/*
* @(#)SelectionTool.java 5.1
*
*/
package CH.ifa.draw.standard;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.util.Vector;
import CH.ifa.draw.framework.*;
/**
* Tool to select and manipulate figures.
* A selection tool is in one of three states, e.g., background
* selection, figure selection, handle manipulation. The different
* states are handled by different child tools.
*
* Design Patterns
*
* State
* SelectionTool is the StateContext and child is the State.
* The SelectionTool delegates state specific
* behavior to its current child tool.
*
*/
public class SelectionTool extends AbstractTool {
private Tool fChild = null;
public SelectionTool(DrawingView view) {
super(view);
}
/**
* Handles mouse down events and starts the corresponding tracker.
*/
public void mouseDown(MouseEvent e, int x, int y)
{
// on Windows NT: AWT generates additional mouse down events
// when the left button is down && right button is clicked.
// To avoid dead locks we ignore such events
if (fChild != null)
return;
view().freezeView();
Handle handle = view().findHandle(e.getX(), e.getY());
if (handle != null) {
fChild = createHandleTracker(view(), handle);
}
else {
Figure figure = drawing().findFigure(e.getX(), e.getY());
if (figure != null) {
fChild = createDragTracker(view(), figure);
}
else {
if (!e.isShiftDown()) {
view().clearSelection();
}
fChild = createAreaTracker(view());
}
}
fChild.mouseDown(e, x, y);
}
/**
* Handles mouse drag events. The events are forwarded to the
* current tracker.
*/
public void mouseDrag(MouseEvent e, int x, int y) {
if (fChild != null) // JDK1.1 doesn't guarantee mouseDown, mouseDrag, mouseUp
fChild.mouseDrag(e, x, y);
}
/**
* Handles mouse up events. The events are forwarded to the
* current tracker.
*/
public void mouseUp(MouseEvent e, int x, int y) {
view().unfreezeView();
if (fChild != null) // JDK1.1 doesn't guarantee mouseDown, mouseDrag, mouseUp
fChild.mouseUp(e, x, y);
fChild = null;
}
/**
* Factory method to create a Handle tracker. It is used to track a handle.
*/
protected Tool createHandleTracker(DrawingView view, Handle handle) {
return new HandleTracker(view, handle);
}
/**
* Factory method to create a Drag tracker. It is used to drag a figure.
*/
protected Tool createDragTracker(DrawingView view, Figure f) {
return new DragTracker(view, f);
}
/**
* Factory method to create an area tracker. It is used to select an
* area.
*/
protected Tool createAreaTracker(DrawingView view) {
return new SelectAreaTracker(view);
}
}