package net.sf.fmj.ejmf.toolkit.gui.controls;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.EventListener;
import javax.media.Controller;
import javax.media.GainChangeEvent;
import javax.media.GainChangeListener;
import javax.media.GainControl;
import javax.swing.AbstractButton;
import javax.swing.SwingUtilities;
/**
* Gain Control for Standard Control Panel. Provides
* two Components, one each for increasing and decreasing
* gain.
* @see net.sf.fmj.ejmf.toolkit.gui.controls.AbstractGainControl
*/
public class StandardGainControl extends AbstractGainControl
implements GainChangeListener {
/** Create a StandardGainControl and associate it
* with a Controller.
* @param controller A Controller with which control is associated.
*/
public StandardGainControl(Skin skin, Controller controller) {
super(skin, controller);
}
/** Create a StandardGainControl */
public StandardGainControl(Skin skin) {
super(skin);
}
/**
* This method is called when <code>setController</code>
* is called on an AbstractListenerControl.
* @param newController A Controller with which this control
* is associated.
*/
@Override
protected void setControllerHook(Controller newController) {
super.setControllerHook(newController);
GainControl gc;
if (isOperational()) {
gc = getGainControl();
setState(gc.getLevel());
gc.addGainChangeListener(this);
}
}
/**
* Create Control Component for Gain Control.
* @return component which acts as gain control.
*/
@Override
protected Component createControlComponent(Skin skin) {
return new StandardGainButtonPanel(skin);
}
/**
* Over-rides addControlListener from AbstractActionListener
* because this Component is a JPanel and buttons need
* to be extracted from it. Same listener is posted to
* both buttons.
* @param listener Listener that implements semantics for
* gain control.
*/
@Override
protected void addControlListener(EventListener listener) {
if (listener instanceof ActionListener) {
AbstractButton ab;
AbstractGainButtonPanel p =
(AbstractGainButtonPanel) getControlComponent();
ab = p.getGainIncreaseButton();
ab.addActionListener((ActionListener) listener);
ab = p.getGainDecreaseButton();
ab.addActionListener((ActionListener) listener);
} else {
throw new IllegalArgumentException("ActionListener required");
}
}
/**
* Remove listener from both gain increase button and gain
* decrease button.
* @param listener Listener is removed from listener list
* associated with this control.
*/
@Override
protected void removeControlListener(EventListener listener) {
if (listener instanceof ActionListener) {
AbstractButton ab;
StandardGainButtonPanel p =
(StandardGainButtonPanel) getControlComponent();
ab = p.getGainIncreaseButton();
ab.removeActionListener((ActionListener) listener);
ab = p.getGainDecreaseButton();
ab.removeActionListener((ActionListener) listener);
} else {
throw new IllegalArgumentException("ActionListener required");
}
}
/**
* Create and return the default listener for gain control.
* Default listener increases gain level by 0.1 for each click
* of up button and decreases gain level by 0.1 for each click
* of down button.
* @return Default listener for gain control.
*/
@Override
protected EventListener createControlListener() {
return new ActionListener() {
public void actionPerformed(ActionEvent e) {
AbstractGainButtonPanel gbp =
(AbstractGainButtonPanel) getControlComponent();
GainControl gc = getGainControl();
float level = gc.getLevel();
if (e.getSource() == gbp.getGainIncreaseButton()) {
level += 0.1f;
gc.setLevel(level > 1.0f ? 1.0f : level);
} else if (e.getSource() == gbp.getGainDecreaseButton()) {
level -= 0.1f;
gc.setLevel(level < 0.0f ? 0.0f : level);
}
}
};
}
/**
* Set enable state of gain buttons based on gain level.
* If level has reached maximum, disable increase button.
* If level has reached minimum, enable descrease button.
* @param e An GainChangeEvent triggerd by a GainControl
* @see javax.media.GainControl
* @see javax.media.GainChangeEvent
*/
public void gainChange(GainChangeEvent e) {
SwingUtilities.invokeLater(new SetStateThread(e.getLevel()));
}
/*
* Runnable that calls setState and is run on
* AWT event queue.
*/
class SetStateThread implements Runnable {
float level;
public SetStateThread(float level) {
this.level = level;
}
public void run() {
setState(level);
}
}
/* Isolate GUI update so that it can be run on
* separate thread.
* This method simply sets the current state of the
* gain control buttons.
*/
private void setState(float level) {
AbstractGainButtonPanel gbp =
(AbstractGainButtonPanel) getControlComponent();
gbp.getGainIncreaseButton().setEnabled(level < 1.0f);
gbp.getGainDecreaseButton().setEnabled(level > 0.0f);
}
/**
* Type-safe way to set Control Component and control listener.
* @param bp An AbstractGainButtonPanel that serves as Control
* component.
* @param listener An ActionListener that implements
* Control semantics.
*/
public void setComponentAndListener(AbstractGainButtonPanel bp, ActionListener listener) {
super.setComponentAndListener(bp, listener);
}
/**
* Type-safe way to set Control Component.
* @param bp An AbstractGainButtonPanel that serves as Control
* component.
*/
public void setComponent(AbstractGainButtonPanel bp) {
super.setComponent(bp);
}
/**
* Type-safe way to set Control listener.
* @param listener An ActionListener that implements
* gain control button semantics.
*/
@Override
public void setControlListener(ActionListener listener) {
super.setControlListener(listener);
}
}