ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Handling events
File Description
AlarmClockApp.mxml
or
AlarmClockApp.fla
Alarm Clock overview
Flash Player 9 and later, Adobe AIR 1.0 and later
The primary functionality of the clock in this example, including tracking the time and displaying the clock face, reuses
the SimpleClock application code, which is described in “Date and time example: Simple analog clock” on page 6. The
AlarmClock class extends the SimpleClock class from that example by adding the functionality required for an alarm
clock, including setting the alarm time and providing notification when the alarm “goes off.”
Providing notification when something happens is the job that events are made for. The AlarmClock class exposes the
Alarm event, which other objects can listen for in order to perform desired actions. In addition, the AlarmClock class
uses an instance of the Timer class to determine when to trigger its alarm. Like the AlarmClock class, the Timer class
provides an event to notify other objects (an AlarmClock instance, in this case) when a certain amount of time has
passed. As with most ActionScript applications, events form an important part of the functionality of the Alarm Clock
sample application.
Triggering the alarm
Flash Player 9 and later, Adobe AIR 1.0 and later
The main application file in Flash (FLA) or Flex (MXML).
com/example/programmingas3/clock/AlarmClock.as A class which extends the SimpleClock class, adding alarm clock
functionality.
com/example/programmingas3/clock/AlarmEvent.as A custom event class (a subclass of flash.events.Event) which serves as
the event object for the AlarmClock class’s alarm event.
com/example/programmingas3/clock/AnalogClockFace.as Draws a round clock face and hour, minute, and seconds hands based
on the time (described in the SimpleClock example).
com/example/programmingas3/clock/SimpleClock.as A clock interface component with simple timekeeping functionality
(described in the SimpleClock example).
As mentioned previously, the only functionality that the AlarmClock class actually provides relates to setting and
triggering the alarm. The built-in Timer class (flash.utils.Timer) provides a way for a developer to define code that will
be executed after a specified amount of time. The AlarmClock class uses a Timer instance to determine when to set off
the alarm.
Last updated 6/6/2012
141