Created attachment 310331 [details] [review]
selections: Load spinner while creating first collection

Created attachment 310371 [details]
proposed solution

Looks good to me, surelly an improvement wrt the previous behaviour

Looks great!

Review of attachment 310331 [details] [review]:

Nice patch, Alessandro. One small thing:

::: data/ui/organize-collection-dialog.ui
@@ +93,3 @@
+            <property name="halign">center</property>
+            <property name="valign">center</property>
+            <property name="active">True</property>

Instead of having it active all the time, I would make the extra effort to start it only when it is shown and then stopping it.

Otherwise it will needlessly keep the CPU busy.

Created attachment 312821 [details] [review]
selections: Load spinner while creating first collection

Start/stop the spinner when needed.

Some updates from #gtk+:
13:06 <rishi> What happens to a GtkSpinner (active=TRUE) that is in a GtkStack  
      but is not the visible widget? Is it still spinning and eating CPU?
13:08 * kalev had the same question the other day.
13:13 <rishi> kalev: I think it does because cosimoc said so in 2012, unless    
      gtk+ got smarter in the last 3 years.
13:13 <ebassi> Unless the style system is using child visibility to decide if   
      an animation should progress, then no: the spinner will continue          
      spinning
13:14 <rishi> ebassi: Ok.
13:15 <mclasen> we're certainly not drawing it
13:16 <mclasen> the expensive part is where it invalidates size and that        
      propagates all the way up to the toplevel
13:16 <ebassi> Yeah, the widget won't be drawn, but the style will be           
      invalidated, AFAIR
13:16 <mclasen> but we're fixing that
13:16 <mclasen> any day now, I hope

It's not a lot of effort to start/stop it, so let's take the defensive approach. Plus we need this in 3.18.x.

Comment on attachment 312821 [details] [review]
selections: Load spinner while creating first collection

Pushed to master and gnome-3-18.