Content providers are meant to be immutable, apart from very special
cases, but in those cases they need to emit
gdk_content_provider_content_changed().
Having a constructor that just uses a get_func invites abuse of this
by not making developers aware of those requirments.
In fact, all users in GTK failed to do this.
Instead, code should use the GtkDragSource::prepare signal to create
content providers when needed.
The same problem exists with gdk_content_provider_new_with_formats(),
but this commit doesn't touch that.
We had a pretty complex setup where we tried to avoid scaling up themes from dirs
that specified a size. However, not only was it very complex, but it didn't quite
work with window scales, because when using e.g. a size 32 directory for 16@2x
the dir size is wrong anyway. Additionally it turns out most code either picks
an existing icon size, or uses the FORCE_SIZE flags, so it doesn't seem
like a useful behaviour.
This change drops the FORCE_SIZE flags, and always scales
icons. Additionally it moves the scaling of the icon to rendering,
which seems more modern, and allows us to (later) share icons loaded
for different sizes that happened to use the same source file (at
different scales).
Note that this changes the behaviour of
gtk_icon_paintable_download_texture() is it now returns the unscaled
source icon. However, ignore thats, as I plan to remove this function
and replace it with a way to render a paintable to a cairo-surface
instead.
Instead, rely on people passing fallbacks explicitly.
Alternatively, GThemedIcon provides the functionality to create
fallbacks, which is what GtkImage and the testsuite now use.
That method is slightly better, too, so the expected test results
have been updated accordingly.
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 ())
Remove arguments from the constructor.
For actions, we now default to COPY, which is the most common one
that we should enable by default (MOVE requires handling deletion
on the the source side, and ASK only makes sense if we have
multiple actions).
For the content provider, we add a new ::prepare signal where
it should be provided just-in-time.
This is to go along with the newly introduced GdkDrop.
This commit includes the necessary updates to the X11, Wayland
and Broadway backends. Other backends have to be updated separately.
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