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

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

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

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

namespace juce
{

//==============================================================================
/**
    An object to take care of the logic for dragging components around with the mouse.

    Very easy to use - in your mouseDown() callback, call startDraggingComponent(),
    then in your mouseDrag() callback, call dragComponent().

    When starting a drag, you can give it a ComponentBoundsConstrainer to use
    to limit the component's position and keep it on-screen.

    e.g. @code
    class MyDraggableComp
    {
        ComponentDragger myDragger;

        void mouseDown (const MouseEvent& e)
        {
            myDragger.startDraggingComponent (this, e);
        }

        void mouseDrag (const MouseEvent& e)
        {
            myDragger.dragComponent (this, e, nullptr);
        }
    };
    @endcode

    @tags{GUI}
*/
class JUCE_API  ComponentDragger
{
public:
    //==============================================================================
    /** Creates a ComponentDragger. */
    ComponentDragger() = default;

    //==============================================================================
    /** Call this from your component's mouseDown() method, to prepare for dragging.

        @param componentToDrag      the component that you want to drag
        @param e                    the mouse event that is triggering the drag
        @see dragComponent
    */
    void startDraggingComponent (Component* componentToDrag,
                                 const MouseEvent& e);

    /** Call this from your mouseDrag() callback to move the component.

        This will move the component, using the given constrainer object to check
        the new position.

        @param componentToDrag      the component that you want to drag
        @param e                    the current mouse-drag event
        @param constrainer          an optional constrainer object that should be used
                                    to apply limits to the component's position. Pass
                                    null if you don't want to constrain the movement.
        @see startDraggingComponent
    */
    void dragComponent (Component* componentToDrag,
                        const MouseEvent& e,
                        ComponentBoundsConstrainer* constrainer);

private:
    //==============================================================================
    Point<int> mouseDownWithinTarget;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ComponentDragger)
};

} // namespace juce
