The following example shows how you can set the corner radius on a Halo MenuBar control in Flex 4 by creating a custom skin and setting the radiusX and radiusY properties.

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 http://www.adobe.com/products/flex/. To download the latest nightly build of the Flex 4 SDK, see http://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/2009/08/23/setting-the-corner-radius-on-a-halo-menubar-control-in-flex-4/ -->
<s:Application name="Halo_MenuBar_cornerRadius_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:controlBarContent>
        <mx:Form paddingTop="0" paddingBottom="0">
            <mx:FormItem label="cornerRadius:">
                <s:HSlider id="slider"
                        minimum="0"
                        maximum="{menuBar.height/2}"
                        value="2" />
            </mx:FormItem>
        </mx:Form>
    </s:controlBarContent>
 
    <mx:MenuBar id="menuBar"
            labelField="@label"
            showRoot="false"
            cornerRadius="{slider.value}"
            backgroundSkin="skins.CustomButtonSkin"
            horizontalCenter="0" verticalCenter="0">
        <mx:dataProvider>
            <fx:XML source="data.xml" />
        </mx:dataProvider>
    </mx:MenuBar>
 
</s:Application>

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

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/08/23/setting-the-corner-radius-on-a-halo-menubar-control-in-flex-4/ -->
<local:SparkSkinForHalo name="CustomButtonSkin"
        xmlns:fx="http://ns.adobe.com/mxml/2009" 
        xmlns:s="library://ns.adobe.com/flex/spark" 
        xmlns:local="mx.skins.spark.*"
        minWidth="21" minHeight="19" 
        alpha.disabled="0.5">
    <!-- states -->
    <local: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="selectedUp" stateGroups="selectedStates, selectedUpStates" />
        <s:State name="selectedOver" stateGroups="overStates, selectedStates" />
        <s:State name="selectedDown" stateGroups="downStates, selectedStates" />
        <s:State name="selectedDisabled" stateGroups="selectedUpStates, disabledStates, selectedStates" />
    </local:states>
 
    <fx:Script>
        <![CDATA[
            /* Define the border items.*/
            static private const borderItem:Array = ["borderEntry1", "borderEntry2"];
 
            override protected function get borderItems():Array {
                return borderItem;
            }
        ]]>
    </fx:Script>
 
    <fx:Declarations>
        <fx:Number id="cornerRad">{getStyle("cornerRadius")}</fx:Number>
    </fx:Declarations>
 
    <!-- layer 1: shadow -->
    <s:Rect left="-1" right="-1" top="-1" bottom="-1"
            radiusX="{cornerRad}" radiusY="{cornerRad}">
        <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="{cornerRad}" radiusY="{cornerRad}">
        <s:fill>
            <s:LinearGradient rotation="90">
                <s:GradientEntry color="0xFFFFFF" 
                        color.selectedUpStates="0xBBBDBD"
                        color.overStates="0xBBBDBD" 
                        color.downStates="0xAAAAAA" 
                        alpha="0.85" 
                        alpha.selectedOver="1" />
                <s:GradientEntry color="0xD8D8D8" 
                        color.selectedUpStates="0x9FA0A1"
                        color.over="0x9FA0A1" 
                        color.selectedOver="0x8E8F90"
                        color.downStates="0x929496" 
                        alpha="0.85"
                        alpha.selectedOver="1" />
            </s:LinearGradient>
        </s:fill>
    </s:Rect>
 
    <!-- layer 3: fill lowlight -->
    <s:Rect left="1" right="1" bottom="1" height="9"
            radiusX="{cornerRad}" radiusY="{cornerRad}">
        <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="{cornerRad}" radiusY="{cornerRad}">
        <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="{cornerRad}" radiusY="{cornerRad}"
            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, selectedOver">
        <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, selectedOver">
        <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, selectedOver">
        <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, selectedOver">
        <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="{cornerRad}" radiusY="{cornerRad}">
        <s:stroke>
            <s:LinearGradientStroke rotation="90" weight="1">
                <s:GradientEntry id="borderEntry1" 
                        alpha="0.5625"
                        alpha.down="0.6375"
                        alpha.selectedStates="0.6375" />
                <s:GradientEntry id="borderEntry2" 
                        alpha="0.75" 
                        alpha.down="0.85"
                        alpha.selectedStates="0.85" />
            </s:LinearGradientStroke>
        </s:stroke>
    </s:Rect>
 
</local:SparkSkinForHalo>

View source is enabled in the following example.

You can also set the backgroundSkin style in an external .CSS file or <Style/> block, as seen in the following example:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/08/23/setting-the-corner-radius-on-a-halo-menubar-control-in-flex-4/ -->
<s:Application name="Halo_MenuBar_cornerRadius_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:controlBarContent>
        <mx:Form paddingTop="0" paddingBottom="0">
            <mx:FormItem label="cornerRadius:">
                <s:HSlider id="slider"
                        minimum="0"
                        maximum="{menuBar.height/2}"
                        value="2" />
            </mx:FormItem>
        </mx:Form>
    </s:controlBarContent>
 
    <fx:Style>
        @namespace s "library://ns.adobe.com/flex/spark";
        @namespace mx "library://ns.adobe.com/flex/halo";
 
        mx|MenuBar {
            backgroundSkin: ClassReference("skins.CustomButtonSkin");
        }
    </fx:Style>
 
    <mx:MenuBar id="menuBar"
            labelField="@label"
            showRoot="false"
            cornerRadius="{slider.value}"
            horizontalCenter="0" verticalCenter="0">
        <mx:dataProvider>
            <fx:XML source="data.xml" />
        </mx:dataProvider>
    </mx:MenuBar>
 
</s:Application>

Or, you can set the backgroundSkin style using ActionScript, as seen in the following example:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/08/23/setting-the-corner-radius-on-a-halo-menubar-control-in-flex-4/ -->
<s:Application name="Halo_MenuBar_cornerRadius_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:controlBarContent>
        <mx:Form paddingTop="0" paddingBottom="0">
            <mx:FormItem label="cornerRadius:">
                <s:HSlider id="slider"
                        minimum="0"
                        maximum="{menuBar.height/2}"
                        value="2" />
            </mx:FormItem>
            <mx:FormItem>
                <s:ToggleButton id="tBtn"
                        label="CustomButtonSkin"
                        change="tBtn_changeHandler(event)" />
            </mx:FormItem>
        </mx:Form>
    </s:controlBarContent>
 
    <fx:Script>
        <![CDATA[
            import skins.CustomButtonSkin;
            import mx.skins.spark.ButtonSkin;
 
            protected function tBtn_changeHandler(evt:Event):void {
                if (tBtn.selected) {
                    menuBar.setStyle("backgroundSkin", CustomButtonSkin);
                } else {
                    menuBar.setStyle("backgroundSkin", ButtonSkin);
                }
            }
        ]]>
    </fx:Script>
 
    <mx:MenuBar id="menuBar"
            labelField="@label"
            showRoot="false"
            cornerRadius="{slider.value}"
            horizontalCenter="0" verticalCenter="0">
        <mx:dataProvider>
            <fx:XML source="data.xml" />
        </mx:dataProvider>
    </mx:MenuBar>
 
</s:Application>

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.

 
Tagged with:
 
About The Author

Peter deHaan

Peter deHaan currently works for Adobe on the Flex SDK QA team. While not working on Flex, Flash, and ColdFusion applications, Peter enjoys making up bios and writing in 3rd person. Peter's rarely updated blog can be found at blogs.adobe.com/pdehaan/, actionscriptexamples.com, airexamples.com, and coldfusionexamples.com.

3 Responses to Setting the corner radius on an MX MenuBar control in Flex 4

  1. Martin Bove says:

    Hi, I try to compile the example but an error is the result, here copy the trace of the error:

    ArgumentError: Error #2004: Uno de los parĂ¡metros no es vĂ¡lido.
    	at flash.display::Graphics/drawRoundRect()
    	at spark.primitives::Rect/drawElement()[E:\dev\beta1\frameworks\projects\flex4\src\spark\primitives\Rect.as:152]
    	at spark.primitives.supportClasses::StrokedElement/updateDisplayList()[E:\dev\beta1\frameworks\projects\flex4\src\spark\primitives\supportClasses\StrokedElement.as:147]
    	at spark.primitives.supportClasses::GraphicElement/http://www.adobe.com/2006/flex/mx/internal::doUpdateDisplayList()[E:\dev\beta1\frameworks\projects\flex4\src\spark\primitives\supportClasses\GraphicElement.as:3270]
    	at spark.primitives.supportClasses::GraphicElement/validateDisplayList()[E:\dev\beta1\frameworks\projects\flex4\src\spark\primitives\supportClasses\GraphicElement.as:3254]
    	at spark.components::Group/updateDisplayList()[E:\dev\beta1\frameworks\projects\flex4\src\spark\components\Group.as:810]
    	at spark.skins::SparkSkin/updateDisplayList()[E:\dev\beta1\frameworks\projects\flex4\src\spark\skins\SparkSkin.as:164]
    	at mx.skins.spark::SparkSkinForHalo/updateDisplayList()[E:\dev\beta1\frameworks\projects\sparkskins\src\mx\skins\spark\SparkSkinForHalo.as:96]
    	at mx.core::UIComponent/validateDisplayList()[E:\dev\beta1\frameworks\projects\framework\src\mx\core\UIComponent.as:7691]
    	at mx.managers::LayoutManager/validateDisplayList()[E:\dev\beta1\frameworks\projects\framework\src\mx\managers\LayoutManager.as:663]
    	at mx.managers::LayoutManager/doPhasedInstantiation()[E:\dev\beta1\frameworks\projects\framework\src\mx\managers\LayoutManager.as:718]
    	at mx.managers::LayoutManager/doPhasedInstantiationCallback()[E:\dev\beta1\frameworks\projects\framework\src\mx\managers\LayoutManager.as:1067]