Java by API/javax.swing/JTextComponent

JTextComponent: addCaretListener(CaretListener listener)

  
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;
public class MainClass {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame("Caret Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextArea textArea = new JTextArea();
    JScrollPane scrollPane = new JScrollPane(textArea);
    frame.add(scrollPane, BorderLayout.CENTER);
    CaretListener listener = new CaretListener() {
      public void caretUpdate(CaretEvent caretEvent) {
        System.out.println("dot:"+ caretEvent.getDot());
        System.out.println("mark"+caretEvent.getMark());
      }
    };
    textArea.addCaretListener(listener);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}

JTextComponent: getActions()

  
//A simple TextAction example.
import javax.swing.Action;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JTextArea;
public class Main {
  public static void main(String[] args) {
    JTextArea ta = new JTextArea();
    ta.setLineWrap(true);
    Action[] actions = ta.getActions();
    JMenuBar menubar = new JMenuBar();
    JMenu actionmenu = new JMenu("Actions");
    menubar.add(actionmenu);
    JMenu firstHalf = new JMenu("1st Half");
    JMenu secondHalf = new JMenu("2nd Half");
    actionmenu.add(firstHalf);
    actionmenu.add(secondHalf);
    int mid = actions.length / 2;
    for (int i = 0; i < mid; i++) {
      firstHalf.add(actions[i]);
    }
    for (int i = mid; i < actions.length; i++) {
      secondHalf.add(actions[i]);
    }
    // Show it . . .
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.getContentPane().add(ta);
    f.setJMenuBar(menubar);
    f.setSize(300, 200);
    f.setVisible(true);
  }
}

JTextComponent: getCaretPosition()

  

import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextComponent c = new JTextArea();
    c.getCaretPosition();
    if (c.getCaretPosition() < c.getDocument().getLength()) {
      char ch = c.getText(c.getCaretPosition(), 1).charAt(0);
    }
    // Move the caret
    int newPosition = 0;
    c.moveCaretPosition(newPosition);
  }
}

JTextComponent: getDocument()

  
 
import javax.swing.JTextPane;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextComponent textcomp = new JTextPane();
    textcomp.setText("Initial Text");
    textcomp.getDocument().addDocumentListener(new DocumentListener() {
      public void insertUpdate(DocumentEvent evt) {
        int off = evt.getOffset();
        System.out.println("off:"+off);
        int len = evt.getLength();
        System.out.println("len:"+len);
        try {
          String str = evt.getDocument().getText(off, len);
          System.out.println(str);
        } catch (BadLocationException e) {
        }
      }
      public void removeUpdate(DocumentEvent evt) {
        int off = evt.getOffset();
        System.out.println("off:"+off);
        int len = evt.getLength();
        System.out.println("len:"+len);
      }
      public void changedUpdate(DocumentEvent evt) {
        int off = evt.getOffset();
        System.out.println("off:"+off);
        int len = evt.getLength();
        System.out.println("len:"+len);
      }
    });
  }
}

JTextComponent: getHighlighter()

  

import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;
public class Main {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame("MultiHighlight");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextArea comp = new JTextArea(5, 20);
    comp.setText("this is a test");
    frame.getContentPane().add(new JScrollPane(comp), BorderLayout.CENTER);
    String charsToHighlight = "a";
    Highlighter h = comp.getHighlighter();
    h.removeAllHighlights();
    String text = comp.getText().toUpperCase();
    for (int j = 0; j < text.length(); j += 1) {
      char ch = text.charAt(j);
      if (charsToHighlight.indexOf(ch) >= 0)
        h.addHighlight(j, j + 1, DefaultHighlighter.DefaultPainter);
    }
    frame.pack();
    frame.setVisible(true);
  }
}

JTextComponent: getSelectedText()

  

import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    // Get text inside selection
    c.getSelectedText();
  }
}

JTextComponent: getText(int offs, int len)

  
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextComponent tc = new JTextArea("Initial Text");
    int docLength = tc.getDocument().getLength();
    // Get all text
    String text = tc.getText();
    // Get the first 3 characters
    int offset = 0;
    int len = 3;
    text = tc.getText(offset, len);
  }
}

JTextComponent.KeyBinding

  

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Insets;
import javax.swing.Icon;
import javax.swing.InputMap;
import javax.swing.UIDefaults;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    UIDefaults uidefs = UIManager.getLookAndFeelDefaults();
    String[] keys = (String[]) uidefs.keySet().toArray(new String[0]);
    for (int i = 0; i < keys.length; i++) {
      Object v = uidefs.get(keys[i]);
      if (v instanceof Integer) {
        int intVal = uidefs.getInt(keys[i]);
      } else if (v instanceof Boolean) {
        boolean boolVal = uidefs.getBoolean(keys[i]);
      } else if (v instanceof String) {
        String strVal = uidefs.getString(keys[i]);
      } else if (v instanceof Dimension) {
        Dimension dimVal = uidefs.getDimension(keys[i]);
      } else if (v instanceof Insets) {
        Insets insetsVal = uidefs.getInsets(keys[i]);
      } else if (v instanceof Color) {
        Color colorVal = uidefs.getColor(keys[i]);
      } else if (v instanceof Font) {
        Font fontVal = uidefs.getFont(keys[i]);
      } else if (v instanceof Border) {
        Border borderVal = uidefs.getBorder(keys[i]);
      } else if (v instanceof Icon) {
        Icon iconVal = uidefs.getIcon(keys[i]);
      } else if (v instanceof javax.swing.text.JTextComponent.KeyBinding[]) {
        JTextComponent.KeyBinding[] keyBindsVal = (JTextComponent.KeyBinding[]) uidefs
            .get(keys[i]);
      } else if (v instanceof InputMap) {
        InputMap imapVal = (InputMap) uidefs.get(keys[i]);
      } else {
        System.out.println("Unknown type"); 
      }
    }
  }
}

JTextComponent: moveCaretPosition(int pos)

  

import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) throws Exception {
    JTextComponent c = new JTextArea();
    c.getCaretPosition();
    if (c.getCaretPosition() < c.getDocument().getLength()) {
      char ch = c.getText(c.getCaretPosition(), 1).charAt(0);
    }
    // Move the caret
    int newPosition = 0;
    c.moveCaretPosition(newPosition);
  }
}

JTextComponent: print(MessageFormat headerFormat, MessageFormat footerFormat, boolean showPrintDialog, PrintService service, PrintRequestAttributeSet attributes, boolean interactive)

  

import java.awt.BorderLayout;
import java.text.MessageFormat;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
public class Main {
  public static void main(String[] args) throws Exception {
    final JTextArea textArea = new JTextArea();
    textArea.setText("text");
    JScrollPane jScrollPane = new JScrollPane(textArea);
    final MessageFormat header = new MessageFormat("My Header");
    final MessageFormat footer = new MessageFormat("My Footer");
    JPanel contentPane = new JPanel();
    contentPane.setLayout(new BorderLayout());
    contentPane.add(jScrollPane, BorderLayout.CENTER);
    JFrame frame = new JFrame();
    frame.setTitle("Text-component Printing Demo");
    frame.setSize(400, 200);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setContentPane(contentPane);
    frame.setVisible(true);
    textArea.print(header, footer, true, null, null, true);
  }
}

JTextComponent: read(Reader in, Object desc)

  
import java.awt.BorderLayout;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class MainClass {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextField nameTextField = new JTextField();
    frame.add(nameTextField, BorderLayout.NORTH);
    
    FileReader reader = null;
    try {
      reader = new FileReader("fileName.txt");
      nameTextField.read(reader, "fileName.txt");
    } catch (IOException exception) {
      System.err.println("Load oops");
      exception.printStackTrace();
    } finally {
      if (reader != null) {
        try {
          reader.close();
        } catch (IOException exception) {
          System.err.println("Error closing reader");
          exception.printStackTrace();
        }
      }
    }
    
    frame.setSize(250, 100);
    frame.setVisible(true);
  }
}

JTextComponent: replaceSelection(String content)

  
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.replaceSelection("replacement text");
  }
}

JTextComponent: select(int selectionStart, int selectionEnd)

  
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.select(10, 20);
  }
}

JTextComponent: setDocument(Document doc)

  

import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
public class Main {
  public static void main(String[] args) {
    JFrame frame = new JFrame("Shared Model");
    JTextArea areaFiftyOne = new JTextArea();
    JTextArea areaFiftyTwo = new JTextArea();
    areaFiftyTwo.setDocument(areaFiftyOne.getDocument());
    JTextArea areaFiftyThree = new JTextArea();
    areaFiftyThree.setDocument(areaFiftyOne.getDocument());
    frame.setLayout(new GridLayout(3, 1));
    frame.add(new JScrollPane(areaFiftyOne));
    frame.add(new JScrollPane(areaFiftyTwo));
    frame.add(new JScrollPane(areaFiftyThree));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300, 300);
    frame.setVisible(true);
  }
}

JTextComponent: setDragEnabled(boolean b)

  
import java.awt.Container;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Main extends JFrame {
  public static void main(String[] args) {
    new Main().setVisible(true);
  }
  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextField field1 = new JTextField("Life"s a drag", 20);
    JTextField field2 = new JTextField("and then you drop", 20);
    field1.setDragEnabled(true);
    field2.setDragEnabled(true);
    Container content = getContentPane();
    content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
    content.add(field1);
    content.add(field2);
    pack();
  }
}

JTextComponent: setFocusAccelerator(char aKey)

  
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class Main {
  public static void main(String[] args) {
    JLabel l;
    JTextField t;
    JButton b;
    JFrame f = new JFrame("Text Accelerator");
    
    f.add(l = new JLabel("Name:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("n");
    f.add(l = new JLabel("House/Street:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("h");
    f.add(l = new JLabel("City:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("c");
    f.add(l = new JLabel("State/County:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("s");
    f.add(l = new JLabel("Zip/Post code:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("z");
    f.add(l = new JLabel("Telephone:", SwingConstants.RIGHT));
    l.setDisplayedMnemonic("t");
    f.add(b = new JButton("Clear"));
    b.setMnemonic("l");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("n");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("h");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("c");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("s");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("z");
    f.add(t = new JTextField(35));
    t.setFocusAccelerator("t");
    f.add(b = new JButton("OK"));
    b.setMnemonic("o");
    f.pack();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
  }
}

JTextComponent: setNavigationFilter(NavigationFilter filter)

  
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.NavigationFilter;
import javax.swing.text.Position;
public class MainClass {
  public static void main(String args[]) throws Exception {
    final String START_STRING = "Start\n";
    final int START_STRING_LENGTH = START_STRING.length();
    JFrame frame = new JFrame("Navigation Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextArea textArea = new JTextArea(START_STRING);
    textArea.setCaretPosition(START_STRING_LENGTH);
    JScrollPane scrollPane = new JScrollPane(textArea);
    frame.add(scrollPane, BorderLayout.CENTER);
    NavigationFilter filter = new NavigationFilter() {
      public void setDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias) {
        if (dot < START_STRING_LENGTH) {
          fb.setDot(START_STRING_LENGTH, bias);
        } else {
          fb.setDot(dot, bias);
        }
      }
      public void moveDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias) {
        if (dot < START_STRING_LENGTH) {
          fb.setDot(START_STRING_LENGTH, bias);
        } else {
          fb.setDot(dot, bias);
        }
      }
    };
    textArea.setNavigationFilter(filter);
    frame.setSize(250, 150);
    frame.setVisible(true);
  }
}

JTextComponent: setSelectedTextColor(Color c)

  
import java.awt.Color;
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.setSelectedTextColor(Color.red);
  }
}

JTextComponent: setSelectionColor(Color c)

  
import java.awt.Color;
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.setSelectionColor(Color.green);
  }
}

JTextComponent: setSelectionEnd(int selectionEnd)

  
 
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.setSelectionEnd(20);
  }
}

JTextComponent: setSelectionStart(int selectionStart)

  
import javax.swing.JTextArea;
import javax.swing.text.JTextComponent;
public class Main {
  public static void main(String[] argv) {
    JTextComponent c = new JTextArea();
    c.setSelectionStart(10);
  }
}

JTextComponent: write(Writer out)

  
import java.awt.BorderLayout;
import java.io.FileWriter;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class MainClass {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextField nameTextField = new JTextField();
    frame.add(nameTextField, BorderLayout.NORTH);
    
    FileWriter writer = null;
    try {
      writer = new FileWriter("filename.txt");
      nameTextField.write(writer);
    } catch (IOException exception) {
      System.err.println("Save oops");
      exception.printStackTrace();
    } finally {
      if (writer != null) {
        try {
          writer.close();
        } catch (IOException exception) {
          System.err.println("Error closing writer");
          exception.printStackTrace();
        }
      }
    }
    
    frame.setSize(250, 100);
    frame.setVisible(true);
  }
}