This adds gtk_style_context_add_paint_for_display() which allows to add
a GdkPaintable with a name to the CSS machinery and then allows using it
via "-gtk-paint(name)" inside the CSS as an image.
This essentially allows applications to register snapshot functions for
any part of the CSS machinery that is an image.
I have no idea if this is a good idea, because it further blurs the
lines between theme and application, but it *is* quite powerful.
The inspiration was
https://drafts.css-houdini.org/css-paint-api/
Though we do not support properties or a constructor, but so far require
the constructed image directly.
This way, we can support external libraries providing implementations of
GtkMediaFile.
We also add a media backend called 'nomedia' that can be enabled to not
compile any support for GtkMediaFile. This is useful when people want to
statically compile GTK into an application that does not use media.
For now, this option is the default.
We also support a new environment variable GTK_MEDIA that allows
selecting the implementation to use.
GTK_MEDIA=help can be used to get info about the available
implementations.
This is necessary so that bidnings work properly and don't make
gdk_gl_texture_release() a function on GdkTexture.
It also allows code to identify what type of texture they are dealing
with.
Finally, we can now decide to add getters later without screwing
anything up, if we want to allow people to access GL textures directly.
If @menu_label == NULL, we create a default page->menu_label. This took
@tab_label.get_label() and passed that to page->menu_label.set_text().
This is wrong because we set the plain text of the menu_label from the
rich text of @tab_label. So, if @tab_label used mnemonics or markup, our
menu_label got the raw underline or markup tags shown in it as raw text.
As we call set_text() on the menu Label, the fix is to be symmetric: use
@tab_label’s get_text() as source, as that strips underlines and markup.
It’s not worth making the default Label ‘inherit’ :use-underline/markup;
that’s a slippery slope, and users wanting such things can just create a
fully fledged GtkLabel to pass as @menu_label to suppress the default.
https://bugzilla.gnome.org/show_bug.cgi?id=705509
That's kinda weird but allows us to delete the texture case from
GtkIconHelper and GTK_IMAGE_TEXTURE from the GtkImageType enum.
And it doesn't cause any other problems because the cell renderer
can't deal with paintables - otherwise it would mirror GtkImage and have
a "paintable" property instead.
If set, the image will draw its contents while keeping their aspect
ratio. That means empty areas show up on the top/bottom or left/right.
Also move the special-case snapshotting code for icons to
GtkIconHelper. That's where it belongs.
This only implements the vfuncs, but does not actually emit signals
yet.
It's also not useed for anything other than snapshot() so far, this
will come in later commits.
... instead of going via surfaces.
A side effect is that the pixbuf property is no longer readable because
we have no good way to get the pixbuf back out of the texture, but I
don't think this matters a lot.
If people want to read the pixbuf property, we need to add some code to
make that work.
Instead of loading them into surfaces (which we want to get rid of), we
load into textures.
In fact, we introduce a new paintable subclass called a GtkScaler that
takes care of tracking scaling.
This also ideally gets rid of an extra conversion once renderers learn
to render textures directly.
Use that instead of hacks to guess when an image is considered invalid
according to https://drafts.csswg.org/css-images-4/#invalid-image
Also add a GtkCssImageInvalid that implements the behavior of invalid
images according to the CSS spec so thjat image implementations can
refer to that image.
This makes demos be compiled/linked before tests. And that means that
while hacking, I can already run widget-factory when the tests are
still linking.
