clutter: Add pointer accessibility features

Add support for click assist, namely simulated secondary click (on a
long primary button press) and hover click support (simulate a click when
the pointer remains static for some time).

https://gitlab.gnome.org/GNOME/mutter/merge_requests/512

clutter/clutter/clutter-input-pointer-a11y-private.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Author: Olivier Fourdan <ofourdan@redhat.com>
+ */
+
+#ifndef __CLUTTER_INPUT_POINTER_A11Y_H__
+#define __CLUTTER_INPUT_POINTER_A11Y_H__
+
+#include <clutter/clutter-types.h>
+#include "clutter-enum-types.h"
+
+G_BEGIN_DECLS
+
+void _clutter_input_pointer_a11y_add_device      (ClutterInputDevice   *device);
+void _clutter_input_pointer_a11y_remove_device   (ClutterInputDevice   *device);
+void _clutter_input_pointer_a11y_on_motion_event (ClutterInputDevice   *device,
+                                                  float                 x,
+                                                  float                 y);
+void _clutter_input_pointer_a11y_on_button_event (ClutterInputDevice   *device,
+                                                  int                   button,
+                                                  gboolean              pressed);
+gboolean _clutter_is_input_pointer_a11y_enabled  (ClutterInputDevice     *device);
+
+G_END_DECLS
+
+#endif /* __CLUTTER_INPUT_POINTER_A11Y_H__ */