# `tkinter.dnd` — Drag and drop support

Source code: Lib/tkinter/dnd.py

Note

This is experimental and due to be deprecated when it is replaced with the Tk DND.

The `tkinter.dnd` module provides drag-and-drop support for objects within a single application, within the same window or between windows. To enable an object to be dragged, you must create an event binding for it that starts the drag-and-drop process. Typically, you bind a ButtonPress event to a callback function that you write (see Bindings and Events). The function should call `dnd_start()`, where ‘source’ is the object to be dragged, and ‘event’ is the event that invoked the call (the argument to your callback function).

Selection of a target object occurs as follows:

1. Top-down search of area under mouse for target widget

> - Target widget should have a callable dnd_accept attribute
> - If dnd_accept is not present or returns None, search moves to parent widget
> - If no target widget is found, then the target object is None

2. Call to <old_target>.dnd_leave(source, event)
3. Call to <new_target>.dnd_enter(source, event)
4. Call to <target>.dnd_commit(source, event) to notify of drop
5. Call to <source>.dnd_end(target, event) to signal end of drag-and-drop

class `tkinter.dnd.``DndHandler`(source, event)

  The DndHandler class handles drag-and-drop events tracking Motion and ButtonRelease events on the root of the event widget.

  `cancel`(event=None)

    Cancel the drag-and-drop process.

  `finish`(event, commit=0)

    Execute end of drag-and-drop functions.

  `on_motion`(event)

    Inspect area below mouse for target objects while drag is performed.

  `on_release`(event)

    Signal end of drag when the release pattern is triggered.

`tkinter.dnd.``dnd_start`(source, event)

  Factory function for drag-and-drop process.

See also

Bindings and Events