Since it's a type with sub-classes, we need to use GTypeInstance (at the
very least), otherwise we won't be able to address each sub-class as
such.
This is similar to how GskRenderNode and GdkEvent are handled, with the
added difficulty that GtkExpression is meant to be used in properties,
in order to be deserialised by GtkBuilder. This requires adding a
GParamSpec sub-class that we can match on from within GtkBuilder,
alongside some convenience API for storing a GtkExpression inside a
GValue.
I couldn't come up with a better way to automatically inherit the scope
in the builder list item factory that didn't involve a magic
incantation in the XML file. And I do not want developers to know magic
incantations to do a thing that should pretty much always be done.
The lightweight inheritance mechanism used for GtkShortcutTrigger is not
going to be usable by bindings, because boxed types cannot have derived
types.
We could use GTypeInstance and derive everything from that, like
GParamSpec, but in the end shortcuts are not really a performance
critical paths, unlike CSS values or render nodes.
If icon lookup fails or if loading it fails later, just always
fall back to the built in image-missing icon. Nobody is handling
missing icons in a sane way anyway.
If you *truly* need to handle missing icons, you need to manually
use gtk_icon_theme_has_icon().
While changing the loading code I also fixed an issue where it
was always passing "png" to pixbuf, now it also handles "xpm" if
that is the filename suffix.
Most users were just forgetting to set the proper flags.
And flags aren't the right way to set this anyway, it was just
acceptable as a workaround during GTK3 to not break API.
The API encouraged wrong usage - most of the users were indeed wrong.
Use the correct version instead:
gtk_icon_theme_get_for_display (gtk_widget_get_display ())
This name can show up in error messages or profiler
traces, so it is nice to provide some hint what
file we are dealing with.
<GtkFileChoser template> is a lot more helpful
than <input>.
GtkBuilderScope is an interface that provides the scope that a builder
instance operates in.
It creates closures and resolves types. Language bindings are meant to
use this interface to customize the behavior of builder files, in
particular when instantiating templates.
A default implementation for C is provided via GtkBuilderCScope (to keep
with the awkward naming that glib uses for closures). It is derivable on
purpose so that languages or extensions that extend C can use it.
The reftest code in fact does derive GtkBuilderCScope for its own scope
implementation that implements looking up symbols in modules.
gtk-widget-factory was updated to use the new GtkBuilderCScope to add
its custom callback symbols.
So it does it different from gtk-demo, which uses the normal way of
exporting symbols for dlsym() and thereby makes the 2 demos test the 2
ways GtkBuilder uses for looking up symbols.
Use it as the default object for expression binds and when connecting
signals. It is intended to work kind of as the "this" object while
parsing. In fact, the term "current object" was stolen from the Java
docs and various C++ tutorials for the this pointer.
Set the current object in gtk_widget_init_template() and
GtkListItemBuilder.
This more-or-less replaces the object passed to
gtk_builder_connect_signals() in GTK3.
... and use it. This function looks up an object like
gtk_builder_get_object() but generates an error on failure.
Unlike the evil function _gtk_builder_lookup_object() which also
generates an error but hides it for later lookup.
Use this to avoid continuing applying properties when an error was
encountered.
- Propagate the error back to the parser, so we get a proper GError
instead of a g_warning().
- Connect closures by id, don't construct a name from the ids so that
glib can take it apart again.
gtk_builder_connect_signals() is no longer necessary, because all the
setup that made it necessary to have this extra step is now done
automatically via the closure functions.
This will be the future way to connect signals automatically (and be
used for other things, too).
For now, gtk_builder_connect_signals_default() is ported to use it.
This is pretty unused and gets in the way of the next steps.
A potential side effect is that for templates the widget was passed as
the user data argument. If that turns out to be important, we have to
special case that situation.
