On Tue, 4 Feb 2025 23:35:32 GMT, Damon Nguyen <dngu...@openjdk.org> wrote:
> Redo for JComboBox infinite scrolling issue. The issue is that when a
> scrollbar is clicked and held, if the user switches focus (ex: ALT+TAB) while
> scrolling, when focused is returned to the scrolling application, the
> JComboBox will still be scrolling even though nothing it being clicked.
>
> Previously, a KeyboardFocusListener was added to determine the focus.
> However, there was a memory leak on Windows and Ubuntu. This current
> implementation uses the current FocusManager and is overall a cleaner,
> simpler approach.
>
> CI testing is green on all platforms.
Unfortunately, the provided test fails for me on Ubuntu 22.04.
On the first `Alt + TAB` it switches to the test frame, so it doesn't trigger
the timer to stop.
BTW, the test can be automated, e.g. do something like the following
<details>
<summary>JComboBoxScrollFocusTestAuto.java</summary>
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicComboPopup;
import java.awt.Component;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.event.InputEvent;
import java.lang.reflect.InvocationTargetException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
public class JComboBoxScrollFocusTestAuto {
private static Robot robot;
private static JFrame comboboxFrame;
private static JComboBox<String> combobox;
public static void main(String[] args) throws Exception {
robot = new Robot();
try {
SwingUtilities.invokeAndWait(JComboBoxScrollFocusTestAuto::createAndShowGUI);
doTest();
} finally {
SwingUtilities.invokeAndWait(comboboxFrame::dispose);
}
}
private static void createAndShowGUI() {
comboboxFrame = new JFrame("JComboBoxScrollFocusTest Test Frame");
combobox = new JComboBox<>();
for (int i = 0; i < 100; i++) {
combobox.addItem(String.valueOf(i));
}
comboboxFrame.add(combobox);
comboboxFrame.setSize(400, 200);
comboboxFrame.setLocationRelativeTo(null);
comboboxFrame.setVisible(true);
}
static Rectangle getOnScreenBoundsOnEDT(Component component)
throws InterruptedException, TimeoutException, ExecutionException {
robot.waitForIdle();
FutureTask<Rectangle> task = new FutureTask<>(()
-> new Rectangle(component.getLocationOnScreen(),
component.getSize()));
SwingUtilities.invokeLater(task);
return task.get(500, TimeUnit.MILLISECONDS);
}
private static int getScrollbarValue()
throws InterruptedException, InvocationTargetException,
ExecutionException, TimeoutException {
FutureTask<Integer> task = new FutureTask<>(() -> {
BasicComboPopup popup = (BasicComboPopup)
combobox.getAccessibleContext().getAccessibleChild(0);
JScrollPane scrollPane = (JScrollPane)
popup.getAccessibleContext().getAccessibleChild(0);
JScrollBar scrollBar = scrollPane.getVerticalScrollBar();
return scrollBar.getValue();
});
SwingUtilities.invokeAndWait(task);
return task.get(500, TimeUnit.MILLISECONDS);
}
private static void doTest() throws Exception {
robot.waitForIdle();
robot.delay(500);
Rectangle rectangle = getOnScreenBoundsOnEDT(combobox);
Point ptOpenComboboxPopup = new Point(rectangle.x + rectangle.width -
5, rectangle.y + rectangle.height / 2);
robot.mouseMove(ptOpenComboboxPopup.x, ptOpenComboboxPopup.y);
robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
robot.waitForIdle();
robot.delay(500);
BasicComboPopup popup = (BasicComboPopup)
combobox.getAccessibleContext().getAccessibleChild(0);
JScrollBar scrollBar = ((JScrollPane)
popup.getAccessibleContext().getAccessibleChild(0)).getVerticalScrollBar();
// Start scrolling
Rectangle scrollbarBounds = getOnScreenBoundsOnEDT(scrollBar);
robot.mouseMove(scrollbarBounds.x + scrollbarBounds.width / 2,
scrollbarBounds.y + scrollbarBounds.height - 5);
robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
robot.delay(1000);
if (getScrollbarValue() == 0) {
throw new RuntimeException("The scrollbar is not scrolling");
}
// closing popup by moving focus to the main window
comboboxFrame.requestFocus();
robot.waitForIdle();
robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
robot.waitForIdle();
robot.delay(500);
// open popup again
robot.mouseMove(ptOpenComboboxPopup.x, ptOpenComboboxPopup.y);
robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
robot.waitForIdle();
robot.delay(500);
if (getScrollbarValue() != 0) {
throw new RuntimeException("The scroll bar is scrolling");
}
}
}
</details>
-------------
PR Comment: https://git.openjdk.org/jdk/pull/23451#issuecomment-2649244315
