It is a little annoying that this demo will not show up
if we don't find librsvg, but I think showing how easy
this paintable is outweights the annoyance.
This adds a bunch of snazz to the gltransitions demo. It is perhaps
a bit overloaded now, but it demos everything that we can do.
Changes:
* The fire shader is now not a bin, it just renders an animating
background with no textures involved.
* The stacks don't all start on the same page.
* The shaderbin passes the mouse coordinate to the shader.
* The shaderbin allows specifying a "border" so that you can
cause effects outside the bin child (something that is new to gtk4).
* All the buttons and the stacks are now in shader-bins that runs
a wobbly-widget effect based on the mouse position that
wobbles outside the child allocation.
Add adds a demo showing off GskGLShaderNode in various ways.
It has a transistion widget, using some examples from
gl-transitions.com, with child widgets being both images, a GL area
and real widgets (that let you edit the transition shaders
themselves.
It also has a fancy fire effect on hove on the buttons.
This adds a small demo of using OpenGL shaders, it renders a quad
over the entire widget with a custom fragment shader. The coordinates
and the uniform names are compatible with the ones on shadertoy.com
(although some features, like texture inputs are missing currently).
The default shader in the demo is
https://www.shadertoy.com/view/wsjBD3 which is CC0, so it is
redistributable by Gtk+ (most other shaders are CC-BY-NC-SA which
isn't obviously compatible). I also added a set of buttons loading
a few other CC0 shaders I found.
There is no agreement that a coverflow widget is
appropriate for GTK 4.
It would be ok as a demo if it could live in gtk-demo,
but that requires us to make GtkListBase public first.
The demo is also somewhat rough and needs more work
to look plausible.
Drop GtkCoverFlow and the related demo for now.
The demo shows creating ones own listmodel and using it to fill a grid.
I am totally getting the hang of React btw:
500 lines of logic with no UI code and 100 lines of GtkBuilder XML and
I get a sweet UI.
It doesn't work anymore, since popovers now need
support in the parent, and we don't really need
a demo just for popovers. They are used everywhere
already.
Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2429
The window picking code has been broken for a while.
Since this is not really functionality that we should
highlight to application developers, remove the demo
instead of patching it up.
