cursor: allow re-focusing xwayland-unmanaged surfaces

We already allow some xwayland-unmanaged surfaces to take focus on map,
if indicated by wlr_xwayland_or_surface_wants_focus(). But once these
surfaces lose focus, they never regain it again.

Add desktop_focus_view_or_surface() and call it in the appropriate
places to allow these views to regain focus in the usual ways (e.g.
clicking on them or focus-follows-mouse).

include/labwc.h

@@ -382,6 +382,14 @@ void foreign_toplevel_update_outputs(struct view *view);
  * session is locked/input is inhibited; it will simply do nothing.
  */
 void desktop_focus_view(struct view *view, bool raise);
+
+/**
+ * desktop_focus_view_or_surface() - like desktop_focus_view() but can
+ * also focus other (e.g. xwayland-unmanaged) surfaces
+ */
+void desktop_focus_view_or_surface(struct seat *seat, struct view *view,
+	struct wlr_surface *surface, bool raise);
+
 void desktop_arrange_all_views(struct server *server);
 void desktop_focus_output(struct output *output);
 struct view *desktop_topmost_focusable_view(struct server *server);

src/desktop.c

@@ -13,6 +13,10 @@
 #include "workspaces.h"
 #include "xwayland.h"
 
+#if HAVE_XWAYLAND
+#include <wlr/xwayland.h>
+#endif
+
 void
 desktop_arrange_all_views(struct server *server)
 {
@@ -84,6 +88,25 @@ desktop_focus_view(struct view *view, bool raise)
 	}
 }
 
+/* TODO: focus layer-shell surfaces also? */
+void
+desktop_focus_view_or_surface(struct seat *seat, struct view *view,
+		struct wlr_surface *surface, bool raise)
+{
+	assert(view || surface);
+	if (view) {
+		desktop_focus_view(view, raise);
+#if HAVE_XWAYLAND
+	} else if (wlr_surface_is_xwayland_surface(surface)) {
+		struct wlr_xwayland_surface *xsurface =
+			wlr_xwayland_surface_from_wlr_surface(surface);
+		if (xsurface && wlr_xwayland_or_surface_wants_focus(xsurface)) {
+			seat_focus_surface(seat, surface);
+		}
+#endif
+	}
+}
+
 static struct wl_list *
 get_prev_item(struct wl_list *item)
 {

src/input/cursor.c

@@ -479,8 +479,9 @@ process_cursor_motion(struct server *server, uint32_t time)
 		dnd_icons_move(seat, seat->cursor->x, seat->cursor->y);
 	}
 
-	if (ctx.view && rc.focus_follow_mouse) {
+	if ((ctx.view || ctx.surface) && rc.focus_follow_mouse) {
-		desktop_focus_view(ctx.view, rc.raise_on_focus);
+		desktop_focus_view_or_surface(seat, ctx.view, ctx.surface,
+			rc.raise_on_focus);
 	}
 
 	struct mousebind *mousebind;
@@ -517,11 +518,12 @@ _cursor_update_focus(struct server *server)
 	/* Focus surface under cursor if it isn't already focused */
 	struct cursor_context ctx = get_cursor_context(server);
 
-	if (ctx.view && rc.focus_follow_mouse
+	if ((ctx.view || ctx.surface) && rc.focus_follow_mouse
 			&& !rc.focus_follow_mouse_requires_movement
 			&& !server->osd_state.cycle_view) {
 		/* Prevents changing keyboard focus during A-Tab */
-		desktop_focus_view(ctx.view, rc.raise_on_focus);
+		desktop_focus_view_or_surface(&server->seat, ctx.view,
+			ctx.surface, rc.raise_on_focus);
 	}
 
 	cursor_update_common(server, &ctx, msec(&now),
@@ -908,13 +910,22 @@ cursor_button_press(struct seat *seat, struct wlr_pointer_button_event *event)
 		return;
 	}
 
-	/* Handle _press_ on a layer surface */
+	/*
+	 * On press, set focus to a non-view surface that wants it.
+	 * Action processing does not run for these surfaces and thus
+	 * the Focus action (used for normal views) does not work.
+	 */
 	if (ctx.type == LAB_SSD_LAYER_SURFACE) {
 		struct wlr_layer_surface_v1 *layer =
 			wlr_layer_surface_v1_from_wlr_surface(ctx.surface);
 		if (layer && layer->current.keyboard_interactive) {
 			seat_set_focus_layer(seat, layer);
 		}
+#ifdef HAVE_XWAYLAND
+	} else if (ctx.type == LAB_SSD_UNMANAGED) {
+		desktop_focus_view_or_surface(seat, NULL, ctx.surface,
+			/*raise*/ false);
+#endif
 	}
 
 	/*