juce_MultiTouchMapper.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   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 7 End-User License
   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-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.
 
  ==============================================================================
*/
 
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