primary-selection: introduce wlr_primary_selection_source

This is a common interface that can be used for all primary selection
protocols, as discussed in [1]. A new function wlr_seat_set_primary_selection
is added to set the primary selection for all protocols.

The seat now owns again the source, and resets the selection to NULL when
destroyed.

[1]: https://github.com/swaywm/wlroots/issues/1367#issuecomment-442403454

include/wlr/types/meson.build

@@ -23,6 +23,7 @@ install_headers(
 	'wlr_output.h',
 	'wlr_pointer.h',
 	'wlr_presentation_time.h',
+	'wlr_primary_selection.h',
 	'wlr_region.h',
 	'wlr_screencopy_v1.h',
 	'wlr_screenshooter.h',

include/wlr/types/wlr_gtk_primary_selection.h

@@ -35,37 +35,11 @@ struct wlr_gtk_primary_selection_device {
 	struct wl_list link; // wlr_gtk_primary_selection_device_manager::devices
 	struct wl_list resources; // wl_resource_get_link
 
-	struct wlr_gtk_primary_selection_source *source;
 	struct wl_list offers; // wl_resource_get_link
 
 	struct wl_listener seat_destroy;
 	struct wl_listener seat_focus_change;
-	struct wl_listener source_destroy;
-
-	void *data;
-};
-
-/**
- * A data source implementation. Only the `send` function is mandatory.
- */
-struct wlr_gtk_primary_selection_source_impl {
-	void (*send)(struct wlr_gtk_primary_selection_source *source,
-		const char *mime_type, int fd);
-	void (*destroy)(struct wlr_gtk_primary_selection_source *source);
-};
-
-/**
- * A source is the sending side of a selection.
- */
-struct wlr_gtk_primary_selection_source {
-	const struct wlr_gtk_primary_selection_source_impl *impl;
-
-	// source metadata
-	struct wl_array mime_types;
-
-	struct {
-		struct wl_signal destroy;
-	} events;
+	struct wl_listener seat_primary_selection;
 
 	void *data;
 };
@@ -75,18 +49,4 @@ struct wlr_gtk_primary_selection_device_manager *
 void wlr_gtk_primary_selection_device_manager_destroy(
 	struct wlr_gtk_primary_selection_device_manager *manager);
 
-void wlr_gtk_primary_selection_device_manager_set_selection(
-	struct wlr_gtk_primary_selection_device_manager *manager,
-	struct wlr_seat *seat,
-	struct wlr_gtk_primary_selection_source *source);
-
-void wlr_gtk_primary_selection_source_init(
-	struct wlr_gtk_primary_selection_source *source,
-	const struct wlr_gtk_primary_selection_source_impl *impl);
-void wlr_gtk_primary_selection_source_destroy(
-	struct wlr_gtk_primary_selection_source *source);
-void wlr_gtk_primary_selection_source_send(
-	struct wlr_gtk_primary_selection_source *source, const char *mime_type,
-	int fd);
-
 #endif

include/wlr/types/wlr_primary_selection.h

@@ -0,0 +1,54 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_PRIMARY_SELECTION_H
+#define WLR_TYPES_WLR_PRIMARY_SELECTION_H
+
+#include <wayland-server.h>
+#include <wlr/types/wlr_seat.h>
+
+struct wlr_primary_selection_source;
+
+/**
+ * A data source implementation. Only the `send` function is mandatory.
+ */
+struct wlr_primary_selection_source_impl {
+	void (*send)(struct wlr_primary_selection_source *source,
+		const char *mime_type, int fd);
+	void (*destroy)(struct wlr_primary_selection_source *source);
+};
+
+/**
+ * A source is the sending side of a selection.
+ */
+struct wlr_primary_selection_source {
+	const struct wlr_primary_selection_source_impl *impl;
+
+	// source metadata
+	struct wl_array mime_types;
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+
+	void *data;
+};
+
+void wlr_primary_selection_source_init(
+	struct wlr_primary_selection_source *source,
+	const struct wlr_primary_selection_source_impl *impl);
+void wlr_primary_selection_source_destroy(
+	struct wlr_primary_selection_source *source);
+void wlr_primary_selection_source_send(
+	struct wlr_primary_selection_source *source, const char *mime_type,
+	int fd);
+
+void wlr_seat_set_primary_selection(struct wlr_seat *seat,
+	struct wlr_primary_selection_source *source);
+
+#endif

include/wlr/types/wlr_seat.h

@@ -184,6 +184,8 @@ struct wlr_seat_touch_state {
 	struct wlr_seat_touch_grab *default_grab;
 };
 
+struct wlr_primary_selection_source;
+
 struct wlr_seat {
 	struct wl_global *global;
 	struct wl_display *display;
@@ -197,8 +199,7 @@ struct wlr_seat {
 	struct wlr_data_source *selection_source;
 	uint32_t selection_serial;
 
-	// not owned by the seat
-	struct wlr_gtk_primary_selection_source *primary_selection_source;
+	struct wlr_primary_selection_source *primary_selection_source;
 
 	// `drag` goes away before `drag_source`, when the implicit grab ends
 	struct wlr_drag *drag;
@@ -211,6 +212,7 @@ struct wlr_seat {
 
 	struct wl_listener display_destroy;
 	struct wl_listener selection_source_destroy;
+	struct wl_listener primary_selection_source_destroy;
 	struct wl_listener drag_source_destroy;
 
 	struct {

include/wlr/xwayland.h

@@ -43,7 +43,6 @@ struct wlr_xwayland {
 	struct wl_display *wl_display;
 	struct wlr_compositor *compositor;
 	struct wlr_seat *seat;
-	struct wlr_gtk_primary_selection_device_manager *gtk_primary_selection;
 
 	struct {
 		struct wl_signal ready;
@@ -226,10 +225,6 @@ void wlr_xwayland_surface_set_fullscreen(struct wlr_xwayland_surface *surface,
 void wlr_xwayland_set_seat(struct wlr_xwayland *xwayland,
 	struct wlr_seat *seat);
 
-void wlr_xwayland_set_gtk_primary_selection_device_manager(
-	struct wlr_xwayland *xwayland,
-	struct wlr_gtk_primary_selection_device_manager *manager);
-
 bool wlr_surface_is_xwayland_surface(struct wlr_surface *surface);
 
 struct wlr_xwayland_surface *wlr_xwayland_surface_from_wlr_surface(

include/xwayland/selection.h

@@ -7,6 +7,8 @@
 
 #define XDND_VERSION 5
 
+struct wlr_primary_selection_source;
+
 struct wlr_xwm_selection;
 
 struct wlr_xwm_selection_transfer {
@@ -62,7 +64,7 @@ int xwm_handle_xfixes_selection_notify(struct wlr_xwm *xwm,
 	xcb_xfixes_selection_notify_event_t *event);
 bool data_source_is_xwayland(struct wlr_data_source *wlr_source);
 bool primary_selection_source_is_xwayland(
-	struct wlr_gtk_primary_selection_source *wlr_source);
+	struct wlr_primary_selection_source *wlr_source);
 
 void xwm_seat_handle_start_drag(struct wlr_xwm *xwm, struct wlr_drag *drag);