Name: sgC58550 Date: 06/17/97


1) The coordinates in a mouseEntered event when the mouse enters
from a different AWT component are in the coordinate space
of the component being exited, not the component being entered.

2) The coordinates in a mouseExited event when the mouse is
being moved from the AWT component to a native Windows95
application window are in the coordinate space of the native
Windows95 application window.

3) Also, when dragging, there is an extraneous mousePressed
event sent to a component immediately after the mouseExited
event.

These observations are based on examining the output of a
program with a Canvas object containing the following code.


    ...

    addMouseListener(this);
    addMouseMotionListener(this);

    ...

    public void mouseEntered(MouseEvent evt)
    {
        int x = evt.getX();
        int y = evt.getY();
        System.out.println("mouseEntered: " + x + ", " + y);
    }

    public void mouseExited(MouseEvent evt)
    {
        int x = evt.getX();
        int y = evt.getY();
        System.out.println("mouseExited: " + x + ", " + y);
    }

    public void mousePressed(MouseEvent evt)
    {
        int x = evt.getX();
        int y = evt.getY();
        System.out.println("mousePressed: " + x + ", " + y);
    }

company - Steam Communications Inc. , email - ###@###.###
======================================================================

sheri.good@Eng 1997-06-26

Release: 1.1.1
Hardware: PC
OSversion: NT

Synopsis: mouseEntered() gets wrong coordinates

Description:
The mouseEntered() Method of a MouseListener receives
incorrect coordinates when registered on a Component. It seems as if they
are relative to a parent Component. The Coordinates of
MouseMotionListener-Events are correct.



Name: krT82822 Date: 10/09/99


To Reproduce Problem:

Extend java.awt.Window.
Catch mouse entered events.
Obtain (x, y) via getX(), getY() of MouseEvent.

Actual Problem:

The obtained (x, y) coordinate is not relative to
the window, or even to the screen.
The values are given by:
       x = winLocation.x * 2 + relativeX
       y = winLocation.y * 2 + relativeY
The values should be:
       x = relativeX
       y = relativeY

Example Application:
/***************************
 ******** Copy This ********
 ***************************/

import java.awt.*;
import java.awt.event.*;

public class WindowErrorTest
{
public static void main(String[] args)
{
Frame f = new Frame("WindowErrorTest");
TextArea text = new TextArea();

text.append("Move into and out of the window (on right).\n\n");
text.append("Window size: 200x200, Window Pos: (400, 200)\n\n");
text.append("event.getX() returns:\n");
text.append(" x = winPos.x * 2 + relativeX\n\n");
text.append("event.getY() returns:\n");
text.append(" y = winPos.y * 2 + relativeY\n\n");

f.add("Center", text);

Window_Subclass w = new Window_Subclass(f, text);
w.setBackground(Color.gray);

f.addWindowListener(
new WindowAdapter()
{
public void windowClosing(WindowEvent ev)
{
System.exit(0);
}
});

f.setSize(350, 400);
f.setLocation(0, 0);
f.show();
w.setSize(200, 200);
w.setLocation(400, 200);
w.show();
}
}

class Window_Subclass extends Window
{
TextArea text;

public Window_Subclass(Frame f, TextArea text)
{
super(f);

this.text = text;

enableEvents(AWTEvent.MOUSE_EVENT_MASK);
}

public void processMouseEvent(MouseEvent ev)
{
if (ev.getID() == MouseEvent.MOUSE_ENTERED)
text.append("MOUSE_ENTERED: ev.getX(): " + ev.getX() + ", ev.getY(): " + ev.getY() + "\n");
// + ", relative X: " + (ev.getX() - 200) + ", relative Y: " + (ev.getY() - 200)
super.processMouseEvent(ev);
}

public void paint(Graphics g)
{
g.drawOval(-3, -3, 7, 7);
FontMetrics fm = getToolkit().getFontMetrics(getFont());
g.drawString("(0, 0)", 5, fm.getMaxAscent());
super.paint(g);
}
}

/*******************************
 ********** End Code ***********
 *******************************/
(Review ID: 43213)
======================================================================