Displaying an icon on a toggle button in Flex 4

The following example shows how you can create a simple toggle button with an icon in Flex 4 by using the Spark ButtonBarButton control and specifying the icon in the data property, and then using a custom skin class.

Full code after the jump.

The following example(s) require Flash Player 10 and the Adobe Flex 4 SDK. To download the Adobe Flash Builder 4 trial, see www.adobe.com/products/flex/. To download the latest nightly build of the Flex 4 SDK, see opensource.adobe.com/wiki/display/flexsdk/Download+Flex+4.

For more information on getting started with Flex 4 and Flash Builder 4, see the official Adobe Flex Team blog.

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/07/28/displaying-an-icon-on-a-toggle-button-in-flex-4/ -->
<s:Application name="Spark_ButtonBarButton_data_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark">
 
    <fx:Style>
        @namespace s "library://ns.adobe.com/flex/spark";
 
        s|ButtonBarButton.iconButton {
            skinClass: ClassReference("skins.CustomIconButtonSkin");
        }
    </fx:Style>
 
    <s:HGroup horizontalCenter="0" verticalCenter="0">
        <s:ButtonBarButton id="redBtn"
                label="Red"
                data="@Embed('assets/bullet_red.png')"
                styleName="iconButton" />
        <s:ButtonBarButton id="orangeBtn"
                label="Orange"
                data="@Embed('assets/bullet_orange.png')"
                styleName="iconButton" />
        <s:ButtonBarButton id="yelloyBtn"
                label="Yellow"
                data="@Embed('assets/bullet_yellow.png')"
                styleName="iconButton" />
        <s:ButtonBarButton id="greenBtn"
                label="Green"
                data="@Embed('assets/bullet_green.png')"
                styleName="iconButton" />
        <s:ButtonBarButton id="blueBtn"
                label="Blue"
                data="@Embed('assets/bullet_blue.png')"
                styleName="iconButton" />
    </s:HGroup>
 
</s:Application>

And the custom skin class, skins/CustomIconButtonSkin.mxml, is as follows:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/07/28/displaying-an-icon-on-a-toggle-button-in-flex-4/ -->
<s:SparkSkin name="CustomIconButtonSkin"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark" 
        minWidth="21" minHeight="21"
        alpha.disabledStates="0.5">
    <!-- states -->
    <s:states>
        <s:State name="up" />
        <s:State name="over" stateGroups="overStates" />
        <s:State name="down" stateGroups="downStates" />
        <s:State name="disabled" stateGroups="disabledStates" />
        <s:State name="upAndSelected" stateGroups="selectedStates, selectedUpStates" />
        <s:State name="overAndSelected" stateGroups="overStates, selectedStates" />
        <s:State name="downAndSelected" stateGroups="downStates, selectedStates" />
        <s:State name="disabledAndSelected" stateGroups="selectedUpStates, disabledStates, selectedStates" />
    </s:states>
 
    <!-- host component -->
    <fx:Metadata>
        <![CDATA[ 
            [HostComponent("spark.components.ButtonBarButton")]
        ]]>
    </fx:Metadata>
 
    <fx:Script>
        /* Define the skin elements that should not be colorized. 
        For toggle button, the graphics are colorized but the label is not. */
        static private const exclusions:Array = ["labelDisplay"];
 
        override public function get colorizeExclusions():Array {return exclusions;}
    </fx:Script>
 
    <!-- layer 1: shadow -->
    <s:Rect left="-1" right="-1" top="-1" bottom="-1"
            radiusX="2" radiusY="2">
        <s:fill>
            <s:LinearGradient rotation="90">
                <s:GradientEntry color="0x000000" 
                        color.downStates="0xFFFFFF"
                        alpha="0.01"
                        alpha.downStates="0" />
                <s:GradientEntry color="0x000000" 
                        color.downStates="0xFFFFFF" 
                        alpha="0.07"
                        alpha.downStates="0.5" />
            </s:LinearGradient>
        </s:fill>
    </s:Rect>
 
    <!-- layer 2: fill -->
    <s:Rect left="1" right="1" top="1" bottom="1" radiusX="2" radiusY="2">
        <s:fill>
            <s:LinearGradient rotation="90">
                <s:GradientEntry color="0xFFFFFF" 
                        color.selectedUpStates="0xBBBDBD"
                        color.overStates="0xBBBDBD" 
                        color.downStates="0xAAAAAA" 
                        alpha="0.85" 
                        alpha.overAndSelected="1" />
                <s:GradientEntry color="0xD8D8D8" 
                        color.selectedUpStates="0x9FA0A1"
                        color.over="0x9FA0A1" 
                        color.overAndSelected="0x8E8F90"
                        color.downStates="0x929496" 
                        alpha="0.85"
                        alpha.overAndSelected="1" />
            </s:LinearGradient>
        </s:fill>
    </s:Rect>
 
    <!-- layer 3: fill lowlight -->
    <s:Rect left="1" right="1" bottom="1" height="9"
            radiusX="2" radiusY="2">
        <s:fill>
            <s:LinearGradient rotation="90">
                <s:GradientEntry color="0x000000" alpha="0.0099" />
                <s:GradientEntry color="0x000000" alpha="0.0627" />
            </s:LinearGradient>
        </s:fill>
    </s:Rect>
 
    <!-- layer 4: fill highlight -->
    <s:Rect left="1" right="1" top="1" height="9"
            radiusX="2" radiusY="2">
        <s:fill>
            <s:SolidColor color="0xFFFFFF" 
                    alpha="0.33" 
                    alpha.selectedUpStates="0.22"
                    alpha.overStates="0.22" 
                    alpha.downStates="0.12" />
        </s:fill>
    </s:Rect>
 
    <!-- layer 5: highlight stroke (all states except down) -->
    <s:Rect left="1" right="1" top="1" bottom="1"
            radiusX="2" radiusY="2"
            excludeFrom="downStates">
        <s:stroke>
            <s:LinearGradientStroke rotation="90" weight="1">
                <s:GradientEntry color="0xFFFFFF"
                        alpha.overStates="0.22"
                        alpha.selectedUpStates="0.33" />
                <s:GradientEntry color="0xD8D8D8"
                        alpha.overStates="0.22"
                        alpha.selectedUpStates="0.33" />
            </s:LinearGradientStroke>
        </s:stroke>
    </s:Rect>
 
    <!-- layer 6: highlight stroke (down state only) -->
    <s:Rect left="1" top="1" bottom="1" width="1"
            includeIn="downStates, selectedUpStates, overAndSelected">
        <s:fill>
            <s:SolidColor color="0x000000" alpha="0.07" />
        </s:fill>
    </s:Rect>
    <s:Rect right="1" top="1" bottom="1" width="1"
            includeIn="downStates, selectedUpStates, overAndSelected">
        <s:fill>
            <s:SolidColor color="0x000000" alpha="0.07" />
        </s:fill>
    </s:Rect>
    <s:Rect left="2" top="1" right="2" height="1"
            includeIn="downStates, selectedUpStates, overAndSelected">
        <s:fill>
            <s:SolidColor color="0x000000" alpha="0.25" />
        </s:fill>
    </s:Rect>
    <s:Rect left="1" top="2" right="1" height="1"
            includeIn="downStates, selectedUpStates, overAndSelected">
        <s:fill>
            <s:SolidColor color="0x000000" alpha="0.09" />
        </s:fill>
    </s:Rect>
 
    <!-- layer 7: border - put on top of the fill so it doesn't disappear when scale is less than 1 -->
    <s:Rect left="0" right="0" top="0" bottom="0"
            width="69" height="20"
            radiusX="2" radiusY="2">
        <s:stroke>
            <s:LinearGradientStroke rotation="90" weight="1">
                <s:GradientEntry color="0x000000"
                        alpha="0.5625"
                        alpha.down="0.6375"
                        alpha.selectedStates="0.6375" />
                <s:GradientEntry color="0x000000" 
                        alpha="0.75"
                        alpha.down="0.85"
                        alpha.selectedStates="0.85" />
            </s:LinearGradientStroke>
        </s:stroke>
    </s:Rect>
 
    <s:HGroup horizontalCenter="0" verticalCenter="1"
            left="10" right="10" top="2" bottom="2"
            creationComplete="img.source = hostComponent.data;">
        <!-- layer 8: icon -->
        <s:BitmapImage id="img" />
 
        <!-- layer 9: text -->
        <s:SimpleText id="labelDisplay"
                textAlign="center"
                verticalAlign="middle"
                maxDisplayedLines="1"
                height="100%"/>
    </s:HGroup>
 
</s:SparkSkin>

View source is enabled in the following example.

[Famfamfam]

This entry is based on a beta version of the Flex 4 SDK and therefore is very likely to change as development of the Flex SDK continues. The API can (and will) change causing examples to possibly not compile in newer versions of the Flex 4 SDK.

4 thoughts on “Displaying an icon on a toggle button in Flex 4

  1. This just typifies everything I hate about flex 4!

    A normal mx button you simply set the icon property to your embedded image. Flex 4 you have to write over 100 lines of code in a skin. Ridiculous!!!

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