Modal Dialogs lose grab when comboboxes are used

[Fernando Nasser <fnasser@redhat.com>]

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This happened in another application and I just checked and we also suffer from 
the same problem.

When we create a modal dialog we usually have a local grab that prevents the 
user to meddle with the main window (and others) before we dismiss the modal 
one.  We use this for preferences, target selection, attaching a target... 
things that we cannot proceed before they are settled.

The problem is that if these dialogs have a combobox and the combobox is 
expanded, a global grab is used by the combobox so that it is unposted 
regardless of where in the desktop you click (Tk menus do the same). 
Unfortunately once you grab the focus, any previous grab is lost (unless you 
take care of saving and restoring it, what the combobox doesn't seem to be doing).

This problem is common to the iwidgets:combobox and our own libgui combobox.

I have a possible fix to libgui that seems to solve our problem. Maybe Martin 
can double check that for us.

Here is the CL (patch attached):

	* library/combobox.tcl (build): New variable to save grabs.
	(widgetProc): Save and restore previous grabs.



-- 
Fernando Nasser
Red Hat - Toronto                       E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9

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Index: library/combobox.tcl
===================================================================
RCS file: /cvs/src/src/libgui/library/combobox.tcl,v
retrieving revision 1.2
diff -c -p -r1.2 combobox.tcl
*** library/combobox.tcl	8 Sep 2001 22:34:46 -0000	1.2
--- library/combobox.tcl	18 Sep 2002 20:40:49 -0000
*************** proc ::combobox::build {w args } {
*** 106,111 ****
--- 106,112 ----
  	variable options
  	variable oldValue
  	variable ignoreTrace
+ 	variable grablist
  	variable this
  
  	array set widgets {}
*************** proc ::combobox::doInternalWidgetCommand
*** 677,682 ****
--- 678,684 ----
  proc ::combobox::widgetProc {w command args} {
      upvar ::combobox::${w}::widgets widgets
      upvar ::combobox::${w}::options options
+     upvar ::combobox::${w}::grablist grablist
  
      # this is just shorthand notation...
      set doWidgetCommand \
*************** proc ::combobox::widgetProc {w command a
*** 787,792 ****
--- 789,795 ----
  
  	    # *gasp* do a global grab!!! Mom always told not to
  	    # do things like this... :-)
+ 	    set grablist [grab current]
  	    grab -global $widgets(this)
  
  	    # fake the listbox into thinking it has focus
*************** proc ::combobox::widgetProc {w command a
*** 802,807 ****
--- 805,813 ----
  	    }
  	    # hides the listbox
  	    grab release $widgets(this)
+ 	    foreach grabitem $grablist {
+ 	       grab set $grabitem
+ 	    }
  	    $widgets(button) configure -relief raised
  	    wm withdraw $widgets(popup)