juce_ListenerList.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2015 - ROLI 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_LISTENERLIST_H_INCLUDED
#define JUCE_LISTENERLIST_H_INCLUDED
 
 
//==============================================================================
template <class ListenerClass,
          class ArrayType = Array<ListenerClass*> >
class ListenerList
{
    // Horrible macros required to support VC7..
    #ifndef DOXYGEN
     #if JUCE_VC8_OR_EARLIER
       #define LL_TEMPLATE(a)   typename P##a, typename Q##a
       #define LL_PARAM(a)      Q##a& param##a
     #else
       #define LL_TEMPLATE(a)   typename P##a
       #define LL_PARAM(a)      PARAMETER_TYPE(P##a) param##a
     #endif
    #endif
 
public:
    //==============================================================================
    ListenerList()
    {
    }
 
    ~ListenerList()
    {
    }
 
    //==============================================================================
    void add (ListenerClass* const listenerToAdd)
    {
        // Listeners can't be null pointers!
        jassert (listenerToAdd != nullptr);
 
        if (listenerToAdd != nullptr)
            listeners.addIfNotAlreadyThere (listenerToAdd);
    }
 
    void remove (ListenerClass* const listenerToRemove)
    {
        // Listeners can't be null pointers!
        jassert (listenerToRemove != nullptr);
 
        listeners.removeFirstMatchingValue (listenerToRemove);
    }
 
    int size() const noexcept
    {
        return listeners.size();
    }
 
    bool isEmpty() const noexcept
    {
        return listeners.size() == 0;
    }
 
    void clear()
    {
        listeners.clear();
    }
 
    bool contains (ListenerClass* const listener) const noexcept
    {
        return listeners.contains (listener);
    }
 
    //==============================================================================
    void call (void (ListenerClass::*callbackFunction) ())
    {
        callChecked (static_cast <const DummyBailOutChecker&> (DummyBailOutChecker()), callbackFunction);
    }
 
    template <class BailOutCheckerType>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) ())
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) ();
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1)>
    void call (void (ListenerClass::*callbackFunction) (P1), LL_PARAM(1))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1),
                      LL_PARAM(1))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1);
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1), LL_TEMPLATE(2)>
    void call (void (ListenerClass::*callbackFunction) (P1, P2),
               LL_PARAM(1), LL_PARAM(2))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1, param2);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1), LL_TEMPLATE(2)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1, P2),
                      LL_PARAM(1), LL_PARAM(2))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1, param2);
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3)>
    void call (void (ListenerClass::*callbackFunction) (P1, P2, P3),
               LL_PARAM(1), LL_PARAM(2), LL_PARAM(3))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1, param2, param3);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1, P2, P3),
                      LL_PARAM(1), LL_PARAM(2), LL_PARAM(3))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1, param2, param3);
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4)>
    void call (void (ListenerClass::*callbackFunction) (P1, P2, P3, P4),
               LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1, P2, P3, P4),
                      LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4);
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4), LL_TEMPLATE(5)>
    void call (void (ListenerClass::*callbackFunction) (P1, P2, P3, P4, P5),
               LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4, param5);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4), LL_TEMPLATE(5)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1, P2, P3, P4, P5),
                      LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4, param5);
    }
 
    //==============================================================================
    template <LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4), LL_TEMPLATE(5), LL_TEMPLATE(6)>
    void call (void (ListenerClass::*callbackFunction) (P1, P2, P3, P4, P5, P6),
               LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5), LL_PARAM(6))
    {
        for (Iterator<DummyBailOutChecker, ThisType> iter (*this); iter.next();)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4, param5, param6);
    }
 
    template <class BailOutCheckerType, LL_TEMPLATE(1), LL_TEMPLATE(2), LL_TEMPLATE(3), LL_TEMPLATE(4), LL_TEMPLATE(5), LL_TEMPLATE(6)>
    void callChecked (const BailOutCheckerType& bailOutChecker,
                      void (ListenerClass::*callbackFunction) (P1, P2, P3, P4, P5, P6),
                      LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5), LL_PARAM(6))
    {
        for (Iterator<BailOutCheckerType, ThisType> iter (*this); iter.next (bailOutChecker);)
            (iter.getListener()->*callbackFunction) (param1, param2, param3, param4, param5, param6);
    }
 
 
    //==============================================================================
    class DummyBailOutChecker
    {
    public:
        inline bool shouldBailOut() const noexcept     { return false; }
    };
 
    //==============================================================================
    template <class BailOutCheckerType, class ListType>
    class Iterator
    {
    public:
        //==============================================================================
        Iterator (const ListType& listToIterate) noexcept
            : list (listToIterate), index (listToIterate.size())
        {}
 
        ~Iterator() noexcept {}
 
        //==============================================================================
        bool next() noexcept
        {
            if (index <= 0)
                return false;
 
            const int listSize = list.size();
 
            if (--index < listSize)
                return true;
 
            index = listSize - 1;
            return index >= 0;
        }
 
        bool next (const BailOutCheckerType& bailOutChecker) noexcept
        {
            return (! bailOutChecker.shouldBailOut()) && next();
        }
 
        typename ListType::ListenerType* getListener() const noexcept
        {
            return list.getListeners().getUnchecked (index);
        }
 
        //==============================================================================
    private:
        const ListType& list;
        int index;
 
        JUCE_DECLARE_NON_COPYABLE (Iterator)
    };
 
    typedef ListenerList<ListenerClass, ArrayType> ThisType;
    typedef ListenerClass ListenerType;
 
    const ArrayType& getListeners() const noexcept          { return listeners; }
 
private:
    //==============================================================================
    ArrayType listeners;
 
    JUCE_DECLARE_NON_COPYABLE (ListenerList)
 
    #undef LL_TEMPLATE
    #undef LL_PARAM
};
 
 
#endif   // JUCE_LISTENERLIST_H_INCLUDED