Swing Hacks

Provide Audio Controls During Playback #78

Chapter 10, Audio

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405

HACK

Having provided these two implementations, it should be clear how you

would create an

EnumControlComponent. The EnumControl.getValues( ) method

returns a

String array that you would use as the model of an uneditable

JComboBox. You’d use getValue( ) to set one of these as the initial value, and

then on user events, you could pull out the

JComboBox’s selection and set the

EnumControl with setValue( ).

Check It Out!

The DataLineControlGUI shown in Example 10-15 is a simple JPanel that

contains a

JLabel with the name of the file to be played on the first line of a

GridBagLayout, and then control-name JLabels and factory-generated con-

trol widgets on each successive line. The sound is played by the

PCMFilePlayer, which was introduced as part of playing uncompressed

AIFFs and WAVs of arbitrary lengths

[Hack #76].

private void setSliderFromControl( ) {

// figure out value as percent of range

float offsetValue = control.getValue( ) - min;

float percent = 0.0f;

if (range != 0.0)

percent = offsetValue / range;

// apply that to SLIDER_RANGE

int sliderValue = (int) (percent * SLIDER_RANGE);

slider.setValue (sliderValue);

}

private void setControlFromSlider( ) {

// figure out slider percentage

float sliderPercentage =

(float) slider.getValue( ) / SLIDER_RANGE;

// figure out value for that percentage of range

float rangeOffset = sliderPercentage ...