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Java example source code file (ProcessListPanel.java)

This example Java source code file (ProcessListPanel.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

abstracttablemodel, actionlistener, awt, comparator, debugger, event, gui, index, jscrollpane, jtable, jtableheader, name, object, processinfo, processlistpanel, runtimeexception, string, swing, table

The ProcessListPanel.java Java example source code

/*
 * Copyright (c) 2001, 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.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;

import sun.jvm.hotspot.debugger.*;

public class ProcessListPanel extends JPanel {
  private Debugger           dbg;
  private AbstractTableModel dataModel;
  private java.util.List     els;
  private boolean            sortByName   = true;
  private boolean            sortReversed = false;
  private javax.swing.Timer  timer;
  private JTable             table;

  /** Takes a Debugger in constructor. Updates the list once during
      construction; list can be updated automatically by "starting"
      the panel. */
  public ProcessListPanel(Debugger dbg) {
    super();

    this.dbg = dbg;

    update();

    dataModel = new AbstractTableModel() {
        public int getColumnCount() { return 2;          }
        public int getRowCount()    { return els.size(); }
        public String getColumnName(int col) {
          switch (col) {
          case 0:
            return "Process Name";
          case 1:
            return "Process ID";
          default:
            throw new RuntimeException("Index " + col + " out of bounds");
          }
        }

        public Object getValueAt(int row, int col) {
          ProcessInfo info = (ProcessInfo) els.get(row);

          switch (col) {
          case 0:
            return info.getName();
          case 1:
            return new Integer(info.getPid());
          default:
            throw new RuntimeException("Index (" + col + ", " + row + ") out of bounds");
          }
        }
      };

    // Create user interface
    setLayout(new BorderLayout());
    table = new JTable(dataModel);
    table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    JTableHeader header = table.getTableHeader();
    header.setReorderingAllowed(false);
    table.setRowSelectionAllowed(true);
    table.setColumnSelectionAllowed(false);
    // Provide sorting in similar fashion to Task Manager
    header.addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
          int viewColumn = table.getColumnModel().getColumnIndexAtX(e.getX());
          int column = table.convertColumnIndexToModel(viewColumn);
          if (column != -1) {
            boolean newSortByName = (column == 0);
            if (newSortByName == sortByName) {
              // Switch sense of "reversed" instead
              sortReversed = !sortReversed;
            } else {
              sortByName = newSortByName;
              sortReversed = false;
            }

            // Keep the current selection if possible
            int i = table.getSelectedRow();
            int pid = getPid(els, i);
            sort(els);
            i = findPid(els, pid);
            dataModel.fireTableDataChanged();
            if ((i >= 0) || (els.size() > 0)) {
              if (i >= 0) {
                table.setRowSelectionInterval(i, i);
              } else {
                table.setRowSelectionInterval(0, 0);
              }
            }
          }
        }
      });

    JScrollPane scrollPane = new JScrollPane(table);
    add(scrollPane, BorderLayout.CENTER);

    if (els.size() > 0) {
      table.setRowSelectionInterval(0, 0);
    }
  }

  /** Set update interval for automatic updating of the process list */

  public void setAutoUpdateInterval(int millis) {
    getTimer().setDelay(millis);
  }

  /** Start auto updating of the panel */
  public void start() {
    getTimer().start();
  }

  /** Stop auto updating of the panel */
  public void stop() {
    getTimer().stop();
  }

  /** Call this to update the panel's notion of the process list */
  public synchronized void update() {
    if (!dbg.hasProcessList()) {
      throw new RuntimeException("ProcessListPanel requires that debugger supports getProcessList()");
    }
    java.util.List newEls = dbg.getProcessList();
    sort(newEls);
    if (table != null) {
      // Keep the current selection if possible
      int i = table.getSelectedRow();
      int pid = getPid(els, i);
      i = findPid(newEls, pid);
      els = newEls;
      dataModel.fireTableDataChanged();
      if ((i >= 0) || (els.size() > 0)) {
        if (i >= 0) {
          table.setRowSelectionInterval(i, i);
        } else {
          table.setRowSelectionInterval(0, 0);
        }
      }
    } else {
      els = newEls;
    }
  }

  /** Call this to get the selected ProcessInfo, or null if none selected */
  public synchronized ProcessInfo getSelectedProcess() {
    int i = table.getSelectedRow();
    if (i < 0) {
      return null;
    }
    return (ProcessInfo) els.get(i);
  }

  private synchronized void sort(java.util.List els) {
    Comparator c;
    if (sortByName) {
      c = new Comparator() {
          public int compare(Object o1, Object o2) {
            int scale = (sortReversed ? -1 : 1);
            return scale * ((ProcessInfo) o1).getName().compareToIgnoreCase(((ProcessInfo) o2).getName());
          }
        };
    } else {
      c = new Comparator() {
          public int compare(Object o1, Object o2) {
            int scale = (sortReversed ? -1 : 1);
            int pid1 = ((ProcessInfo) o1).getPid();
            int pid2 = ((ProcessInfo) o2).getPid();
            int ret;
            if      (pid1 <  pid2) ret = -1;
            else if (pid1 == pid2) ret = 0;
            else ret = 1;
            return ret * scale;
          }
        };
    }
    Collections.sort(els, c);
  }

  private javax.swing.Timer getTimer() {
    if (timer == null) {
      timer = new javax.swing.Timer(1000, new ActionListener() {
          public void actionPerformed(ActionEvent e) {
            update();
          }
        });
    }
    return timer;
  }

  private synchronized int getPid(java.util.List els, int index) {
    return ((ProcessInfo) els.get(index)).getPid();
  }

  private synchronized int findPid(java.util.List els, int pid) {
    for (int i = 0; i < els.size(); i++) {
      ProcessInfo info = (ProcessInfo) els.get(i);
      if (info.getPid() == pid) {
        return i;
      }
    }
    return -1;
  }
}

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