vlcj - 处理键盘事件

让我们进一步增强应用程序，我们将在其中更新vlcj - 处理鼠标事件一章，使其具有键盘事件处理功能。

处理键盘事件

使用以下语法添加鼠标事件处理程序（模板方法）−

mediaPlayerComponent = new EmbeddedMediaPlayerComponent() {
   @Override
   public void keyPressed(KeyEvent e) {
   }
};

或者我们可以使用以下语法添加键盘事件处理程序（监听器方法）−

Component videoSurface = mediaPlayerComponent.videoSurfaceComponent();

videoSurface.addKeyListener(new KeyAdapter() {
   @Override
   public void keyPressed(KeyEvent e) {
   }
});

如果在 Windows 上使用 Listener 方法，我们需要使用以下语法禁用本机键盘输入处理。

mediaPlayerComponent.mediaPlayer().input().enableKeyInputHandling(false);

当我们按下任意键时，就会引发键盘事件。

示例

打开 Eclipse 中环境设置一章中创建的项目 mediaPlayer。

使用以下代码更新 App.java−

App.java

package com.tutorialspoint.media;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import uk.co.caprica.vlcj.player.base.MediaPlayer;
import uk.co.caprica.vlcj.player.component.EmbeddedMediaPlayerComponent;

public class App extends JFrame {
   private static final long serialVersionUID = 1L;
   private static final String TITLE = "My First Media Player";
   private static final String VIDEO_PATH = "D:\Downloads\sunset-beach.mp4";
   private final EmbeddedMediaPlayerComponent mediaPlayerComponent;
   private JButton playButton;
   private JButton pauseButton;
   private JButton rewindButton;
   private JButton skipButton;

   public App(String title) {
      super(title);
      mediaPlayerComponent = new EmbeddedMediaPlayerComponent() {
         @Override
         public void mouseClicked(MouseEvent e) {
            super.mouseClicked(e);
            System.out.println("Mouse Clicked. (" + e.getX() + "," + e.getY() + ")");
         }
         @Override
         public void mouseWheelMoved(MouseWheelEvent e) {
            super.mouseWheelMoved(e);
            System.out.println("Mouse wheel moved. " + e.getScrollAmount());
         } 
         @Override
         public void keyPressed(KeyEvent e) {
            super.keyPressed(e);
            System.out.println("Key pressed. " + e.getKeyCode());
         }
         @Override
         public void playing(MediaPlayer mediaPlayer) {
            super.playing(mediaPlayer);
            System.out.println("Media Playback started.");
         }
         @Override
         public void finished(MediaPlayer mediaPlayer) {
            super.playing(mediaPlayer);
            System.out.println("Media Playback finished.");
         }
         @Override
         public void error(MediaPlayer mediaPlayer) {
            SwingUtilities.invokeLater(new Runnable() {        		
               public void run() {
                  System.out.println("Failed to load Media.");
               }        	       
            });
         }
      };
   }
   public void initialize() {
      this.setBounds(100, 100, 600, 400);
      this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      this.addWindowListener(new WindowAdapter() {
         @Override
         public void windowClosing(WindowEvent e) {
            mediaPlayerComponent.release();
            System.exit(0);
         }
      });    	
      JPanel contentPane = new JPanel();
      contentPane.setLayout(new BorderLayout());   	 
      contentPane.add(mediaPlayerComponent, BorderLayout.CENTER);
      JPanel controlsPane = new JPanel();
      playButton = new JButton("Play");
      controlsPane.add(playButton);    
      pauseButton = new JButton("Pause");
      controlsPane.add(pauseButton);
      rewindButton = new JButton("Rewind");
      controlsPane.add(rewindButton);
      skipButton = new JButton("Skip");
      controlsPane.add(skipButton);
      contentPane.add(controlsPane, BorderLayout.SOUTH);

      playButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            mediaPlayerComponent.mediaPlayer().controls().play();
         }
      });  
      pauseButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            mediaPlayerComponent.mediaPlayer().controls().pause();
         }
      });
      rewindButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            mediaPlayerComponent.mediaPlayer().controls().skipTime(-14000);
         }
      });
      skipButton.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            mediaPlayerComponent.mediaPlayer().controls().skipTime(4000);
         }
      });
      this.setContentPane(contentPane);
      this.setVisible(true);
   }
   public void loadVideo(String path) {
      mediaPlayerComponent.mediaPlayer().media().startPaused(path);   	
   }
   public static void main( String[] args ){
      try {
         UIManager.setLookAndFeel(
         UIManager.getSystemLookAndFeelClassName());
      } 
      catch (Exception e) {
         System.out.println(e);
      }
      App application = new App(TITLE);
      application.initialize(); 
      application.setVisible(true);  
      application.loadVideo(VIDEO_PATH);
   }
}

通过右键单击该文件并选择作为 Java 应用程序运行来运行应用程序。 成功启动后，如果一切正常那么它应该显示以下结果−

现在按任意键，您将在控制台中看到如下消息−

Media Playback started.
Media Playback started.
Mouse Clicked. (345,231)
Key pressed. 82
Media Playback finished.
Key pressed. 82