Tkinter.event.widget: handler gets name instead of widget.

Frederic Rentsch anthra.norell at bluewin.ch
Sun Jul 8 23:19:13 CEST 2012


Hi widget wizards,

	The manual describes the "event" attribute "widget" as "The widget
which generated this event. This is a valid Tkinter widget instance, not
a name. This attribute is set for all events."
	Ans so it is--has been until on the latest occasion "event.widget" was
not the widget, but its name, crashing the handler. 	
# Here I build a list of selectable records having each four fields.
# The fields are labels. The selectable line is a frame containing the 
# labels side by side. The line frames go into self, which is a Frame. 

for n in range (len (records)):
	record = records [n]
	line_frame = Frame (self, name = '-%d-' % n, relief = RAISED, **BUTTON_FRAME_)
	line_frame.bind ('<Enter>', self.enter)
	line_frame.bind ('<Leave>', self.leave)
	line_frame.bind ('<ButtonRelease-1>', self.pick_record)
	line_frame.bind ('<ButtonRelease-3>', self.info_profile)
	line_frame.grid (row = n+2, column = 1)
	for i in self.range_n_fields:   # (0, 1, 2, 3)
		field = Label (line_frame, text = record [self.INDICES [i]], anchor = W, width = self.COLUMN_WIDTHS [i], **DB_LIST_LABEL_)
		field.grid (row = 0, column = i, sticky = NW)

# Here is the <Enter> handler:

def enter (self, event):
	w = event.widget
	print 'hit list.enter (). Event, widget', event, w, w.__class__ # Tracing line
 	w.config (bg = SELECTED_BG_COLOR)

# And here is what comes out. The first line is my tracing line. The name is correct in that it 
# names the entered line_frame, but is wrong because it should be the line_frame, not its name.
# The rest is the red exception message:

hit list.enter (). Event, widget <Tkinter.Event instance at 0x9115dcc> .main-frame.data-frame.title-hit-list.-10- <type 'str'>
Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.6/lib-tk/Tkinter.py", line 1413, in __call__
    return self.func(*args)
  File "/home/fr/python/finance/piam/hit_list.py", line 83, in enter
    w.config (bg = SELECTABLE_BG_COLOR)
AttributeError: 'str' object has no attribute 'config'

# The same thing happens with <Leave>. The other handlers I haven't done yet. The same bindings work well in 
# a Menu class with the difference that the bindings are on the Labels, not a containing Frame.

# Dell E6500, Ubuntu 10.04, Python 2.6


Frederic





More information about the Python-list mailing list