User Guide

678 Chapter 2: ActionScript Language Reference
on()
Availability
Flash 2. Not all events are supported in Flash 2.
Usage
on(mouseEvent) {
// your statements here
}
Parameters
statement(s)
The instructions to execute when the mouseEvent occurs.
A
mouseEvent is a trigger called an event. When the event occurs, the statements following it
within curly braces ({ }) execute. Any of the following values can be specified for the
mouseEvent parameter:
• press The mouse button is pressed while the pointer is over the button.
• release The mouse button is released while the pointer is over the button.
• releaseOutside While the pointer is over the button, the mouse button is pressed and then
rolls outside the button area just before it is released. Both the
press and the dragOut events
always precede a
releaseOutside event.
• rollOut The pointer rolls outside the button area.
• rollOver The mouse pointer rolls over the button.
• dragOut While the pointer is over the button, the mouse button is pressed and then rolls
outside the button area.
• dragOver While the pointer is over the button, the mouse button has been pressed, then
rolled outside the button, and then rolled back over the button.
• keyPress ("key") The specified keyboard key is pressed. For the key portion of the
parameter, specify a key code or key constant. You can use this parameter to intercept a key
press, that is, to override any built-in behavior for the specified key. The button can be
anywhere in your application, on or off the Stage. One limitation of this technique is that you
can't apply the
on() handler at runtime; you must do it at authoring time. For a list of key
codes associated with the keys on a standard keyboard, see Appendix C, “Keyboard Keys and
Key Code Values” in Using ActionScript in Flash; for a list of key constants, see “Property
summary for the Key class” on page 341.
Description
Event handler; specifies the mouse event or keypress that triggers an action.
Example
In the following script, the startDrag() function executes when the mouse is pressed, and the
conditional script is executed when the mouse is released and the object is dropped:
on (press) {
startDrag(this);
}
CHAPTER 2
ActionScript Language Reference