Java example source code file (CommandProcessorPanel.java)

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Java - Java tags/keywords

actionlistener, awt, badlocationexception, borderlayout, bytearrayoutputstream, clear, commandprocessorpanel, debugging, editableatenddocument, event, gui, jbutton, jframe, jscrollpane, jtextarea, printstream, string, swing, text

The CommandProcessorPanel.java Java example source code

/*
 * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

package sun.jvm.hotspot.ui;

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;

import sun.jvm.hotspot.CommandProcessor;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.utilities.*;

/** A JPanel subclass containing a scrollable text area displaying the
    debugger's console, if it has one. This should not be created for
    a debugger which does not have a console. */

public class CommandProcessorPanel extends JPanel {
    private CommandProcessor commands;
    private JTextArea editor;
    private boolean updating;
    private int     mark;
    private String  curText;  // handles multi-line input via '\'

    // Don't run the "main" method of this class unless this flag is set to true first
    private static final boolean DEBUGGING = false;

    ByteArrayOutputStream baos = new ByteArrayOutputStream(10240);


    public CommandProcessorPanel(CommandProcessor cp) {

        commands = cp;

        setLayout(new BorderLayout());

        editor = new JTextArea();
        editor.setDocument(new EditableAtEndDocument());
        editor.setFont(GraphicsUtilities.lookupFont("Courier"));
        JScrollPane scroller = new JScrollPane();
        scroller.getViewport().add(editor);
        add(scroller, BorderLayout.CENTER);

        // Set up out
        PrintStream o = new PrintStream(baos, true);
        cp.setOutput(o);
        cp.setErr(o);

        editor.getDocument().addDocumentListener(new DocumentListener() {
                public void changedUpdate(DocumentEvent e) {
                }

                public void insertUpdate(DocumentEvent e) {
                    if (updating) return;
                    beginUpdate();
                    editor.setCaretPosition(editor.getDocument().getLength());
                    if (insertContains(e, '\n')) {
                        String cmd = getMarkedText();
                        // Handle multi-line input
                        if ((cmd.length() == 0) || (cmd.charAt(cmd.length() - 1) != '\\')) {
                            // Trim "\\n" combinations
                            final String ln = trimContinuations(cmd);
                            SwingUtilities.invokeLater(new Runnable() {
                                    public void run() {
                                        beginUpdate();
                                        try {
                                            commands.executeCommand(ln, true);
                                            commands.printPrompt();
                                            Document d = editor.getDocument();
                                            try {
                                                d.insertString(d.getLength(), baos.toString(), null);
                                            }
                                            catch (BadLocationException ble) {
                                                ble.printStackTrace();
                                            }
                                            baos.reset();
                                            editor.setCaretPosition(editor.getDocument().getLength());
                                            setMark();
                                        } finally {
                                            endUpdate();
                                        }
                                    }
                                });
                        }
                    } else {
                        endUpdate();
                    }
                }

                public void removeUpdate(DocumentEvent e) {
                }
            });

        // This is a bit of a hack but is probably better than relying on
        // the JEditorPane to update the caret's position precisely the
        // size of the insertion
        editor.addCaretListener(new CaretListener() {
                public void caretUpdate(CaretEvent e) {
                    int len = editor.getDocument().getLength();
                    if (e.getDot() > len) {
                        editor.setCaretPosition(len);
                    }
                }
            });

        Box hbox = Box.createHorizontalBox();
        hbox.add(Box.createGlue());
        JButton button = new JButton("Clear Saved Text");
        button.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    clear();
                }
            });
        hbox.add(button);
        hbox.add(Box.createGlue());
        add(hbox, BorderLayout.SOUTH);

        clear();
    }

    public void requestFocus() {
        editor.requestFocus();
    }

    public void clear() {
        EditableAtEndDocument d = (EditableAtEndDocument) editor.getDocument();
        d.clear();
        commands.executeCommand("", false);
        setMark();
        editor.requestFocus();
    }

    public void setMark() {
        ((EditableAtEndDocument) editor.getDocument()).setMark();
    }

    public String getMarkedText() {
        try {
            String s = ((EditableAtEndDocument) editor.getDocument()).getMarkedText();
            int i = s.length();
            while ((i > 0) && (s.charAt(i - 1) == '\n')) {
                i--;
            }
            return s.substring(0, i);
        }
        catch (BadLocationException e) {
            e.printStackTrace();
            return null;
        }
    }

    //--------------------------------------------------------------------------------
    // Internals only below this point
    //

    private void beginUpdate() {
        updating = true;
    }

    private void endUpdate() {
        updating = false;
    }

    private boolean insertContains(DocumentEvent e, char c) {
        String s = null;
        try {
            s = editor.getText(e.getOffset(), e.getLength());
            for (int i = 0; i < e.getLength(); i++) {
                if (s.charAt(i) == c) {
                    return true;
                }
            }
        }
        catch (BadLocationException ex) {
            ex.printStackTrace();
        }
        return false;
    }

    private String trimContinuations(String text) {
        int i;
        while ((i = text.indexOf("\\\n")) >= 0) {
            text = text.substring(0, i) + text.substring(i+2, text.length());
        }
        return text;
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.getContentPane().setLayout(new BorderLayout());
        CommandProcessorPanel panel = new CommandProcessorPanel(null);
        frame.getContentPane().add(panel, BorderLayout.CENTER);
        frame.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                    System.exit(0);
                }
            });
        frame.setSize(500, 500);
        frame.setVisible(true);
        panel.requestFocus();
    }
}