+static void timer_tick(void *data, XtIntervalId *id)
+{
+ struct app_state *state = data;
+ XtAppContext app;
+
+ if (state->board.x > 4) {
+ /* Game is over */
+ state->flags &= ~FLAG_TIMER_RUNNING;
+ return;
+ }
+
+ ui_timer_update(state, game_elapsed(&state->board));
+ app = XtWidgetToApplicationContext(state->game);
+ XtAppAddTimeOut(app, TIMER_UPDATE_MS, timer_tick, state);
+}
+
+static void do_input_move(struct app_state *state, int x, int y)
+{
+ uint_fast32_t mask;
+
+ if ((mask = game_do_move(&state->board, x, y)) != 0) {
+ if (game_check_goal(&state->board) == 0) {
+ ui_timer_update(state, game_finish(&state->board));
+ mask |= ~GOAL_MASK;
+ }
+
+ x11_redraw_game(state, mask);
+ }
+}
+
+static void set_view_goal(struct app_state *state, int view_goal)
+{
+ state->flags &= ~FLAG_VIEW_GOAL_ON_GAME;
+ state->flags |= view_goal ? FLAG_VIEW_GOAL_ON_GAME : 0;
+
+ x11_redraw_game(state, game_check_goal(&state->board));
+}
+
+static void game_input(Widget w, void *data, void *cb_data)
+{
+ XmDrawingAreaCallbackStruct *cbs = cb_data;
+ XButtonEvent *b = &cbs->event->xbutton;
+ struct app_state *state = data;
+
+ switch (cbs->event->type) {
+ case ButtonPress:
+ switch (b->button) {
+ case Button1:
+ if (b->state & Button3Mask)
+ break;
+
+ do_input_move(state, b->x / state->game_tile_sz,
+ b->y / state->game_tile_sz);
+ break;
+ case Button3:
+ set_view_goal(state, 1);
+ break;
+ }
+ break;
+ case ButtonRelease:
+ switch (b->button) {
+ case Button3:
+ set_view_goal(state, 0);
+ break;
+ }
+ }
+}
+