"""
MouseModes define various mouse gestures.
MouseModes are generally activated and deactivated by toolbar buttons, although
not necessarily so. The toolbar maintains a list of MouseModes from the
visualization it is assigned to, and sees to it that only one MouseMode is
active at a time.
Each MouseMode appears as an Icon in the toolbar. Classes can assign methods to
the press_callback, move_callback, and release_callback methods of each Mouse
Mode, to implement custom functionality
The basic usage pattern is thus:
* visualization object instantiates the MouseModes it wants
* each of these is passed to the add_tool method of the toolbar
* visualization object optionally attaches methods to the 3 _callback
methods in a MouseMode, for additional behavior
"""
from __future__ import absolute_import, division, print_function
__all__ = ['MouseMode']
[docs]class MouseMode(object):
"""
The base class for all MouseModes.
MouseModes have the following attributes:
* press_callback : Callback method that will be called
whenever a MouseMode processes a mouse press event
* move_callback : Same as above, for move events
* release_callback : Same as above, for release events
* key_callback : Same as above, for release events
The _callback hooks are called with the MouseMode as its only
argument
"""
def __init__(self, viewer,
press_callback=None,
move_callback=None,
release_callback=None,
key_callback=None):
self._axes = getattr(viewer, 'axes', None)
self._canvas = viewer.central_widget.canvas
self._press_callback = press_callback
self._move_callback = move_callback
self._release_callback = release_callback
self._key_callback = key_callback
self._event_x = None
self._event_y = None
self._event_xdata = None
self._event_ydata = None
self._connections = []
def _log_position(self, event):
if event is None:
return
self._event_x, self._event_y = event.x, event.y
self._event_xdata, self._event_ydata = event.xdata, event.ydata
[docs] def press(self, event):
"""
Handles mouse presses.
Logs mouse position and calls press_callback method.
Parameters
----------
event : :class:`~matplotlib.backend_bases.MouseEvent`
The event that was triggered
"""
self._log_position(event)
if self._press_callback is not None:
self._press_callback(self)
[docs] def move(self, event):
"""
Handles mouse move events.
Logs mouse position and calls move_callback method.
Parameters
----------
event : :class:`~matplotlib.backend_bases.MouseEvent`
The event that was triggered
"""
self._log_position(event)
if self._move_callback is not None:
self._move_callback(self)
[docs] def release(self, event):
"""
Handles mouse release events.
Logs mouse position and calls release_callback method.
Parameters
----------
event : :class:`~matplotlib.backend_bases.MouseEvent`
The event that was triggered
"""
self._log_position(event)
if self._release_callback is not None:
self._release_callback(self)
[docs] def key(self, event):
"""
Handles key press events.
Calls key_callback method.
Parameters
----------
event : :class:`~matplotlib.backend_bases.KeyEvent`
The event that was triggered
"""
if self._key_callback is not None:
self._key_callback(self)
[docs] def activate(self):
"""
Activates all MPL event handlers associated with this mouse mode.
"""
self._connections.append(self._canvas.mpl_connect('button_press_event', self.press))
self._connections.append(self._canvas.mpl_connect('motion_notify_event', self.move))
self._connections.append(self._canvas.mpl_connect('button_release_event', self.release))
self._connections.append(self._canvas.mpl_connect('key_press_event', self.key))
[docs] def deactivate(self):
"""
Deactivates all MPL event handlers associated with this mouse mode.
"""
for connection in self._connections:
self._canvas.mpl_disconnect(connection)
self._connections = []