Creating a custom track highlight skin on an MX HSlider control in Flex 4

The following example shows how you can create a custom track highlight skin on an MX HSlider control in Flex 4 by setting the trackHighlightSkin style and the Boolean showTrackHighlight style.

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/2010/04/14/creating-a-custom-track-highlight-skin-on-an-mx-hslider-control-in-flex-4/ -->
<s:Application name="MX_HSlider_trackHighlightSkin_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>
        <s:CheckBox id="chckBx"
                label="showTrackHighlight"
                selected="true" />
    </s:controlBarContent>
 
    <mx:HSlider id="hSl"
            value="5"
            trackHighlightSkin="skins.CustomSliderTrackHighlightSkin"
            showTrackHighlight="{chckBx.selected}"
            horizontalCenter="0" verticalCenter="0" />
 
</s:Application>

The default Spark skins for the MX/Halo controls/containers can be found in the Flex SDK at:
%Flex SDK%\frameworks\projects\sparkskins\src\mx\skins\spark\*.

And the custom MX HSlider track highlight skin, skins/CustomSliderTrackHighlightSkin.mxml, is as follows:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2010/04/14/creating-a-custom-track-highlight-skin-on-an-mx-hslider-control-in-flex-4/ -->
<s:Skin name="CustomSkiderTrackHightlightSkin"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark" 
        width="200" height="11"
        disabledAlpha="0.5">
 
    <s:Rect left="0" right="0" top="2" height="4" radiusX="2">
        <s:fill>
            <s:BitmapFill source="@Embed('assets/pattern_143.gif')" fillMode="repeat" alpha="0.35" />
        </s:fill>
    </s:Rect>
 
</s:Skin>

View source is enabled in the following example.

Background image pattern copyright of Squidfingers.com.

You can also set the showTrackHighlight and trackHighlightSkin styles 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/2010/04/14/creating-a-custom-track-highlight-skin-on-an-mx-hslider-control-in-flex-4/ -->
<s:Application name="MX_HSlider_trackHighlightSkin_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">
 
    <fx:Style>
        @namespace s "library://ns.adobe.com/flex/spark";
        @namespace mx "library://ns.adobe.com/flex/mx";
 
        mx|HSlider {
            showTrackHighlight: true;
            trackHighlightSkin: ClassReference("skins.CustomSliderTrackHighlightSkin");
        }
    </fx:Style>
 
    <mx:HSlider id="hSl"
            value="5"
            horizontalCenter="0" verticalCenter="0" />
 
</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 as: Gumbo, showTrackHighlight, trackHighlightSkin

{ 3 comments… read them below or add one }

Brian Davis April 19, 2010 at 10:44 am

Uh — what happen to the “tick” in the Flex 4 HSlider? Can seem to find it/

Peter deHaan April 19, 2010 at 10:56 am: @Brian Davis,

Currently, the Spark HSlider only supports a single thumb, no track highlight, no ticks, and no labels. If you need that functionality, you either have to extend s:HSlider and add it yourself, or you can still use the mx:HSlider control.

Peter

Godspeed May 16, 2010 at 10:36 pm