JUCE/modules/juce_gui_basics/native/juce_MultiTouchMapper.h

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

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

   For this technical preview, this file is not subject to commercial licensing.

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

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

JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wzero-as-null-pointer-constant")

namespace juce
{

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

    int getIndexOfTouch (ComponentPeer* peer, IDType touchID)
    {
        jassert (touchID != 0); // need to rethink this if IDs can be 0!
        TouchInfo info {touchID, peer};

        int touchIndex = currentTouches.indexOf (info);

        if (touchIndex < 0)
        {
            auto emptyTouchIndex = currentTouches.indexOf ({});
            touchIndex = (emptyTouchIndex >= 0 ? emptyTouchIndex : currentTouches.size());

            currentTouches.set (touchIndex, info);
        }

        return touchIndex;
    }

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

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

    bool areAnyTouchesActive() const noexcept
    {
        for (auto& t : currentTouches)
            if (t.touchId != 0)
                return true;

        return false;
    }

    void deleteAllTouchesForPeer (ComponentPeer* peer)
    {
        for (auto& t : currentTouches)
            if (t.owner == peer)
                t.touchId = 0;
    }

private:
    //==============================================================================
    struct TouchInfo
    {
        TouchInfo() noexcept  : touchId (0), owner (nullptr) {}
        TouchInfo (IDType idToUse, ComponentPeer* peer) noexcept  : touchId (idToUse), owner (peer) {}

        TouchInfo (const TouchInfo&) = default;
        TouchInfo& operator= (const TouchInfo&) = default;
        TouchInfo (TouchInfo&&) noexcept = default;
        TouchInfo& operator= (TouchInfo&&) noexcept = default;

        IDType touchId;
        ComponentPeer* owner;

        bool operator== (const TouchInfo& o) const noexcept     { return (touchId == o.touchId); }
    };

    //==============================================================================
    Array<TouchInfo> currentTouches;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MultiTouchMapper)
};

} // namespace juce

JUCE_END_IGNORE_WARNINGS_GCC_LIKE