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      1 /*
      2  * Copyright (C) 2010 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 <wtf/Vector.h>
     30 #include "IntRect.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_columnCount(1)
     41         , m_columnHeight(0)
     42         , m_minimumColumnHeight(0)
     43         , m_forcedBreaks(0)
     44         , m_maximumDistanceBetweenForcedBreaks(0)
     45         , m_forcedBreakOffset(0)
     46         { }
     47 
     48     int desiredColumnWidth() const { return m_desiredColumnWidth; }
     49     void setDesiredColumnWidth(int width) { m_desiredColumnWidth = width; }
     50 
     51     unsigned desiredColumnCount() const { return m_desiredColumnCount; }
     52     void setDesiredColumnCount(unsigned count) { m_desiredColumnCount = count; }
     53 
     54     unsigned columnCount() const { return m_columnCount; }
     55     int columnHeight() const { return m_columnHeight; }
     56 
     57     // Set our count and height.  This is enough info for a RenderBlock to compute page rects
     58     // dynamically.
     59     void setColumnCountAndHeight(int count, int height)
     60     {
     61         m_columnCount = count;
     62         m_columnHeight = height;
     63     }
     64     void setColumnHeight(int height) { m_columnHeight = height; }
     65 
     66     void updateMinimumColumnHeight(int height) { m_minimumColumnHeight = std::max(height, m_minimumColumnHeight); }
     67     int minimumColumnHeight() const { return m_minimumColumnHeight; }
     68 
     69     int forcedBreaks() const { return m_forcedBreaks; }
     70     int forcedBreakOffset() const { return m_forcedBreakOffset; }
     71     int maximumDistanceBetweenForcedBreaks() const { return m_maximumDistanceBetweenForcedBreaks; }
     72     void clearForcedBreaks()
     73     {
     74         m_forcedBreaks = 0;
     75         m_maximumDistanceBetweenForcedBreaks = 0;
     76         m_forcedBreakOffset = 0;
     77     }
     78     void addForcedBreak(int offsetFromFirstPage)
     79     {
     80         ASSERT(!m_columnHeight);
     81         int distanceFromLastBreak = offsetFromFirstPage - m_forcedBreakOffset;
     82         if (!distanceFromLastBreak)
     83             return;
     84         m_forcedBreaks++;
     85         m_maximumDistanceBetweenForcedBreaks = std::max(m_maximumDistanceBetweenForcedBreaks, distanceFromLastBreak);
     86         m_forcedBreakOffset = offsetFromFirstPage;
     87     }
     88 
     89 private:
     90     int m_desiredColumnWidth;
     91     unsigned m_desiredColumnCount;
     92 
     93     unsigned m_columnCount;
     94     int m_columnHeight;
     95     int m_minimumColumnHeight;
     96     int m_forcedBreaks; // FIXME: We will ultimately need to cache more information to balance around forced breaks properly.
     97     int m_maximumDistanceBetweenForcedBreaks;
     98     int m_forcedBreakOffset;
     99 };
    100 
    101 }
    102 
    103 #endif
    104