I'm running the Qt4 backend, and I noticed that I'd frequently get error messages saying I was pressing unrecognized keys. It turns out that the direction keys aren't recognized in the qt4 backend. (I'm using direction keys to switch between spaces in OSX, so this error gets triggered quite frequently)
One possible fix is to just add the direction keys to the list of valid keys (see patch below). Alternatively, the key event code could just ignore unrecognized keys (i.e. `key == None`). This change could be made in FigureCanvasQT.keyPressEvent (in backends.backend_qt4.py) or, more generally, in FigureCanvasBase.key_press_event (in backend_bases.py).
-Tony
%---Diff
Index: lib/matplotlib/backends/backend_qt4.py
···
===================================================================
--- lib/matplotlib/backends/backend_qt4.py (revision 8315)
+++ lib/matplotlib/backends/backend_qt4.py (working copy)
@@ -129,6 +129,10 @@
keyvald = { QtCore.Qt.Key_Control : 'control',
QtCore.Qt.Key_Shift : 'shift',
QtCore.Qt.Key_Alt : 'alt',
+ QtCore.Qt.Key_Up : 'up',
+ QtCore.Qt.Key_Right : 'right',
+ QtCore.Qt.Key_Down : 'down',
+ QtCore.Qt.Key_Left : 'left',
}
# left 1, middle 2, right 3
buttond = {1:1, 2:3, 4:2}
%---Full traceback
Traceback (most recent call last):
File "/Users/Tony/python/devel/mpl/lib/matplotlib/backends/backend_qt4.py", line 198, in keyPressEvent
FigureCanvasBase.key_press_event( self, key )
File "/Users/Tony/python/devel/mpl/lib/matplotlib/backend_bases.py", line 1459, in key_press_event
self.callbacks.process(s, event)
File "/Users/Tony/python/devel/mpl/lib/matplotlib/cbook.py", line 169, in process
func(*args, **kwargs)
File "/Users/Tony/python/devel/mpl/lib/matplotlib/backend_bases.py", line 2079, in key_press
if event.key in fullscreen_keys:
TypeError: 'in <string>' requires string as left operand, not NoneType