/* ============================================================================== 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. ============================================================================== */ namespace juce { //============================================================================== /** Components derived from this class can have things dropped onto them by a DragAndDropContainer. To create a component that can receive things drag-and-dropped by a DragAndDropContainer, derive your component from this class, and make sure that it is somewhere inside a DragAndDropContainer component. Note: If all that you need to do is to respond to files being drag-and-dropped from the operating system onto your component, you don't need any of these classes: instead see the FileDragAndDropTarget class. @see DragAndDropContainer, FileDragAndDropTarget @tags{GUI} */ class JUCE_API DragAndDropTarget { public: /** Destructor. */ virtual ~DragAndDropTarget() = default; //============================================================================== /** Contains details about the source of a drag-and-drop operation. */ class JUCE_API SourceDetails { public: /** Creates a SourceDetails object from its various settings. */ SourceDetails (const var& description, Component* sourceComponent, Point localPosition) noexcept; /** A descriptor for the drag - this is set DragAndDropContainer::startDragging(). */ var description; /** The component from the drag operation was started. */ WeakReference sourceComponent; /** The local position of the mouse, relative to the target component. Note that for calls such as isInterestedInDragSource(), this may be a null position. */ Point localPosition; }; //============================================================================== /** Callback to check whether this target is interested in the type of object being dragged. @param dragSourceDetails contains information about the source of the drag operation. @returns true if this component wants to receive the other callbacks regarding this type of object; if it returns false, no other callbacks will be made. */ virtual bool isInterestedInDragSource (const SourceDetails& dragSourceDetails) = 0; /** Callback to indicate that something is being dragged over this component. This gets called when the user moves the mouse into this component while dragging something. Use this callback as a trigger to make your component repaint itself to give the user feedback about whether the item can be dropped here or not. @param dragSourceDetails contains information about the source of the drag operation. @see itemDragExit */ virtual void itemDragEnter (const SourceDetails& dragSourceDetails); /** Callback to indicate that the user is dragging something over this component. This gets called when the user moves the mouse over this component while dragging something. Normally overriding itemDragEnter() and itemDragExit() are enough, but this lets you know what happens in-between. @param dragSourceDetails contains information about the source of the drag operation. */ virtual void itemDragMove (const SourceDetails& dragSourceDetails); /** Callback to indicate that something has been dragged off the edge of this component. This gets called when the user moves the mouse out of this component while dragging something. If you've used itemDragEnter() to repaint your component and give feedback, use this as a signal to repaint it in its normal state. @param dragSourceDetails contains information about the source of the drag operation. @see itemDragEnter */ virtual void itemDragExit (const SourceDetails& dragSourceDetails); /** Callback to indicate that the user has dropped something onto this component. When the user drops an item this get called, and you can use the description to work out whether your object wants to deal with it or not. Note that after this is called, the itemDragExit method may not be called, so you should clean up in here if there's anything you need to do when the drag finishes. @param dragSourceDetails contains information about the source of the drag operation. */ virtual void itemDropped (const SourceDetails& dragSourceDetails) = 0; /** Overriding this allows the target to tell the drag container whether to draw the drag image while the cursor is over it. By default it returns true, but if you return false, then the normal drag image will not be shown when the cursor is over this target. */ virtual bool shouldDrawDragImageWhenOver(); }; } // namespace juce