Theme scroll button in the tray

[erikos]

see how it looks like at the moment:  http://bugs.sugarlabs.org/attachment/ticket/3522/bookmarks_tray.png

and how it could look like (example from Record), note that Record has a different behavior as well as the icons are shown all the time but changes the state active/inactive:
 http://bugs.sugarlabs.org/attachment/ticket/3522/tray_record.png

 http://bugs.sugarlabs.org/attachment/ticket/3522/tray_record_can_scroll.png

Not a regression, but if there is an easy fix, let's do it.

[erikos]

Moving out that we fix the regressions first.

[manuq]

Preliminar patch

[manuq]

Sugar trays are gtk boxes that pack buttons in both ends, and a gtk viewport in the middle. The viewport packs a gtk toolbar.

What we need here is 1. paint the background of those boxes, and 2. style the buttons.

For 2 we just need to add the gtype_name and the attached patch does so.

For 1 we have to convert the boxes to EventBoxes because otherwise the background is not themeable:  https://bugzilla.gnome.org/show_bug.cgi?id=678790

I did so in the attached patch but now I have an issue in the _size_allocate_cb of _TrayViewport:

(tray.py:18161): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -1280350453 and height 1

So I need fix that. Then, a patch for artwork is trivial.

Runing the testcase in toolkit-gtk3 tests/graphics/test.py is being useful to work on this.

[manuq]

Candidate patch for 1.

[manuq]

Artwork patch for 2.

[manuq]

The two patches, one for artwork and one for toolkit, make the style correct again.

[manuq]

Pushed toolkit d418d1cb artwork 8b24e667 .

[erikos]

When testing #3565 I came across #4279. Your theme changes do works well, thanks for this.

[greenfeld]

The favorites bar in Browse now has sugar-like dark-background arrows in Sugar 0.98.3 (although the oblong oval highlight when touched/hovered looks a bit odd).