Fix widgets not updating with parent's widget

apps/spline.c

@@ -129,6 +129,7 @@ static twin_dispatch_result_t _apps_spline_update_pos(apps_spline_t *spline,
     spline->points[spline->which].y = twin_sfixed_to_fixed(
         _twin_matrix_y(&(spline->inverse_transition), x, y));
     _twin_widget_queue_paint(&spline->widget);
+    twin_widget_children_paint((spline->widget).parent);
     return TwinDispatchDone;
 }
 

include/twin.h

@@ -1124,6 +1124,9 @@ twin_angle_t twin_acos(twin_fixed_t x);
  * widget.c
  */
 
+/* Paint the widget children of the box. */
+void twin_widget_children_paint(twin_box_t *box);
+
 twin_widget_t *twin_widget_create(twin_box_t *parent,
                                   twin_argb32_t background,
                                   twin_coord_t width,

src/box.c

@@ -163,6 +163,7 @@ twin_dispatch_result_t _twin_box_dispatch(twin_widget_t *widget,
     case TwinEventConfigure:
         return _twin_box_configure(box);
     case TwinEventButtonDown:
+        twin_window_show(widget->window);
         box->button_down =
             _twin_box_xy_to_widget(box, event->u.pointer.x, event->u.pointer.y);
         if (box->button_down && box->button_down->want_focus)

src/widget.c

@@ -200,6 +200,13 @@ void _twin_widget_bevel(twin_widget_t *widget, twin_fixed_t b, bool down)
     }
 }
 
+void twin_widget_children_paint(twin_box_t *box)
+{
+    /* Paint the widget children of the box. */
+    for (twin_widget_t *child = box->children; child; child = child->next)
+        _twin_widget_queue_paint(child);
+}
+
 twin_widget_t *twin_widget_create(twin_box_t *parent,
                                   twin_argb32_t background,
                                   twin_coord_t width,