Merge pull request #1513 from emersion/fix-dnd

data-device: fix drag-and-drop

include/rootston/seat.h

@@ -29,7 +29,7 @@ struct roots_seat {
 	struct wl_list views; // roots_seat_view::link
 	bool has_focus;
 
-	struct wl_list drag_icons; // roots_drag_icon::link
+	struct roots_drag_icon *drag_icon; // can be NULL
 
 	struct wl_list keyboards;
 	struct wl_list pointers;
@@ -61,7 +61,6 @@ struct roots_seat_view {
 struct roots_drag_icon {
 	struct roots_seat *seat;
 	struct wlr_drag_icon *wlr_drag_icon;
-	struct wl_list link;
 
 	double x, y;
 

include/wlr/types/wlr_seat.h

@@ -135,6 +135,7 @@ struct wlr_seat_pointer_state {
 	struct wlr_seat *seat;
 	struct wlr_seat_client *focused_client;
 	struct wlr_surface *focused_surface;
+	double sx, sy;
 
 	struct wlr_seat_pointer_grab *grab;
 	struct wlr_seat_pointer_grab *default_grab;

rootston/cursor.c

@@ -101,8 +101,7 @@ static void seat_view_deco_button(struct roots_seat_view *view, double sx,
 }
 
 static void roots_passthrough_cursor(struct roots_cursor *cursor,
-		int64_t time) {
-	bool focus_changed;
+		uint32_t time) {
 	double sx, sy;
 	struct roots_view *view = NULL;
 	struct roots_seat *seat = cursor->seat;
@@ -146,23 +145,26 @@ static void roots_passthrough_cursor(struct roots_cursor *cursor,
 	cursor->wlr_surface = surface;
 
 	if (surface) {
-		focus_changed = (seat->seat->pointer_state.focused_surface != surface);
 		wlr_seat_pointer_notify_enter(seat->seat, surface, sx, sy);
-		if (!focus_changed && time > 0) {
 		wlr_seat_pointer_notify_motion(seat->seat, time, sx, sy);
-		}
 	} else {
 		wlr_seat_pointer_clear_focus(seat->seat);
 	}
 
-	struct roots_drag_icon *drag_icon;
-	wl_list_for_each(drag_icon, &seat->drag_icons, link) {
-		roots_drag_icon_update_position(drag_icon);
+	if (seat->drag_icon != NULL) {
+		roots_drag_icon_update_position(seat->drag_icon);
 	}
 }
 
+static inline int64_t timespec_to_msec(const struct timespec *a) {
+	return (int64_t)a->tv_sec * 1000 + a->tv_nsec / 1000000;
+}
+
 void roots_cursor_update_focus(struct roots_cursor *cursor) {
-	roots_passthrough_cursor(cursor, -1);
+	struct timespec now;
+	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	roots_passthrough_cursor(cursor, timespec_to_msec(&now));
 }
 
 void roots_cursor_update_position(struct roots_cursor *cursor,

rootston/input.c

@@ -136,10 +136,11 @@ static inline int64_t timespec_to_msec(const struct timespec *a) {
 }
 
 void input_update_cursor_focus(struct roots_input *input) {
-	struct roots_seat *seat;
 	struct timespec now;
-	wl_list_for_each(seat, &input->seats, link) {
 	clock_gettime(CLOCK_MONOTONIC, &now);
+
+	struct roots_seat *seat;
+	wl_list_for_each(seat, &input->seats, link) {
 		roots_cursor_update_position(seat->cursor, timespec_to_msec(&now));
 	}
 }

rootston/output.c

@@ -120,16 +120,15 @@ static void drag_icons_for_each_surface(struct roots_input *input,
 		void *user_data) {
 	struct roots_seat *seat;
 	wl_list_for_each(seat, &input->seats, link) {
-		struct roots_drag_icon *drag_icon;
-		wl_list_for_each(drag_icon, &seat->drag_icons, link) {
-			if (!drag_icon->wlr_drag_icon->mapped) {
+		struct roots_drag_icon *drag_icon = seat->drag_icon;
+		if (drag_icon == NULL || !drag_icon->wlr_drag_icon->mapped) {
 			continue;
 		}
+
 		surface_for_each_surface(drag_icon->wlr_drag_icon->surface,
 			drag_icon->x, drag_icon->y, 0, layout_data,
 			iterator, user_data);
 	}
-	}
 }
 
 static void layer_for_each_surface(struct wl_list *layer,

rootston/seat.c

@@ -594,7 +594,9 @@ static void roots_drag_icon_handle_destroy(struct wl_listener *listener,
 		wl_container_of(listener, icon, destroy);
 	roots_drag_icon_damage_whole(icon);
 
-	wl_list_remove(&icon->link);
+	assert(icon->seat->drag_icon == icon);
+	icon->seat->drag_icon = NULL;
+
 	wl_list_remove(&icon->surface_commit.link);
 	wl_list_remove(&icon->unmap.link);
 	wl_list_remove(&icon->destroy.link);
@@ -622,7 +624,8 @@ static void roots_seat_handle_new_drag_icon(struct wl_listener *listener,
 	icon->destroy.notify = roots_drag_icon_handle_destroy;
 	wl_signal_add(&wlr_drag_icon->events.destroy, &icon->destroy);
 
-	wl_list_insert(&seat->drag_icons, &icon->link);
+	assert(seat->drag_icon == NULL);
+	seat->drag_icon = icon;
 
 	roots_drag_icon_update_position(icon);
 }
@@ -706,7 +709,6 @@ struct roots_seat *roots_seat_create(struct roots_input *input, char *name) {
 	wl_list_init(&seat->tablet_pads);
 	wl_list_init(&seat->switches);
 	wl_list_init(&seat->views);
-	wl_list_init(&seat->drag_icons);
 
 	seat->input = input;
 

types/data_device/wlr_drag.c

@@ -122,6 +122,9 @@ static void drag_end(struct wlr_drag *drag) {
 			drag_icon_set_mapped(drag->icon, false);
 		}
 
+		assert(drag->seat->drag == drag);
+		drag->seat->drag = NULL;
+
 		wlr_signal_emit_safe(&drag->events.destroy, drag);
 		free(drag);
 	}
@@ -174,7 +177,9 @@ static uint32_t drag_handle_pointer_button(struct wlr_seat_pointer_grab *grab,
 			};
 			wlr_signal_emit_safe(&drag->events.drop, &event);
 		} else if (drag->source->impl->dnd_finish) {
+			// This will end the grab and free `drag`
 			wlr_data_source_destroy(drag->source);
+			return 0;
 		}
 	}
 
@@ -432,6 +437,13 @@ bool seat_client_start_drag(struct wlr_seat_client *client,
 		return true;
 	}
 
+	if (seat->drag != NULL) {
+		wlr_log(WLR_DEBUG, "Refusing to start drag, "
+			"another drag is already in progress");
+		free(drag);
+		return true;
+	}
+
 	if (icon_surface) {
 		int32_t touch_id = (point ? point->touch_id : 0);
 		struct wlr_drag_icon *icon =

types/seat/wlr_seat_pointer.c

@@ -187,6 +187,13 @@ void wlr_seat_pointer_enter(struct wlr_seat *wlr_seat,
 
 	wlr_seat->pointer_state.focused_client = client;
 	wlr_seat->pointer_state.focused_surface = surface;
+	if (surface != NULL) {
+		wlr_seat->pointer_state.sx = sx;
+		wlr_seat->pointer_state.sy = sy;
+	} else {
+		wlr_seat->pointer_state.sx = NAN;
+		wlr_seat->pointer_state.sy = NAN;
+	}
 
 	struct wlr_seat_pointer_focus_change_event event = {
 		.seat = wlr_seat,
@@ -209,6 +216,10 @@ void wlr_seat_pointer_send_motion(struct wlr_seat *wlr_seat, uint32_t time,
 		return;
 	}
 
+	if (wlr_seat->pointer_state.sx == sx && wlr_seat->pointer_state.sy == sy) {
+		return;
+	}
+
 	struct wl_resource *resource;
 	wl_resource_for_each(resource, &client->pointers) {
 		if (wlr_seat_client_from_pointer_resource(resource) == NULL) {
@@ -218,6 +229,9 @@ void wlr_seat_pointer_send_motion(struct wlr_seat *wlr_seat, uint32_t time,
 		wl_pointer_send_motion(resource, time, wl_fixed_from_double(sx),
 			wl_fixed_from_double(sy));
 	}
+
+	wlr_seat->pointer_state.sx = sx;
+	wlr_seat->pointer_state.sy = sy;
 }
 
 uint32_t wlr_seat_pointer_send_button(struct wlr_seat *wlr_seat, uint32_t time,