The appropriate relation is already set with the mnemonic_widget property.
In particular, this also fixes an issue where a screenreader would
emit "Crosshairs" every time a new tab was entered in the Zoom dialog
because of some incorrect labelled-by relations.
This commit turns the ZoomOptions into a template class that
subclasses GtkDialog.
This is also a follow-up from commit c82deede1 where we started
using the non-deprecated GdkMonitor API.
We can simply use a GtkBox and set the orientation property.
Since this property defaults to 'horizontal', we actually
only need to set it when replacing GtkVBox.
The behaviour of the GtkBox expand child property changed in
GTK+ 3.10, back to its traditional behaviour: It no longer
propagates up. Propagation is now reserved for the GtkWidget
hexpand property. Therefore, we can get the sliders back
to the way they were in 3.8 by setting hexpand to TRUE.
http://bugzilla.gnome.org/show_bug.cgi?id=708493
Add 'Color effects' section to zoom options dialogue:
- a toggle for inversion (White on black)
- a slider for brightness
- a slider for contrast
- a slider for grey scale
https://bugzilla.gnome.org/show_bug.cgi?id=676817
Added UI and code to spawn a zoom options preferences dialog to
modify various magnifier settings. Modified the 'Seeing'
section of the universal access panel to enable the 'Options...'
button.
https://bugzilla.gnome.org/show_bug.cgi?id=643086
