If you want to draw a widget to cairo today, you create a widget
paintable, snapshot it to a render node and then draw the render node to
cairo.
And yes, this is that complicated on purpose. Don't draw widgets to
Cairo.
This allows being more specific about the size.
It's useful in particular when the resulting render nodes might be
too small for the size, not only when they are too large. For the
latter case, using a clip node would be enough.
It also requires adding a clip node when rendering the resulting
paintable, but that should be optimized out by GtkSnapshot when not
necessary.
This is actually not just a mechnaism to protect against too many
signals, but it's also a method to getting those signals at the wrong
time.
For every size/content change, a widget needs to invalidate twice:
Once when it queues a resize/redraw (going valid => invalid) and once
when the new size/content is actually assigned (going invalid => valid).
However, one of those invalidations might be inconvenient for the
listener. GtkImage for example does not like receiving
invalidate-contents signals when new contents are assigned, but is fine
with them when the old ones go invalid. And it will not try to draw the
paintable in between anyway.
So by bypassing the 2nd emission if nothing was changed, we can make
GtkImage happy.
This error message is printed into the journal if a GTK app can't
connect to eithre Wayland or X11. Make it at least mention who is not
capable of connecting to a server.
Unrelated, we might want to improve our error reporting when a GTK app
can't start, so that debugging issues with system startup / login get
easier to resolve.
When the clip changes that is passed to a snapshot function, we need to
create eventual cached render nodes because they might not have drawn
their whole area before.
Fixes issues with redrawing when scrolling.
When the max cost for finding a path gets to high, the diff can now be
aborted.
Because render nodes have a fallback method (by just marking the whole
bounds of the nodes as different), we use this to improve performance
of diffs.
This brings fishbowl (which is basically a container node with N images
that change every frame) back to close to previous performance.
Now that we have the full render nodes available, there is not much
benefit in fine-grained control over multiple rectangles.
In particular, it's causing pain with complex regions.
There might be a benefit in clipping to the region's rectangles in cases
like widget-factory where the whole diff is made up of the 2 rectangles
of spinner and the pulsing progress bar, but it needs a good heuristic
for where this is useful.
Instead of calling gdk_surface_invalidate_region(), just
gdk_surface_queue_expose() and rely on the renderer computing the diff
from the previous rendering.
... and diff the previous node with the current one to determine the
clip region.
This doubles the work necessary to track clip regions, but the following
commits will clean that up.
It doesn't need to be exported anymore.
As a side effect, the inspector no longer has any information about the
render region, so remove the code that was taking care of that.
Now that we don't clip the created render nodes anymore, we don't have
to compute the clip region beforehand.
So snapshot the render nodes before initializing the renderer.
This includes a copy of the diff(1) algorithm used by git diff by Davide
Libenzi.
It's used for the common case ofcontainer nodes having only very few
changes for the few nodes of child widgets that changed (like a button
lighting up when hilighted or a spinning spinner).
This requires a bunch of refactorings:
1. Don't pass the current clip region to gtk_widget_snapshot()
so we don't create full widget contents
3. Have a widget->priv->draw_needed that we invalidate on every
queue_draw() call and set on every snapshot()
2. In queue_draw(), walk the widget chain to invalidate the
render nodes of all parents
... and gsk_render_node_can_diff(). Those are vfuncs to compute a region
containing all the pixels that differ between the two nodes.
This is just the plumbing that chains into node classes. No node
implements it yet.
delete_range_cb is set to be called before the text suppression done by
the gtktextlayout (otherwise it does not work properly). But at that
point the cursor position is not yet up to date. We thus need to move
the accessibility cursor notification to after the actual text
suppression, by using another callback.
This fixes cursor position in brltty screen reading.
(cherry picked from commit fa6994d033)
The second parameter of the text-changed::delete event is to be the length,
not the end position. This fixes spurious text removals in brltty
screen reading.
(cherry picked from commit 209f908a03)
Like other widgets, this returns a floating reference, so
(transfer full) is wrong. Just omit the annotation as others do,
thus implying (transfer none).
Close https://gitlab.gnome.org/GNOME/gtk/issues/156
This is meant as an input to the font chooser.
We don't want the user to select a language, but
rather have fonts presented as they would work for
the current language. Therefore, do away with the
lang/script combo on the tweak page.
Really exclude the portions in the gtkfontchooserwidget.c that are built
when HarfBuzz and PangoFT2 are built, and update the Meson files to
exclude such sources as well from the main GTK SO/DLL and from the
gtk4-demo program.
https://bugzilla.gnome.org/show_bug.cgi?id=773299
Remove g_auto*() usage from these sources and use the traditional
g_free(), as g_auto*() are GCCisms (or CLangisms).
Also, don't include unistd.h unconditionally and stop including
langinfo.h and dirent.h, since they seem to be unused.
https://bugzilla.gnome.org/show_bug.cgi?id=773299
The demos are now built as GUI programs, which will require the presence
of WinMain() on Visual Studio builds, unless we specify the entry point.
Pass the /entry:mainCRTStartup linker flag on Visual Studio builds for
the demo programs so that they can link properly.
https://bugzilla.gnome.org/show_bug.cgi?id=773299
For some font features, we can figure out affected
glyphs, and show before/after. For some others, we
hardcode typical sequences.
Still to do: figure out how to find ligatures and
show them.
