Calling Function across Classes

Question

How do I call a function across classes?
I have a primary class ("ChordLib.as") that contains a function that manages options for TileList component, that includes prescribing a custom Cell Rendering class, "MyRenderer".  I want to be able to call a function in the primary "ChordLib.as" class from the "MyRenderer.as" class.  Here is the function in "ChordLib" that refers to the "MyRenderer" class. Perhaps there is a way here to pass reference of the primary class into "MyRenderer"?
// SET CHORD LIST  //////////////////////////////////////////
public function setChordList(song:int):void {
var dpChords:DataProvider = new DataProvider();
var i:uint;
// determine chord set
if (song == -1) {
     activeChords = allChords;
} else {
     activeChords = songChordSets[song];
// fill dataProvider
for(i=0; i<activeChords.length; i++) {
     var tt = activeChords[i];
     dpChords.addItem({ label:tt, source:ChordBar, data:i, scaleContent:true }); 
chordList.dataProvider = dpChords;
chordList.columnWidth     = 70;
chordList.rowHeight     = 30;
chordList.direction = ScrollBarDirection.VERTICAL;
chordList.setStyle("contentPadding", 5);
chordList.setRendererStyle("imagePadding", 0);
chordList.scrollPolicy  = ScrollPolicy.ON;
// set style for labels
chordList.setRendererStyle("textFormat", textFormat1);
// set the background skin
chordList.setStyle("skin", lightBackground);
//set the cell renderer
chordList.setStyle("cellRenderer", MyRenderer);
This last line ("chordList.setStyle("cellRenderer", MyRenderer);") refers to this custom class, that includes some event listeners:
package {
   import fl.controls.listClasses.ICellRenderer;
   import fl.controls.listClasses.ImageCell;
   import flash.events.*;
   public class MyRenderer extends ImageCell implements ICellRenderer {
      public function MyRenderer() {
            this.buttonMode    = true;
          // set state skins to same skin so background is static
          setStyle("upSkin", lightBackground);
          setStyle("downSkin", lightBackground);
          setStyle("overSkin", lightBackground);
          setStyle("selectedUpSkin", lightBackground);
          setStyle("selectedDownSkin", lightBackground);
          setStyle("selectedOverSkin", lightBackground);
          // turn off text background by setting to 0
          setStyle("textOverlayAlpha", 0);
          setStyle("textPadding", 7);
            // event listeners
            this.addEventListener(MouseEvent.CLICK, clickHandler);
            this.addEventListener(MouseEvent.MOUSE_OVER, mouseOverHandler);
            this.addEventListener(MouseEvent.MOUSE_OUT, mouseOutHandler);
       // EVENTS
       private function clickHandler(event:MouseEvent):void {
       private function mouseOverHandler(event:MouseEvent):void {
       private function mouseOutHandler(event:MouseEvent):void {
I want to insert calls to functions that are in the primary class (that contains the first function listed here), "ChordLib.as".
How do I do this?

Answer 1

In order for ClassA to call a function of another ClassB (or instance of it) it needs to be aware of two facts: 1) That ClassB does exist and 2) that ClassB has a particular function.
Another approach could be establishing communication between classes via events.
From you explanation it is not clear what you want to accomplish. Do you need to call a function on Class itself or an instance of this Class?
If former - you need to create a static function and just call it:
inside ClassB:
public static function classBFunction()
ClassA can call it:
ClassB.classBFunction()
If you need to call the function on an instance - you, naturally, need to instantiate the class and only then call the function.
Say you have function inside ClassB
public function classBAnotherFunction() - note that there is no word static
There is another fork here: either you instantiate the ClassB inside ClassA or you pass a reference of the instance of ClassB into ClassA