JUCE/modules/juce_gui_basics/layout/juce_StretchableObjectResizer.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2013 - Raw Material Software Ltd.

   Permission is granted to use this software under the terms of either:
   a) the GPL v2 (or any later version)
   b) the Affero GPL v3

   Details of these licenses can be found at: www.gnu.org/licenses

   JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

   ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.juce.com for more information.

  ==============================================================================
*/

#ifndef JUCE_STRETCHABLEOBJECTRESIZER_H_INCLUDED
#define JUCE_STRETCHABLEOBJECTRESIZER_H_INCLUDED


//==============================================================================
/**
    A utility class for fitting a set of objects whose sizes can vary between
    a minimum and maximum size, into a space.

    This is a trickier algorithm than it would first seem, so I've put it in this
    class to allow it to be shared by various bits of code.

    To use it, create one of these objects, call addItem() to add the list of items
    you need, then call resizeToFit(), which will change all their sizes. You can
    then retrieve the new sizes with getItemSize() and getNumItems().

    It's currently used by the TableHeaderComponent for stretching out the table
    headings to fill the table's width.
*/
class StretchableObjectResizer
{
public:
    //==============================================================================
    /** Creates an empty object resizer. */
    StretchableObjectResizer();

    /** Destructor. */
    ~StretchableObjectResizer();

    //==============================================================================
    /** Adds an item to the list.

        The order parameter lets you specify groups of items that are resized first when some
        space needs to be found. Those items with an order of 0 will be the first ones to be
        resized, and if that doesn't provide enough space to meet the requirements, the algorithm
        will then try resizing the items with an order of 1, then 2, and so on.
    */
    void addItem (double currentSize,
                  double minSize,
                  double maxSize,
                  int order = 0);

    /** Resizes all the items to fit this amount of space.

        This will attempt to fit them in without exceeding each item's miniumum and
        maximum sizes. In cases where none of the items can be expanded or enlarged any
        further, the final size may be greater or less than the size passed in.

        After calling this method, you can retrieve the new sizes with the getItemSize()
        method.
    */
    void resizeToFit (double targetSize);

    /** Returns the number of items that have been added. */
    int getNumItems() const noexcept                        { return items.size(); }

    /** Returns the size of one of the items. */
    double getItemSize (int index) const noexcept;


private:
    //==============================================================================
    struct Item
    {
        double size;
        double minSize;
        double maxSize;
        int order;
    };

    Array<Item> items;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (StretchableObjectResizer)
};


#endif   // JUCE_STRETCHABLEOBJECTRESIZER_H_INCLUDED