juce/source/src/gui/components/layout/juce_StretchableObjectResizer.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #include "../../../core/juce_StandardHeader.h"
  27
  28 BEGIN_JUCE_NAMESPACE
  29
  30 #include "juce_StretchableObjectResizer.h"
  31
  32
  33 //==============================================================================
  34 StretchableObjectResizer::StretchableObjectResizer()
  35 {
  36 }
  37
  38 StretchableObjectResizer::~StretchableObjectResizer()
  39 {
  40 }
  41
  42 void StretchableObjectResizer::addItem (const double size,
  43                                         const double minSize, const double maxSize,
  44                                         const int order)
  45 {
  46     // the order must be >= 0 but less than the maximum integer value.
  47     jassert (order >= 0 && order < std::numeric_limits<int>::max());
  48
  49     Item* const item = new Item();
  50     item->size = size;
  51     item->minSize = minSize;
  52     item->maxSize = maxSize;
  53     item->order = order;
  54     items.add (item);
  55 }
  56
  57 double StretchableObjectResizer::getItemSize (const int index) const noexcept
  58 {
  59     const Item* const it = items [index];
  60     return it != nullptr ? it->size : 0;
  61 }
  62
  63 void StretchableObjectResizer::resizeToFit (const double targetSize)
  64 {
  65     int order = 0;
  66
  67     for (;;)
  68     {
  69         double currentSize = 0;
  70         double minSize = 0;
  71         double maxSize = 0;
  72
  73         int nextHighestOrder = std::numeric_limits<int>::max();
  74
  75         for (int i = 0; i < items.size(); ++i)
  76         {
  77             const Item* const it = items.getUnchecked(i);
  78             currentSize += it->size;
  79
  80             if (it->order <= order)
  81             {
  82                 minSize += it->minSize;
  83                 maxSize += it->maxSize;
  84             }
  85             else
  86             {
  87                 minSize += it->size;
  88                 maxSize += it->size;
  89                 nextHighestOrder = jmin (nextHighestOrder, it->order);
  90             }
  91         }
  92
  93         const double thisIterationTarget = jlimit (minSize, maxSize, targetSize);
  94
  95         if (thisIterationTarget >= currentSize)
  96         {
  97             const double availableExtraSpace = maxSize - currentSize;
  98             const double targetAmountOfExtraSpace = thisIterationTarget - currentSize;
  99             const double scale = targetAmountOfExtraSpace / availableExtraSpace;
 100
 101             for (int i = 0; i < items.size(); ++i)
 102             {
 103                 Item* const it = items.getUnchecked(i);
 104
 105                 if (it->order <= order)
 106                     it->size = jmin (it->maxSize, it->size + (it->maxSize - it->size) * scale);
 107             }
 108         }
 109         else
 110         {
 111             const double amountOfSlack = currentSize - minSize;
 112             const double targetAmountOfSlack = thisIterationTarget - minSize;
 113             const double scale = targetAmountOfSlack / amountOfSlack;
 114
 115             for (int i = 0; i < items.size(); ++i)
 116             {
 117                 Item* const it = items.getUnchecked(i);
 118
 119                 if (it->order <= order)
 120                     it->size = jmax (it->minSize, it->minSize + (it->size - it->minSize) * scale);
 121             }
 122         }
 123
 124         if (nextHighestOrder < std::numeric_limits<int>::max())
 125             order = nextHighestOrder;
 126         else
 127             break;
 128     }
 129 }
 130
 131
 132 END_JUCE_NAMESPACE