Flex, null object reference [SOLVED]

[vincent 0 Likes (Newbie)]

Hi there,

 

I have created a Flex project and I want use the transform manager but I have a probleme when I have tried to move object.

 

	var manager:TransformManager = new TransformManager();
       // instance a new mxml canvas object
var cont:IObject = new SimpleCanvas() as IObject;
anotherCanvas.addChild(cont as DisplayObject);
manager.addItem(cont as DisplayObject);

 

The simpleCanvas (an image in my example) is displayed but when a event occurs : (matrix is null)

 

public static function getDirectionX($m:Matrix):Number {
    var sx:Number = Math.sqrt($m.a * $m.a + $m.b * $m.;

Main Thread (Suspended: TypeError: Error #1009: Cannot access a property or method of a null object reference.)	
gs.transform.utils::MatrixTools$/getDirectionX	
gs.transform::TransformManager/renderSelection	
gs.transform::TransformManager/setOrigin	
gs.transform::TransformManager/centerOrigin	
gs.transform::TransformManager/updateSelection	
gs.transform::TransformManager/onSelectItem	
flash.events::EventDispatcher/dispatchEventFunction [no source]	
flash.events::EventDispatcher/dispatchEvent [no source]	
gs.transform::TransformItem/set selected	
gs.transform::TransformManager/onMouseDownItem	
flash.events::EventDispatcher/dispatchEventFunction [no source]	
flash.events::EventDispatcher/dispatchEvent [no source]	
gs.transform::TransformItem/onMouseDown	

 

Any help will be really appreciate

 

Thanks

[GreenSock 18,251 Likes (Superhero)]

It sounds like your SimpleCanvas isn't actually a DisplayObject. All DisplayObjects have a "transform.matrix" property which is necessary for TransformManager to do its work.

[vincent 0 Likes (Newbie)]

Hum, but my SimpleCanvas is a mxml canvas :

 

and when I read the canvas documentation, the Inheritance tree show me that DisplayObject is present.

http://livedocs.adobe.com/flex/3/langre ... anvas.html

 

To be sure, I make the previous test without any cast (IObject)

 

 var manager:TransformManager = new TransformManager();
       // instance a new mxml canvas object
  var cont:DisplayObject = new SimpleCanvas();
  anotherCanvas.addChild(cont);
  manager.addItem(cont);

 

The problem persists.

 

Thanks

[GreenSock 18,251 Likes (Superhero)]

I wonder if it's another bug in the Flex framework. There are tons of them (acknowledged by Adobe). Have you tried tracing cont.transform.matrix? Is it null? If so, I'm almost positive that's a Flex bug.

[vincent 0 Likes (Newbie)]

cont.transform.matrix is always null. But matrix3D is set !

 

If the matrix property is set to a value (not null), the matrix3D property is null. And if the matrix3D property is set to a value (not null), the matrix property is null.

For all three-dimensional objects, a Matrix3D object is created automatically when you assign a z value to a display object.

 

I have removed a property on my mxml and now it's works !!

 

Thanks for your help