Andy Hulstkamp

about creating online experiences

16. September 2008

Gumbo plays generated sound

The past few days I was digging a bit into Gumbo (Flex 4 beta). I was happy to see that Flex 4 will take a lightweight approach regarding components. Components are stripped down to their most basic behaviour and there’s now a clean separation between model, controller and view.

This, in combination with an enhanced state architecture and the newly integrated graphics tag library FXG, makes it a snap to create a custom look and feel in flex (especially when CS4 export or thermo integration will be ready)

Here is a little example of a GUI done in Gumbo (flex 4 beta) to wrap up my sound experiments done earlier.

Gumbo Mixer Slider

Demo. Needs the latest Flash-Player 10 (rc of 091508).

The GUI for the player is straight forward. It uses some FXG-Elements to draw the background and the description box. Buttons are embedded within containers which serve as a hook for the transitions.

<!-- Player Container -->
<Group id="playerContainer"  horizontalCenter="0" verticalCenter="0" >
<!-- the background -->
   <Rect id="playerBackground" radiusX="7" radiusY="7" width="380" height="120">
        <LinearGradient rotation="90">
                <GradientEntry color="0x606060" alpha="1" ratio="0" /> 
                <GradientEntry color="0x303030" alpha="1" ratio="1" /> 

    <Group id="descriptionTextBox" left="120" top="10">
       <Rect radiusX="7" radiusY="7" width="250" height="100">

            <LinearGradient rotation="90">
                <GradientEntry color="0xffffff" alpha="1" ratio="0" /> 
                <GradientEntry color="0xc0c0c0" alpha="1" ratio="1" /> 

            <TextGraphic color="0x606060" 
                    <p fontWeight="bold" fontSize="12" >A silly flash 10 music example</p>
                    <p marginTop="4">Testing flash 10 sound features and the new skinning architecture in Gumbo.</p>
                    <p marginTop="4">Plays dynamically generated sounds based on an absurdly simple sequencer</p>
                    <p marginTop="4">UI done in Flex 4 beta 1 (Gumbo)</p>

    <Group id="playButton" left="10" top="10">
        <Button width="100" selected="false" buttonMode="true" height="100" skinZZ="com.hulstkamp.lab.gumbo.skins.buttons.StandbyButtonSkin" click="togglePlay(event)" />

    <!-- Mute Buttons for voices, included in on-mode, only -->
     <Group id="mixerButtons" left="10" top="120" alpha="0" >
        <Button id="drumsBtn" styleName="bassButton" label="Bass" selected="true" buttonMode="true" left="0"  width="60" height="60"  click="toggleInstrument(event)"  />                     <Button id="bassBtn" styleName="drumsButton" label="Glass" selected="true" buttonMode="true" left="70" width="60" height="60" click="toggleInstrument(event)" />
        <Button id="hookBtn" styleName="hookButton" label="Hook" selected="true" buttonMode="true" left="140" width="60" height="60" click="toggleInstrument(event)"  />

Skinning a button in Gumbo is simple. Create a skin and apply this to a component via the skinZZ-property (name about to change in final version). Here’s the skin for the MuteButtons. To get a more generic skin I used styles from the hostComponent. Don’t know if this is best practice.

<?xml version="1.0" encoding="utf-8"?>
  To get a more generic skin, this class uses some styles (colors and icon) applied to the hostComponent.
  I'm not sure if styles could be applied to skins directly (sdk So, this might not be best practice.
<Skin xmlns="">


        <State name="up" />
        <State name="over" />
        <State name="down" />

    <!-- get width and height via hostComponent -->
        <Rect radiusX="7" radiusY="7" width="{hostComponent.width}" height="{hostComponent.height}">
              <LinearGradient rotation="90">
              <!-- get Styles via the hostComponent. Haven't found a way to apply styles to skins directly -->
              <!-- if you want binding grap those and make them bindable -->
                <GradientEntry color="{hostComponent.getStyle('gradientColors')[0]}" color.over="{hostComponent.getStyle('gradientColorsOver')[0]}" alpha="1" ratio="0" /> 
                <GradientEntry color="{hostComponent.getStyle('gradientColors')[1]}" color.over="{hostComponent.getStyle('gradientColorsOver')[1]}" alpha="1" ratio="1" /> 
    <TextBox id="labelText" 
    <!-- get the icon via style and show below label -->

Transitions are done in a similar fashion to flex 3.

Grab the source here(sdk UPDATE: Adobe changed the sound api. Use SampleDataEvent.SAMPLE_DATA instead of Event.SAMPLE_DATA for the listener.

further reading

Generating Sounds. Waveforms, Timbre Loundness and Pitch.

Introduction to generating sounds covering samplerates, waveform, timbres and pitch. In Flash but should be applicable to any technology.

Custom Spark CheckBox Component in Flex 4 (Gumbo)

Post abput how to customize the Flex Spark Checkbox.