test/jdk/java/awt/List/ScrollbarPositionTest.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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/*
 * @test
 * @bug 4024943
 * @summary  Test for position of List scrollbar when it is added
 * @library /java/awt/regtesthelpers
 * @build PassFailJFrame
 * @run main/manual ScrollbarPositionTest
 */

import java.awt.Button;
import java.awt.Frame;
import java.awt.GridLayout;
import java.awt.List;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class ScrollbarPositionTest {
    static int item = 0;
    static List list;
    static Button addButton, delButton;

    private static final String INSTRUCTIONS = """
        Click on the "Add List Item" button many times
        until the vertical scrollbar appears.
        Verify that the displayed vertical scrollbar does not take the space
        that was occupied by buttons before the scrollbar is shown.""";

    public static void main(String[] args) throws Exception {
        PassFailJFrame.builder()
                .title("ScrollbarPositionTest Instructions")
                .instructions(INSTRUCTIONS)
                .rows((int) INSTRUCTIONS.lines().count() + 2)
                .columns(35)
                .testUI(ScrollbarPositionTest::createTestUI)
                .build()
                .awaitAndCheck();
    }

    private static Frame createTestUI() {
        Panel pan;

        Frame frame = new Frame("ScrollbarPositionTest Frame");
        frame.setLayout(new GridLayout(1, 2));
        list = new List();
        frame.add(list);
        frame.add(pan = new Panel());
        pan.setLayout(new GridLayout(4, 1));

        MyListener listener = new MyListener();
        addButton = new Button("Add List Item");
        addButton.addActionListener(listener);
        pan.add(addButton);

        delButton = new Button("Delete List Item");
        delButton.addActionListener(listener);
        pan.add(delButton);

        frame.pack();
        return frame;
    }

    static class MyListener implements ActionListener {
        public void actionPerformed(ActionEvent evt) {
            if (evt.getSource() == addButton) {
                String s = "item";
                for (int i = 0; i <= item; i++) {
                    s = s +" "+Integer.toString(i);
                }
                item++;
                list.addItem(s);
            } else if (evt.getSource() == delButton) {
                int i;
                if ((i = list.countItems()) > 0) {
                    list.delItem(i - 1);
                    --item;
                }
            }
        }
    }
}