GdkEvent has been a "I-can't-believe-this-is-not-OOP" type for ages,
using a union of sub-types. This has always been problematic when it
comes to implementing accessor functions: either you get generic API
that takes a GdkEvent and uses a massive switch() to determine which
event types have the data you're looking for; or you create namespaced
accessors, but break language bindings horribly, as boxed types cannot
have derived types.
The recent conversion of GskRenderNode (which had similar issues) to
GTypeInstance, and the fact that GdkEvent is now a completely opaque
type, provide us with the chance of moving GdkEvent to GTypeInstance,
and have sub-types for GdkEvent.
The change from boxed type to GTypeInstance is pretty small, all things
considered, but ends up cascading to a larger commit, as we still have
backends and code in GTK trying to access GdkEvent structures directly.
Additionally, the naming of the public getter functions requires
renaming all the data structures to conform to the namespace/type-name
pattern.
1. GdkDrop does deserialization, so add the deserialize formats
2. If the drop is local, we can copy straight from the drag, so we can
also copy all its formats. This fixes cases where the backend would
drop formats it doesn't support.
The GdkDrop emit... apis take root coordinates.
That should be changed to surface coordinates,
eventually. For now, make the functions fill
the x, y fields.
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.
This uses the new method without GDK_ACTION_ASK:
Either it is a single action (queryable via gdk_drag_action_is_unique())
or it is not and then the drop target has to make a decision
(potentially by asking someone).
The ultimate goal of this patch series is to split GdkDragContext into
GdkDrop + GdkDrag classes for the destination and source side of a dnd
operation.
The refactoring is meant to work something like this:
1. Introduce GdkDrop as a base class
2. Make all drop related code (like GdkEvent) use GdkDrop instead of
GdkDragContext. Move/duplicate APIs to allow that.
3. Port all drop contexts in the backends from GdkDragContext to GdkDrop
4. Delete all APIs in GdkDragContext that aren't needed anymore.
5. Make GdkDragContext no longer a GdkDrop subclass
6. Rename GdkDragContext to GdkDrag
