java - JButton & Action & KeyBinding

Question

我创建了一个接收 Action 的 JButton 类，该 JButton 类包括击键和鼠标监听器，因此我可以根据需要在多个框架中使用相同的类。

我的问题是: JButton 在按下键时没有获得焦点，但它执行了操作。 我需要制作一个新的背景或其他东西来告诉用户按钮执行了操作。

有什么想法吗？？

这是我的代码:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.Action;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
import javax.swing.SwingConstants;
import javax.swing.border.LineBorder;
import swtdesigner.SwingResourceManager;

public class IButtonSave extends JButton{
    private static final long serialVersionUID = 1L;
    private Action action = null;
    public IButtonSave() {
        super();
        setFocusPainted(true);
        setFocusable(true);

        try {
            jbInit();
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }

    private void jbInit() throws Exception {
        setMargin(new Insets(0, 0, 0, 0));
        setBorder(new LineBorder(Color.black, 1, true));
        setIconTextGap(0);
        setHorizontalTextPosition(SwingConstants.CENTER);
        setVerticalTextPosition(SwingConstants.TOP);
        setPreferredSize(new Dimension(50, 43));
        setMinimumSize(new Dimension(50, 43));
        setMaximumSize(new Dimension(50, 43));
        addMouseListener(new ThisMouseListener());
        setVerifyInputWhenFocusTarget(true);
    }

    public void setAction(Action a){
        action = a;
        KeyStroke ks = KeyStroke.getKeyStroke(KeyEvent.VK_F1,0,true);
        KeyStroke ks2 = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER,0);
        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(ks, "Save");
        getInputMap(JComponent.WHEN_FOCUSED).put(ks2, "Save");

        getActionMap().put("Save", a);
        setText("Save [F1]");
        setIcon(SwingResourceManager.getIcon(SwingResourceManager.class, "/images/small/save.png"));
        setToolTipText("[F1]");
    }

    private class ThisMouseListener extends MouseAdapter {
        public void mouseClicked(MouseEvent e) {
            this_mouseClicked(e);
        }
    }
    protected void this_mouseClicked(MouseEvent e) {
        if(e.getClickCount() >= 1){
            action.actionPerformed(null);
        }
    }
}

Answer 1

当您可以简单地向其实例添加 KeyBinding 时，为什么要扩展 JButton 类？

不确定你想要什么，但这对我来说很好:

基本上是一个 JButton，可以通过鼠标单击或按 F1 激活(只要焦点在窗口中，如果按下会将焦点转移到 JButton ) 或 ENTER(仅当焦点位于 JButton 时)。

当 AbstractAction 被调用时，它将调用 JButton 上的 requestFocusInWindow()(因此按 F1 将使按钮获得焦点，这是我认为你想要的):

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class Test {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                final JButton btn = new JButton("Button");

                AbstractAction aa = new AbstractAction() {
                    @Override
                    public void actionPerformed(ActionEvent ae) {
                        System.out.println("Here");

                        btn.requestFocusInWindow();//request that the button has focus
                    }
                };

                //so button can be pressed using F1 and ENTER
                btn.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "Enter");
                btn.getActionMap().put("Enter", aa);
                btn.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_F1, 0), "F1");
                btn.getActionMap().put("F1", aa);

                btn.addActionListener(aa);//so button can be clicked

                JTextField tf = new JTextField("added to show ENTER wont work unless button in focus");

                frame.add(tf);
                frame.add(btn, BorderLayout.SOUTH);

                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}

更新:

或者按照@GuillaumePolet 的建议(向他+1)覆盖JButton 的processKeyBinding 并检查适当的键然后调用方法:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;

public class Test {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                final JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                final JButton btn = new JButton("Button") {
                    @Override
                    protected boolean processKeyBinding(KeyStroke ks, KeyEvent ke, int i, boolean bln) {
                        boolean b = super.processKeyBinding(ks, ke, i, bln);

                        if (b && ks.getKeyCode() == KeyEvent.VK_F1) {
                            requestFocusInWindow();
                        }

                        return b;
                    }
                };

                AbstractAction aa = new AbstractAction() {
                    @Override
                    public void actionPerformed(ActionEvent ae) {
                        System.out.println("Here");
                    }
                };

                //so button can be pressed using F1 and ENTER
                btn.getInputMap(JComponent.WHEN_FOCUSED).put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "Enter");
                btn.getActionMap().put("Enter", aa);
                btn.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_F1, 0), "F1");
                btn.getActionMap().put("F1", aa);

                btn.addActionListener(aa);//so button can be clicked

                JTextField tf = new JTextField("added to show ENTER wont work unless button in focus");

                frame.add(tf);
                frame.add(btn, BorderLayout.SOUTH);

                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}