| :mod:`tkinter.dnd` --- Drag and drop support |
| ============================================ |
| |
| .. module:: tkinter.dnd |
| :platform: Tk |
| :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` |