/*
* 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;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Rectangle;
import org.geotools.geometry.DirectPosition2D;
import org.geotools.geometry.Envelope2D;
import org.geotools.swt.event.MapMouseEvent;
import org.geotools.swt.utils.CursorManager;
import org.geotools.swt.utils.Messages;
/**
* A zoom-out tool for JMapPane.
* <p>
* For mouse clicks, the display will be zoomed-out such that the
* map centre is the position of the mouse click and the map
* width and height are calculated as:
* <pre> {@code len = len.old * z} </pre>
* where {@code z} is the linear zoom increment (>= 1.0)
*
* @author Michael Bedward
* @author Andrea Antonello (www.hydrologis.com)
* @since 2.6
*
*
*
* @source $URL$
*/
public class ZoomOutTool extends AbstractZoomTool {
/** Tool name */
public static final String TOOL_NAME = Messages.getString("tool_name_zoom_out");
/** Tool tip text */
public static final String TOOL_TIP = Messages.getString("tool_tip_zoom_out");
private Cursor cursor;
/**
* Constructs a new zoom out 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 ZoomOutTool(int triggerButtonMask) {
super(triggerButtonMask);
cursor = CursorManager.getInstance().getZoomoutCursor();
}
/**
* Constructs a new zoom out tool which is triggered by any mouse button.
*/
public ZoomOutTool() {
this(CursorTool.ANY_BUTTON);
}
/**
* Zoom out by the currently set increment, with the map
* centred at the location (in world coords) of the mouse
* click
*
* @param ev the mouse event
*/
@Override
public void onMouseClicked( MapMouseEvent ev ) {
if ( ! isTriggerMouseButton(ev)) {
return;
}
Rectangle paneArea = getMapPane().getBounds();
DirectPosition2D mapPos = ev.getMapPosition();
double scale = getMapPane().getWorldToScreenTransform().getScaleX();
double newScale = scale / zoom;
DirectPosition2D corner = new DirectPosition2D(mapPos.getX() - 0.5d * paneArea.width / newScale, mapPos.getY() + 0.5d
* paneArea.height / newScale);
Envelope2D newMapArea = new Envelope2D();
newMapArea.setFrameFromCenter(mapPos, corner);
getMapPane().setDisplayArea(newMapArea);
}
/**
* Get the mouse cursor for this tool
*/
@Override
public Cursor getCursor() {
return cursor;
}
public boolean canDraw() {
return false;
}
public boolean canMove() {
return false;
}
}