data-device, primary-selection: add request_set_selection

This makes compositors able to block and/or customize set_selection requests
coming from clients. For instance, it's possible for a compositor to disable
rich selection content (by removing all MIME types except text/plain). This
commit implements the design proposed in [1].

Two new events are added to wlr_seat: request_set_selection and
request_set_primary_selection. Compositors need to listen to these events and
either destroy the source or effectively set the selection.

Fixes https://github.com/swaywm/wlroots/issues/1138

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

2 files changed, 16 insertions, 15 deletions

diff --git a/xwayland/selection/incoming.c b/xwayland/selection/incoming.c
index 79197e60..e3f68ea7 100644
--- a/xwayland/selection/incoming.c
+++ b/xwayland/selection/incoming.c
@@ -350,7 +350,7 @@ static void xwm_selection_get_targets(struct wlr_xwm_selection *selection) {
 		bool ok = source_get_targets(selection, &source->base.mime_types,
 			&source->mime_types_atoms);
 		if (ok) {
-			wlr_seat_set_selection(xwm->seat, &source->base,
+			wlr_seat_request_set_selection(xwm->seat, &source->base,
 				wl_display_next_serial(xwm->xwayland->wl_display));
 		} else {
 			wlr_data_source_cancel(&source->base);
@@ -425,10 +425,10 @@ int xwm_handle_xfixes_selection_notify(struct wlr_xwm *xwm,
 			// A real X client selection went away, not our
 			// proxy selection
 			if (selection == &xwm->clipboard_selection) {
-				wlr_seat_set_selection(xwm->seat, NULL,
+				wlr_seat_request_set_selection(xwm->seat, NULL,
 					wl_display_next_serial(xwm->xwayland->wl_display));
 			} else if (selection == &xwm->primary_selection) {
-				wlr_seat_set_primary_selection(xwm->seat, NULL,
+				wlr_seat_request_set_primary_selection(xwm->seat, NULL,
 					wl_display_next_serial(xwm->xwayland->wl_display));
 			} else if (selection == &xwm->dnd_selection) {
 				// TODO: DND
diff --git a/xwayland/selection/selection.c b/xwayland/selection/selection.c
index dee7f9c3..a8cb5df4 100644
--- a/xwayland/selection/selection.c
+++ b/xwayland/selection/selection.c
@@ -255,11 +255,11 @@ static void xwm_selection_set_owner(struct wlr_xwm_selection *selection,
 	}
 }
 
-static void seat_handle_selection(struct wl_listener *listener,
+static void handle_seat_set_selection(struct wl_listener *listener,
 		void *data) {
 	struct wlr_seat *seat = data;
 	struct wlr_xwm *xwm =
-		wl_container_of(listener, xwm, seat_selection);
+		wl_container_of(listener, xwm, seat_set_selection);
 	struct wlr_data_source *source = seat->selection_source;
 
 	if (source != NULL && data_source_is_xwayland(source)) {
@@ -269,11 +269,11 @@ static void seat_handle_selection(struct wl_listener *listener,
 	xwm_selection_set_owner(&xwm->clipboard_selection, source != NULL);
 }
 
-static void seat_handle_primary_selection(struct wl_listener *listener,
+static void handle_seat_set_primary_selection(struct wl_listener *listener,
 		void *data) {
 	struct wlr_seat *seat = data;
 	struct wlr_xwm *xwm =
-		wl_container_of(listener, xwm, seat_primary_selection);
+		wl_container_of(listener, xwm, seat_set_primary_selection);
 	struct wlr_primary_selection_source *source =
 		seat->primary_selection_source;
 
@@ -294,8 +294,8 @@ static void seat_handle_start_drag(struct wl_listener *listener, void *data) {
 
 void xwm_set_seat(struct wlr_xwm *xwm, struct wlr_seat *seat) {
 	if (xwm->seat != NULL) {
-		wl_list_remove(&xwm->seat_selection.link);
-		wl_list_remove(&xwm->seat_primary_selection.link);
+		wl_list_remove(&xwm->seat_set_selection.link);
+		wl_list_remove(&xwm->seat_set_primary_selection.link);
 		wl_list_remove(&xwm->seat_start_drag.link);
 		xwm->seat = NULL;
 	}
@@ -306,13 +306,14 @@ void xwm_set_seat(struct wlr_xwm *xwm, struct wlr_seat *seat) {
 
 	xwm->seat = seat;
 
-	wl_signal_add(&seat->events.selection, &xwm->seat_selection);
-	xwm->seat_selection.notify = seat_handle_selection;
-	wl_signal_add(&seat->events.primary_selection, &xwm->seat_primary_selection);
-	xwm->seat_primary_selection.notify = seat_handle_primary_selection;
+	wl_signal_add(&seat->events.set_selection, &xwm->seat_set_selection);
+	xwm->seat_set_selection.notify = handle_seat_set_selection;
+	wl_signal_add(&seat->events.set_primary_selection,
+		&xwm->seat_set_primary_selection);
+	xwm->seat_set_primary_selection.notify = handle_seat_set_primary_selection;
 	wl_signal_add(&seat->events.start_drag, &xwm->seat_start_drag);
 	xwm->seat_start_drag.notify = seat_handle_start_drag;
 
-	seat_handle_selection(&xwm->seat_selection, seat);
-	seat_handle_primary_selection(&xwm->seat_primary_selection, seat);
+	handle_seat_set_selection(&xwm->seat_set_selection, seat);
+	handle_seat_set_primary_selection(&xwm->seat_set_primary_selection, seat);
 }