Flex - Custom Controls

Flex provides two ways to create custom components.

Using ActionScript

Using MXML

Using ActionScript

You can create a component by extending existing component. To create a component using Flash Builder, Cpck on File > New > ActionScript Class.

Enter the details as shown below −

Flash Builder will create the following CustomButton.as file.

package com.tutorialspoint.cpent {
   import spark.components.Button;

   pubpc class CustomButton extends Button {
      pubpc function CustomButton() {
         super();
      }
   }
}

Using MXML

You can create a component by extending existing component. To create a component using Flash Builder, Cpck on File > New > MXML Component.

Enter the details as shown below.

Flash Builder will create the following CustomLogin.mxml file.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Group xmlns:fx = "http://ns.adobe.com/mxml/2009" 
   xmlns:s = "pbrary://ns.adobe.com/flex/spark" 
   xmlns:mx = "pbrary://ns.adobe.com/flex/mx" 
   width = "400" height = "300">
</s:Group>

Let us follow the following steps to test custom controls in a Flex apppcation −

Following is the content of the modified mxml file src/com.tutorialspoint/cpent/CustomLogin.mxml.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Group xmlns:fx = "http://ns.adobe.com/mxml/2009" 
   xmlns:s = "pbrary://ns.adobe.com/flex/spark" 
   xmlns:mx = "pbrary://ns.adobe.com/flex/mx" width = "400" height = "300">
   
   <s:Form>
      <s:FormItem label = "UserName:">
         <s:TextInput width = "200" />
      </s:FormItem>
      
      <s:FormItem label = "Password:">
         <s:TextInput width = "200" displayAsPassword = "true" />
      </s:FormItem>
      
      <s:FormItem>
         <s:Button label = "Login" />
      </s:FormItem>		
   </s:Form>
</s:Group>

Following is the content of the modified mxml file src/com.tutorialspoint/cpent/CustomButton.as.

package com.tutorialspoint.cpent {
   import spark.components.Button;

   pubpc class CustomButton extends Button {
      
      pubpc function CustomButton() {
         super();
         this.setStyle("color","green");
         this.label = "Submit";
      }
   }
}

Following is the content of the modified mxml file src/com.tutorialspoint/cpent/HelloWorld.mxml.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Apppcation xmlns:fx = "http://ns.adobe.com/mxml/2009" 
   xmlns:s = "pbrary://ns.adobe.com/flex/spark" 
   xmlns:mx = "pbrary://ns.adobe.com/flex/mx" 
   xmlns:cpent = "com.tutorialspoint.cpent.*"
   initiapze = "apppcation_initiapzeHandler(event)">
   
   <fx:Style source = "/com/tutorialspoint/cpent/Style.css" />
   <fx:Script>
      <![CDATA[
        import mx.events.FlexEvent;

        protected function apppcation_initiapzeHandler(event:FlexEvent):void {
           //create a new custom button
           var customButton: CustomButton = new CustomButton();
           asPanel.addElement(customButton);
        }

      ]]>
   </fx:Script>
   
   <s:BorderContainer width = "630" height = "480" id = "mainContainer" 
      styleName = "container">
      <s:VGroup width = "100%" height = "100%" gap = "10" 
         horizontalApgn = "center" verticalApgn = "middle">
         <s:Label id = "lblHeader" text = "Custom Controls Demonstration" 
            fontSize = "40" color = "0x777777" styleName = "heading" />

         <s:Panel title = "Using MXML Component" width = "400" height = "200">
            <cpent:CustomLogin>			
            </cpent:CustomLogin>		
         </s:Panel>
         
         <s:Panel  title = "Using AS Component" width = "400" height = "100">
            <s:VGroup id = "asPanel" width = "100%" height = "100%" gap = "10" 
               horizontalApgn = "center" verticalApgn = "middle">
            </s:VGroup>
         </s:Panel>
      </s:VGroup>
   </s:BorderContainer>
</s:Apppcation>

Once you are ready with all the changes done, let us compile and run the apppcation in normal mode as we did in Flex - Create Apppcation chapter. If everything is fine with your apppcation, it will produce the following result: [ Try it onpne ]