gtk: Handle seatless displays

If you run weston with the headless backend, you get a Wayland
display with no seat, which is just fine by the protocol.

gdk_display_get_default_seat() returns NULL in this case. Various
widgets assume that we always have a seat with a keyboard and a
pointer, since that is what X guarantees. Make things survive
without that, so we can run the testsuite under a headless
Wayland compositor.

1 files changed, 23 insertions, 6 deletions

diff --git a/gtk/gtktooltip.c b/gtk/gtktooltip.c
index 4af709f19e..a6962641af 100644
--- a/gtk/gtktooltip.c
+++ b/gtk/gtktooltip.c
@@ -371,9 +371,10 @@ void
 gtk_tooltip_trigger_tooltip_query (GtkWidget *widget)
 {
   GdkDisplay *display;
-  double x, y;
-  GdkSurface *surface;
+  GdkSeat *seat;
   GdkDevice *device;
+  GdkSurface *surface;
+  double x, y;
   GtkWidget *toplevel;
   int dx, dy;
 
@@ -382,8 +383,15 @@ gtk_tooltip_trigger_tooltip_query (GtkWidget *widget)
   display = gtk_widget_get_display (widget);
 
   /* Trigger logic as if the mouse moved */
-  device = gdk_seat_get_pointer (gdk_display_get_default_seat (display));
-  surface = gdk_device_get_surface_at_position (device, &x, &y);
+  seat = gdk_display_get_default_seat (display);
+  if (seat)
+    device = gdk_seat_get_pointer (seat);
+  else
+    device = NULL;
+  if (device)
+    surface = gdk_device_get_surface_at_position (device, &x, &y);
+  else
+    surface = NULL;
   if (!surface)
     return;
 
@@ -673,6 +681,7 @@ gtk_tooltip_show_tooltip (GdkDisplay *display)
   gint x, y;
   GdkSurface *surface;
   GtkWidget *tooltip_widget;
+  GdkSeat *seat;
   GdkDevice *device;
   GtkTooltip *tooltip;
   gboolean return_value = FALSE;
@@ -684,9 +693,17 @@ gtk_tooltip_show_tooltip (GdkDisplay *display)
 
   surface = gtk_native_get_surface (GTK_NATIVE (tooltip->native));
 
-  device = gdk_seat_get_pointer (gdk_display_get_default_seat (display));
+  seat = gdk_display_get_default_seat (display);
+  if (seat)
+    device = gdk_seat_get_pointer (seat);
+  else
+    device = NULL;
+
+  if (device)
+    gdk_surface_get_device_position (surface, device, &px, &py, NULL);
+  else
+    px = py = 0;
 
-  gdk_surface_get_device_position (surface, device, &px, &py, NULL);
   x = round (px);
   y = round (py);