package org.limewire.ui.swing.components;
import javax.swing.JSlider;
/**
* An extension of JSlider to select a range of values using two thumb controls.
* The thumb controls are used to select the lower and upper value of a range
* with pre-determined minimum and maximum values. Either thumb control may
* be disabled.
*
* <p>Note that RangeSlider makes use of the default BoundedRangeModel, which
* supports an inner range defined by a value and an extent. The upper value
* returned by RangeSlider is simply the lower value plus the extent.</p>
*/
public class RangeSlider extends JSlider {
/** Indicator that determines whether the lower thumb is displayed. */
private boolean lowerThumbEnabled = true;
/** Indicator that determines whether the upper thumb is displayed. */
private boolean upperThumbEnabled = true;
/**
* Constructs a RangeSlider with default minimum and maximum values of 0
* and 100.
*/
public RangeSlider() {
initSlider();
}
/**
* Constructs a RangeSlider with the specified default minimum and maximum
* values.
*/
public RangeSlider(int min, int max) {
super(min, max);
initSlider();
}
/**
* Initializes the slider by setting default properties.
*/
private void initSlider() {
setOrientation(HORIZONTAL);
}
/**
* Overrides the superclass method to install the UI delegate to draw two
* thumbs.
*/
@Override
public void updateUI() {
setUI(new RangeSliderUI(this));
// Update UI for slider labels. This must be called after updating the
// UI of the slider. Refer to JSlider.updateUI().
updateLabelUIs();
}
/**
* Returns an indicator that determines whether the lower thumb is enabled.
* The default value is true.
*/
public boolean isLowerThumbEnabled() {
return lowerThumbEnabled;
}
/**
* Sets an indicator that determines whether the lower thumb is enabled.
*/
public void setLowerThumbEnabled(boolean lowerThumbEnabled) {
this.lowerThumbEnabled = lowerThumbEnabled;
}
/**
* Returns an indicator that determines whether the upper thumb is enabled.
* The default value is true.
*/
public boolean isUpperThumbEnabled() {
return upperThumbEnabled;
}
/**
* Sets an indicator that determines whether the upper thumb is enabled.
*/
public void setUpperThumbEnabled(boolean upperThumbEnabled) {
this.upperThumbEnabled = upperThumbEnabled;
}
/**
* Returns the lower value in the range.
*/
@Override
public int getValue() {
return super.getValue();
}
/**
* Sets the lower value in the range.
*/
@Override
public void setValue(int value) {
int oldValue = getValue();
if (oldValue == value) {
return;
}
// Compute new value and extent to maintain upper value.
int oldExtent = getExtent();
int newValue = Math.min(Math.max(getMinimum(), value), oldValue + oldExtent);
int newExtent = oldExtent + oldValue - newValue;
// Set new value and extent, and fire a single change event.
getModel().setRangeProperties(newValue, newExtent, getMinimum(),
getMaximum(), getValueIsAdjusting());
}
/**
* Returns the upper value in the range.
*/
public int getUpperValue() {
return getValue() + getExtent();
}
/**
* Sets the upper value in the range.
*/
public void setUpperValue(int value) {
// Compute new extent.
int lowerValue = getValue();
int newExtent = Math.min(Math.max(0, value - lowerValue), getMaximum() - lowerValue);
// Set extent to set upper value.
setExtent(newExtent);
}
}