RangeModel.java

/*******************************************************************************
 * Copyright (c) 2000, 2010, 2012 IBM Corporation, Gerhardt Informatics Kft. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Gerhardt Informatics Kft. - GEFGWT port
 *******************************************************************************/
package org.eclipse.draw2d;

import java.beans.PropertyChangeListener;

/**
 * This interface represents a range of possible values as well as the current
 * values. There is a minumum and maximum value, a current value, and the
 * extent. One use for a RangeModel is a scrollbar. There is a minimum value
 * (the top of the scrollbar), a maximum value (the bottom of the scrollbar), a
 * current value (the top of the thumb), and an extent (the length of the
 * thumb).
 */
public interface RangeModel {

	/** Value property name */
	String PROPERTY_VALUE = "value"; //$NON-NLS-1$
	/** Extent property name */
	String PROPERTY_EXTENT = "extent"; //$NON-NLS-1$
	/** Minimum property name */
	String PROPERTY_MINIMUM = "minimum"; //$NON-NLS-1$
	/** Maximum property name */
	String PROPERTY_MAXIMUM = "maximum"; //$NON-NLS-1$

	/**
	 * Registers listener as a PropertyChangeListener of this RangeModel.
	 * Listeners will be notified of changes to {@link #PROPERTY_VALUE value},
	 * {@link #PROPERTY_EXTENT extent}, {@link #PROPERTY_MINIMUM minimum} and
	 * {@link #PROPERTY_MAXIMUM maximum} properties.
	 * 
	 * @param listener
	 *            The listener to add
	 */
	void addPropertyChangeListener(PropertyChangeListener listener);

	/**
	 * Returns the extent.
	 * 
	 * @return The extent
	 */
	int getExtent();

	/**
	 * Returns the maximum value in the range.
	 * 
	 * @return The maximum value
	 */
	int getMaximum();

	/**
	 * Returns the minimum value in the range.
	 * 
	 * @return The minimum value
	 */
	int getMinimum();

	/**
	 * Returns the current value.
	 * 
	 * @return The current value
	 */
	int getValue();

	/**
	 * Returns <code>true</code> if this RangeModel is enabled.
	 * 
	 * @return <code>true</code> if this Rangel Model is enabled
	 */
	boolean isEnabled();

	/**
	 * Removes the given listener from this RangeModel's list of
	 * PropertyChangeListeners.
	 * 
	 * @param listener
	 *            The listener to remove
	 */
	void removePropertyChangeListener(PropertyChangeListener listener);

	/**
	 * Sets min, extent, and max all at once.
	 * 
	 * @param min
	 *            the new mininum
	 * @param extent
	 *            the new extent
	 * @param max
	 *            the new maximum
	 */
	void setAll(int min, int extent, int max);

	/**
	 * Sets the extent.
	 * 
	 * @param extent
	 *            The extent
	 */
	void setExtent(int extent);

	/**
	 * Sets the maximum value of the range.
	 * 
	 * @param max
	 *            The maximum value
	 */
	void setMaximum(int max);

	/**
	 * Sets the minimum value of the range.
	 * 
	 * @param min
	 *            The minimum value
	 */
	void setMinimum(int min);

	/**
	 * Sets the current value.
	 * 
	 * @param value
	 *            The current value
	 */
	void setValue(int value);

}