This causes the snapshotting algorithm to dump all widget nodes into
their own container node. We then name that group accordingly (ie
"GtkSwitch<0xdeadbeef>") so you can easily see which node belongs where.
The feature is toggleable in the inspector's visual tab.
There's a few problems with it, becuse GtkSnapshot optimized container
nodes away if they are not needed, so we are losing some widgets...
It turns out, some simple getters - such as
gdk_drawing_context_get_clip() - love copying things before returning
them.
I guess somebody has to burn cycles...
That way we can capture both the actual changes (clip region) and the
area that was redrawn (render region), which in OpenGL might not be
identical.
Nothing shows the render region yet though...
Just to avoid having to do NULL checks when calling
widget_class->snapshot. We were crashing with drawing areas who don't
have a draw or a snapshot vfunc (woot!).
We need so subtract the allocation from the clip to get the clip offset,
not the other way around.
This was screwing in particular with marks on GtkScale, because GtkScale
mark clip computation is broken and always returns (0,0) which makes
scales have a waaaaay too large clip.
But that's another bug.
And use this to cull widgets and gadgets that are completely outside the
clip region.
A potential optimization is to apply this clip region to cairo contexts
created with gtk_snapshot_append_cairo_node(), but for that we'd need to
apply the inverse matrix to the clip region, and that causes rounding
errors.
Plus, I hope that cairo drawing becomes exceedingly rare so it won't be
used for the whole widget factory like today (which might also explain
why no culling happens in the widget factory outside the header bar.
We now look at which of get_render_mode, draw or snapshot vfuncs is the
latest to have been overwritten in the class tree and then use that one.
This allows GtkContainerClass and GtkBinClass to override all of them
for without screwing things up.
We now try to emulate cairo_t:
We keep a stack of nodes via push/pop and a transform matrix.
So whenever a new node is added to the snapshot, we transform it
by the current transform matrix and append it to the current node.
This one introduces the Recording object which is essentially a single
instance of something that happened.
The RenderRecording is an instance of an actual rendering operation.
Switch code to use gdk_display_is_composited() instead.
The new code also doesn't use a vfunc to query the property but rather
requires the backend to call set_composited()/set_rgba() to change the
value.
Before, we would immediately invalidate the GdkWindow of the widget, now
we call the parent's GtkWidgetClass.queue_draw_child() function.
This allows the parent to track redraw queueing of children.
By default GtkWidgetClass.queue_draw_child() will again chain up to its
parent while respecting the GdkWindow hierarchy for clipping.
GtkWindow is then the only widget actually invalidating the GdkWindow.
This essentially moves redraw queueing from GDK to GTK.
