ActionScript: The Definitive Guide

Name

MovieClip.localToGlobal( ) Method — convert a point in a clip to main Stage coordinates

Availability

Flash 5

Synopsis

mc.localToGlobal(point)

Arguments

point

A reference to an object with two properties, x and y, that describe a point in mc’s coordinate space. Both x and y may be any floating-point number.

Description

The localToGlobal( ) method converts the x and y properties of point from coordinates given in mc’s coordinate space to coordinates on the main Stage of the Player. Note that localToGlobal( ) does not return a new object, it merely modifies the existing x and y values of point.

To use localToGlobal( ), we must first create a so-called point or coordinates object with x and y properties. To do so, we’ll simply create a generic object from the Object class, and add x and y properties to it:

myPoint = new Object( );
myPoint.x = 10;
myPoint.y = 20;

The x and y properties of our object are positions on the horizontal and vertical axes of mc, relative to mc’s registration point (shown as a crosshair in mc’s Library symbol). For example, an x of 10 is 10 pixels to the right of mc’s registration point, and a y of 20 is 20 pixels below mc’s registration point. With our object created and our x and y properties set, we then pass the object to the localToGlobal( ) method, as in:

myClip.localToGlobal(myPoint);

When localToGlobal( ) is executed, the values of myPoint’s x and y properties are transformed to represent the corresponding point on the main Stage, measured from the Stage’s ...