Tk Source Code

This  code is called (within panedwindow.tcl) due to a
binding of a panedwindow widget as my application is
starting up (but prior to any user input):

proc ::tk::panedwindow::Motion {w x y} {
set id [$w identify $x $y]
....

The trouble appears to be that while the application is
starting up (widgets are being created), there is a
race (within the various widgets, as I don't see how I
can influence this...) between when this binding is
assigned and when various resources are actually
created (to the point that they support an "identify"
call).

I randomly get this error:
Error: bad option "identify": should be one of...
....

It happens 1 out of of 3 times I start up the
application - the other 2 of 3 times everything works...

It never occurs again after the application is running,
presumably because now the resources is fully
initialized and responds as expected to an "identify"
request.

The flow of my application is:

1. create toplevel
2. create panedwdiget
3. create child(ren) of panedwidget within "childsite(s)"
4. place, place, place
5. enter event loop

I have had no luck creating a smaller application to
demonstrate this as it appears that the shear size of
my application is what increases the likelyhood that
this race will occur.  This root cause (failure to
answer the "identify" request) might be a bigger
problem, but it seems that this library code
could/should trap this case as a matter of  cleanliness
(other calls in this file do similar things that
ideally would have similar traps).

As an additionaly note, running with a slower link to
the Xserver (i.e remote display over wireless ethernet)
reduces the occurance of this error to near zero -
further demonstrating that this is a race of some sort...

System info:
Using VTCL as an IDE, but hand editing code after
inital widget creation/placement
RH 7/8/9 (same result on all)
Window managers (same result on all): 
a. KDE
b. remote display to NT + Xwin32 client
c. gnome 

Using Tcl/tk ("wish") with itcl/itk/BLT/iwidgets all
latest stable versions as of ~2/12/2004

The easy solution seems simple and harmless enough and
perhaps should be applied to most of the bound
functions in this file (panedwindow.tcl):
--- panedwindow.tcl     Fri Feb 20 17:08:23 2004
+++ panedwindow.tcl~    Mon Feb  9 13:14:48 2004
@@ -108,12 +108,7 @@
 #
 proc ::tk::panedwindow::Motion {w x y} {
     variable ::tk::Priv
-    # this resource may not yet be fully initialized,
if so return without
-    # doing anything...
-    if {[catch {set id [$w identify $x $y]}]} {
-       return
-    }
-
+    set id [$w identify $x $y]
     if {([llength $id] == 2) && \
            (!$::tk_strictMotif || [string equal
[lindex $id 1] "handle"])} {
        if { ![info exists Priv($w,panecursor)] } {

Logged In: YES 
user_id=72656

This is highly unlikely to be a core bug, as a core
panedwindow binding is being called on something other than
a panedwindow.

Logged In: YES 
user_id=886869

oops - panedwindow is in the tk8.4 dir...  not tkincr

Just to clarify...

Logged In: YES 
user_id=886869

Sorry for the delay in responding...

1. Do not have any files called panedwindow.tcl in my project
2. mixing widget sets?  hmm, yes... using BLT and tkincr...

tkincr is the paned window (obviously)
BLT is being used for its container capabilities...

The BLT container is a sub-frame within one of the pane
childsites....

3. The "should be" is a little harder, I will remove my
patch and try to catch it (it is rather non-deterministic -
dependant on CPU load...)
/mike

Logged In: YES 
user_id=72656

What is the "should be one of ..." part of the error?  That
is critical, as I don't think this is a core error.  Are you
sure that you aren't mixing widget sets, or have some main
file called panedwindow.tcl, or some other case where
Panedwindow class would be assigned somewhere it shouldn't be?