java - Java-JTextFieldとJPasswordFieldに関する質問

Question

import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.awt.*;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;


public class HintTextField extends JTextField implements FocusListener
{

    private String hint;

    public HintTextField ()
    {
        this("");
    }

    public HintTextField(final String hint)
    {
        setHint(hint);
        super.addFocusListener(this);
    }

    public void setHint(String hint)
    {
        this.hint = hint;
        setUI(new HintTextFieldUI(hint, true));
        //setText(this.hint);
    }


    public void focusGained(FocusEvent e)
    {
        if(this.getText().length() == 0)
        {
            super.setText("");
        }
    }

    public void focusLost(FocusEvent e)
    {
        if(this.getText().length() == 0)
        {
            setHint(hint);
        }
    }

    public String getText()
    {
        String typed = super.getText();
        return typed.equals(hint)?"":typed;
    }
}

class HintTextFieldUI extends javax.swing.plaf.basic.BasicTextFieldUI implements FocusListener
{

    private String hint;
    private boolean hideOnFocus;
    private Color color;

    public Color getColor()
    {
        return color;
    }

    public void setColor(Color color)
    {
        this.color = color;
        repaint();
    }

    private void repaint()
    {
        if(getComponent() != null)
        {
            getComponent().repaint();
        }
    }

    public boolean isHideOnFocus()
    {
        return hideOnFocus;
    }

    public void setHideOnFocus(boolean hideOnFocus)
    {
        this.hideOnFocus = hideOnFocus;
        repaint();
    }

    public String getHint()
    {
        return hint;
    }

    public void setHint(String hint)
    {
        this.hint = hint;
        repaint();
    }

    public HintTextFieldUI(String hint)
    {
        this(hint, false);
    }

    public HintTextFieldUI(String hint, boolean hideOnFocus)
    {
        this(hint, hideOnFocus, null);
    }

    public HintTextFieldUI(String hint, boolean hideOnFocus, Color color)
    {
        this.hint = hint;
        this.hideOnFocus = hideOnFocus;
        this.color = color;
    }


    protected void paintSafely(Graphics g)
    {
        super.paintSafely(g);
        JTextComponent comp = getComponent();
        if(hint != null && comp.getText().length() == 0 && (!(hideOnFocus && comp.hasFocus())))
        {
            if(color != null)
            {
                g.setColor(color);
            }
            else
            {
                g.setColor(Color.gray);
            }
            int padding = (comp.getHeight() - comp.getFont().getSize()) / 2;
            g.drawString(hint, 5, comp.getHeight() - padding - 1);
        }
    }


    public void focusGained(FocusEvent e)
    {
        if(hideOnFocus) repaint();

    }


    public void focusLost(FocusEvent e)
    {
        if(hideOnFocus) repaint();
    }

    protected void installListeners()
    {
        super.installListeners();
        getComponent().addFocusListener(this);
    }

    protected void uninstallListeners()
    {
        super.uninstallListeners();
        getComponent().removeFocusListener(this);
    }
}

これは私のコードです（JTextField入力ヒント付き）。誰かが私のコードを改善するのを手伝ってもらえますか？

1）テキストフィールドをクリックしたときに、ヒントが消えないようにします。テキストフィールドに何かを入力したときにのみヒントが消えるようにしたい。

JPasswordField2）入力ヒントを使用してコーディングする方法は？

FacebookのモバイルログインページのようにJTextFieldとJPasswordFieldを作成するにはどうすればよいですか（丸めてJTextField/PasswordField一緒に貼り付けてください）？

score 2 · Accepted Answer

テキストフィールドをクリックしたときに、ヒントが消えないようにしたいです。テキストフィールドに何かを入力したときだけヒントが消えるようにしたい。

テキストプロンプトは、この機能を提供します。

以前に JPasswordField で試したことはありませんが、そこでも機能するはずです。

score 1 · Accepted Answer

public class Hints
{
    public static void main (String [] args)
    {
        Box mainPanel = Box.createVerticalBox ();
        mainPanel.setBackground (Color.LIGHT_GRAY);
        mainPanel.setOpaque (true);
        mainPanel.add (new HintedTextField (12, "Login"));
        mainPanel.add (Box.createVerticalStrut (1));
        mainPanel.add (new HintedPasswordField (12, "Password"));

        JPanel panel = new JPanel (new BorderLayout ());
        panel.add (mainPanel, BorderLayout.CENTER);
        panel.setBorder (BorderFactory.createEmptyBorder (8, 8, 8, 8));

        JFrame frame = new JFrame ();
        frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
        frame.getContentPane ().setLayout (new BorderLayout ());
        frame.getContentPane ().add (panel, BorderLayout.CENTER);
        frame.pack ();
        frame.setVisible (true);
    }

    private static class RoundedRectableBorder implements Border
    {
        private final boolean top;
        private final boolean bottom;

        public RoundedRectableBorder (boolean top, boolean bottom)
        {
            this.top = top;
            this.bottom = bottom;
        }

        @Override
        public void paintBorder (Component c, Graphics g, int x, int y,
                int width, int height)
        {
            Area clipArea = new Area (new Rectangle (x, y, width, height));
            clipArea.subtract (
                new Area (
                    new Rectangle (
                        x + 5, top ? y + 5 : y, width - 10, height - (top ? 5 : 0) - (bottom ? 5 : 0))));

            g.setClip (clipArea);

            g.setColor (c.getParent ().getParent ().getBackground ());
            g.fillRect (x, y, width, height);
            g.setColor (c.getBackground ());
            g.fillRoundRect (x, top ? y : (y - 5), width - 1, height + (top ? 5 : 0) + (bottom ? 5 : 0) - 1, 10, 10);
            g.setColor (c.getParent ().getBackground ());
            g.drawRoundRect (x, top ? y : (y - 5), width - 1, height + (top ? 5 : 0) + (bottom ? 5 : 0) - 1, 10, 10);
        }

        @Override
        public Insets getBorderInsets (Component c)
        {
            return new Insets (5, 5, 5, 5);
        }

        @Override
        public boolean isBorderOpaque ()
        {
            return false;
        }
    }

    private static class HintedTextField extends JTextField
    {
        private final JTextField hintField;

        public HintedTextField (int columns, String hint)
        {
            super (columns);

            setBorder (new RoundedRectableBorder (true, false));

            hintField = new JTextField (hint);
            hintField.setBorder (BorderFactory.createEmptyBorder (5, 5, 5, 5));
        }

        @Override
        protected void paintComponent (Graphics g)
        {
            super.paintComponent (g);

            if (getText ().isEmpty ())
            {
                hintField.setBounds (getBounds ());
                hintField.setForeground (getDisabledTextColor());
                hintField.setOpaque (false);
                hintField.paint (g);
            }
        }
    }

    private static class HintedPasswordField extends JPasswordField
    {
        private final JTextField hintField;

        public HintedPasswordField (int columns, String hint)
        {
            super (columns);

            setBorder (new RoundedRectableBorder (false, true));

            hintField = new JTextField (hint);
            hintField.setBorder (BorderFactory.createEmptyBorder (5, 5, 5, 5));
        }

        @Override
        protected void paintComponent (Graphics g)
        {
            super.paintComponent (g);

            if (getPassword ().length == 0)
            {
                hintField.setBounds (getBounds ());
                hintField.setForeground (getDisabledTextColor());
                hintField.setOpaque (false);
                hintField.paint (g);
            }
        }
    }
}

score 0 · Accepted Answer

テキストフィールドに入力したときにヒントを消すには、Keylistener を実装する必要があります。そして、その keyPressed 実装で書くことができます。

@Override
public void keyPressed(KeyEvent e) {
    // TODO Auto-generated method stub
    if(hideOnFocus) repaint();
}

また、focusGained() の実装もコメントアウトします。

score 0 · Accepted Answer

私はswingファンではありませんが、あなたの最初の問題はこの方法にあると思います:

public void focusGained(FocusEvent e)
{
    if(this.getText().length() == 0)
    {
        super.setText("");
    }
}

そのためには、テキストフィールドに含まれるテキストを制御するスレッドを作成する必要があると言います。

new Thread(){
    public void run(){
        while(true){
          String s = this.getText();
          if(s.length == 0 || s.equals(hint))
              super.setText(hint);
          else //significa che è cambiato il testo
              if(s.contains(hint))
                 super.setText(s.replace(hint, ""));
        }
    }
}.start();

score 0 · Accepted Answer

JTextField のテキストを設定する代わりに、ヒントを直接ペイントします。paintComponent()この例のメソッドを参照してください。

import java.awt.*;
import javax.swing.*;
import javax.swing.text.Document;

public class PlaceholderTextField extends JTextField {

    public static void main(final String[] args) {
        final PlaceholderTextField tf = new PlaceholderTextField("");
        tf.setColumns(20);
        tf.setPlaceholder("All your base are belong to us!");
        final Font f = tf.getFont();
        tf.setFont(new Font(f.getName(), f.getStyle(), 30));
        JOptionPane.showMessageDialog(null, tf);
    }

    private String placeholder;

    public PlaceholderTextField() {
    }

    public PlaceholderTextField(
        final Document pDoc,
        final String pText,
        final int pColumns)
    {
        super(pDoc, pText, pColumns);
    }

    public PlaceholderTextField(final int pColumns) {
        super(pColumns);
    }

    public PlaceholderTextField(final String pText) {
        super(pText);
    }

    public PlaceholderTextField(final String pText, final int pColumns) {
        super(pText, pColumns);
    }

    public String getPlaceholder() {
        return placeholder;
    }

    @Override
    protected void paintComponent(final Graphics pG) {
        super.paintComponent(pG);

        if (placeholder.length() == 0 || getText().length() > 0) {
            return;
        }

        final Graphics2D g = (Graphics2D) pG;
        g.setRenderingHint(
            RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);
        g.setColor(getDisabledTextColor());
        g.drawString(placeholder, getInsets().left, pG.getFontMetrics()
            .getMaxAscent() + getInsets().top);
    }

    public void setPlaceholder(final String s) {
        placeholder = s;
    }

}

java - Java-JTextFieldとJPasswordFieldに関する質問

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