/*
* @(#)BasicMarqueeHandler.java 1.0 03-JUL-04
*
* Copyright (c) 2001-2004 Gaudenz Alder
*
*/
package org.jgraph.graph;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import org.jgraph.JGraph;
/**
* A simple implementation of a marquee handler for JGraph.
*
* @version 1.0 1/1/02
* @author Gaudenz Alder
*/
public class BasicMarqueeHandler {
/* Restore previous cursor after operation. */
protected transient Cursor previousCursor = null;
/* The rectangle that defines the current marquee selection. */
protected Rectangle2D marqueeBounds;
/* The start start and current point of the marquee session. */
protected Point2D startPoint, currentPoint;
/* Return true if this handler should be preferred over other handlers. */
public boolean isForceMarqueeEvent(MouseEvent event) {
return event.isAltDown();
}
/**
* Stops the current marquee selection.
*/
public void mouseReleased(MouseEvent e) {
try {
if (e != null && marqueeBounds != null) {
if (!(e.getSource() instanceof JGraph))
throw new IllegalArgumentException(
"MarqueeHandler cannot "
+ "handle event from unknown source: "
+ e);
JGraph graph = (JGraph) e.getSource();
Rectangle2D bounds =
graph.fromScreen((Rectangle2D) marqueeBounds.clone());
handleMarqueeEvent(e, graph, bounds);
graph.setCursor(previousCursor);
Rectangle dirty =
new Rectangle(
(int) marqueeBounds.getX(),
(int) marqueeBounds.getY(),
(int) marqueeBounds.getWidth() + 1,
(int) marqueeBounds.getHeight() + 1);
dirty.width++;
dirty.height++;
graph.repaint(dirty);
}
} finally {
currentPoint = null;
startPoint = null;
marqueeBounds = null;
previousCursor = null;
}
}
/**
* Hook for subclassers. Current implementation checks if graph selection is enabled.
* This is called from mouseReleased to execute the marquee selection.
*/
public void handleMarqueeEvent(MouseEvent e, JGraph graph, Rectangle2D bounds) {
CellView[] views = graph.getGraphLayoutCache().getRoots(bounds);
ArrayList list = new ArrayList();
for (int i = 0; i < views.length; i++)
// above returns intersection, we want containment
if (bounds.contains(views[i].getBounds()))
list.add(views[i].getCell());
Object[] cells = list.toArray();
graph.getUI().selectCellsForEvent(graph, cells, e);
}
/**
* Includes the specified startPoint in the marquee selection. Calls
* overlay.
*/
public void mouseDragged(MouseEvent e) {
if (startPoint != null) {
if (!(e.getSource() instanceof JGraph))
throw new IllegalArgumentException(
"MarqueeHandler cannot handle event from unknown source: "
+ e);
JGraph graph = (JGraph) e.getSource();
Graphics g = graph.getGraphics();
// Xor the current display
Color bg = graph.getBackground();
Color fg = graph.getMarqueeColor();
g.setColor(fg);
g.setXORMode(bg);
overlay(graph, g, true);
processMouseDraggedEvent(e);
// Repaint
g.setColor(bg);
g.setXORMode(fg);
overlay(graph, g, false);
}
}
/**
* Called from mouse dragged to update the marquee state during a repaint.
*/
protected void processMouseDraggedEvent(MouseEvent e) {
if (startPoint != null) {
currentPoint = e.getPoint();
marqueeBounds = new Rectangle2D.Double(startPoint.getX(), startPoint.getY(), 0, 0);
marqueeBounds.add(currentPoint);
}
}
/**
* Called after the component was repainted (after autoscroll).
* This is used to indicate that the graphics is no more dirty.
*/
public void paint(JGraph graph, Graphics g) {
overlay(graph, g, false);
}
/**
* Draw the current state of the handler. This is called twice by the overlay
* method and also by the paint method. The caller's intention is that the overlay
* method draws exactly the current state of the handler so that it may be used
* for XOR paint. The drag method calls overlay, changes the state, and calls
* overlay again to use this. However, since it is not always possible to clear
* the screen with an exact repaint the caller passes a flag to indicate if the
* graphics object should be cleared with this call (eg. if a subsequent call
* follows).
* @param g
*/
public void overlay(JGraph graph, Graphics g, boolean clear) {
if (marqueeBounds != null)
g.drawRect(
(int) marqueeBounds.getX(),
(int) marqueeBounds.getY(),
(int) marqueeBounds.getWidth(),
(int) marqueeBounds.getHeight());
}
/**
* Start the marquee at the specified startPoint. This invokes
* expandMarqueeToPoint to initialize marquee selection.
*/
public void mousePressed(MouseEvent e) {
startPoint = e.getPoint();
marqueeBounds = new Rectangle2D.Double(startPoint.getX(), startPoint.getY(), 0, 0);
if (e != null) {
if (!(e.getSource() instanceof JGraph))
throw new IllegalArgumentException(
"MarqueeHandler cannot handle event from unknown source: "
+ e);
JGraph graph = (JGraph) e.getSource();
if (isMarqueeTriggerEvent(e, graph)) {
previousCursor = graph.getCursor();
graph.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
}
}
}
/**
* Hook for subclassers. Current implementation checks if graph selection is enabled.
* This is called from mousePressed before initiating the marquee selection.
*/
public boolean isMarqueeTriggerEvent(MouseEvent e, JGraph graph) {
return graph.isSelectionEnabled();
}
/**
* Empty.
*/
public void mouseMoved(MouseEvent e) {
// do nothing
}
/**
* Returns the currentPoint.
* @return Point
*/
public Point2D getCurrentPoint() {
return currentPoint;
}
/**
* Returns the marqueeBounds.
* @return Rectangle
*/
public Rectangle2D getMarqueeBounds() {
return marqueeBounds;
}
/**
* Returns the previousCursor.
* @return Cursor
*/
public Cursor getPreviousCursor() {
return previousCursor;
}
/**
* Returns the startPoint.
* @return Point
*/
public Point2D getStartPoint() {
return startPoint;
}
/**
* Sets the currentPoint.
* @param currentPoint The currentPoint to set
*/
public void setCurrentPoint(Point2D currentPoint) {
this.currentPoint = currentPoint;
}
/**
* Sets the marqueeBounds.
* @param marqueeBounds The marqueeBounds to set
*/
public void setMarqueeBounds(Rectangle2D marqueeBounds) {
this.marqueeBounds = marqueeBounds;
}
/**
* Sets the previousCursor.
* @param previousCursor The previousCursor to set
*/
public void setPreviousCursor(Cursor previousCursor) {
this.previousCursor = previousCursor;
}
/**
* Sets the startPoint.
* @param startPoint The startPoint to set
*/
public void setStartPoint(Point2D startPoint) {
this.startPoint = startPoint;
}
}