Flex - Fade Effect
Introduction
The Fade effect animates the alpha property of a component. If played on an object having visible property as false, and set to animate alpha from zero to a nonzero value, it will set object visible to true as a side-effect of fading it in.
Class declaration
Following is the declaration for spark.effects.Fade class:
public class Fade extends Animate
Public properties
| S.N. | Property & Description |
|---|---|
| 1 | alphaFrom : Number Initial value of the alpha property, between 0.0 and 1.0, where 0.0 means transparent and 1.0 means fully opaque. |
| 2 | alphaTo : Number Final value of the alpha property, between 0.0 and 1.0, where 0.0 means transparent and 1.0 means fully opaque. |
Public methods
| S.N. | Method & Description |
|---|---|
| 1 | Fade(target:Object = null) Constructor. |
Methods inherited
This class inherits methods from the following classes:
spark.effects.Animate
mx.effects.Effect
flash.events.EventDispatcher
Object
Flex Fade Effect Example
Let us follow the following steps to check usage of Fade Effect in a Flex application by creating a test application:
| Step | Description |
|---|---|
| 1 | Create a project with a name HelloWorld under a package com.tutorialspoint.client as explained in the Flex - Create Application chapter. |
| 2 | Modify HelloWorld.mxml as explained below. Keep rest of the files unchanged. |
| 3 | Compile and run the application to make sure business logic is working as per the requirements. |
Following is the content of the modified mxml file src/com.tutorialspoint/HelloWorld.mxml.
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
width="100%" height="100%" minWidth="500" minHeight="500"
>
<fx:Style source="/com/tutorialspoint/client/Style.css"/>
<fx:Script>
<![CDATA[
protected function btnFadeIn_clickHandler
(event:MouseEvent):void {
fadeIn.play();
}
protected function btnFadeOut_clickHandler
(event:MouseEvent):void {
fadeOut.play();
}
]]>
</fx:Script>
<fx:Declarations>
<s:Fade id="fadeIn" duration="2000" target="{imageFlex}"
alphaFrom="0" alphaTo="1"/>
<s:Fade id="fadeOut" duration="2000" target="{imageFlex}"
alphaFrom="1" alphaTo="0"/>
</fx:Declarations>
<s:BorderContainer width="630" height="480" id="mainContainer"
styleName="container">
<s:VGroup width="100%" height="100%" gap="50"
horizontalAlign="center" verticalAlign="middle">
<s:Label id="lblHeader" text="Effects Demonstration"
fontSize="40" color="0x777777" styleName="heading"/>
<s:Panel id="fadePanel" title="Using Fade Effect"
width="500" height="300" includeInLayout="true" visible="true">
<s:layout>
<s:VerticalLayout gap="10" verticalAlign="middle"
horizontalAlign="center"/>
</s:layout>
<s:Image id="imageFlex"
source="http://www.tutorialspoint.com/images/flex-mini.png" />
<s:HGroup>
<s:Button id="btnFadeOut" label="Fade Out"
click="btnFadeOut_clickHandler(event)"/>
<s:Button id="btnFadeIn" label="Fade In"
click="btnFadeIn_clickHandler(event)"/>
</s:HGroup>
</s:Panel>
</s:VGroup>
</s:BorderContainer>
</s:Application>
Once you are ready with all the changes done, let us compile and run the application in normal mode as we did in Flex - Create Application chapter. If everything is fine with your application, this will produce following result: [ Try it online ]
