Support for breakpoints

- Adds a new window that allows adding and deleting breakpoints.
  Will halt the simulator when a breakpoint is reached.

src/main/java/com/loomcom/symon/Cpu.java

@@ -911,13 +911,6 @@ public class Cpu implements InstructionTable {
         this.clockPeriodInNs = clockPeriodInNs;
     }
 
-    /**
-     * @return The simulated clock period, in nanoseconds
-     */
-    public long getClockPeriodInNs() {
-        return clockPeriodInNs;
-    }
-
     /**
      * Return the current Cpu State.
      *

src/main/java/com/loomcom/symon/Main.java

@@ -97,8 +97,8 @@ public class Main {
             });
         
         
-            Simulator.MAIN_CMD cmd = simulator.waitForCommand();
+            Simulator.MainCommand cmd = simulator.waitForCommand();
-            if (cmd.equals(Simulator.MAIN_CMD.SELECTMACHINE)) {
+            if (cmd.equals(Simulator.MainCommand.SELECTMACHINE)) {
                 machineClass = null;
             } else {
                 break;

src/main/java/com/loomcom/symon/Simulator.java

@@ -24,10 +24,7 @@
 package com.loomcom.symon;
 
 import com.loomcom.symon.devices.Memory;
-import com.loomcom.symon.exceptions.FifoUnderrunException;
+import com.loomcom.symon.exceptions.*;
-import com.loomcom.symon.exceptions.MemoryAccessException;
-import com.loomcom.symon.exceptions.MemoryRangeException;
-import com.loomcom.symon.exceptions.SymonException;
 import com.loomcom.symon.machines.Machine;
 import com.loomcom.symon.ui.*;
 import com.loomcom.symon.ui.Console;
@@ -39,6 +36,8 @@ import javax.swing.border.EmptyBorder;
 import java.awt.*;
 import java.awt.event.*;
 import java.io.*;
+import java.util.SortedSet;
+import java.util.TreeSet;
 
 /**
  * Symon Simulator Interface and Control.
@@ -53,9 +52,9 @@ public class Simulator {
     private final static Logger logger = LoggerFactory.getLogger(Simulator.class.getName());
 
     // UI constants
-    private static final int  DEFAULT_FONT_SIZE    = 12;
+    private static final int DEFAULT_FONT_SIZE = 12;
-    private static final Font DEFAULT_FONT         = new Font(Font.MONOSPACED, Font.PLAIN, DEFAULT_FONT_SIZE);
+    private static final Font DEFAULT_FONT = new Font(Font.MONOSPACED, Font.PLAIN, DEFAULT_FONT_SIZE);
-    private static final int  CONSOLE_BORDER_WIDTH = 10;
+    private static final int CONSOLE_BORDER_WIDTH = 10;
 
     // Clock periods, in NS, for each speed. 0MHz, 1MHz, 2MHz, 3MHz, 4MHz, 5MHz, 6MHz, 7MHz, 8MHz.
     private static final long[] CLOCK_PERIODS = {0, 1000, 500, 333, 250, 200, 167, 143, 125};
@@ -105,22 +104,28 @@ public class Simulator {
 
     private final VideoWindow videoWindow;
 
+    private final BreakpointsWindow breakpointsWindow;
+
     private SimulatorMenu menuBar;
 
-    private RunLoop     runLoop;
+    private RunLoop runLoop;
-    private Console     console;
+    private Console console;
     private StatusPanel statusPane;
 
     private JButton runStopButton;
     private JButton stepButton;
     private JComboBox<String> stepCountBox;
 
-    private JFileChooser      fileChooser;
+    private JFileChooser fileChooser;
     private PreferencesDialog preferences;
 
+    private SortedSet<Integer> breakpoints;
+
     private final Object commandMonitorObject = new Object();
-    private MAIN_CMD command = MAIN_CMD.NONE;
+
-    public enum MAIN_CMD  {
+    private MainCommand command = MainCommand.NONE;
+
+    public enum MainCommand {
         NONE,
         SELECTMACHINE
     }
@@ -131,12 +136,16 @@ public class Simulator {
     private static final String[] STEPS = {"1", "5", "10", "20", "50", "100"};
 
     public Simulator(Class machineClass) throws Exception {
+        this.breakpoints = new TreeSet<>();
+
         this.machine = (Machine) machineClass.getConstructors()[0].newInstance();
 
         // Initialize final fields in the constructor.
         this.traceLog = new TraceLog();
         this.memoryWindow = new MemoryWindow(machine.getBus());
-        if(machine.getCrtc() != null) {
+        this.breakpointsWindow = new BreakpointsWindow(breakpoints, mainWindow);
+
+        if (machine.getCrtc() != null) {
             videoWindow = new VideoWindow(machine.getCrtc(), 2, 2);
         } else {
             videoWindow = null;
@@ -236,8 +245,8 @@ public class Simulator {
         handleReset(false);
     }
 
-    public MAIN_CMD waitForCommand() {
+    public MainCommand waitForCommand() {
-        synchronized(commandMonitorObject) {
+        synchronized (commandMonitorObject) {
             try {
                 commandMonitorObject.wait();
             } catch (InterruptedException ex) {
@@ -274,7 +283,7 @@ public class Simulator {
         }
 
         try {
-            logger.info("Reset requested. Resetting CPU.");
+            logger.debug("Reset requested. Resetting CPU.");
             // Reset CPU
             machine.getCpu().reset();
             // Clear the console.
@@ -349,7 +358,6 @@ public class Simulator {
             updateVisibleState();
             stepsSinceLastUpdate = 0;
         }
-
     }
 
     /**
@@ -389,7 +397,7 @@ public class Simulator {
         }
 
         public void run() {
-            logger.info("Starting main run loop.");
+            logger.debug("Starting main run loop.");
             isRunning = true;
 
             SwingUtilities.invokeLater(() -> {
@@ -426,12 +434,12 @@ public class Simulator {
         }
 
         /**
-         * Returns true if the run loop should proceed to the next step.
-         *
          * @return True if the run loop should proceed to the next step.
          */
         private boolean shouldContinue() {
-            return isRunning && !(preferences.getHaltOnBreak() && machine.getCpu().getInstruction() == 0x00);
+            return !breakpoints.contains(machine.getCpu().getProgramCounter()) &&
+                    isRunning &&
+                    !(preferences.getHaltOnBreak() && machine.getCpu().getInstruction() == 0x00);
         }
     }
 
@@ -560,19 +568,19 @@ public class Simulator {
         }
 
         public void actionPerformed(ActionEvent actionEvent) {
-            if(runLoop != null) {
+            if (runLoop != null) {
                 runLoop.requestStop();
             }
 
             memoryWindow.dispose();
             traceLog.dispose();
-            if(videoWindow != null) {
+            if (videoWindow != null) {
                 videoWindow.dispose();
             }
             mainWindow.dispose();
 
-            command = MAIN_CMD.SELECTMACHINE;
+            command = MainCommand.SELECTMACHINE;
-            synchronized(commandMonitorObject) {
+            synchronized (commandMonitorObject) {
                 commandMonitorObject.notifyAll();
             }
         }
@@ -682,6 +690,23 @@ public class Simulator {
         }
     }
 
+    class ToggleBreakpointWindowAction extends AbstractAction {
+        public ToggleBreakpointWindowAction() {
+            super("Breakpoints...", null);
+            putValue(SHORT_DESCRIPTION, "Show or Hide Breakpoints");
+        }
+
+        public void actionPerformed(ActionEvent actionEvent) {
+            synchronized (breakpointsWindow) {
+                if (breakpointsWindow.isVisible()) {
+                    breakpointsWindow.setVisible(false);
+                } else {
+                    breakpointsWindow.setVisible(true);
+                }
+            }
+        }
+    }
+
     class SimulatorMenu extends JMenuBar {
         // Menu Items
         private JMenuItem loadProgramItem;
@@ -779,7 +804,7 @@ public class Simulator {
             });
             viewMenu.add(showMemoryTable);
 
-            if(videoWindow != null) {
+            if (videoWindow != null) {
                 final JCheckBoxMenuItem showVideoWindow = new JCheckBoxMenuItem(new ToggleVideoWindowAction());
                 videoWindow.addWindowListener(new WindowAdapter() {
                     @Override
@@ -795,7 +820,15 @@ public class Simulator {
             /*
              * Simulator Menu
              */
+
+
             JMenu simulatorMenu = new JMenu("Simulator");
+
+            // "Select Machine..." item.
+            JMenuItem selectMachineItem = new JMenuItem(new SelectMachineAction());
+            simulatorMenu.add(selectMachineItem);
+
+            // "Clock Speed" sub-menu
             JMenu speedSubMenu = new JMenu("Clock Speed");
             ButtonGroup speedGroup = new ButtonGroup();
 
@@ -806,8 +839,16 @@ public class Simulator {
 
             simulatorMenu.add(speedSubMenu);
 
-            JMenuItem selectMachineItem = new JMenuItem(new SelectMachineAction());
+            // "Breakpoints"
-            simulatorMenu.add(selectMachineItem);
+            final JCheckBoxMenuItem showBreakpoints = new JCheckBoxMenuItem(new ToggleBreakpointWindowAction());
+            // Un-check the menu item if the user closes the window directly
+            breakpointsWindow.addWindowListener(new WindowAdapter() {
+                @Override
+                public void windowClosing(WindowEvent e) {
+                    showBreakpoints.setSelected(false);
+                }
+            });
+            simulatorMenu.add(showBreakpoints);
 
             add(simulatorMenu);
         }

src/main/java/com/loomcom/symon/ui/BreakpointsWindow.java

@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2016 Seth J. Morabito <web@loomcom.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package com.loomcom.symon.ui;
+
+import com.loomcom.symon.util.HexUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.swing.*;
+import javax.swing.border.EmptyBorder;
+import java.awt.*;
+import java.util.ArrayList;
+import java.util.SortedSet;
+
+/**
+ * Simple window to enter breakpoints.
+ */
+public class BreakpointsWindow extends JFrame {
+
+    private static final Logger logger = LoggerFactory.getLogger(BreakpointsWindow.class);
+
+    private static final Dimension FRAME_SIZE = new Dimension(240, 280);
+    private static final String EMPTY_STRING = "";
+
+    private JFrame mainWindow;
+    private SortedSet<Integer> breakpoints;
+
+    /**
+     * Simple ListModel to back the list of breakpoints.
+     */
+    private class BreakpointsListModel extends AbstractListModel<String> {
+        private SortedSet<Integer> breakpoints;
+
+        public BreakpointsListModel(SortedSet<Integer> breakpoints) {
+            this.breakpoints = breakpoints;
+        }
+
+        @Override
+        public int getSize() {
+            return breakpoints.size();
+        }
+
+        @Override
+        public String getElementAt(int index) {
+            ArrayList<Integer> values = new ArrayList<>(breakpoints);
+            return "$" + HexUtil.wordToHex(values.get(index));
+        }
+
+        public void addElement(Integer breakpoint) {
+            breakpoints.add(breakpoint);
+            ArrayList<Integer> values = new ArrayList<>(breakpoints);
+            int index = values.indexOf(breakpoint);
+            fireIntervalAdded(this, index, index);
+        }
+
+        public void removeElement(int index) {
+            ArrayList<Integer> values = new ArrayList<>(breakpoints);
+            Integer breakpoint = values.get(index);
+            breakpoints.remove(breakpoint);
+            fireIntervalRemoved(this, index, index);
+        }
+    }
+
+    public BreakpointsWindow(SortedSet<Integer> breakpoints,
+                             JFrame mainWindow) {
+        this.breakpoints = breakpoints;
+        this.mainWindow = mainWindow;
+        createUi();
+    }
+
+    private void createUi() {
+        setTitle("Breakpoints");
+
+        JPanel breakpointsPanel = new JPanel();
+        JPanel controlPanel = new JPanel();
+
+        breakpointsPanel.setLayout(new BorderLayout());
+        breakpointsPanel.setBorder(new EmptyBorder(10, 10, 10, 10));
+
+        JButton addButton = new JButton("Add");
+        JButton removeButton = new JButton("Del");
+        removeButton.setEnabled(false);
+
+        JTextField addTextField = new JTextField(5);
+
+        BreakpointsListModel listModel = new BreakpointsListModel(breakpoints);
+        JList<String> breakpointsList = new JList<>(listModel);
+        breakpointsList.setFont(new Font("Monospace", Font.PLAIN, 14));
+        breakpointsList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
+
+        JScrollPane scrollPane = new JScrollPane(breakpointsList);
+        scrollPane.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
+        scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
+
+        breakpointsPanel.add(scrollPane, BorderLayout.CENTER);
+
+
+        breakpointsList.addListSelectionListener(le -> {
+            int idx = breakpointsList.getSelectedIndex();
+
+            if (idx == -1) {
+                removeButton.setEnabled(false);
+            } else {
+                removeButton.setEnabled(true);
+            }
+        });
+
+        addButton.addActionListener(e -> {
+            int value = -1;
+
+            String newBreakpoint = addTextField.getText();
+
+            if (newBreakpoint == null || newBreakpoint.isEmpty()) {
+                return;
+            }
+
+            try {
+                value = Integer.parseInt(addTextField.getText(), 16);
+            } catch (NumberFormatException ex) {
+                logger.warn("Can't parse page number {}", newBreakpoint);
+                return;
+            }
+
+            if (value < 0) {
+                return;
+            }
+
+            listModel.addElement(value);
+
+            logger.debug("Added breakpoint ${}", HexUtil.wordToHex(value));
+
+            addTextField.setText(EMPTY_STRING);
+        });
+
+        removeButton.addActionListener(e -> listModel.removeElement(breakpointsList.getSelectedIndex()));
+
+        controlPanel.add(addTextField);
+        controlPanel.add(addButton);
+        controlPanel.add(removeButton);
+
+        setLayout(new BorderLayout());
+        getContentPane().add(breakpointsPanel, BorderLayout.CENTER);
+        getContentPane().add(controlPanel, BorderLayout.SOUTH);
+
+        setMinimumSize(FRAME_SIZE);
+        setMaximumSize(FRAME_SIZE);
+        setPreferredSize(FRAME_SIZE);
+
+        setLocationRelativeTo(mainWindow);
+        setResizable(false);
+
+        pack();
+    }
+}

src/main/java/com/loomcom/symon/ui/MemoryWindow.java

@@ -26,6 +26,8 @@ package com.loomcom.symon.ui;
 import com.loomcom.symon.Bus;
 import com.loomcom.symon.exceptions.MemoryAccessException;
 import com.loomcom.symon.util.HexUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.swing.*;
 import javax.swing.border.EmptyBorder;
@@ -37,8 +39,7 @@ import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.util.EventObject;
-import java.util.logging.Level;
+
-import java.util.logging.Logger;
 
 /**
  * This Frame displays the contents of a page of memory. The page number to be displayed
@@ -46,6 +47,8 @@ import java.util.logging.Logger;
  */
 public class MemoryWindow extends JFrame implements ActionListener {
 
+    private static final Logger logger = LoggerFactory.getLogger(MemoryWindow.class);
+
     private MemoryTableModel memoryTableModel;
     private JTable memoryTable;
     private JTextField pageNumberTextField;
@@ -209,9 +212,9 @@ public class MemoryWindow extends JFrame implements ActionListener {
             } catch (NumberFormatException ex) {
                 // An invalid number was entered. Log the error, but otherwise
                 // take no action.
-                Logger.getLogger(this.getClass().getName()).log(Level.WARNING, "Can't parse page number " +
+                logger.warn("Can't parse page number {}", pageNumberInput);
-                        pageNumberInput);
             }
+
             updateControls();
         }
     }