Step Five: The ActionscriptNow the set up is all done we will add all the actionscript. To understand exactly how the slider works you need to understand a little actionscript. Firstly there is the property "scroll". Scroll is a value assigned by Flash to the current top row of text in a textbox. By changing this value we can move text up and down in a text box. Secondly we will use the 'globalToLocal' movie clip method. This action is a way of converting the coordinates of one movie clip to new coordinates that are relative to the coordinates of another movie clip. We will convert the coordinates of the slider to coordinates relative to the paths coordinates. In essence this means our return value will be number between 0 and 100. We can use this to scroll the textbox.
Select the slider instance and add this code under the onClipEvent(load) action
1. Use the onClipEvent(enterFrame) action (Actions <%gt%> onClipEvent), this means this code will continually be run
2. We are creating a new object to hold our new coordinates information. Use objects <%gt%> object <%gt%> newObject to add this line and give the object a name, I have simply used 'a'.
3. The next two lines set the x and y properties of our new object to the x and y coordinates of the slider.
4. This is where we add the globalToLocal (objects <%gt%> movieClip <%gt%> globalToLocal) method which converts the coordinates to coordinates relative to the path Movie Clip.
5. Lastly we convert newObject (a) 'y' coordinate into a useable variable 'b'.
The property 'maxscroll' is the maximum value 'scroll' needs to be to allow all the text to be visible. So if maxscroll equalled 100 we could use the value of 'a.y' directly to scroll the text. As it rarely would turn out this perfect we do a little math to convert the 'a.y' value to variable 'b' that coorelates to the length of the 100 pixel path.
b=a.y/(100/_root.text.textbox.maxscroll)The 'int' in front of the formula just converts the answer to an integer and is purely cosmetic.
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