/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.swt.tool;
import org.eclipse.swt.SWT;
/**
* Abstract base class for the zoom-in and zoom-out tools. Provides getter / setter
* methods for the zoom increment.
*
* @author Michael Bedward
* @since 2.6
*
*
*
* @source $URL$
*/
public abstract class AbstractZoomTool extends CursorTool {
/** The default zoom increment */
public static final double DEFAULT_ZOOM_FACTOR = 1.5;
/** The working zoom increment */
protected double zoom;
/**
* Constructs a new abstract zoom tool. To activate the tool only on certain
* mouse events provide a single mask, e.g. {@link SWT#BUTTON1}, or
* a combination of multiple SWT-masks.
*
* @param triggerButtonMask Mouse button which triggers the tool's activation
* or {@value #ANY_BUTTON} if the tool is to be triggered by any button
*/
public AbstractZoomTool(int triggerButtonMask) {
super(triggerButtonMask);
setZoom(DEFAULT_ZOOM_FACTOR);
}
/**
* Constructs a new abstract zoom tool which is triggered by any mouse button.
*/
public AbstractZoomTool() {
this(CursorTool.ANY_BUTTON);
}
/**
* Get the current areal zoom increment.
*
* @return the current zoom increment as a double
*/
public double getZoom() {
return zoom;
}
/**
* Set the zoom increment
*
* @param newZoom the new zoom increment; values <= 1.0
* will be ignored
*
* @return the previous zoom increment
*/
public double setZoom(double newZoom) {
double old = zoom;
if (newZoom > 1.0d) {
zoom = newZoom;
}
return old;
}
}