Java Swing, 2nd Edition

The Timer Class

The Timer class provides a mechanism to generate timed events. It has properties and events, and thus can be used in application builders that understand JavaBeans. It fires an ActionEvent at a given time. The timer can be set to repeat, and an optional initial delay can be set before the repeating event starts.

Properties

The Timer class properties give you access to the timer delays and nature of the event firing loops. They are listed in Table 27-2. The delay property dictates the length between repeated timer events (if repeats is true) and initialDelay determines how long to wait before starting the regular, repeating events. Both properties expect values in milliseconds. If your timer is not repeating, then the value of initialDelay determines when the timer fires its event. You can check to see if the timer is running with the running property. The coalesce property dictates whether or not the timer combines pending events into one single event (to help listeners keep up). For example, if the timer fires a tick every 10 milliseconds, but the application is busy and has not handled events for 100 milliseconds, 10 action events are queued up for delivery. If coalesce is false, all 10 of these are delivered in rapid succession. If coalesce is true (the default), only one event is fired. The logTimers property can be turned on to generate simple debugging information to the standard output stream each time an event is processed.

Table 27-2. Timer properties ...