test/jdk/java/awt/Robot/CreateScreenCapture.java

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/*
 * @test
 * @bug 4292503
 * @summary OutOfMemoryError with lots of Robot.createScreenCapture
 * @library /java/awt/regtesthelpers
 * @build PassFailJFrame
 * @requires (os.family == "linux")
 * @run main/manual CreateScreenCapture
*/

import java.awt.Dialog;
import java.awt.Frame;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.TextArea;

public class CreateScreenCapture {

    static TextArea messageText;

    private static final String INSTRUCTIONS = """
         This test is linux only!
         Once you see these instructions, run 'top' program.
         Watch for java process.
         The memory size used by this process should stop growing after several steps.
         Numbers of steps test is performing are displayed in output window.
         After 5-7 steps the size taken by the process should become stable.
         If this happens, then test passed otherwise test failed.

         Small oscillations of the memory size are, however, acceptable.""";

    public static void main(String[] args) throws Exception {
        Robot robot = new Robot();
        PassFailJFrame passFail = new PassFailJFrame(INSTRUCTIONS);
        Dialog dialog = new Dialog(new Frame(), "Instructions");
        messageText = new TextArea("", 5, 80, TextArea.SCROLLBARS_BOTH);
        dialog.add(messageText);
        PassFailJFrame.addTestWindow(dialog);
        PassFailJFrame.positionTestWindow(dialog, PassFailJFrame.Position.HORIZONTAL);
        dialog.setSize(200, 300);
        dialog.setVisible(true);
        Rectangle rect = new Rectangle(0, 0, 1000, 1000);
        for (int i = 0; i < 100; i++) {
            Image image = robot.createScreenCapture(rect);
            image.flush();
            image = null;
            robot.delay(200);
            log("step #" + i);
        }
        passFail.awaitAndCheck();
    }

    private static void log(String messageIn) {
        messageText.append(messageIn + "\n");
    }
}