+ /**
+ * All modifiers and their states.
+ */
+ this.modifiers = {
+
+ /**
+ * Whether shift is currently pressed.
+ */
+ "shift": false,
+
+ /**
+ * Whether ctrl is currently pressed.
+ */
+ "ctrl" : false,
+
+ /**
+ * Whether alt is currently pressed.
+ */
+ "alt" : false
+
+ };
+
+ /**
+ * The state of every key, indexed by keysym. If a particular key is
+ * pressed, the value of pressed for that keysym will be true. If a key
+ * is not currently pressed, the value for that keysym may be false or
+ * undefined.
+ */
+ this.pressed = [];