PlaceholderTextField.as

package {
	import flash.text.TextField;
	import flash.text.TextFieldType;
	import flash.events.FocusEvent;

	public class PlaceholderTextField extends TextField {

		public var placeholder:String;
		public var placeholderColor:uint;
		private var defaultTextColor:uint;

		public function PlaceholderTextField(placeholder:String="", placeholderColor:uint=0x999999) {
			trace("call before super();");
			this.placeholder=placeholder;
			this.placeholderColor=placeholderColor;
			super();
			trace("call after super();");
			this.defaultTextColor=this.textColor;
			this.type=TextFieldType.INPUT;
			this.addEventListener(FocusEvent.FOCUS_IN, this.onFocusIn);
			this.addEventListener(FocusEvent.FOCUS_OUT, this.onFocusOut);
			this.showDefaultMessage();
		}

		public override function set textColor(textColor:uint):void {
			super.textColor=textColor;
			this.defaultTextColor=textColor;
		}

		private function onFocusIn(event:FocusEvent):void {
			if (this.text==this.placeholder) {
				this.hideDefaultMessage();
			}
		}

		private function onFocusOut(event:FocusEvent):void {
			if (! this.text) {
				this.showDefaultMessage();
			}
		}

		private function showDefaultMessage():void {
			this.text=this.placeholder;
			super.textColor=this.placeholderColor;
		}

		private function hideDefaultMessage():void {
			this.text="";
			super.textColor=this.defaultTextColor;
		}
	}
}