Drop use of deprecated GtkHSV widget

[Alex Valavanis]

Gimp and Inkscape currently use the GtkHSV widget to provide a "color wheel"

* Inkscape: widgets/sp-color-wheel-selector.cpp.
* GIMP: modules/color-selector-wheel.c

This widget is deprecated in GTK+ 3 [1] and will eventually be removed. We will need to adapt our code accordingly

Options:

1. Drop our color-wheel widget entirely; only use color-scales instead.

2. Adopt the GtkHSV code, and maintain it ourselves.

3. Make our own replacement color-wheel widget

4. Other suggestions...??

[1] http://developer.gnome.org/gtk3/3.6/GtkHSV.html

[jazzynico (jazzynico)]

First talk to Gimp devs in order to know their plan? We already adopted and adapted their sliders. If it's relevant, we could also adapt their wheel.

[Alex Valavanis (valavanisalex)]

Tracked in GIMP at https://bugzilla.gnome.org/show_bug.cgi?id=689371

[Alex Valavanis (valavanisalex)]

GIMP devs plan to pull the widget back into their tree. It was their widget before it was adopted by GTK+.

Should we pull it from GIMP when they do, or adopt it directly from GTK+?

[Alex Valavanis (valavanisalex)]

OK, the GTK+ version apparently has some big errors, and the widget will be maintained in GIMP from now on. We should grab it from GIMP when it's ready.

[Alex Valavanis (valavanisalex)]

First attempt at patch added. I can't test this properly, as I'm running a slow remote Xserver

[su_v (suv-lp)]

> First attempt at patch added.

Quick test with Fill&Stroke color selector on OS X 10.7.4:
- GTK2 builds seem ok (the wheel looks slightly slimmer than the one before)
- GTK3 builds crash when selecting the color wheel in Fill&Stroke
  (both GTK+/X11 3.4.4 and GTK+/Quartz 3.6.3)

[Alex Valavanis (valavanisalex)]

Should be fixed in lp:inkscape r12011. I have switched over to using the upstream GTK+ 3 code, which should hopefully have fixed the crash.

@suv - please could you check whether the crash is still there on either platform?

[su_v (suv-lp)]

>please could you check whether the crash is still there on either platform?

r12011 works ok with GTK2 and GTK3 builds (no more crashes) on OS X 10.7.4, with either backend of GTK+:
- GTK+/X11 2.24.13, gtkmm 2.24.2, glib 2.32.4
- GTK+/X11 3.4.4, gtkmm 3.4.0, glib 2.32.4
- GTK+/Quartz 2.24.15 (git branch), gtkmm 2.24.2, glib 2.34.3
- GTK+/Quartz 3.6.4, gtkmm 3.6.0, glib 2.34.3

I do get some warnings when compiling (with llvm-gcc.4.2), both with GTK2 and GTK3, but they don't cause the build to fail. From the GTK+/Quartz 3.6.4 build:
../../src/ui/widget/gimpcolorwheel.c: In function ‘set_cross_grab’:
../../src/ui/widget/gimpcolorwheel.c:690: warning: ‘gdk_pointer_grab’ is deprecated (declared at /Volumes/cyan/mp-quartz/with-a-long-long-long-directory-name/include/gtk-3.0/gdk/gdkmain.h:86)
../../src/ui/widget/gimpcolorwheel.c: In function ‘gimp_color_wheel_grab_broken’:
../../src/ui/widget/gimpcolorwheel.c:704: warning: unused parameter ‘event’
../../src/ui/widget/gimpcolorwheel.c: In function ‘gimp_color_wheel_button_release’:
../../src/ui/widget/gimpcolorwheel.c:800: warning: ‘gdk_display_pointer_ungrab’ is deprecated (declared at /Volumes/cyan/mp-quartz/with-a-long-long-long-directory-name/include/gtk-3.0/gdk/gdkdisplay.h:56)
../../src/ui/widget/gimpcolorwheel.c: At top level:
../../src/ui/widget/gimpcolorwheel.c:106: warning: ‘gimp_color_wheel_size_request’ declared ‘static’ but never defined