shell: Start the input panel slide slightly on the output

If a surface is not on any output, scheduling a repaint for it is a no-op.
weston_view_schedule_repaint() schedules repaints for all outputs that
overlap with the surface extents, but if the surface is completely
outside all outputs nothing will be scheduled.  Fix this for now by starting
the slide slightly into the output.

desktop-shell/input-panel.c

@@ -75,7 +75,7 @@ show_input_panels(struct wl_listener *listener, void *data)
 		weston_view_geometry_dirty(ipsurf->view);
 		weston_view_update_transform(ipsurf->view);
 		weston_surface_damage(ipsurf->surface);
-		weston_slide_run(ipsurf->view, ipsurf->surface->height,
+		weston_slide_run(ipsurf->view, ipsurf->surface->height * 0.9,
 				 0, NULL, NULL);
 	}
 }
@@ -138,7 +138,7 @@ input_panel_configure(struct weston_surface *surface, int32_t sx, int32_t sy)
 			       &ip_surface->view->layer_link);
 		weston_view_update_transform(ip_surface->view);
 		weston_surface_damage(surface);
-		weston_slide_run(ip_surface->view, ip_surface->view->surface->height, 0, NULL, NULL);
+		weston_slide_run(ip_surface->view, ip_surface->view->surface->height * 0.9, 0, NULL, NULL);
 	}
 }