Using mouse clicks to draw on a JFrame, problem probably with coordinates

[michael perkins]

I'm having problems drawing a rectangle, circle, and a straight line of a JFrame. I'm pretty sure I'm getting my coordinates off and I've spent hours trying to fix it which usually leads me to messing it up even more. If I somewhat fix one part of it, it just ends up messing up another part, so if anyone could help me out and show me what I am messing up it would be very much appreciated. The polygon part can be ignored, I will work on it once I get my coordinates fixed. Sorry if its a little long, I didn't know if I needed to attach all or just the part I'm having problems with so I went with the first. Thanks again.

    

    public void mousePressed(MouseEvent event) {
        x1 = event.getX();
        y1 = event.getY();
        
        if (event.isMetaDown()) {
            Graphics g = getGraphics();
            Rectangle r = getBounds();
            g.clearRect(0,0, r.width, r.height);
            g.dispose();
        }
        else{
            lastx = x1;
            lasty = y1;
        }
    }

    public void mouseClicked(MouseEvent event) {
        Graphics g = getGraphics();
        Graphics2D g2 = (Graphics2D)g;
        x1 = event.getX();
        y1 = event.getY();

        if(event.isMetaDown()){
            Rectangle r = getBounds();
            g2.clearRect(0,0, r.width, r.height);
            g.dispose();
        }

        else if (rectanglef) {
           g2.setPaint(color);
	   if(x1<x2 && y1<y2){
	      g2.fillRect(x1, y1, Math.abs(x2-x1), Math.abs(y2-y1));
           }
           else if(x1>x2 && y1> y2){
               g2.fillRect(x2, y2, Math.abs(x2-x1), Math.abs(y2-y1));
           }
	   else if (y1<y2){
   	      g2.fillRect(x2, y1, Math.abs(x2-x1), Math.abs(y2-y1));
           }
	   else if (y1>y2){
	      g2.fillRect(x1, y2, Math.abs(x2-x1), Math.abs(y2-y1));
           }
        }

        else if(ovalf){
           g2.setPaint(color);
           if(x1<x2 && y1<y2){
              g2.fillOval(x1, y1, Math.abs(x2-x1), Math.abs(y2-y1));
           }
           else if(x1>x2 && y1> y2){
              g2.fillOval(x2, y2, Math.abs(x2-x1), Math.abs(y2-y1));
           }
	   else if (y1<y2){
              g2.fillOval(x2, y1, Math.abs(x2-x1), Math.abs(y2-y1));
           }
	   else if (y1>y2){
              g2.fillOval(x1, y2, Math.abs(x2-x1), Math.abs(y2-y1));
           }
        }

        else if(polygonf){
            g2.setPaint(color);
            while(!twice){

            }
        }
        
        else if (linef) {
            x2 = event.getX();
            y2 = event.getY();
            g2.setPaint(color);
            g2.drawLine(lastx, lasty, x1, y1);
        }
        lastx = x2;
        lasty = y2;
    }

    public void mouseDragged(MouseEvent event) {
        Graphics g = getGraphics();
        g.setColor(color);
        int x = event.getX();
        int y = event.getY();
        if(event.isMetaDown())
            g.dispose();
        
        else if(ffflag){
           g.drawLine(lastx, lasty, x, y);
           lastx = x;
           lasty = y;
        }
    }
    public void mouseEntered(MouseEvent event) { }
    public void mouseExited(MouseEvent event) { }
    public void mouseReleased(MouseEvent event) { }
    public void mouseMoved(MouseEvent event) { }
}


    
 

[Darryl Burke]

Never use getGraphics of a Component, and don't perform custom painting in a top level window but rather in a JPanel or JComponent that is then added to the window.

[michael perkins]

Darryl Burke wrote:Never use getGraphics of a Component, and don't perform custom painting in a top level window but rather in a JPanel or JComponent that is then added to the window.

I know I needed a JPanel to do the painting on, but believe it or not that was the way my teacher recommended so I left out the extra work. I wish I had a teacher that knew java, but I've asked her many questions and she hasn't been able to answer any of them. I asked her the question I asked here before I posted it here and she couldn't help me. But thanks for pointing that out, I wish I had a more formal exposure but there's not much I can do about it.