Drawing rectangle using mouse

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Possible Duplicate:
How to draw a rectangle on a java applet using mouse drag event and make it stay

Hello. I would like to know how I can draw rectangle using mousedragged event. I know that I must record mouse location using class Point. I need to implement paint function in paint method and in mousedragged call it or my paint code should implement in mousedragged event?

At this time I put my code in mouse dragged event. This is code:

@Override
    public void mousePressed(MouseEvent e)
    {
        super.mousePressed(e);
        System.out.println("f.getGlassPane() mousePressed");
        if(e.getButton() == MouseEvent.BUTTON1)


        frame.getGlassPane().setVisible(true);

        startPoint=e.getPoint();

        Graphics2D g = null;
            Graphics2D g2 = (Graphics2D) g;
        Rectangle2D prostokat = new Rectangle2D.Double();
        prostokat.setFrameFromDiagonal(e.getPoint().x, e.getPoint().y,startPoint.x, startPoint.y);
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5F));
        g2.setColor(Color.BLUE);
        g2.fill(prostokat);
        g2.draw(prostokat);

    }

    });

There are a lot of comparable questions on SO - this one could have an answer for your problem: http://stackoverflow.com/questions/1115359/how-to-draw-a-rectangle-on-a-java-applet-using-mouse-drag-event-and-make-it-stay — Andreas Dolk, May 16 '11 at 13:07
use mousePressed and store the location and store the location of the mouseReleased. With those values you can calculate your rect. — monty, May 16 '11 at 13:13
I have a question. When I will be painting my rectangle using mousedragged, he will be blinking? In example from Andreas_D post when I draw rectangle he blinking. I don't want to see this effect — edi233, May 16 '11 at 13:19
`JPanel` is double buffered by default; this is usually satisfactory. +1 for using `AlphaComposite`. — trashgod, May 16 '11 at 14:49

score 2 · Accepted Answer · edited May 23 '17 at 12:10

2

You'll also need to handle mouseReleased and mouseDragged, as shown here and here.

edited May 23 '17 at 12:10

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answered May 16 '11 at 13:16

trashgod

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This second link is exacly what I want. Thx a lot :) – edi233 May 16 '11 at 13:23

Drawing rectangle using mouse

1 Answers1