:mod:!tkinter.dnd --- Drag and drop support

.. module:: tkinter.dnd :synopsis: Tkinter drag-and-drop interface

Source code: :source:Lib/tkinter/dnd.py

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

The :mod:!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 :ref:Bindings-and-Events). The function should call :func: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:

#. 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) #. Call to <new_target>.dnd_enter(source, event) #. Call to <target>.dnd_commit(source, event) to notify of drop #. Call to <source>.dnd_end(target, event) to signal end of drag-and-drop

.. class:: DndHandler(source, event)

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

.. method:: cancel(event=None)

  Cancel the drag-and-drop process.

.. method:: finish(event, commit=0)

  Execute end of drag-and-drop functions.

.. method:: on_motion(event)

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

.. method:: on_release(event)

  Signal end of drag when the release pattern is triggered.

.. function:: dnd_start(source, event)

Factory function for drag-and-drop process.

.. seealso::

:ref:Bindings-and-Events