1.2RC1: copyArea is VERY slow in a container

Name: tb29552 Date: 11/11/98


/*

copyArea in 1.2RC1 seems to be several orders of magnitude slower in a
container than it is with 1.1.7 or 1.1.6. This is EXTREMELY important
to us as we use copyArea to scroll areas of our UI. In 1.1.7, scroll
speed is fairly good. With 1.2, it is completely unacceptable.

I've attached a sample program below. On 1.1.7, it can scroll about
100 times a second. On 1.2, it scrolls about 5 times a second.

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

public class copyAreaTest extends Container implements Runnable {
    int top = 0;
    public copyAreaTest()
    {
        super();
        (new Thread(this)).start();
        Button bt = new Button("Hello");
        bt.setBounds(50, 10, 50, 22);
        bt.setVisible(false);
        add(bt);
    }

    public void update(Graphics g)
    {
        paint(g);
    }

    public void paint(Graphics g)
    {
        synchronized(this) {
            Rectangle rct = g.getClipBounds();
            g.setColor(Color.white);
            g.fillRect(rct.x, rct.y, rct.width, rct.height);
            g.setFont(getFont());
            g.setColor(Color.black);

            Dimension dm = size();
            for (int y = 0; y <= (dm.height + 10); y += 20) {
                if (y > rct.y) {
                    int z = y / 20 + top;
                    g.drawString("" + z, 10, y);
                } /* endif */
            } // endfor
        }
    }

    public void run()
    {
        while (1 == 1) {
            Dimension dm = size();
            if (dm != null && dm.width != 0 && dm.height != 0) {
                synchronized(this) {
                    top++;
                    Graphics g = getGraphics();
                    g.copyArea(0, 20, dm.width, dm.height - 20, 0, -20);
                    g.setClip(0, dm.height - 20, dm.width, 20);
                    paint(g);
                    g.dispose();
                }
            } /* endif */
            try {
                Thread.sleep(1);
            } catch(Exception ex) {
                ex.printStackTrace();
            }
        }
    }

    public static void main(String args[]) {
        Frame frm = new Frame("copyAreaTest");
        frm.add(new copyAreaTest());
        frm.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent ev) {
                System.exit(0);
            }
        });
        frm.setSize(500, 500);
        frm.show();
    }
}

(Review ID: 42513)
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