Execution Trace Log

Introduces an execution trace window that will keep track of the most
recent 10000 execution steps. I'm not entirely happy with the
implementation, yet.

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

@@ -33,6 +33,7 @@ import com.loomcom.symon.exceptions.SymonException;
 import com.loomcom.symon.ui.Console;
 import com.loomcom.symon.ui.PreferencesDialog;
 import com.loomcom.symon.ui.StatusPanel;
+import com.loomcom.symon.ui.TraceLog;
 
 import javax.swing.*;
 import javax.swing.border.EmptyBorder;
@@ -118,7 +119,7 @@ public class Simulator implements Observer {
     /**
      * The Trace Window shows the most recent 50,000 CPU states.
      */
-    private JFrame traceWindow;
+    private TraceLog traceLog;
 
     /**
      * The Zero Page Window shows the contents of page 0.
@@ -229,6 +230,9 @@ public class Simulator implements Observer {
             }
         });
 
+        // Prepare the log window
+        traceLog = new TraceLog();
+
         mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
         console.requestFocus();
@@ -264,8 +268,9 @@ public class Simulator implements Observer {
                 statusPane.updateState(cpu);
             }
         });
-
-        // TODO: Write to Log window, if frame is visible.
+        if (traceLog.isVisible()) {
+            traceLog.refresh();
+        }
         // TODO: Update memory window, if frame is visible.
     }
 
@@ -317,6 +322,11 @@ public class Simulator implements Observer {
     private void step() throws MemoryAccessException {
 
         cpu.step();
+        // TODO: We need to profile this for performance. Possibly allow
+        // a flag to turn trace on/off
+        synchronized(traceLog) {
+            traceLog.append(cpu.getCpuState());
+        }
 
         // Read from the ACIA and immediately update the console if there's
         // output ready.
@@ -607,6 +617,24 @@ public class Simulator implements Observer {
         }
     }
 
+    class ToggleTraceWindowAction extends AbstractAction {
+        public ToggleTraceWindowAction() {
+            super("Trace Log", null);
+            putValue(SHORT_DESCRIPTION, "Show or Hide the Trace Log Window");
+        }
+
+        public void actionPerformed(ActionEvent actionEvent) {
+            synchronized(traceLog) {
+                if (traceLog.isVisible()) {
+                    traceLog.setVisible(false);
+                } else {
+                    traceLog.refresh();
+                    traceLog.setVisible(true);
+                }
+            }
+        }
+    }
+
     class SimulatorMenu extends JMenuBar {
         // Menu Items
         private JMenuItem    loadProgramItem;
@@ -675,6 +703,9 @@ public class Simulator implements Observer {
             makeFontSizeMenuItem(20, fontSubMenu, group);
 
             viewMenu.add(fontSubMenu);
+
+            JMenuItem showTraceLog = new JMenuItem(new ToggleTraceWindowAction());
+            viewMenu.add(showTraceLog);
             add(viewMenu);
         }
 

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

@@ -177,19 +177,21 @@ public class StatusPanel extends JPanel {
      * @param cpu The simulated 6502 CPU.
      */
     public void updateState(Cpu cpu) {
-        // Update the Processor Status Flag display
-        int state = cpu.getProcessorStatus();
+        Cpu.CpuState cpuState = cpu.getCpuState();
 
-        carryFlagLabel.setIcon(iconForFlag(state, 0));
-        zeroFlagLabel.setIcon(iconForFlag(state, 1));
-        irqDisableFlagLabel.setIcon(iconForFlag(state, 2));
-        decimalModeFlagLabel.setIcon(iconForFlag(state, 3));
-        breakFlagLabel.setIcon(iconForFlag(state, 4));
-        overflowFlagLabel.setIcon(iconForFlag(state, 6));
-        negativeFlagLabel.setIcon(iconForFlag(state, 7));
+        // Update the Processor Status Flag display
+        int status = cpu.getCpuState().getStatusFlag();
+
+        carryFlagLabel.setIcon(iconForFlag(status, 0));
+        zeroFlagLabel.setIcon(iconForFlag(status, 1));
+        irqDisableFlagLabel.setIcon(iconForFlag(status, 2));
+        decimalModeFlagLabel.setIcon(iconForFlag(status, 3));
+        breakFlagLabel.setIcon(iconForFlag(status, 4));
+        overflowFlagLabel.setIcon(iconForFlag(status, 6));
+        negativeFlagLabel.setIcon(iconForFlag(status, 7));
 
         // Update the register and address displays
-        opcodeField.setText(cpu.getOpcodeStatus());
+        opcodeField.setText(cpu.getCpuState().disassembleOp());
         pcField.setText(cpu.getProgramCounterStatus());
         spField.setText(cpu.getStackPointerStatus());
         aField.setText(cpu.getAccumulatorStatus());

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

@@ -24,17 +24,61 @@
 
 package com.loomcom.symon.ui;
 
+import com.loomcom.symon.Cpu;
 import com.loomcom.symon.util.FifoRingBuffer;
 
 import javax.swing.*;
+import java.awt.*;
 
 /**
  * This frame displays a trace of CPU execution. The most recent TRACE_LENGTH lines
  * are captured in a buffer and rendered to the JFrame's main text area upon request.
  */
-public class TraceLog extends JFrame {
+public class TraceLog {
 
-    private FifoRingBuffer<String> traceLog;
+    private FifoRingBuffer<Cpu.CpuState> traceLog;
+    private JFrame                       traceLogWindow;
+    private JTextArea                    logArea;
 
+    private static final Dimension SIZE           = new Dimension(640, 480);
+    private static final int       MAX_LOG_LENGTH = 10000;
 
+    public TraceLog() {
+        traceLog = new FifoRingBuffer<Cpu.CpuState>(MAX_LOG_LENGTH);
+        traceLogWindow = new JFrame();
+        traceLogWindow.setPreferredSize(SIZE);
+        traceLogWindow.setResizable(true);
+
+        traceLogWindow.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
+
+        logArea = new JTextArea();
+        logArea.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 12));
+
+        JScrollPane scrollableView = new JScrollPane(logArea);
+
+        traceLogWindow.getContentPane().add(scrollableView);
+        traceLogWindow.pack();
+        // Don't show the frame. That action is controlled by the Simulator.
+    }
+
+    public void refresh() {
+        StringBuilder logString = new StringBuilder();
+        for (Cpu.CpuState state : traceLog) {
+            logString.append(state.toString());
+            logString.append("\n");
+        }
+        logArea.setText(logString.toString());
+    }
+
+    public void append(Cpu.CpuState state) {
+        traceLog.push(new Cpu.CpuState(state));
+    }
+
+    public boolean isVisible() {
+        return traceLogWindow.isVisible();
+    }
+
+    public void setVisible(boolean b) {
+        traceLogWindow.setVisible(b);
+    }
 }