Handling focus #34

defaultxr commented 2025年09月29日 03:22:45 +02:00

Hi.

I'm going back to my sequencer project now and I'm not sure how to handle this situation:

I have a text box, i.e. (make-text ...). I want the user to be able to press space to insert a space into the text box when it's selected/focused, but when the text box isn't focused, space should perform a different action.

I also want to be able to switch the currently-focused widget using <Ctrl-tab>. I have the text box, but I also have several canvases ((make-canvas ...)) - four by default, but it's possible for there to be more or less than that. So I'm not sure how to write a function that will cycle through each focusable widget in the correct order. I see that nodgui:bind-tag-set-focus-next is a function that exists and the warning in set-focus-next makes it sound like bind-tag-set-focus-next is what I will need to use, but it seems that it requires the currently-focused widget as its first argument, and I don't think Nodgui has a function to get the currently-focused widget. It looks like Tk has a focus_get function but it seems that Nodgui doesn't have this yet. I tried implementing it myself but I'm pretty sure I"m doing something wrong. I also thought maybe I could just use (event-widget event) in the function that <Ctrl-tab> is being bound to, but event-widget doesn't exist either.

So, I'm curious how you'd handle implementing something like this, if you have any suggestions.

Hi. I'm going back to my sequencer project now and I'm not sure how to handle this situation: I have a text box, i.e. `(make-text ...)`. I want the user to be able to press space to insert a space into the text box when it's selected/focused, but when the text box isn't focused, space should perform a different action. I also want to be able to switch the currently-focused widget using `<Ctrl-tab>`. I have the text box, but I also have several canvases (`(make-canvas ...)`) - four by default, but it's possible for there to be more or less than that. So I'm not sure how to write a function that will cycle through each focusable widget in the correct order. I see that `nodgui:bind-tag-set-focus-next` is a function that exists and the warning in `set-focus-next` makes it sound like `bind-tag-set-focus-next` is what I will need to use, but it seems that it requires the currently-focused widget as its first argument, and I don't think Nodgui has a function to get the currently-focused widget. It looks like Tk has a `focus_get` function but it seems that Nodgui doesn't have this yet. I tried implementing it myself but I'm pretty sure I"m doing something wrong. I also thought maybe I could just use `(event-widget event)` in the function that `<Ctrl-tab>` is being bound to, but `event-widget` doesn't exist either. So, I'm curious how you'd handle implementing something like this, if you have any suggestions.

defaultxr commented 2025年09月29日 03:51:10 +02:00

Also, I think (setf (text textbox) ...) has a bug? When I do (setf (text textbox) "[foo]") the textbox's text is set to \[foo\] (including the backslashes).

Also, I think `(setf (text textbox) ...)` has a bug? When I do `(setf (text textbox) "[foo]")` the textbox's text is set to `\[foo\]` (including the backslashes).

defaultxr commented 2025年09月29日 04:52:29 +02:00

Also, when I change (make-instance 'frame ...) to (make-instance 'scrolled-frame ...) it puts the scrollbar in a weird place. Does this happen for you? My use of (make-instance 'frame ...) works totally fine so I'm not sure what I would be doing wrong to make the scrollbar show up like this. The only change I made is changing 'frame to 'scrolled-frame.

Also, when I change `(make-instance 'frame ...)` to `(make-instance 'scrolled-frame ...)` it puts the scrollbar in a weird place. Does this happen for you? My use of `(make-instance 'frame ...)` works totally fine so I'm not sure what I would be doing wrong to make the scrollbar show up like this. The only change I made is changing `'frame` to `'scrolled-frame`.

cage commented 2025年09月29日 20:11:03 +02:00

Hi!

@defaultxr wrote in #34 (comment):

Also, I think (setf (text textbox) ...) has a bug? When I do (setf (text textbox) "[foo]") the textbox's text is set to \[foo\] (including the backslashes).

This is definitely a bug. I am opening a separate issue for that.

Bye!
C.

Hi! @defaultxr wrote in https://codeberg.org/cage/nodgui/issues/34#issuecomment-7423219: > Also, I think `(setf (text textbox) ...)` has a bug? When I do `(setf (text textbox) "[foo]")` the textbox's text is set to `\[foo\]` (including the backslashes). This is definitely a bug. I am opening a separate issue for that. Bye! C.

cage commented 2025年09月29日 20:16:56 +02:00

@defaultxr wrote in #34 (comment):

Also, when I change (make-instance 'frame ...) to (make-instance 'scrolled-frame ...) it puts the scrollbar in a weird place. Does this happen for you?

Honestly no, but despite being TK boring technology, sometimes it is able to surprise you anyway! 😄

Can you please, show a minimal example that reproduce the bug? Or, alternatively, instruction to reproduce the bug?

Bye!
C.

@defaultxr wrote in https://codeberg.org/cage/nodgui/issues/34#issuecomment-7423618: > Also, when I change `(make-instance 'frame ...)` to `(make-instance 'scrolled-frame ...)` it puts the scrollbar in a weird place. Does this happen for you? Honestly no, but despite being TK boring technology, sometimes it is able to surprise you anyway! 😄 Can you please, show a minimal example that reproduce the bug? Or, alternatively, instruction to reproduce the bug? Bye! C.

cage commented 2025年09月29日 20:27:06 +02:00

@defaultxr wrote in #34 (comment):

Hi.

I'm going back to my sequencer project

Happy to hear that! 😄

It looks like Tk has a focus_get function but it seems that Nodgui doesn't have this yet.

I think should be implemented, if possible. Likely i just need just pass to the TK interpreter the command focus , without arguments.

Let's see if this works!

I tried implementing it myself but I'm pretty sure I"m doing something wrong. I also thought maybe I could just use (event-widget event) in the function that <Ctrl-tab> is being bound to, but event-widget doesn't exist either.

So, I'm curious how you'd handle implementing something like this, if you have any suggestions.

Maybe is fire-events a function that could help you?

https://codeberg.org/cage/nodgui/src/branch/master/src/events.lisp#L193

Thanks for helping improving the library!
C.

@defaultxr wrote in https://codeberg.org/cage/nodgui/issues/34#issue-2444059: > Hi. > > I'm going back to my sequencer project Happy to hear that! 😄 > It looks like Tk has a `focus_get` function but it seems that Nodgui doesn't have this yet. I think should be implemented, if possible. Likely i just need just pass to the TK interpreter the command `focus` , without arguments. Let's see if this works! > > > I tried implementing it myself but I'm pretty sure I"m doing something wrong. I also thought maybe I could just use `(event-widget event)` in the function that `<Ctrl-tab>` is being bound to, but `event-widget` doesn't exist either. > > So, I'm curious how you'd handle implementing something like this, if you have any suggestions. Maybe is `fire-events` a function that could help you? https://codeberg.org/cage/nodgui/src/branch/master/src/events.lisp#L193 Thanks for helping improving the library! C.

cage commented 2025年09月29日 22:07:34 +02:00

Hi @defaultxr !

I have added a function: widget-with-focus that i think could help you (and other people too, i hope!). Please take a look the following code, when run, will print the widget that got the focus:

(defun test ()
 (with-nodgui ()
 (let* ((frame (make-instance 'frame))
 (button (make-instance 'button :text "test" :master frame)))
 (grid button 0 0)
 (grid frame 0 0)
 (force-focus button)
 (wait-complete-redraw)
 (format t
 "focus to ~a~%"
 (widget-with-focus)))))

Bye!
C.

Hi @defaultxr ! I have added a function: `widget-with-focus` that i think could help you (and other people too, i hope!). Please take a look the following code, when run, will print the widget that got the focus: ``` lisp (defun test () (with-nodgui () (let* ((frame (make-instance 'frame)) (button (make-instance 'button :text "test" :master frame))) (grid button 0 0) (grid frame 0 0) (force-focus button) (wait-complete-redraw) (format t "focus to ~a~%" (widget-with-focus))))) ``` Bye! C.

cage commented 2025年09月30日 17:56:26 +02:00

@cage wrote in #34 (comment):

Hi @defaultxr !

Also, I think (setf (text textbox) ...) has a bug? When I do (setf (text textbox) "[foo]") the textbox's text is set to \[foo\] (including the backslashes).

I tried the code below but i was unable to reproduce the issue, can you please, provide some code to get the bug on my machine?

Thanks in advance!
C.

(in-package :nodgui)
(defun main ()
 (with-nodgui ()
 (let ((textarea (make-instance 'scrolled-text))
 (scrolled-textarea (make-instance 'text)))
 (grid-implicit (list textarea scrolled-textarea))
 (wait-complete-redraw)
 (setf (text textarea) "[foo]")
 (setf (text scrolled-textarea) "[bar]"))))

@cage wrote in https://codeberg.org/cage/nodgui/issues/34#issuecomment-7443964: Hi @defaultxr ! > > Also, I think `(setf (text textbox) ...)` has a bug? When I do `(setf (text textbox) "[foo]")` the textbox's text is set to `\[foo\]` (including the backslashes). I tried the code below but i was unable to reproduce the issue, can you please, provide some code to get the bug on my machine? Thanks in advance! C. ``` lisp (in-package :nodgui) (defun main () (with-nodgui () (let ((textarea (make-instance 'scrolled-text)) (scrolled-textarea (make-instance 'text))) (grid-implicit (list textarea scrolled-textarea)) (wait-complete-redraw) (setf (text textarea) "[foo]") (setf (text scrolled-textarea) "[bar]")))) ```