CODEWITHSUNDEEP
actionscript-3apache-flexflex4flex-spark
ggkmath
ggkmath

Reputation: 4246

Flex: how to control Spark datagrid header-text alignment?

If I have 10 columns in a Spark datagrid, and some headers need to be left-justified, some headers right-justified, and some centered, what's the simplest way to accomplish this?

Assuming a custom headerRenderer is needed, are there any simple examples that can walk me through it?

Thanks in advance for any comments.

Upvotes: 3

Views: 7379

Answers (2)

ggkmath
ggkmath

Reputation: 4246

The simplest way I could find to solve this is to override the settings in the spark DefaultGridHeaderRenderer, as discussed in this link:

http://flexponential.com/2011/10/30/changing-fontweight-of-spark-datagrid-headers/

More specifically, I used the following custom headerRenderer, saved as file: myRightHeaderRenderer.mxml:

<?xml version="1.0" encoding="utf-8"?>
<s:DefaultGridHeaderRenderer 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:Declarations>
    <s:Label id="labelDisplay" 
             verticalCenter="1" left="0" right="0" top="0" bottom="0"
             verticalAlign="middle"
             maxDisplayedLines="1"
             textAlign="right"
             fontWeight="bold"
             showTruncationTip="true" />
</fx:Declarations>

</s:DefaultGridHeaderRenderer>

This custom header renderer right-justifies header text. To use it, simply add it to one or more columns of the Spark DataGrid as follows:

...
<fx:Array>
    <s:GridColumn ... />
    <s:GridColumn headerRenderer="myRightHeaderRenderer" ...>
    <s:GridColumn ... />
    ...
</fx:Array>
...

I'm not sure how to do it, but I'm sure it can be made more flexible by parameterizing the textAlign attribute to be center, left, or right.

Upvotes: 4

Sam DeHaan
Sam DeHaan

Reputation: 10325

If you take a look at this blog post, there's a decent amount of source code available showing you how to do this.

However, I think that the blog's example is much more complex than you'll need. You will need a custom headerRenderer, as you feared, but your code should be pretty straightforward. I've only tested this lightly, so if you have any issues, let me know.

Custom Header Renderer

package
{
    import spark.skins.spark.DefaultGridHeaderRenderer;

    public class CustomGridHeader extends DefaultGridHeaderRenderer
    {
        public function CustomGridHeader()
        {
            super();
        }

        public function set headerTextAlign(value:String):void
        {
            labelDisplay.setStyle("textAlign",value);
            labelDisplay.styleChanged("textAlign");
        }
    }
}

Variables Available to Your Columns...

[Bindable] private var leftFactory:ClassFactory = new ClassFactory(CustomGridHeader);
[Bindable] private var rightFactory:ClassFactory = new ClassFactory(CustomGridHeader);
[Bindable] private var centerFactory:ClassFactory = new ClassFactory(CustomGridHeader);

On initialize or preinitialize...

leftFactory.properties = {headerTextAlign: "left"};
rightFactory.properties = {headerTextAlign: "right"};
centerFactory.properties = {headerTextAlign: "center"};

For Each Column...

<s:GridColumn headerText="..." headerRenderer="{centerFactory}"/>

Upvotes: 2

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