New Flex 4 Theme and Class Renaming

NOTE: See my comment below about updating this example until I have the chance to.

A few times a day I update my subversion checkout of the Gumbo trunk. Last night I noticed a major overhaul which renamed all the Flex 4 classes, repackaged them into the mx package instead of flex. The new classes are now all (at least temporarily) prefixed with Fx, so if you are trying to compile your previously working Flex 4 code against the up-to-date SDK and suddenly see the following error:

Error: Could not resolve <Application> to a component implementation.

your issue will be resolved by changing Application to FxApplication. You'll need to do the same for most of the other Flex 4 controls (Group, VGroup, and HGroup are exceptions that don't need to be prefixed with Fx).

Spark Theme

You may also notice the new spark folder added in the skins directory. Below is an example application showing what these new skins look like for some of the Gumbo components:

[flash /wp-content/uploads/2008/10/spark_controls.swf]

As usual here is the code:


<?xml version="1.0" encoding="utf-8"?>
<FxApplication xmlns="">

    <VGroup horizontalCenter="0" verticalCenter="0">

        <FxButton label="Button" />

        <FxCheckBox label="Check Box" />

        <FxRadioButton label="Radio Button" />

        <FxHScrollBar />

        <FxNumericStepper />

        <FxHSlider />

        <FxTextInput />



Remember, you'll need Flash Player 10 in order to run this SWF after you've compiled it.

I hope everyone’s enjoying their Gumbo!