juce_SelectedItemSet.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_SELECTEDITEMSET_H_INCLUDED
#define JUCE_SELECTEDITEMSET_H_INCLUDED
 
 
//==============================================================================
template <class SelectableItemType>
class SelectedItemSet   : public ChangeBroadcaster
{
public:
    //==============================================================================
    typedef SelectableItemType ItemType;
    typedef Array<SelectableItemType> ItemArray;
    typedef PARAMETER_TYPE (SelectableItemType) ParameterType;
 
    //==============================================================================
    SelectedItemSet()
    {
    }
 
    explicit SelectedItemSet (const ItemArray& items)
        : selectedItems (items)
    {
    }
 
    SelectedItemSet (const SelectedItemSet& other)
        : selectedItems (other.selectedItems)
    {
    }
 
    SelectedItemSet& operator= (const SelectedItemSet& other)
    {
        if (selectedItems != other.selectedItems)
        {
            selectedItems = other.selectedItems;
            changed();
        }
 
        return *this;
    }
 
    //==============================================================================
    void selectOnly (ParameterType item)
    {
        if (isSelected (item))
        {
            for (int i = selectedItems.size(); --i >= 0;)
            {
                if (selectedItems.getUnchecked(i) != item)
                {
                    deselect (selectedItems.getUnchecked(i));
                    i = jmin (i, selectedItems.size());
                }
            }
        }
        else
        {
            deselectAll();
            changed();
 
            selectedItems.add (item);
            itemSelected (item);
        }
    }
 
    void addToSelection (ParameterType item)
    {
        if (! isSelected (item))
        {
            changed();
 
            selectedItems.add (item);
            itemSelected (item);
        }
    }
 
    void addToSelectionBasedOnModifiers (ParameterType item,
                                         ModifierKeys modifiers)
    {
        if (modifiers.isShiftDown())
        {
            addToSelection (item);
        }
        else if (modifiers.isCommandDown())
        {
            if (isSelected (item))
                deselect (item);
            else
                addToSelection (item);
        }
        else
        {
            selectOnly (item);
        }
    }
 
    bool addToSelectionOnMouseDown (ParameterType item,
                                    ModifierKeys modifiers)
    {
        if (isSelected (item))
            return ! modifiers.isPopupMenu();
 
        addToSelectionBasedOnModifiers (item, modifiers);
        return false;
    }
 
    void addToSelectionOnMouseUp (ParameterType item,
                                  ModifierKeys modifiers,
                                  const bool wasItemDragged,
                                  const bool resultOfMouseDownSelectMethod)
    {
        if (resultOfMouseDownSelectMethod && ! wasItemDragged)
            addToSelectionBasedOnModifiers (item, modifiers);
    }
 
    void deselect (ParameterType item)
    {
        const int i = selectedItems.indexOf (item);
 
        if (i >= 0)
        {
            changed();
            itemDeselected (selectedItems.remove (i));
        }
    }
 
    void deselectAll()
    {
        if (selectedItems.size() > 0)
        {
            changed();
 
            for (int i = selectedItems.size(); --i >= 0;)
            {
                itemDeselected (selectedItems.remove (i));
                i = jmin (i, selectedItems.size());
            }
        }
    }
 
    //==============================================================================
    int getNumSelected() const noexcept                         { return selectedItems.size(); }
 
    SelectableItemType getSelectedItem (const int index) const  { return selectedItems [index]; }
 
    bool isSelected (ParameterType item) const noexcept         { return selectedItems.contains (item); }
 
    const ItemArray& getItemArray() const noexcept              { return selectedItems; }
 
    SelectableItemType* begin() const noexcept                  { return selectedItems.begin(); }
 
    SelectableItemType* end() const noexcept                    { return selectedItems.end(); }
 
    //==============================================================================
    virtual void itemSelected (SelectableItemType)              {}
 
    virtual void itemDeselected (SelectableItemType)            {}
 
    void changed()
    {
        sendChangeMessage();
    }
 
    void changed (const bool synchronous)
    {
        if (synchronous)
            sendSynchronousChangeMessage();
        else
            sendChangeMessage();
    }
 
private:
    //==============================================================================
    ItemArray selectedItems;
 
    JUCE_LEAK_DETECTOR (SelectedItemSet<SelectableItemType>)
};
 
 
#endif   // JUCE_SELECTEDITEMSET_H_INCLUDED