ActionScript: The Definitive Guide

Name

getTimer( ) Global Function — determine the age of a movie, in milliseconds

Availability

Flash 4 and later

Synopsis

getTimer( )

Returns

The number of milliseconds that have passed since the movie started playing.

Description

The getTimer( ) function indicates how long a movie has been playing, in milliseconds. We can use multiple getTimer( ) checks to govern the timed execution of a block of code or to add time-based features to a movie, such as a countdown in a video game. For example, when attached to a movie clip that contains a text field named counterOutput, the following code counts down from 60 to 0:

onClipEvent (load) {
  // Record the current time
  var startTime = getTimer( );
  // Set the number of seconds to count down
  var countAmount = 60;
  // Initialize a variable to keep track of how much time has passed
  var elapsed = 0;
}

onClipEvent (enterFrame) {
  // Check how much time has passed
  elapsed = getTimer( ) - startTime;
  // If the time passed is less than the length of our countdown...
  if (elapsed < countAmount * 1000) {
    // ...set the text field to show the amount of time left
    counterOutput = countAmount - Math.floor(elapsed / 1000);
  } else {
    // ...otherwise, our countdown is done, so tell the user
    counterOutput = "Time's UP!";
  }
}

To determine the number of full seconds that have passed in a movie (rather than milliseconds), divide the return of getTimer( ) by 1000 and trim off the decimal portion with either Math.floor( ), Math.round( ), or Math.ceil( ). For example:

numSeconds ...