lz.Timer is used to invoke functionality after a specific amount of time. By using a <handler> to refer to a particular method, and then by adding a timer to that delegate, the developer can control the timing of the method's start. Use lz.Timer to tweak sequence and timing of visual animations, delay the effects of user events, or implement user experiences with expiration features.
It should be noted that the time passed to the lz.Timer service describes the time before which the delegate may not run -- it is not guaranteed that the delegate will run at that time. Depending on application needs and client performance, the specified delegate may be invoked at any time after the amount of time specified.
The following example displays some text when a button is clicked, and uses lz.Timer to fade the text away after three seconds.
Example 30. Using lz.Timer to invoke method
<canvas height="50">
<button text="Show then Fade" onclick="canvas.showText()"/>
<text name="myText" opacity="0.0" bgcolor="#CCCCCC">The Invisible Man</text>
<simplelayout axis="y" spacing="10"/>
<method name="showText">
myText.setAttribute( "opacity", 1.0 );
lz.Timer.addTimer( new LzDelegate( this, "fadeText" ), 3000 );
</method>
<method name="fadeText">
myText.animate( "opacity", 0.0, 1000 );
</method>
</canvas>
| Name | Type (tag) | Type (js) | Default | Category |
|---|---|---|---|---|
LzTimer
|
LzTimerService | readonly | ||
The timer service. Also available as the global
lz.Timer.
|
||||
Methods
-
addTimer() -
Adds a timer. Note: The timer guarantees that the delegate will not be called before the number of milliseconds specified here, but cannot guarantee that it will be called at exactly that time.
Parameter Name Type Description d LzDelegate The delegate to call when the timer expires millisecs Number The number of millisecondss to wait before calling the delegate.
-
countTimers() -
-
removeTimer() -
Parameter Name Type Description d LzDelegate The delegate called by the timer to be removed. If there are multiple timerList entries that call delegate d, removes the first in the order received.
-
resetTimer() -
Resets the timer for the given delegate to the new amount of time. If a timer for the delegate is not found, a new timer is created.
Parameter Name Type Description d LzDelegate The delegate whose timer to reset. If there are multiple timers for this delegate, the first one is reset. If this delegate is not found in the timer list, a new timer event is created for it. millisecs The number of milliseconds to wait before calling the timer.