Difference between revisions of "Oolite JavaScript Reference: Timer"
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'''new Timer'''(this : Object, function : Function, delay : Number [, interval : Number]) : Timer | '''new Timer'''(this : Object, function : Function, delay : Number [, interval : Number]) : Timer | ||
Creates a new timer which will call <code>function</code> after <code>delay</code> seconds, and optionally repeatedly every <code>interval</code> seconds. If <code>delay</code> is zero or more, the timer will be started automatically. If <code>interval</code> is 0 or less, the timer will not repeat. If <code>interval</code> is greater than 0 but less than 0.25, it will be rounded up to 0.25. | Creates a new timer which will call <code>function</code> after <code>delay</code> seconds, and optionally repeatedly every <code>interval</code> seconds. If <code>delay</code> is zero or more, the timer will be started automatically. If <code>interval</code> is 0 or less, the timer will not repeat. If <code>interval</code> is greater than 0 but less than 0.25, it will be rounded up to 0.25. | ||
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| + | If <code>delay</code> is negative and <code>interval</code> is positive, the timer will initially be stopped. After it is start, it will fire at multiples of <code>interval</code> after its creation time. For instance, if a timer is created stopped with a five-second interval, and started after seven seconds, it will fire after ten seconds. | ||
If the <code>this</code> parameter becomes invalid (usually because it’s attached to a ship that’s destroyed, or left behind when the player executes a hyperspace jump), the timer will be stopped and removed automatically. | If the <code>this</code> parameter becomes invalid (usually because it’s attached to a ship that’s destroyed, or left behind when the player executes a hyperspace jump), the timer will be stopped and removed automatically. | ||
Revision as of 20:40, 20 February 2011
Prototype: Object
Subtypes: none
Timer objects are used to perform tasks after a delay or on a repeating schedule. When a timer is created, it is given a function to call, and a delay and an optional interval in seconds in game real time. The next fire time of the timer is set to the current time + the delay. When the game clock reaches (or passes) the next fire time, the function is called. If the timer has a positive interval, the interval is added to the next fire time. Otherwise, the timer stops.
Note: in order for a timer to work consistently, you must keep a reference to it as long as it is in use. The easiest way is to make it a property of your script: this.timer = new Timer(this, this.doSomething, 5, 5). If this is not done, the JavaScript runtime may delete the timer at any time to free up memory.
Contents
Constructor
new Timer(this : Object, function : Function, delay : Number [, interval : Number]) : Timer
Creates a new timer which will call function after delay seconds, and optionally repeatedly every interval seconds. If delay is zero or more, the timer will be started automatically. If interval is 0 or less, the timer will not repeat. If interval is greater than 0 but less than 0.25, it will be rounded up to 0.25.
If delay is negative and interval is positive, the timer will initially be stopped. After it is start, it will fire at multiples of interval after its creation time. For instance, if a timer is created stopped with a five-second interval, and started after seven seconds, it will fire after ten seconds.
If the this parameter becomes invalid (usually because it’s attached to a ship that’s destroyed, or left behind when the player executes a hyperspace jump), the timer will be stopped and removed automatically.
Properties
interval
interval : Number (read/write)
The rate at which the timer repeats. For a one-shot timer, this will be -1. If set to 0 or a negative number, it will be treated as -1. If set to a number between 0 and 0.25, it will be rounded up to 0.25.
isRunning
isRunning : Boolean (read-only)
true if the timer is running, false if it is stopped.
nextTime
nextTime : Number (read/write when stopped)
The next time the timer will fire, if it is running at that time. This can be modified if the timer is stopped. Note that this is an absolute time, not a delay. You can get the current absolute time using clock.absoluteSeconds.
Methods
start
function start() : Boolean
Starts the timer, if it is not currently running. This will fail if it is a one-shot timer (i.e., its interval is -1) and its nextTime is in the past. Returns true if successful or the timer was already running, false on failure (i.e., the same as isRunning after start() is called).
stop
function stop()
Stops the timer, if it is currently running.
