selectionexample.java

java swing 开发代码

// SelectionExample.java
// A simple multiplication table with the ability to play with row and column
// selections.  You can alter the cell, column and row selection properties
// of the table at runtime.
//
package	jswing.ch15;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;

public class SelectionExample extends JFrame {

  public SelectionExample() {
    super("Selection Model Test");
    setSize(450, 350);
    setDefaultCloseOperation(EXIT_ON_CLOSE);

    TableModel tm = new AbstractTableModel() {
      // We'll create a simple multiplication table to serve as a noneditable
      // table with several rows and columns
      public int getRowCount() { return 10; }
      public int getColumnCount() { return 10; }
      public Object getValueAt(int r, int c) { return "" + (r+1)*(c+1); }
    };

    final JTable jt = new JTable(tm);

    JScrollPane jsp = new JScrollPane(jt);
    getContentPane().add(jsp, BorderLayout.CENTER);

    // Now set up our selection controls
    JPanel controlPanel, buttonPanel, columnPanel, rowPanel;
    
    buttonPanel = new JPanel();
    final JCheckBox cellBox, columnBox, rowBox;
    cellBox = new JCheckBox("Cells", jt.getCellSelectionEnabled());
    columnBox = new JCheckBox("Columns", jt.getColumnSelectionAllowed());
    rowBox = new JCheckBox("Rows", jt.getRowSelectionAllowed());
    cellBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        jt.setCellSelectionEnabled(cellBox.isSelected());
        columnBox.setSelected(jt.getColumnSelectionAllowed());
        rowBox.setSelected(jt.getRowSelectionAllowed());
      }
    } );

    columnBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        jt.setColumnSelectionAllowed(columnBox.isSelected());
	cellBox.setSelected(jt.getCellSelectionEnabled());
      }
    } );

    rowBox.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        jt.setRowSelectionAllowed(rowBox.isSelected());
	cellBox.setSelected(jt.getCellSelectionEnabled());
      }
    } );

    buttonPanel.add(new JLabel("Selections allowed:"));
    buttonPanel.add(cellBox);
    buttonPanel.add(columnBox);
    buttonPanel.add(rowBox);

    columnPanel = new JPanel();
    ListSelectionModel csm = jt.getColumnModel().getSelectionModel();
    JLabel columnCounter = new JLabel("(Selected Column Indices Go Here)");
    csm.addListSelectionListener(new SelectionDebugger(columnCounter,
                                                       csm));
    columnPanel.add(new JLabel("Selected columns:"));
    columnPanel.add(columnCounter);

    rowPanel = new JPanel();
    ListSelectionModel rsm = jt.getSelectionModel();
    JLabel rowCounter = new JLabel("(Selected Row Indices Go Here)");
    rsm.addListSelectionListener(new SelectionDebugger(rowCounter, rsm));
    rowPanel.add(new JLabel("Selected rows:"));
    rowPanel.add(rowCounter);

    controlPanel = new JPanel(new GridLayout(0, 1));
    controlPanel.add(buttonPanel);
    controlPanel.add(columnPanel);
    controlPanel.add(rowPanel);

    getContentPane().add(controlPanel, BorderLayout.SOUTH);
  }

  public static void main(String args[]) {
    SelectionExample se = new SelectionExample();
    se.setVisible(true);
  }
  
  public class SelectionDebugger implements ListSelectionListener {
    JLabel debugger;
    ListSelectionModel model;

    public SelectionDebugger(JLabel target, ListSelectionModel lsm) {
      debugger = target;
      model = lsm;
    }
    public void valueChanged(ListSelectionEvent lse) {
      if (!lse.getValueIsAdjusting()) {
        // skip all the intermediate events . . .
        StringBuffer buf = new StringBuffer();
        int[] selection = getSelectedIndices(model.getMinSelectionIndex(),
                                             model.getMaxSelectionIndex());
        if (selection.length == 0) {
          buf.append("none");
        }
        else {
          for (int i = 0; i < selection.length -1; i++) {
            buf.append(selection[i]);
            buf.append(", ");
          }
          buf.append(selection[selection.length - 1]);
        }
        debugger.setText(buf.toString());
      }
    }

    // This method returns an array of selected indices. It's guaranteed to
    // return a nonnull value.
    protected int[] getSelectedIndices(int start, int stop) {
      if ((start == -1) || (stop == -1)) {
        // no selection, so return an empty array
        return new int[0];
      }

      int guesses[] = new int[stop - start + 1];
      int index = 0;
      // manually walk through these . . .
      for (int i = start; i <= stop; i++) {
        if (model.isSelectedIndex(i)) {
          guesses[index++] = i;
        }
      }
      
      // ok, pare down the guess array to the real thing
      int realthing[] = new int[index];
      System.arraycopy(guesses, 0, realthing, 0, index);
      return realthing;
    }
  }
}