# Why won't my FXRuby widgets update?

**URL:** <https://www.ruby-forum.com/t/why-wont-my-fxruby-widgets-update/75700>\
**Category:** Ruby\
**Created:** [November 12, 2006, 3:01pm UTC](https://www.ruby-forum.com/t/why-wont-my-fxruby-widgets-update/75700 "2006-11-12T15:01:44Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![gsiener](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/3ec8ea/32.png) [@gsiener](https://www.ruby-forum.com/u/gsiener)\
**Post date:** [November 12, 2006, 3:01pm UTC](https://www.ruby-forum.com/t/why-wont-my-fxruby-widgets-update/75700/1 "2006-11-12T15:01:44Z")

</div>

Hi,

Anybody out there faced this ? (the code below is actually just the core  
of the “babelfish” example). But there’s a “flaw” in the code that isn’t  
mentioned in the documentation. Specifically, when the button press  
invokes procAll, any updates to the widgets are sort of “queued up”  
until procAll finishes and only then are they applied - I discovered  
this by painstaking trial and error. What if I want procAll to go away  
and process a load of stuff that might take 20 minutes, but I want to  
update the screen with messages about progress and stuff. I just find  
that I get nothing until procAll ends. Clearly I’ve missed a step with  
setting up the messaging, but the documentation is persuading me that  
there’s nothing more to do.

Can anybody tell me what’s wrong with the code below ? Why won’t the  
text field show the text as soon as the data target is updated as the  
documentation implies it will ? Other widgets behave in a similar  
fashion with the exception of the progress bar which will update  
immediately. Very peculiar. Any help appreciated.

Regards,  
Graham Stokes

#!/usr/bin/env ruby  
require ‘fox16’  
include Fox

class Update\_test \< FXMainWindow

def initialize(app)  
super(app, “Test”, nil, nil, DECOR\_ALL,  
0, 0, 600, 400, 0, 0)  
controlsFrame = FXHorizontalFrame.new(self,  
LAYOUT\_SIDE\_BOTTOM|LAYOUT\_FILL\_X)

```
btn = FXButton.new(controlsFrame, "Go", nil, nil, 0,
  BUTTON_NORMAL|LAYOUT_SIDE_RIGHT)
btn.connect(SEL_COMMAND, method (:procAll))

bottomFrame = FXVerticalFrame.new(self, LAYOUT_FILL_X|LAYOUT_FILL_Y)
FXLabel.new(bottomFrame, "Text:", nil, LAYOUT_FILL_X)
sunkenFrame = FXHorizontalFrame.new(bottomFrame,
  FRAME_SUNKEN|FRAME_THICK|LAYOUT_FILL_X|LAYOUT_FILL_Y)
@stringVal = FXDataTarget.new("", nil, 0)
@translatedText = FXText.new(sunkenFrame, @stringVal, 

```

FXDataTarget::ID\_VALUE,  
TEXT\_READONLY|LAYOUT\_FILL\_X|LAYOUT\_FILL\_Y)  
end

def create  
super  
show(PLACEMENT\_CURSOR)  
end

def procAll(sender, sel, ptr)  
@stringVal.value += “This is new text\n” # This doesn’t appear  
\<20-minutes-processing here\>  
end # until here. Why is  
this ?

end

if **FILE** == $0  
application = FXApp.new(“Test”, “Test”)  
window = Update\_test.new(application)  
application.create  
application.run  
end

---

<div class="post-metadata">

**Author:** ![gsiener](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/3ec8ea/32.png) [@gsiener](https://www.ruby-forum.com/u/gsiener)\
**Post date:** [November 13, 2006, 6:02am UTC](https://www.ruby-forum.com/t/why-wont-my-fxruby-widgets-update/75700/2 "2006-11-13T06:02:00Z")

</div>

Graham Stokes wrote:

> that I get nothing until procAll ends. Clearly I’ve missed a step with  
> setting up the messaging, but the documentation is persuading me that  
> there’s nothing more to do.
> 
> Can anybody tell me what’s wrong with the code below ? Why won’t the  
> text field show the text as soon as the data target is updated as the  
> documentation implies it will ? Other widgets behave in a similar  
> fashion with the exception of the progress bar which will update  
> immediately. Very peculiar. Any help appreciated.

I think your diagnosis is right. Your ruby code is never giving Fox a  
chance to update the GUI. You can fix it by explicitly sharing time with  
Fox:

def procAll(sender, sel, ptr)  
@stringVal.value += “This is new text\n”  
500.times do  
getApp.runOneEvent  
sleep 0.01 # or do some fraction of your processing  
end  
end

There’s still a little delay, but it’s probably acceptable.

You might want to do the runOneEvent calls in one ruby thread, and do  
your non-GUI processing in another.

In some cases, you really want “as soon as” semantics, and in those a  
good alternative to FXDataTarget is my FoxTails lib. See  
[FoxTails](http://redshift.sourceforge.net/foxtails) or search the fxruby-users list  
archive.

---

<div class="post-metadata">

**Author:** ![gsiener](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/g/3ec8ea/32.png) [@gsiener](https://www.ruby-forum.com/u/gsiener)\
**Post date:** [November 13, 2006, 11:31am UTC](https://www.ruby-forum.com/t/why-wont-my-fxruby-widgets-update/75700/3 "2006-11-13T11:31:18Z")

</div>

Joel VanderWerf wrote:

> I think your diagnosis is right. Your ruby code is never giving Fox a  
> chance to update the GUI. You can fix it by explicitly sharing time with  
> Fox:
> 
> def procAll(sender, sel, ptr)  
> @stringVal.value += “This is new text\n”  
> 500.times do  
> getApp.runOneEvent  
> sleep 0.01 # or do some fraction of your processing  
> end  
> end
> 
> There’s still a little delay, but it’s probably acceptable.
> 
> You might want to do the runOneEvent calls in one ruby thread, and do  
> your non-GUI processing in another.

Joel, thanks a lot for pointing me in the right direction - this indeed  
turns out to be the problem and event processing in a separate thread is  
easy and elegant. How curious that none of the examples supplied pays  
any attention to this requirement.

> In some cases, you really want “as soon as” semantics, and in those a  
> good alternative to FXDataTarget is my FoxTails lib. See  
> [FoxTails](http://redshift.sourceforge.net/foxtails) or search the fxruby-users list  
> archive.

I will check this out to see the benefits. Thanks again.

Best Regards,  
Graham