Question

I am writing a class that extends mx.core.UIComponent. In the constructor of this class, I would like to add a Button (spark.components.Button). However, creating a new Button object (such as var b:Button = new Button();) and then doing this.addChild(b) doesn’t work — no button is appearing. Is there any reason why a Button object can’t be added as a child?

Edit: Just to add, when I print out the children, it says that the Button object is a child, but the Button doesn’t show up.

Answer 1

Using UIComponent directly, you aren’t getting the layout of the child handled for you; you would need to set the position and size of your child components manually (see docs).

Consider using a Group (or Canvas, if you’re still on MX components) to handle child layout. You can still add rendering in updateDisplayList, just make sure you call super.updateDisplayList() as well.