单击其他位置时如何隐藏 Swing 弹出窗口

2022-01-20 00:00:00 popup java swing

我有一个弹出窗口，当用户单击按钮时会显示.当发生以下任何事件时，我想隐藏弹出窗口:

I have a Popup that is shown when a user clicks on a button. I would like to hide the popup when any of the following events occur:

  1. 用户单击应用程序中的其他位置.(例如背景面板)
  2. 用户最小化应用程序.

JPopupMenu 有这种行为，但我需要的不仅仅是 JMenuItems.以下代码块是用于演示当前用法的简化插图.

The JPopupMenu has this behavior, but I need more than just JMenuItems. The following code block is a simplified illustration to demonstrate the current usage.

import java.awt.*;
import java.awt.event.ActionEvent;
import javax.swing.*;

public class PopupTester extends JFrame {
  public static void main(String[] args) {
    final PopupTester popupTester = new PopupTester();
    popupTester.setLayout(new FlowLayout());
    popupTester.setSize(300, 100);
    popupTester.add(new JButton("Click Me") {
      @Override
      protected void fireActionPerformed(ActionEvent event) {
        Point location = getLocationOnScreen();
          int y = (int) (location.getY() + getHeight());
          int x = (int) location.getX();
          JLabel myComponent = new JLabel("Howdy");
          Popup popup = PopupFactory.getSharedInstance().getPopup(popupTester, myComponent, x, y);
          popup.show();
        }
      });
      popupTester.add(new JButton("No Click Me"));
      popupTester.setVisible(true);
      popupTester.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

推荐答案

正如 pajton 在之前的评论中指出的那样，Popup 不是一个可以轻松绑定侦听器的 JComponent.但是，正如其文档所述，Popup 的实现负责创建和维护自己的组件以将 [其主题] 呈现给用户."

As pajton noted in a previous comment, Popup is not a JComponent to which listeners can be readily bound. But, as its documentation states, "implementations of Popup are responsible for creating and maintaining their own Components to render [its subject] to the user."

因此，在使用它作为您的展示机制时，您的 Popup 将不得不将自己展示为一个实际的 Swing 组件无论如何.让它自己注册到那个组件.当组件失去焦点时让它隐藏起来.

So in using it as your presentation mechanism, your Popup is going to have to present itself as an actual Swing component anyway. Have it register itself to that component. Have it hide itself when the component loses focus.

import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.Popup;

public class PopupTester extends JFrame {
    private static class MessagePopup extends Popup
        implements WindowFocusListener
    {
        private final JDialog dialog;

        public MessagePopup(Frame base, String message) {
            super();
            dialog = new JOptionPane().createDialog( base, "Message" );
            dialog.setModal( false );
            dialog.setContentPane( new JLabel( message ) );
        }
        @Override public void show() {
            dialog.addWindowFocusListener( this );
            dialog.setVisible( true );
        }
        @Override public void hide() {
            dialog.setVisible( false );
            dialog.removeWindowFocusListener( this );
        }
        public void windowGainedFocus( WindowEvent e ) {
            // NO-OP
        }

        public void windowLostFocus( WindowEvent e ) {
            hide();
        }
    }

    public static void main(String[] args) {
    final PopupTester popupTester = new PopupTester();
    popupTester.setLayout(new FlowLayout());
    popupTester.setSize(300, 100);
    popupTester.add(new JButton("Click Me") {
      @Override
      protected void fireActionPerformed(ActionEvent event) {
        Point location = getLocationOnScreen();
          MessagePopup popup = new MessagePopup( popupTester, "Howdy" );
          popup.show();
        }
      });
      popupTester.add(new JButton("No Click Me"));
      popupTester.setVisible(true);
      popupTester.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

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