[WIP] xwayland: add incoming drag'n'drop support

include/wlr/types/wlr_data_device.h

@@ -5,13 +5,13 @@
 #include <wlr/types/wlr_seat.h>
 
 extern const struct
-wlr_pointer_grab_interface wlr_data_device_pointer_drag_interface;
+	wlr_pointer_grab_interface wlr_data_device_pointer_drag_interface;
 
 extern const struct
-wlr_keyboard_grab_interface wlr_data_device_keyboard_drag_interface;
+	wlr_keyboard_grab_interface wlr_data_device_keyboard_drag_interface;
 
 extern const struct
-wlr_touch_grab_interface wlr_data_device_touch_drag_interface;
+	wlr_touch_grab_interface wlr_data_device_touch_drag_interface;
 
 struct wlr_data_device_manager {
 	struct wl_global *global;
@@ -221,4 +221,8 @@ void wlr_data_source_dnd_finish(struct wlr_data_source *source);
 void wlr_data_source_dnd_action(struct wlr_data_source *source,
 	enum wl_data_device_manager_dnd_action action);
 
+struct wlr_drag *wlr_seat_client_start_grab(struct wlr_seat_client *client,
+	struct wlr_data_source *source, struct wlr_surface *icon_surface,
+	struct wlr_touch_point *point);
+
 #endif

include/wlr/types/wlr_seat.h

@@ -188,7 +188,6 @@ struct wlr_seat {
 	// `drag` goes away before `drag_source`, when the implicit grab ends
 	struct wlr_drag *drag;
 	struct wlr_data_source *drag_source;
-	uint32_t drag_serial;
 
 	struct wlr_seat_pointer_state pointer_state;
 	struct wlr_seat_keyboard_state keyboard_state;

include/xwayland/selection.h

@@ -1,6 +1,8 @@
 #ifndef XWAYLAND_SELECTION_H
 #define XWAYLAND_SELECTION_H
 
+#include <wlr/types/wlr_data_device.h>
+#include <wlr/types/wlr_primary_selection.h>
 #include <xcb/xfixes.h>
 
 #define INCR_CHUNK_SIZE (64 * 1024)
@@ -39,6 +41,18 @@ struct wlr_xwm_selection {
 	struct wl_list outgoing;
 };
 
+struct wlr_xwayland_data_source {
+	struct wlr_data_source base;
+	struct wlr_xwm_selection *selection;
+	struct wl_array mime_types_atoms;
+};
+
+struct wlr_xwayland_primary_selection_source {
+	struct wlr_primary_selection_source base;
+	struct wlr_xwm_selection *selection;
+	struct wl_array mime_types_atoms;
+};
+
 void xwm_selection_transfer_remove_source(
 	struct wlr_xwm_selection_transfer *transfer);
 void xwm_selection_transfer_close_source_fd(
@@ -63,8 +77,14 @@ int xwm_handle_xfixes_selection_notify(struct wlr_xwm *xwm,
 bool data_source_is_xwayland(struct wlr_data_source *wlr_source);
 bool primary_selection_source_is_xwayland(
 	struct wlr_primary_selection_source *wlr_source);
+struct wlr_xwayland_data_source *xwayland_data_source_create(
+	struct wlr_xwm_selection *selection);
+struct wlr_xwayland_data_source *xwayland_data_source_from_wlr_data_source(
+	struct wlr_data_source *wlr_source);
 
 void xwm_seat_handle_start_drag(struct wlr_xwm *xwm, struct wlr_drag *drag);
+int xwm_dnd_handle_xfixes_selection_notify(struct wlr_xwm *xwm,
+	xcb_xfixes_selection_notify_event_t *event);
 
 void xwm_selection_init(struct wlr_xwm *xwm);
 void xwm_selection_finish(struct wlr_xwm *xwm);

include/xwayland/xwm.h

@@ -116,6 +116,8 @@ struct wlr_xwm {
 	struct wl_list surfaces; // wlr_xwayland_surface::link
 	struct wl_list unpaired_surfaces; // wlr_xwayland_surface::unpaired_link
 
+	struct wlr_drag *incoming_drag;
+
 	struct wlr_drag *drag;
 	struct wlr_xwayland_surface *drag_focus;
 
@@ -134,6 +136,7 @@ struct wlr_xwm {
 	struct wl_listener seat_drag_drop;
 	struct wl_listener seat_drag_destroy;
 	struct wl_listener seat_drag_source_destroy;
+	struct wl_listener incoming_drag_destroy;
 };
 
 struct wlr_xwm *xwm_create(struct wlr_xwayland *wlr_xwayland);

types/data_device/wlr_drag.c

@@ -56,7 +56,7 @@ static void drag_set_focus(struct wlr_drag *drag,
 	}
 
 	struct wlr_seat_client *focus_client = wlr_seat_client_for_wl_client(
-		drag->seat_client->seat, wl_resource_get_client(surface->resource));
+		drag->seat, wl_resource_get_client(surface->resource));
 	if (!focus_client) {
 		return;
 	}
@@ -80,8 +80,7 @@ static void drag_set_focus(struct wlr_drag *drag,
 	}
 
 	if (!wl_list_empty(&focus_client->data_devices)) {
-		uint32_t serial =
-			wl_display_next_serial(drag->seat_client->seat->display);
+		uint32_t serial = wl_display_next_serial(drag->seat->display);
 		struct wl_resource *resource;
 		wl_resource_for_each(resource, &focus_client->data_devices) {
 			wl_data_device_send_enter(resource, serial, surface->resource,
@@ -384,54 +383,33 @@ static void seat_handle_drag_source_destroy(struct wl_listener *listener,
 	seat->drag_source = NULL;
 }
 
-bool seat_client_start_drag(struct wlr_seat_client *client,
+struct wlr_drag *wlr_seat_client_start_grab(struct wlr_seat_client *client,
 		struct wlr_data_source *source, struct wlr_surface *icon_surface,
-		struct wlr_surface *origin, uint32_t serial) {
+		struct wlr_touch_point *point) {
+	struct wlr_seat *seat = client->seat;
+
 	struct wlr_drag *drag = calloc(1, sizeof(struct wlr_drag));
 	if (drag == NULL) {
-		return false;
+		return NULL;
 	}
-
+	drag->seat = seat;
 	wl_signal_init(&drag->events.focus);
 	wl_signal_init(&drag->events.motion);
 	wl_signal_init(&drag->events.drop);
 	wl_signal_init(&drag->events.destroy);
 
-	struct wlr_seat *seat = client->seat;
-	drag->seat = seat;
-
-	drag->is_pointer_grab = !wl_list_empty(&client->pointers) &&
-		seat->pointer_state.button_count == 1 &&
-		seat->pointer_state.grab_serial == serial &&
-		seat->pointer_state.focused_surface &&
-		seat->pointer_state.focused_surface == origin;
-
-	bool is_touch_grab = !wl_list_empty(&client->touches) &&
-		wlr_seat_touch_num_points(seat) == 1 &&
-		seat->touch_state.grab_serial == serial;
-
-	// set in the iteration
-	struct wlr_touch_point *point = NULL;
-	if (is_touch_grab) {
-		wl_list_for_each(point, &seat->touch_state.touch_points, link) {
-			is_touch_grab = point->surface && point->surface == origin;
-			break;
-		}
-	}
-
-	if (!drag->is_pointer_grab && !is_touch_grab) {
-		free(drag);
-		return true;
+	if (point == NULL) {
+		drag->is_pointer_grab = true;
 	}
 
 	if (icon_surface) {
-		int32_t touch_id = (point ? point->touch_id : 0);
+		int32_t touch_id = point ? point->touch_id : 0;
 		struct wlr_drag_icon *icon =
 			drag_icon_create(icon_surface, client, drag->is_pointer_grab,
 				touch_id);
 		if (!icon) {
 			free(drag);
-			return false;
+			return NULL;
 		}
 
 		drag->icon = icon;
@@ -446,6 +424,7 @@ bool seat_client_start_drag(struct wlr_seat_client *client,
 	}
 
 	drag->seat_client = client;
+
 	drag->pointer_grab.data = drag;
 	drag->pointer_grab.interface = &data_device_pointer_drag_interface;
 
@@ -468,7 +447,6 @@ bool seat_client_start_drag(struct wlr_seat_client *client,
 	}
 
 	seat->drag = drag; // TODO: unset this thing somewhere
-	seat->drag_serial = serial;
 
 	seat->drag_source = source;
 	if (source != NULL) {
@@ -477,6 +455,38 @@ bool seat_client_start_drag(struct wlr_seat_client *client,
 	}
 
 	wlr_signal_emit_safe(&seat->events.start_drag, drag);
+	return drag;
+}
+
+bool seat_client_start_drag(struct wlr_seat_client *client,
+		struct wlr_data_source *source, struct wlr_surface *icon_surface,
+		struct wlr_surface *origin, uint32_t serial) {
+	struct wlr_seat *seat = client->seat;
+
+	bool is_pointer_grab = !wl_list_empty(&client->pointers) &&
+		seat->pointer_state.button_count == 1 &&
+		seat->pointer_state.grab_serial == serial &&
+		seat->pointer_state.focused_surface &&
+		seat->pointer_state.focused_surface == origin;
+
+	bool is_touch_grab = !wl_list_empty(&client->touches) &&
+		wlr_seat_touch_num_points(seat) == 1 &&
+		seat->touch_state.grab_serial == serial;
+
+	// set in the iteration
+	struct wlr_touch_point *point = NULL;
+	if (is_touch_grab) {
+		wl_list_for_each(point, &seat->touch_state.touch_points, link) {
+			is_touch_grab = point->surface && point->surface == origin;
+			break;
+		}
+	}
+
+	if (!is_pointer_grab && !is_touch_grab) {
+		return true;
+	}
 
-	return true;
+	struct wlr_drag *drag = wlr_seat_client_start_grab(client, source,
+		icon_surface, point);
+	return drag != NULL;
 }