Setting a repeating background image on a Spark Application in Flex 4

By Peter deHaan On March 23, 2009 · 5 Comments

In a previous example, “Setting a background image on an Spark Application in Flex 4″, we saw how you can add a scaled background image to a Flex 4 Spark Application by creating a custom skin with a BitmapGraphic and setting the skinClass style in MXML, CSS, or ActionScript.

The following example shows how you can create a tiled background image by creating a custom skin, creating a repeating bitmap fill, and setting the skinClass 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/2009/03/23/setting-a-repeating-background-image-on-an-fxapplication-in-flex-gumbo/ -->
<s:Application name="Spark_Application_skinClass_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"
        skinClass="skins.CustomApplicationSkin"
        controlBarVisible="{chckBx.selected}">
    <s:controlBarContent>
        <s:Label id="sdkVer" initialize="sdkVer.text = mx_internal::VERSION;" />
    </s:controlBarContent>
 
    <s:CheckBox id="chckBx"
            label="controlBarVisible"
            selected="true"
            horizontalCenter="0" verticalCenter="0" />
 
</s:Application>

The custom skin class, skins/CustomApplicationSkin.mxml, is as follows:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/03/23/setting-a-repeating-background-image-on-an-fxapplication-in-flex-gumbo/ -->
<s:Skin name="CustomApplicationSkin"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:fb="http://ns.adobe.com/flashbuilder/2009"
        alpha.disabled="0.5"
        alpha.disabledWithControlBar="0.5">
    <!-- states -->
    <s:states>
        <s:State name="normal" />
        <s:State name="disabled" />
        <s:State name="normalWithControlBar" />
        <s:State name="disabledWithControlBar" />
    </s:states>
 
    <fx:Metadata>
        [HostComponent("spark.components.Application")]
    </fx:Metadata> 
 
    <!-- fill -->
    <!--- 
    A rectangle with a solid color fill that forms the background of the application.
    The color of the fill is set to the Application's backgroundColor property.
    -->
    <s:Rect id="backgroundRect" left="0" right="0" top="0" bottom="0"  >
        <s:fill>
            <s:BitmapFill source="@Embed('skins/pattern_147.gif')" fillMode="repeat" />
        </s:fill>
    </s:Rect>
 
    <s:Group left="0" right="0" top="0" bottom="0">
        <s:layout>
            <s:VerticalLayout gap="0" horizontalAlign="justify" />
        </s:layout>
 
        <!--- Application Control Bar -->
        <s:Group id="topGroup" minWidth="0" minHeight="0"
                 includeIn="normalWithControlBar, disabledWithControlBar" >
 
            <!-- layer 0: control bar highlight -->
            <s:Rect left="0" right="0" top="0" bottom="1" >
                <s:stroke>
                    <s:LinearGradientStroke rotation="90" weight="1">
                        <s:GradientEntry color="0xFFFFFF" />
                        <s:GradientEntry color="0xD8D8D8" />
                    </s:LinearGradientStroke>
                </s:stroke>
            </s:Rect>
 
            <!-- layer 1: control bar fill -->
            <s:Rect left="1" right="1" top="1" bottom="2" >
                <s:fill>
                    <s:LinearGradient rotation="90">
                        <s:GradientEntry color="0xEDEDED" />
                        <s:GradientEntry color="0xCDCDCD" />
                    </s:LinearGradient>
                </s:fill>
            </s:Rect>
 
            <!-- layer 2: control bar divider line -->
            <s:Rect left="0" right="0" bottom="0" height="1" alpha="0.55">
                <s:fill>
                    <s:SolidColor color="0x000000" />
                </s:fill>
            </s:Rect>
 
            <!-- layer 3: control bar -->
            <s:Group id="controlBarGroup" left="0" right="0" top="1" bottom="1" minWidth="0" minHeight="0">
                <s:layout>
                    <s:HorizontalLayout paddingLeft="10" paddingRight="10" paddingTop="7" paddingBottom="7" gap="10" />
                </s:layout>
            </s:Group>
        </s:Group>
 
        <s:Group id="contentGroup" width="100%" height="100%" minWidth="0" minHeight="0" />
    </s:Group>
 
</s:Skin>

View source is enabled in the following example.

Background image pattern copyright of Squidfingers.com.

You can also set the skinClass 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/2009/03/23/setting-a-repeating-background-image-on-an-fxapplication-in-flex-gumbo/ -->
<s:Application name="Spark_Application_skinClass_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";
 
        s|Application {
            skinClass: ClassReference("skins.CustomApplicationSkin");
        }
    </fx:Style>
 
    <s:Label id="sdkVer"
            horizontalCenter="0" verticalCenter="0"
            initialize="sdkVer.text = mx_internal::VERSION;" />
 
</s:Application>

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

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/03/23/setting-a-repeating-background-image-on-an-fxapplication-in-flex-gumbo/ -->
<s:Application name="Spark_Application_skinClass_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:Button id="btn"
                label="Click to set application skin"
                click="btn_clickHandler(event);" />
    </s:controlBarContent>
 
    <fx:Script>
        <![CDATA[
            import mx.core.FlexGlobals;
            import skins.CustomApplicationSkin;
 
            protected function btn_clickHandler(evt:MouseEvent):void {
                FlexGlobals.topLevelApplication.setStyle("skinClass", CustomApplicationSkin);
            }
        ]]>
    </fx:Script>
 
    <s:Label id="sdkVer"
            horizontalCenter="0" verticalCenter="0"
            initialize="sdkVer.text = mx_internal::VERSION;" />
 
</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: Gumbo • skinClass

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.

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5 Responses to Setting a repeating background image on a Spark Application in Flex 4

Shawn says:

January 2, 2010 at 6:06 am

My html repeating background of the same image works fine, but when I
tried the repeating background with your Flex 4 code I copied and pasted your
App and skin pages and replaced the source image, but its stretching the
image horizontally across the page instead of repeating it. Does this method
require that the image is a square ? My image is 10 x 684 and I want it to repeat
horizontally

Reply
Jim says:

January 6, 2010 at 9:44 am

Trying to use this example. When I do, the image (pattern_147.gif) is not repeating but being stretched across the background.

Reply
- Peter deHaan says:
  
  January 6, 2010 at 10:35 am
  
  @Shawn/Jim,
  
  Looks like a few things have changed since I originally posted this.
  The short answer is that you’ll now need to set the BitmapFill object’s fillMode property to “repeat” (as it seems to default to “scale”):
  <s:BitmapFill source="@Embed('pattern_147.gif')" fillMode="repeat" />
  I’ll update the big example above, as the Spark Application skin has changed significantly to add support for control bars, etc.
  
  Peter
  
  Reply
Jason says:

March 9, 2010 at 8:50 pm

Since Flex4 beta2 fillMode has disappeared and is replaced with resizeMode

Note: repeat (boolean) is supported although deprecated.

Reply
- Peter deHaan says:
  
  May 8, 2010 at 10:08 am
  
  @Jason,
  
  Thanks. Example above updated to the release Flex 4.0 SDK.
  
  Peter
  
  Reply