Setting the focus blend mode on a TextArea control in Flex

The following example shows how you can set the focus blend mode of the focus rectangle on a Flex TextArea control by setting the focusBlendMode style.

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/01/11/setting-the-focus-blend-mode-on-a-textarea-control-in-flex/ -->
<mx:Application name="TextArea_focusBlendMode_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle">

    <mx:ApplicationControlBar dock="true" styleName="plain">
        <mx:Form styleName="plain">
            <mx:FormItem label="focusThickness:">
                <mx:HSlider id="slider"
                        minimum="0"
                        maximum="24"
                        value="10"
                        snapInterval="1"
                        tickInterval="1"
                        change="textArea.setFocus();" />
            </mx:FormItem>
            <mx:FormItem label="focusBlendMode:">
                <mx:ComboBox id="comboBox"
                        selectedIndex="10"
                        change="textArea.setFocus();">
                    <mx:dataProvider>
                        <mx:Array>
                            <mx:String>{BlendMode.ADD}</mx:String>
                            <mx:String>{BlendMode.ALPHA}</mx:String>
                            <mx:String>{BlendMode.DARKEN}</mx:String>
                            <mx:String>{BlendMode.DIFFERENCE}</mx:String>
                            <mx:String>{BlendMode.ERASE}</mx:String>
                            <mx:String>{BlendMode.HARDLIGHT}</mx:String>
                            <mx:String>{BlendMode.INVERT}</mx:String>
                            <mx:String>{BlendMode.LAYER}</mx:String>
                            <mx:String>{BlendMode.LIGHTEN}</mx:String>
                            <mx:String>{BlendMode.MULTIPLY}</mx:String>
                            <mx:String>{BlendMode.NORMAL}</mx:String>
                            <mx:String>{BlendMode.OVERLAY}</mx:String>
                            <mx:String>{BlendMode.SCREEN}</mx:String>
                            <!--
                            <mx:String>{BlendMode.SHADER}</mx:String>
                            -->
                            <mx:String>{BlendMode.SUBTRACT}</mx:String>
                        </mx:Array>
                    </mx:dataProvider>
                </mx:ComboBox>
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:TextArea id="textArea"
            text="The quick brown fox jumps over the lazy dog."
            focusThickness="{slider.value}"
            focusBlendMode="{comboBox.selectedItem}" />

</mx:Application>

View source is enabled in the following example.

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

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/01/11/setting-the-focus-blend-mode-on-a-textarea-control-in-flex/ -->
<mx:Application name="TextArea_focusBlendMode_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle">

    <mx:Style>
        TextArea {
            focusThickness: 20;
            focusBlendMode: difference;
        }
    </mx:Style>

    <mx:TextArea id="textArea"
            text="The quick brown fox jumps over the lazy dog."  />

</mx:Application>

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

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2009/01/11/setting-the-focus-blend-mode-on-a-textarea-control-in-flex/ -->
<mx:Application name="TextArea_focusBlendMode_test"
        xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle">

    <mx:Script>
        <![CDATA[
            import mx.events.ListEvent;
            import mx.events.SliderEvent;

            private function slider_change(evt:SliderEvent):void {
                textArea.setStyle("focusThickness", evt.value);
                textArea.setFocus();
            }

            private function comboBox_change(evt:ListEvent):void {
                textArea.setStyle("focusBlendMode", comboBox.selectedItem);
                textArea.setFocus();
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true" styleName="plain">
        <mx:Form styleName="plain">
            <mx:FormItem label="focusThickness:">
                <mx:HSlider id="slider"
                        minimum="0"
                        maximum="24"
                        value="10"
                        snapInterval="1"
                        tickInterval="1"
                        change="slider_change(event);" />
            </mx:FormItem>
            <mx:FormItem label="focusBlendMode:">
                <mx:ComboBox id="comboBox"
                        selectedIndex="10"
                        change="comboBox_change(event);">
                    <mx:dataProvider>
                        <mx:Array>
                            <mx:String>{BlendMode.ADD}</mx:String>
                            <mx:String>{BlendMode.ALPHA}</mx:String>
                            <mx:String>{BlendMode.DARKEN}</mx:String>
                            <mx:String>{BlendMode.DIFFERENCE}</mx:String>
                            <mx:String>{BlendMode.ERASE}</mx:String>
                            <mx:String>{BlendMode.HARDLIGHT}</mx:String>
                            <mx:String>{BlendMode.INVERT}</mx:String>
                            <mx:String>{BlendMode.LAYER}</mx:String>
                            <mx:String>{BlendMode.LIGHTEN}</mx:String>
                            <mx:String>{BlendMode.MULTIPLY}</mx:String>
                            <mx:String>{BlendMode.NORMAL}</mx:String>
                            <mx:String>{BlendMode.OVERLAY}</mx:String>
                            <mx:String>{BlendMode.SCREEN}</mx:String>
                            <!--
                            <mx:String>{BlendMode.SHADER}</mx:String>
                            -->
                            <mx:String>{BlendMode.SUBTRACT}</mx:String>
                        </mx:Array>
                    </mx:dataProvider>
                </mx:ComboBox>
            </mx:FormItem>
        </mx:Form>
    </mx:ApplicationControlBar>

    <mx:TextArea id="textArea"
            text="The quick brown fox jumps over the lazy dog." />

</mx:Application>

4 thoughts on “Setting the focus blend mode on a TextArea control in Flex

  1. Strange behavior: clicking a location on the slider bar so the pointer moves there doesn’t update the outline. You have to drag the pointer to get an update.

    1. @Eric,

      That’s probably just my crappy code. I probably should have looked into a way of clearing the focus on the TextArea and resetting it after changing the slider.

      Peter

Comments are closed.