/*

 * Copyright (c) 1998, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

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/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

package com.sun.tools.example.debug.gui;

import javax.swing.*;

import javax.swing.event.*;

import java.awt.*;

import com.sun.jdi.*;

import com.sun.tools.example.debug.bdi.*;

public class StackTraceTool extends JPanel {

    private static final long serialVersionUID = 9140041989427965718L;

    private Environment env;

    private ExecutionManager runtime;

    private ContextManager context;

    private ThreadInfo tinfo;

    private JList list;

    private ListModel stackModel;

    public StackTraceTool(Environment env) {

        super(new BorderLayout());

        this.env = env;

        this.runtime = env.getExecutionManager();

        this.context = env.getContextManager();

        stackModel = new DefaultListModel();  // empty

        list = new JList(stackModel);

        list.setCellRenderer(new StackFrameRenderer());

        JScrollPane listView = new JScrollPane(list);

        add(listView);

        // Create listener.

        StackTraceToolListener listener = new StackTraceToolListener();

        context.addContextListener(listener);

        list.addListSelectionListener(listener);

        //### remove listeners on exit!

    }

    private class StackTraceToolListener

        implements ContextListener, ListSelectionListener

    {

        // ContextListener

        // If the user selects a new current frame, display it in

        // this view.

        //### I suspect we handle the case badly that the VM is not interrupted.

        @Override

        public void currentFrameChanged(CurrentFrameChangedEvent e) {

            // If the current frame of the thread appearing in this

            // view is changed, move the selection to track it.

            int frameIndex = e.getIndex();

            ThreadInfo ti = e.getThreadInfo();

            if (e.getInvalidate() || tinfo != ti) {

                tinfo = ti;

                showStack(ti, frameIndex);

            } else {

                if (frameIndex < stackModel.getSize()) {

                    list.setSelectedIndex(frameIndex);

                    list.ensureIndexIsVisible(frameIndex);

                }

            }

        }

        // ListSelectionListener

        @Override

        public void valueChanged(ListSelectionEvent e) {

            int index = list.getSelectedIndex();

            if (index != -1) {

                //### should use listener?

                try {

                    context.setCurrentFrameIndex(index);

                } catch (VMNotInterruptedException exc) {

                }

            }

        }

    }

    private class StackFrameRenderer extends DefaultListCellRenderer {

        @Override

        public Component getListCellRendererComponent(JList list,

                                                      Object value,

                                                      int index,

                                                      boolean isSelected,

                                                      boolean cellHasFocus) {

            //### We should indicate the current thread independently of the

            //### selection, e.g., with an icon, because the user may change

            //### the selection graphically without affecting the current

            //### thread.

            super.getListCellRendererComponent(list, value, index,

                                               isSelected, cellHasFocus);

            if (value == null) {

                this.setText("<unavailable>");

            } else {

                StackFrame frame = (StackFrame)value;

                Location loc = frame.location();

                Method meth = loc.method();

                String methName =

                    meth.declaringType().name() + '.' + meth.name();

                String position = "";

                if (meth.isNative()) {

                    position = " (native method)";

                } else if (loc.lineNumber() != -1) {

                    position = ":" + loc.lineNumber();

                } else {

                    long pc = loc.codeIndex();

                    if (pc != -1) {

                        position = ", pc = " + pc;

                    }

                }

                // Indices are presented to the user starting from 1, not 0.

                this.setText("[" + (index+1) +"] " + methName + position);

            }

            return this;

        }

    }

    // Point this view at the given thread and frame.

    private void showStack(ThreadInfo tinfo, int selectFrame) {

        StackTraceListModel model = new StackTraceListModel(tinfo);

        stackModel = model;

        list.setModel(stackModel);

        list.setSelectedIndex(selectFrame);

        list.ensureIndexIsVisible(selectFrame);

    }

    private static class StackTraceListModel extends AbstractListModel {

        private final ThreadInfo tinfo;

        public StackTraceListModel(ThreadInfo tinfo) {

            this.tinfo = tinfo;

        }

        @Override

        public Object getElementAt(int index) {

            try {

                return tinfo == null? null : tinfo.getFrame(index);

            } catch (VMNotInterruptedException e) {

                //### Is this the right way to handle this?

                //### Would happen if user scrolled stack trace

                //### while not interrupted -- should probably

                //### block user interaction in this case.

                return null;

            }

        }

        @Override

        public int getSize() {

            try {

                return tinfo == null? 1 : tinfo.getFrameCount();

            } catch (VMNotInterruptedException e) {

                //### Is this the right way to handle this?

                return 0;

            }

        }

    }

}