[RFC] New Non-modal Dialogs

[Keith Seitz <keiths at cygnus dot com>]

Hi,

I posted some notes on modal dialog problems. Actually, the problem is
that all of our dialogs are modal. Really. Try opening a memory window and
entering a bad value for a location. It uses tk_messageBox to display the
error message. Without dismissing the dialog, try to do anything. In
particular, drag the source window over it. Notice that the focus has been
grabbed. The dialog demands attention, but does not keep itself raised.
This is just plain bad. I really don't understand why the error dialog
needs to be modal. I don't think it matters.

To combat this, I've created an "IconDialog" class which is supposed to
look/behave like tk_messageBox except without the annoying grab/focus
problems. Right now, it only displays a single button ("OK"), but you can
add buttons at will in derived classes.

There is a base "Dialog" class which does very little, but it is
explicitly ignored by ManagedWin, since we don't want dialogs to show up
in our active window list. I plan to check modal.tcl and merge it with
this, since I noticed it, too, had some problems doing the right thing
(TM).

I have also added an "ErrorDialog" class, which is simply a non-modal
error dialog. I've put in some cheesy graphics for the icon. I'd like to
change this, but for now, it looks like the Windows one. (Note: we are
losing some native look 'n' feel with this. Does anyone care? If so, we
need to do a lot more work to fix this problem "properly".) I will check
if tk8.3 has fixed this problem before I go committing anything.

The attached snapshots were taken on my Linux box and my Win2000 cygwin
box. Both were opened via:

(gdb) tk ErrorDialog::create -title "Well?" -message "How do you like
it?\nI know, it's not perfect,\nbut it's a good start at getting
something\nwhich works better than tk_messageBox."

[Yes, you can also specify a "-parent" flag to center the dialog over a
parent widget/toplevel."]

These dialogs are non-modal. They will just sit there forever if the user
does not get rid of them. This will replace all the calls to
"tk_messageBox" for non-fatal errors.

Sound plausible?
Keith

cygwin.gif

linux.gif