnHeight() const { return m_minimumColumnHeight; }
     80 
     81     int forcedBreaks() const { return m_forcedBreaks; }
     82     LayoutUnit forcedBreakOffset() const { return m_forcedBreakOffset; }
     83     LayoutUnit maximumDistanceBetweenForcedBreaks() const { return m_maximumDistanceBetweenForcedBreaks; }
     84     void clearForcedBreaks()
     85     {
     86         m_forcedBreaks = 0;
     87         m_maximumDistanceBetweenForcedBreaks = 0;
     88         m_forcedBreakOffset = 0;
     89     }
     90     void addForcedBreak(LayoutUnit offsetFromFirstPage)
     91     {
     92         ASSERT(!m_columnHeight);
     93         LayoutUnit distanceFromLastBreak = offsetFromFirstPage - m_forcedBreakOffset;
     94         if (!distanceFromLastBreak)
     95             return;
     96         m_forcedBreaks++;
     97         m_maximumDistanceBetweenForcedBreaks = std::max(m_maximumDistanceBetweenForcedBreaks, distanceFromLastBreak);
     98         m_forcedBreakOffset = offsetFromFirstPage;
     99     }
    100 
    101     enum PaginationUnit { Column, Page };
    102     PaginationUnit paginationUnit() const { return m_paginationUnit; }
    103     void setPaginationUnit(PaginationUnit paginationUnit) { m_paginationUnit = paginationUnit; }
    104 
    105 private:
    106     LayoutUnit m_desiredColumnWidth;
    107     unsigned m_desiredColumnCount;
    108     Axis m_progressionAxis;
    109     bool m_progressionIsReversed;
    110 
    111     unsigned m_columnCount;
    112     LayoutUnit m_columnHeight;
    113     LayoutUnit m_minimumColumnHeight;
    114     int m_forcedBreaks; // FIXME: We will ultimately need to cache more information to balance around forced breaks properly.
    115     LayoutUnit m_maximumDistanceBetweenForcedBreaks;
    116     LayoutUnit m_forcedBreakOffset;
    117     PaginationUnit m_paginationUnit;
    118 };
    119 
    120 }
    121 
    122 #endif
    123