[Java] 如何在JTabbedPane頁籤上增加關閉之按鈕－Elsaの程式學習筆記

1. CustomJTabbedPaneUI之程式範例

public class CustomJTabbedPaneUI extends JTabbedPane {
    String[] imgPath = null;
    
    public CustomJTabbedPaneUI() {}
    
    public CustomJTabbedPaneUI(String[] imgPath) {
        this.imgPath = imgPath;
    }
    
    @Override 
    public void addTab(String title, final Component content) {
        JPanel tab = new JPanel(new BorderLayout());
        JLabel label = new JLabel(title);
        label.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 4));
        JButton button = new CloseButton(imgPath);
        button.setBorder(BorderFactory.createEmptyBorder());
        button.addActionListener(new ActionListener() {
            @Override public void actionPerformed(ActionEvent e) {
                removeTabAt(indexOfComponent(content));
            }
        });
        tab.add(label, BorderLayout.WEST);
        tab.add(button, BorderLayout.EAST);
        tab.setOpaque(false);
        tab.setBorder(BorderFactory.createEmptyBorder(2, 1, 1, 1));
        super.addTab(title, content);
        setTabComponentAt(getTabCount() - 1, tab);
    }
}

2. CloseButton之程式範例

// 客製 關閉頁籤 的按鈕內容
class CloseButton extends JButton implements MouseListener {
    String[] imgPath = null;
    
    public CloseButton(String[] imgPath) {
        this.imgPath = imgPath;
        int size = 17;
        setPreferredSize(new Dimension(size, size));
        setToolTipText("關閉頁籤");
        setUI(new BasicButtonUI());
        setContentAreaFilled(false);
        setFocusable(false);
        setBorder(BorderFactory.createEtchedBorder());
        setBorderPainted(false);
        addMouseListener(this);
        setRolloverEnabled(true);
    }
   
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        
        // 如無圖片，則利用繪圖的方式繪製出來
        Graphics2D g2 = (Graphics2D) g.create();
        if(imgPath == null) {
            if (getModel().isPressed()) {
                g2.translate(1, 1);
            }
            g2.setStroke(new BasicStroke(3));
            g2.setColor(Color.BLACK);
            if (getModel().isRollover()) {
                g2.setColor(Color.RED);
            }
            g2.drawLine(5, 5, 12, 12);
            g2.drawLine(12, 6, 6, 12);
            g2.dispose();
        }
        else {
            ImageIcon img, imgEntered, imgPressed;
            int size = imgPath.length;
            if(size == 3) {
                img = new ImageIcon(this.getClass().getResource(imgPath[0]));
                imgEntered = new ImageIcon(this.getClass().getResource(imgPath[1]));
                imgPressed = new ImageIcon(this.getClass().getResource(imgPath[2]));
            }
            else if(size == 2) {
                img = new ImageIcon(this.getClass().getResource(imgPath[0]));
                imgEntered = new ImageIcon(this.getClass().getResource(imgPath[1]));
                imgPressed = imgEntered;
            }
            else {
                img = new ImageIcon(this.getClass().getResource(imgPath[0]));
                imgEntered = img;
                imgPressed = img;
            }
            
            if (getModel().isRollover()) {
                 g2.drawImage(imgEntered.getImage(), 1, 2, null, this);
            }
            else if(getModel().isPressed()) {
                g2.drawImage(imgPressed.getImage(), 1, 2, null, this);
            }
            else {
                g2.drawImage(img.getImage(), 1, 1, null, this);
            }
            g2.dispose();
        }
    }

    @Override
    public void mouseClicked(MouseEvent e) {}

    @Override
    public void mousePressed(MouseEvent e) {}

    @Override
    public void mouseReleased(MouseEvent e) {}

    @Override
    public void mouseEntered(MouseEvent e) {
        Component component = e.getComponent();
        if (component instanceof AbstractButton) {
            AbstractButton button = (AbstractButton) component;
            button.setBorderPainted(true);
        }
    }

    @Override
    public void mouseExited(MouseEvent e) {
        Component component = e.getComponent();
        if (component instanceof AbstractButton) {
            AbstractButton button = (AbstractButton) component;
            button.setBorderPainted(false);
        }
    }
}

3. 主程式範例

    public void createAndShowGUI() {
        // 1.設置頁籤關閉按鈕之圖片來源
        //private final CustomJTabbedPaneUI tab = new CustomJTabbedPaneUI();        // 無圖片版本
        String[] imgPath = {"/test2/Res/btnClose.png", "/test2/Res/btnClose_Entered.png", "/test2/Res/btnClose_Pressed.png"};       // 有圖片版本
        
        // 2.建立 JFrame
        JFrame frame = new JFrame("如何在JTabbedPane頁籤上增加關閉之按鈕");
        frame.setLayout(new BorderLayout());
        
        // 3.設置 Title
        JLabel labTitle = new JLabel("  在JTabbedPane頁籤上增加關閉之按鈕");
        labTitle.setPreferredSize(new Dimension(600, 50));
        labTitle.setFont(new java.awt.Font("微軟正黑體", 1, 16));
        frame.getContentPane().add(labTitle, BorderLayout.NORTH);
        
        // 4.設置 頁籤內容
        CustomJTabbedPaneUI tabPane = new CustomJTabbedPaneUI(imgPath);
        tabPane.addTab("第一個頁籤", new JLabel("第一個頁籤"));
        tabPane.addTab("第二個頁籤*第二個頁籤",  new JLabel("第二個頁籤*第二個頁籤"));
        tabPane.addTab("第三個頁籤/第三個頁籤/第三個頁籤",  new JScrollPane(new JTree()));
        tabPane.setSelectedIndex(2);                 // 預設顯示第三個頁籤之內容
        tabPane.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);      // 頁籤滿時，多出往前往後之按鈕，以防頁籤變成上下擠之樣貌
        frame.getContentPane().add(tabPane, BorderLayout.CENTER);
        
        // 5.設置 增加頁籤 與 關閉全部頁籤 之 Menu
        JPopupMenu popMenu = new JPopupMenu();
        popMenu.add(new NewTabAction("增加頁籤", tabPane));
        popMenu.addSeparator();
        popMenu.add(new CloseAllAction("關閉全部頁籤", tabPane));
        tabPane.setComponentPopupMenu(popMenu);
        
        // 6.設置 JFrame 基本設定
        frame.setPreferredSize(new Dimension(600, 550));
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

▲主程式之程式

    // 增加頁籤 之 Action
    private int count = 4;
    class NewTabAction extends AbstractAction {
        CustomJTabbedPaneUI tabPane = null;
        
        protected NewTabAction(String label, CustomJTabbedPaneUI tabPane) {
            super(label);
            this.tabPane = tabPane;
        }
        
        @Override 
        public void actionPerformed(ActionEvent e) {
            if(tabPane != null) {
                tabPane.addTab("第" + count + "個頁籤", new JLabel("我是內容" + count));
                tabPane.setSelectedIndex(tabPane.getTabCount() - 1);
                count++;
            }
        }
    }

▲增加頁籤之 Action

    // 關閉全部頁籤 之 Action
    class CloseAllAction extends AbstractAction {
        CustomJTabbedPaneUI tabPane = null;
        
        protected CloseAllAction(String label, CustomJTabbedPaneUI tabPane) {
            super(label);
            this.tabPane = tabPane;
        }
        
        @Override 
        public void actionPerformed(ActionEvent e) {
            if(tabPane != null) {
                tabPane.removeAll();
            }
        }
    }

▲關閉全部頁籤之 Action

4. 執行結果

執行結果01.png