When tabs are not shown, and the notebook is used as a container,
we should not set the notebook style, otherwise the theme has no
way to know whether tabs are shown or not, and which colour to draw
the background.
https://bugzilla.gnome.org/show_bug.cgi?id=640692
The render order for tabs is now
- left to right until the active tab
- right to left until the active tab
- active tab
This allows themes that use non-straight lines for the tab curvature to
draw them not worrying about flipping one side after the active tab.
Let the tab overlap eat the padding, otherwise having tab-overlap >
tab-curvature without cutting the label is impossible.
This way we give the label widget all the allocation possible before
giving up and cutting it if the values for tab-overlap are too extreme
for the given padding.
We expand a tab if either tab-expand is set, or the generic widget
expand property in the correct direction is set. And we do not
propagate expand flags from tab labels to the notebook, only
the expand flags from the pages.
It doesn't make sense to keep them separate as GtkSizeRequest requires a
GtkWidget and GtkWidget implements GtkSizeRequest, so you can never have
one without the other.
It also makes the code a lot easier because no casts are required when
calling functions.
Also, the names would translate to gtk_widget_get_width() and people
agreed that this would be a too generic name, so a "preferred" was added
to the names.
So this patch moves the functions:
gtk_size_request_get_request_mode() => gtk_widget_get_request_mode()
gtk_size_request_get_width() => gtk_widget_get_preferred_width()
gtk_size_request_get_height() => gtk_widget_get_preferred_height()
gtk_size_request_get_size() => gtk_widget_get_preferred_size()
gtk_size_request_get_width_for_height() =>
gtk_widget_get_preferred_width_for_height()
gtk_size_request_get_height_for_width() =>
gtk_widget_get_preferred_height_for_width()
... and moves the corresponding vfuncs to the GtkWidgetClass.
The patch also renames the implementations of the vfuncs in widgets to
include the word "preferrred".
