JUCE/modules/juce_gui_basics/native/juce_MultiTouchMapper.h

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

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

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

#pragma once

template <typename IDType>
class MultiTouchMapper
{
public:
    MultiTouchMapper() {}

    int getIndexOfTouch (IDType touchID)
    {
        jassert (touchID != 0); // need to rethink this if IDs can be 0!

        int touchIndex = currentTouches.indexOf (touchID);

        if (touchIndex < 0)
        {
            for (touchIndex = 0; touchIndex < currentTouches.size(); ++touchIndex)
                if (currentTouches.getUnchecked (touchIndex) == 0)
                    break;

            currentTouches.set (touchIndex, touchID);
        }

        return touchIndex;
    }

    void clear()
    {
        currentTouches.clear();
    }

    void clearTouch (int index)
    {
        currentTouches.set (index, 0);
    }

    bool areAnyTouchesActive() const noexcept
    {
        for (int i = currentTouches.size(); --i >= 0;)
            if (currentTouches.getUnchecked(i) != 0)
                return true;

        return false;
    }

private:
    Array<IDType> currentTouches;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MultiTouchMapper)
};