User Guide

on keyDown 179
// JavaScript syntax
function isOKToAttach(aSpriteType, aSpriteNum) {
switch (aSpriteType) {
case symbol("graphic"): // any graphic sprite type
return sprite(aSpriteNum).member.type != symbol("shape");
// works for everything but shape cast members
case symbol("script"): // the frame script channel
return false; // doesn't work as a frame script
}
}
on keyDown
Usage
-- Lingo syntax
on keyDown
statement(s)
end
// JavaScript syntax
function keyDown() {
statement(s);
}
Description
System message and event handler; contains statements that run when a key is pressed.
When a key is pressed, Director searches these locations, in order, for an
on keyDown handler:
primary event handler, editable field sprite script, field cast member script, frame script, and
movie script. For sprites and cast members,
on keyDown handlers work only for editable text and
field members. A
keyDown event on a different type of cast member, such as a bitmap, has no
effect. (If pressing a key should have the same response throughout the movie, set
keyDownScript.)
Director stops searching when it reaches the first location that has an
on keyDown handler,
unless the handler includes the
pass command to explicitly pass the keyDown message on to the
next location.
The
on keyDown event handler is a good place to put Lingo that implements keyboard shortcuts
or other interface features that you want to occur when the user presses keys.
When the movie plays back as an applet, an
on keyDown handler always traps key presses, even if
the handler is empty. If the user is typing in an editable field, an on keyDown handler attached to
the field must include the
pass command for the key to appear in the field.
Where you place an
on keyDown handler can affect when it runs.
• To apply the handler to a specific editable field sprite, put the handler in a sprite script.
• To apply the handler to an editable field cast member in general, put the handler in a cast
member script.
• To apply the handler to an entire frame, put the handler in a frame script.
• To apply the handler throughout the entire movie, put the handler in a movie script.