From Newsgroup: comp.windows.x

On Sun, 13 Jul 2025 18:07:09 -0400, Winston wrote:

However, I'd like to have a Resize function that gets called when the application window resizes, without having to create a widget just to
have Resize() called.

At the lowest level, there is no fundamental distinction in X11 between a rCLwindowrCY and a rCLwidgetrCY. So if you can attach a handler for a particular
message to one, you should be able to do the same to the other. Any reason
why you canrCOt would be down to limitations of your GUI toolkit, not X11 itself.
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From Newsgroup: comp.windows.x

I originally asked:

However, I'd like to have a Resize function that gets called when the
application window resizes, without having to create a widget just to
have Resize() called.

to which Lawrence D'Oliveiro <ldo@nz.invalid> kindly replied:

At the lowest level, there is no fundamental distinction in X11 between a i#windowi# and a i#widgeti#. So if you can attach a handler for a particular message to one, you should be able to do the same to the other. Any reason why you cani>t would be down to limitations of your GUI toolkit, not X11 itself.

Ah, I wasn't careful enough in my wording: I was using "window" in the
window manager sense, not in the X11 Widget+Window object sense.

Again, I'd like to get notifications (in the generic sense, not
necessarily the strict X11 sense) of resize changes to the application's
Shell widget without having to create another widget just to have a ClassRec->resize function that I can set. ISTM that something akin to

XtAddCallback (shellwidget, XtNresize, myfunc, cldata)

[but it's not clear that would work: myfunc would need to be an
(XtCallbackProc), not an (XtWidgetProc) which the resize function
normally is; I can adapt myfunc easily enough, but the X11 code that
calls the resize function expects an (XtWidgetProc) [1 argument] and
might not like an (XtCallbackProc) [3 arguments]]

or that adding myfunc to some *_hook list would be the "X11 way" rather
than just setting

applicationShellClassRec.CoreClassPart.resize = myfunction

eliminating the function call that's already there.

Or I may be confused ...
-WBE
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From Newsgroup: comp.windows.x

I previously posted:

XtAddCallback (shellwidget, XtNresize, myfunc, cldata)

Just for the heck of it, I tried this. Unsurprisingly, it didn't work.
The XtAddCallback issued a warning printf of the form: couldn't find
named callback list. [I didn't save the exact message.]
-WBE
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From Newsgroup: comp.windows.x

On Tue, 15 Jul 2025 00:34:46 -0400, Winston wrote:

I originally asked:

However, I'd like to have a Resize function that gets called when
the application window resizes, without having to create a widget
just to have Resize() called.

to which Lawrence D'Oliveiro <ldo@nz.invalid> kindly replied:

At the lowest level, there is no fundamental distinction in X11
between a rCLwindowrCY and a rCLwidgetrCY. So if you can attach a handler
for a particular message to one, you should be able to do the same
to the other. Any reason why you canrCOt would be down to limitations
of your GUI toolkit, not X11 itself.

Ah, I wasn't careful enough in my wording: I was using "window" in
the window manager sense, not in the X11 Widget+Window object sense.

It shouldnrCOt be up to the window manager to control what happens
within a window.
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From Newsgroup: comp.windows.x

I originally asked (in part):

However, I'd like to have a Resize function that gets called when the application window resizes, without having to create a widget just to
have Resize() called.

What's a proper way to do that?

Found it: one good way is by adding a "<ResizeRequest>: action()" X11 translation. The XtActionProc is passed the (XResizeRequestEvent*) with
the new width and height as the (XEvent*) argument.
-WBE
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From Newsgroup: comp.windows.x

I originally asked (in part):

However, I'd like to have a Resize function that gets called when the
application window resizes, without having to create a widget just to
have Resize() called.

What's a proper way to do that?

A bit later, I answered:

Found it: one good way is by adding a "<ResizeRequest>: action()" X11 translation. The XtActionProc is passed the (XResizeRequestEvent*) with
the new width and height as the (XEvent*) argument.

A better way is to use <ConfigureNotify> instead of <ResizeRequest>.

ResizeRequest appears to be *instead of* the regular resize action.
Also, the ResizeRequest action observably gets called when the window is
merely moved on the desktop, even when the window's size hasn't changed.

By contrast, with ConfigureNotify the regular resize code is still run
and the translation action is called when the width or height changes,
but not when the window is just moved.
-WBE
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From Newsgroup: comp.windows.x

A few minutes ago, I posted:

By contrast, with ConfigureNotify the regular resize code is still run
and the translation action is called when the width or height changes,
but not when the window is just moved.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Oops. That last part is incorrect. My initial testing wasn't testing
what I thought it was. ConfigureNotify does, indeed, call the action
proc when the window is just moved. My apologies for the error.
-WBE
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