/*
* @(#)DefaultDragTracker.java
*
* Copyright (c) 1996-2010 The authors and contributors of JHotDraw.
* You may not use, copy or modify this file, except in compliance with the
* accompanying license terms.
*/
package org.jhotdraw.draw.tool;
import edu.umd.cs.findbugs.annotations.Nullable;
import org.jhotdraw.draw.event.TransformEdit;
import org.jhotdraw.draw.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.util.*;
/**
* <code>DefaultDragTracker</code> implements interactions with the content area of a
* <code>Figure</code>.
* <p>
* The <code>DefaultDragTracker</code> handles one of the three states of the
* <code>SelectionTool</code>. It comes into action, when the user presses
* the mouse button over the content area of a <code>Figure</code>.
* <p>
* Design pattern:<br>
* Name: Chain of Responsibility.<br>
* Role: Handler.<br>
* Partners: {@link SelectionTool} as Handler, {@link SelectAreaTracker} as
* Handler, {@link HandleTracker} as Handler.
* <p>
* Design pattern:<br>
* Name: State.<br>
* Role: State.<br>
* Partners: {@link SelectAreaTracker} as State, {@link SelectionTool} as
* Context, {@link HandleTracker} as State.
*
* @see SelectionTool
*
* @author Werner Randelshofer
* @version $Id$
*/
public class DefaultDragTracker extends AbstractTool implements DragTracker {
private static final long serialVersionUID = 1L;
@Nullable
protected Figure anchorFigure;
/**
* The drag rectangle encompasses the bounds of all dragged figures.
*/
@Nullable
protected Rectangle2D.Double dragRect;
/**
* The previousOrigin holds the origin of all dragged figures of the
* previous mouseDragged event. This coordinate is constrained using
* the Constrainer of the DrawingView.
*/
protected Point2D.Double previousOrigin;
/**
* The anchorOrigin holds the origin of all dragged figures of the
* mousePressed event.
*/
protected Point2D.Double anchorOrigin;
/**
* The previousPoint holds the location of the mouse of the previous
* mouseDragged event. This coordinate is not constrained using
* the Constrainer of the DrawingView.
*/
protected Point2D.Double previousPoint;
/**
* The anchorPoint holds the location of the mouse of the
* mousePressed event. This coordinate is not constrained using
* the Constrainer of the DrawingView.
*/
protected Point2D.Double anchorPoint;
private boolean isDragging;
@Nullable
private HashSet<Figure> transformedFigures;
/** Creates a new instance. */
public DefaultDragTracker(Figure figure) {
anchorFigure = figure;
}
public DefaultDragTracker() {
}
@Override
public void mouseMoved(MouseEvent evt) {
updateCursor(editor.findView((Container) evt.getSource()), evt.getPoint());
}
@Override
public void mousePressed(MouseEvent evt) {
super.mousePressed(evt);
DrawingView view = getView();
if (evt.isShiftDown()) {
view.setHandleDetailLevel(0);
view.toggleSelection(anchorFigure);
if (!view.isFigureSelected(anchorFigure)) {
anchorFigure = null;
}
} else if (!view.isFigureSelected(anchorFigure)) {
view.setHandleDetailLevel(0);
view.clearSelection();
view.addToSelection(anchorFigure);
}
if (!view.getSelectedFigures().isEmpty()) {
dragRect = null;
transformedFigures = new HashSet<Figure>();
for (Figure f : view.getSelectedFigures()) {
if (f.isTransformable()) {
transformedFigures.add(f);
if (dragRect == null) {
dragRect = f.getBounds();
} else {
dragRect.add(f.getBounds());
}
}
}
if (dragRect != null) {
anchorPoint = previousPoint = view.viewToDrawing(anchor);
anchorOrigin = previousOrigin = new Point2D.Double(dragRect.x, dragRect.y);
}
}
}
@Override
public void mouseDragged(MouseEvent evt) {
DrawingView view = getView();
if (!transformedFigures.isEmpty()) {
if (isDragging == false) {
isDragging = true;
updateCursor(editor.findView((Container) evt.getSource()), new Point(evt.getX(), evt.getY()));
}
Point2D.Double currentPoint = view.viewToDrawing(new Point(evt.getX(), evt.getY()));
dragRect.x += currentPoint.x - previousPoint.x;
dragRect.y += currentPoint.y - previousPoint.y;
Rectangle2D.Double constrainedRect = (Rectangle2D.Double) dragRect.clone();
if (view.getConstrainer() != null) {
view.getConstrainer().constrainRectangle(
constrainedRect);
}
AffineTransform tx = new AffineTransform();
tx.translate(
constrainedRect.x - previousOrigin.x,
constrainedRect.y - previousOrigin.y);
for (Figure f : transformedFigures) {
f.willChange();
f.transform(tx);
f.changed();
}
previousPoint = currentPoint;
previousOrigin = new Point2D.Double(constrainedRect.x, constrainedRect.y);
}
}
@Override
public void mouseReleased(MouseEvent evt) {
super.mouseReleased(evt);
DrawingView view = getView();
if (transformedFigures != null && !transformedFigures.isEmpty()) {
isDragging = false;
int x = evt.getX();
int y = evt.getY();
updateCursor(editor.findView((Container) evt.getSource()), new Point(x, y));
Point2D.Double newPoint = view.viewToDrawing(new Point(x, y));
Figure dropTarget = getDrawing().findFigureExcept(newPoint, transformedFigures);
if (dropTarget != null) {
boolean snapBack = dropTarget.handleDrop(newPoint, transformedFigures, view);
if (snapBack) {
AffineTransform tx = new AffineTransform();
tx.translate(
anchorOrigin.x - previousOrigin.x,
anchorOrigin.y - previousOrigin.y);
for (Figure f : transformedFigures) {
f.willChange();
f.transform(tx);
f.changed();
}
Rectangle r = new Rectangle(anchor.x, anchor.y, 0, 0);
r.add(evt.getX(), evt.getY());
maybeFireBoundsInvalidated(r);
fireToolDone();
return;
}
}
AffineTransform tx = new AffineTransform();
tx.translate(
-anchorOrigin.x + previousOrigin.x,
-anchorOrigin.y + previousOrigin.y);
if (!tx.isIdentity()) {
getDrawing().fireUndoableEditHappened(new TransformEdit(
transformedFigures, tx));
}
}
Rectangle r = new Rectangle(anchor.x, anchor.y, 0, 0);
r.add(evt.getX(), evt.getY());
maybeFireBoundsInvalidated(r);
transformedFigures = null;
fireToolDone();
}
@Override
public void setDraggedFigure(Figure f) {
anchorFigure = f;
}
}