GtkDialog - How to change the value of a variable?

[MochiMoppel]

I'm stuck with a simple task: to toggle a button label. I have a variable defined outside of the dialog

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TEXT="go"

I now want a togglebutton to change its label whenever it's pushed. Something like this:

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	<togglebutton>
		<label>'"$TEXT"'</label>
		<variable>BTN</variable>
		<action>if true let TEXT="stop"</action>
		<action>if false let TEXT="go"</action>
		<action>refresh:BTN</action>
	</togglebutton>

This doesn't work. Is it somehow possible to change the value of TEXT and let the button refresh accordingly?

[zigbert]

The 'refresh' command does only manage the <input> tag, so the text can only be refreshed for <entry>, <combo...>, <edit>, <text>, <tree> and <table>.

The way I get around this is to build a svg-icon for a <button> widget, and rebuild it with new label when refreshing.


Sigmund

[don570]

-to ZIGBERT's post...

I made a simple example of SVG buttons (YES and NO)
in my manual

http://murga-linux.com/puppy/viewtopic.php?t=89045

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[MochiMoppel]

@ zigbert
Thanks for your prompt reply. Though this is quite a limitation, there is also something wrong with (the syntax?) of my code. The variabel doesn't change. Let's try another example with the <entry> tag. Outside of the dialog I've defined a variable TEXT="home". My code would look like this:

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	<togglebutton>
		<input file stock="gtk-'"$TEXT"'"></input>
		<variable>BTN</variable>
		<action>if true let TEXT="yes"</action>
		<action>if false let TEXT="no"</action>
		<action>refresh:BTN</action>
	</togglebutton>

Doesn't work either. The button shows the home icon, but doesn't change. No wonder: After I've left the dialog the variable hasn't changed to "yes" or "no". Where is my mistake? Changing the value of the variable is my primary problem, having the dialog pick up the value would be the next.

@don570
Your manual is the first thing I look for when I need a good example. Thanks for work Actually I studied your togglebutton example before posting, but I don't want to use icons, and if I must use them, I would like to stick to gtk stock icons. Does it really have to be svg icons?

[zigbert]

The mistake is the call for gtk stock icons. - You should refresh a file. don570 shows the solution.
When you first get used to svg, it is rather simple and powerful.


Sigmund

[don570]

To avoid using an SVG image button I tried a togglebutton instead.

http://murga-linux.com/puppy/viewtopic. ... 690#756690



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In my manual this is example that is closest ---->
The button changes color and label text changes. The signal that is
emitted changes the entry box text.


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[MochiMoppel]

The mistake is the call for gtk stock icons.

Hmmm...I'm afraid I failed to discribe my problem properly - though I tried to put it into the thread title. This thread was intended to clarify variable values and their scope, not togglebuttons and their limitations. I used togglebuttons only as an example. If this was a bad example, I'm sorry.
But I think I figured it out myself more or less: The variables in the main script that builds the dialog are accessible during the creation process. Once gtkdialog runs the MAIN_DIALOG (or whatever it was called) variable, this is done in a subshell (?), and this subshell has no access to the variables of other shells, not even the starting shell (unless the variables had been exported). But even in case of exported variables they would be read-only (?) and therefore can't be changed. So my real mistake was to assume that I can change the variable TEXT (containing the value "home") from within the dialog. My second mistake seems to be the value assignment in the <action> tags. Given that the TEXT variables declared in the main script and the variable in the dialog have nothing in common except the name, following assignment would fail:

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<action>if true let TEXT="yes";xmessage $TEXT</action> 

This also fails:

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<action>TEXT="yes"</action>
<action>xmessage $TEXT</action>

However this works:

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<action>TEXT="yes";xmessage $TEXT</action>

So we have exported read-only variables that can be used anywhere in the dialog, read-only variables declared with the <variable> tags that also can be used anywhere in the dialog, and finally read/write variables declared in the <action> tags that are local to the tag where they are declared. A bit confusing, but correct so far?

In my manual this is example that is closest

I didn't find this example in your manual.

To avoid using an SVG image button I tried a togglebutton instead.

Thanks, I've seen this example and it's a bit funny. The irony here: The togglebutton is the only button that does NOT toggle. The image doesn't change, the label doesn't change, but this would be essential for a togglebutton since the user needs a clue what the button will trigger.
I've played with your example and came up with a version that changes button image and label. I simply use 2 buttons (is that cheating?), which for the user appear as one. This also avoids the need to juggle symlinks and all other problems associated with using 2 sets of resources for only 1 button:

[Moose On The Loose]

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<action>TEXT="yes"</action>
<action>xmessage $TEXT</action>

However this works:

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<action>TEXT="yes";xmessage $TEXT</action>

I have found a reliable way to think about this sort of thing. In all cases where gtkdialog doesn't know the item used directly, I think of <action> as meaning "fire up a subshell and pass this string as a command to it". The subshell closes at the end of the command.

When the <action> starts with an item that gtkdialog knows then it does the work internally.

This breaks <action> into two very different things. The differences in behavior are kept from being confused this way. Variables created in the subshell only live until the end of the subshell. This explains why "TEXT" goes away between <action> lines.