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Handling Python/GTK's GtkScale value-changed event.

Date published: 2022-01-29T00:00:00+0200

It took me way too long, but now I know how to handle the value-changed event of GtkScale.

In Glade:

Create a GtkScale widget. We will ID it foo_scale.
In the Signals -> GtkRange -> value-changed line change the Handler field to something sensible like on_foo_scale_value_changed. That will be the name of the handler.

Make a new Adjustment in:

General ->
Adjustment ->
(little pen button in the field) ->
Choose a [sic] Adjustment in this project ->
New

Rename the adjustment to something sensible like foo_adjustment and set the Value, Minimum Value, Maximum Value, etc. Those are kind of self explanatory…
In Python, your handler will be called with a single argument - the signal emitting object, which is the GtkScale object itself. It has a method, get_value(), used to get its current value:
```
def on_foo_scale_value_changed(emitter):
    scale_value = emitter.get_value()
do_stuff_with_scale_value(scale_value)
```

Fin.

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