javax.sound.sampled

Class FloatControl

java.lang.Object

javax.sound.sampled.Control

javax.sound.sampled.FloatControl

public abstract class FloatControl
extends Control

A FloatControl object provides control over a range of floating-point values. Float controls are often represented in graphical user interfaces by continuously adjustable objects such as sliders or rotary knobs. Concrete subclasses of FloatControl implement controls, such as gain and pan, that affect a line's audio signal in some way that an application can manipulate. The FloatControl.Type inner class provides static instances of types that are used to identify some common kinds of float control.

The FloatControl abstract class provides methods to set and get the control's current floating-point value. Other methods obtain the possible range of values and the control's resolution (the smallest increment between returned values). Some float controls allow ramping to a new value over a specified period of time. FloatControl also includes methods that return string labels for the minimum, maximum, and midpoint positions of the control.

Since:

1.3

See Also:

Line.getControls(), Line.isControlSupported(javax.sound.sampled.Control.Type)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FloatControl.Type An instance of the FloatControl.Type inner class identifies one kind of float control.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FloatControl(FloatControl.Type type, float minimum, float maximum, float precision, int updatePeriod, float initialValue, String units) Constructs a new float control object with the given parameters.
protected	FloatControl(FloatControl.Type type, float minimum, float maximum, float precision, int updatePeriod, float initialValue, String units, String minLabel, String midLabel, String maxLabel) Constructs a new float control object with the given parameters.

Method Summary

Modifier and Type	Method and Description
float	getMaximum() Obtains the maximum value permitted.
String	getMaxLabel() Obtains the label for the maximum value, such as "Right" or "Full".
String	getMidLabel() Obtains the label for the mid-point value, such as "Center" or "Default".
float	getMinimum() Obtains the minimum value permitted.
String	getMinLabel() Obtains the label for the minimum value, such as "Left" or "Off".
float	getPrecision() Obtains the resolution or granularity of the control, in the units that the control measures.
String	getUnits() Obtains the label for the units in which the control's values are expressed, such as "dB" or "frames per second."
int	getUpdatePeriod() Obtains the smallest time interval, in microseconds, over which the control's value can change during a shift.
float	getValue() Obtains this control's current value.
void	setValue(float newValue) Sets the current value for the control.
void	shift(float from, float to, int microseconds) Changes the control value from the initial value to the final value linearly over the specified time period, specified in microseconds.
String	toString() Provides a string representation of the control.

Methods inherited from class javax.sound.sampled.Control

getType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FloatControl

protected FloatControl(FloatControl.Type type,
                       float minimum,
                       float maximum,
                       float precision,
                       int updatePeriod,
                       float initialValue,
                       String units,
                       String minLabel,
                       String midLabel,
                       String maxLabel)

Constructs a new float control object with the given parameters.

Parameters:

type - the kind of control represented by this float control object

minimum - the smallest value permitted for the control

maximum - the largest value permitted for the control

precision - the resolution or granularity of the control. This is the size of the increment between discrete valid values.

updatePeriod - the smallest time interval, in microseconds, over which the control can change from one discrete value to the next during a shift

initialValue - the value that the control starts with when constructed

units - the label for the units in which the control's values are expressed, such as "dB" or "frames per second"

minLabel - the label for the minimum value, such as "Left" or "Off"

midLabel - the label for the midpoint value, such as "Center" or "Default"

maxLabel - the label for the maximum value, such as "Right" or "Full"

Throws:

IllegalArgumentException - if minimum is greater than maximum or initialValue does not fall within the allowable range

FloatControl

protected FloatControl(FloatControl.Type type,
                       float minimum,
                       float maximum,
                       float precision,
                       int updatePeriod,
                       float initialValue,
                       String units)

Constructs a new float control object with the given parameters. The labels for the minimum, maximum, and mid-point values are set to zero-length strings.

Parameters:

type - the kind of control represented by this float control object

minimum - the smallest value permitted for the control

maximum - the largest value permitted for the control

precision - the resolution or granularity of the control. This is the size of the increment between discrete valid values.

updatePeriod - the smallest time interval, in microseconds, over which the control can change from one discrete value to the next during a shift

initialValue - the value that the control starts with when constructed

units - the label for the units in which the control's values are expressed, such as "dB" or "frames per second"

Throws:

IllegalArgumentException - if minimum is greater than maximum or initialValue does not fall within the allowable range

Method Detail

setValue

public void setValue(float newValue)

Sets the current value for the control. The default implementation simply sets the value as indicated. If the value indicated is greater than the maximum value, or smaller than the minimum value, an IllegalArgumentException is thrown. Some controls require that their line be open before they can be affected by setting a value.

Parameters:

newValue - desired new value

Throws:

IllegalArgumentException - if the value indicated does not fall within the allowable range

getValue

public float getValue()

Obtains this control's current value.

Returns:

the current value

getMaximum

public float getMaximum()

Obtains the maximum value permitted.

Returns:

the maximum allowable value

getMinimum

public float getMinimum()

Obtains the minimum value permitted.

Returns:

the minimum allowable value

getUnits

public String getUnits()

Obtains the label for the units in which the control's values are expressed, such as "dB" or "frames per second."

Returns:

the units label, or a zero-length string if no label

getMinLabel

public String getMinLabel()

Obtains the label for the minimum value, such as "Left" or "Off".

Returns:

the minimum value label, or a zero-length string if no label has been set

getMidLabel

public String getMidLabel()

Obtains the label for the mid-point value, such as "Center" or "Default".

Returns:

the mid-point value label, or a zero-length string if no label has been set

getMaxLabel

public String getMaxLabel()

Obtains the label for the maximum value, such as "Right" or "Full".

Returns:

the maximum value label, or a zero-length string if no label has been set

getPrecision

public float getPrecision()

Obtains the resolution or granularity of the control, in the units that the control measures. The precision is the size of the increment between discrete valid values for this control, over the set of supported floating-point values.

Returns:

the control's precision

getUpdatePeriod

public int getUpdatePeriod()

Obtains the smallest time interval, in microseconds, over which the control's value can change during a shift. The update period is the inverse of the frequency with which the control updates its value during a shift. If the implementation does not support value shifting over time, it should set the control's value to the final value immediately and return -1 from this method.

Returns:

update period in microseconds, or -1 if shifting over time is unsupported

See Also:

shift(float, float, int)

shift

public void shift(float from,
                  float to,
                  int microseconds)

Changes the control value from the initial value to the final value linearly over the specified time period, specified in microseconds. This method returns without blocking; it does not wait for the shift to complete. An implementation should complete the operation within the time specified. The default implementation simply changes the value to the final value immediately.

Parameters:

from - initial value at the beginning of the shift

to - final value after the shift

microseconds - maximum duration of the shift in microseconds

Throws:

IllegalArgumentException - if either from or to value does not fall within the allowable range

See Also:

getUpdatePeriod()

toString

public String toString()

Provides a string representation of the control.

Overrides:

toString in class Control

Returns:

a string description