Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/14/styling-the-flex-hrule-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:ApplicationControlBar dock="true">
        <mx:Form>
            <mx:FormItem label="stokeWidth:">
                <mx:HSlider id="strokeWidthSlider"
                        minimum="0"
                        maximum="20"
                        value="2"
                        liveDragging="true"
                        snapInterval="1"
                        tickInterval="1"
                        dataTipPrecision="0" />
            </mx:FormItem>
            <mx:FormItem label="strokeColor:">
                <mx:ColorPicker id="strokeColorColorPicker"
                        selectedColor="red" />
            </mx:FormItem>
            <mx:FormItem label="shadowColor:">
                <mx:ColorPicker id="shadowColorColorPicker"
                        selectedColor="blue" />
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:HRule id="hrule"
            strokeWidth="{strokeWidthSlider.value}"
            strokeColor="{strokeColorColorPicker.selectedColor}"
            shadowColor="{shadowColorColorPicker.selectedColor}"
            width="100%" />

</mx:Application>

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