Implement dynamic addon loading

Addons are standalone jars, loaded at runtime. They can be developed
independently of the simulator and can provide some additional functionality.

An example addon is shown in `addons/rand`. When building a jar file,
main class should extend abstract class `sic.sim.addons.Addon`. Only
the methods, needed for functinality of the addon, have to be overriden.

The abstract class Addon currently contains methods for initializing the
addon and some other methods (documented in the source file itself). The
class could be extended at any time (with non-abstract methods) without
breaking any older addons.

Addons can be loaded with `-a path[@params]` command line options.
Parametres are passed to the `load` method of the loaded addon.

.gitignore

@@ -1,6 +1,7 @@
 .idea
 SicTools.iml
 out
+addons/out
 /.project
 *.class
 tests/linker/factorial/factdemo.obj
@@ -35,4 +36,4 @@ tests/linker/factorial/stack.log
 tests/linker/factorial/stack.lst
 tests/linker/one2/linked.obj
 tests/linker/one2/prog.log
-tests/linker/one2/prog.lst
+tests/linker/one2/prog.lst

Makefile

@@ -1,6 +1,6 @@
 OUT = out/make
 
-all: outdir img
+all: outdir img addons
 	javac -encoding UTF-8 -sourcepath src -d "$(OUT)" src/sic/*.java
 
 sim: outdir img
@@ -15,6 +15,9 @@ asm: outdir
 link: outdir
 	javac -encoding UTF-8 -sourcepath src -d "$(OUT)" src/sic/Link.java
 
+addons: outdir
+	javac -encoding UTF-8 -sourcepath src -d "$(OUT)" src/sic/sim/addons/*/*.java
+
 jar: all
 	jar --create --file "$(OUT)/sictools.jar" --manifest MANIFEST.MF -C "$(OUT)" .
 

addons/Makefile

@@ -0,0 +1,21 @@
+NAME=${name}
+# MAIN is the class which extends the abstract class sic.sim.plugins.Plugin.
+MAIN="${name}.Main"
+OUT=out/make
+# SICPATH should be changed if building from a different tree.
+# It can also point to sictools.jar file.
+SICPATH=../out/make
+
+
+.PHONY: main
+main: outdir
+	javac -encoding UTF-8 -cp ".:$(SICPATH)" -d "$(OUT)/$(NAME)" $(NAME)/*.java
+	jar --create --file "$(OUT)/$(NAME).jar" --main-class $(MAIN) -C "$(OUT)/$(NAME)" .
+
+.PHONY: outdir
+outdir:
+	@mkdir -p "$(OUT)"
+
+.PHONY: clean
+clean:
+	rm -rf "$(OUT)"

addons/rand/Main.java

@@ -0,0 +1,23 @@
+package rand;
+
+import java.util.Vector;
+
+import sic.sim.addons.Addon;
+import sic.sim.Executor;
+
+public class Main extends Addon {
+    private int device = 3;
+    public void load(String args) {
+        System.out.println("Loading rand");
+        if (args != null) {
+            device = Integer.parseInt(args);
+        }
+    }
+
+    @Override
+    public Vector<AddonDevice> getDevices() {
+        Vector<AddonDevice> vc = new Vector<AddonDevice>();
+        vc.add(new Addon.AddonDevice(device, new RandDevice(), true));
+        return vc;
+    }
+}

addons/rand/RandDevice.java

@@ -0,0 +1,14 @@
+package rand;
+
+import java.util.Random;
+
+import sic.sim.vm.Device;
+
+public class RandDevice extends Device {
+    private Random random = new Random();
+
+    @Override
+    public int read() {
+        return random.nextInt(256);
+    }
+}

src/sic/Sim.java

@@ -6,11 +6,15 @@
 import sic.sim.Executor;
 import sic.sim.MainView;
 import sic.sim.vm.Machine;
+import sic.sim.addons.Addon;
+import sic.sim.addons.AddonLoader;
 
 import javax.swing.UIManager;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.io.File;
+import java.io.IOException;
+import java.util.Vector;
 
 /**
  * Simulator of the SIC/XE computer.
@@ -49,12 +53,39 @@ public static void main(String[] args) throws Exception {
             return;
         }
 
+        Vector<Addon> addons = new Vector<Addon>();
+
+        for (Args.AddonArgs a : processedArgs.getAddons()) {
+            try {
+                Addon p = AddonLoader.loadJar(a.path);
+                p.load(a.pars);
+                addons.add(p);
+            } catch (IOException e) {
+                System.out.printf("cannot open addon file %s%n", a.path);
+                System.out.println(e);
+                System.exit(1);
+            } catch (ClassCastException e) {
+                System.out.printf("main class of %s does not extend Addon class%n", a.path);
+                System.exit(1);
+            }
+        }
+
         Machine machine = new Machine();
         Executor executor = new Executor(machine, processedArgs);
         Disassembler disassembler = new Disassembler(new Mnemonics(), machine);
 
         final MainView mainView = new MainView(executor, disassembler, processedArgs);
 
+        for (Addon a : addons) {
+            a.init(executor);
+            machine.devices.setDevices(a.getDevices());
+            mainView.addMenuEntries(a.getMenuEntries());
+            mainView.addTimerTasks(a.getTimerTasks());
+            mainView.addSettingsPanels(a.getSettingsPanels());
+        }
+        mainView.addAddonMenu();
+        mainView.updateTimerTasks();
+
         if (processedArgs.hasFilename()) mainView.load(new File(processedArgs.getFilename()));
 
         mainView.updateView();

src/sic/VM.java

@@ -6,8 +6,11 @@
 import sic.sim.Executor;
 import sic.sim.addons.GraphicalScreen;
 import sic.sim.addons.TextualScreen;
+import sic.sim.addons.Addon;
+import sic.sim.addons.AddonLoader;
 import sic.sim.vm.Machine;
 
+import java.io.IOException;
 import java.util.*;
 
 /**
@@ -34,9 +37,36 @@ public static void main(String[] args) throws Exception {
             System.exit(0);
         }
 
+        Vector<Addon> addons = new Vector<Addon>();
+
+        for (Args.AddonArgs a : arg.getAddons()) {
+            try {
+                Addon p = AddonLoader.loadJar(a.path);
+                p.load(a.pars);
+                addons.add(p);
+            } catch (IOException e) {
+                System.out.printf("cannot open addon file %s%n", a.path);
+                System.out.println(e);
+                System.exit(1);
+            } catch (ClassCastException e) {
+                System.out.printf("main class of %s does not extend Addon class%n", a.path);
+                System.exit(1);
+            }
+        }
+
         Machine machine = new Machine();
         Executor executor = new Executor(machine, arg);
 
+        Vector<TimerTask> timerTasks = new Vector<TimerTask>();
+        for (Addon a : addons) {
+            a.init(executor);
+            machine.devices.setDevices(a.getDevices());
+            Vector<TimerTask> tasks = a.getTimerTasks();
+            if (tasks != null) {
+                timerTasks.addAll(tasks);
+            }
+        }
+
         if (arg.hasFilename()) {
             String ext = arg.getFileext();
             if ("asm".equals(ext)) Loader.loadAsm(machine, arg.getFilename());
@@ -57,6 +87,9 @@ public static void main(String[] args) throws Exception {
                 graphicalScreen.toggleView();
             }
             java.util.Timer timer = new java.util.Timer();
+            for (TimerTask t : timerTasks) {
+                timer.schedule(t, 0, 50);
+            }
             TimerTask timerTask = new TimerTask() {
                 public void run() {
                     if (textScreen != null) textScreen.updateView();

src/sic/sim/Args.java

@@ -1,5 +1,7 @@
 package sic.sim;
 
+import java.util.Vector;
+
 import sic.common.Utils;
 
 /**
@@ -56,6 +58,8 @@ public class Args extends  AbstractCmdLineArgs {
     private boolean keyb;
     private int keybAddress;
 
+    private Vector<AddonArgs> addons = new Vector<AddonArgs>();
+
     public boolean isHelp() {
         return help;
     }
@@ -128,6 +132,10 @@ public int getGraphScrFreq() {
         return graphScrFreq;
     }
 
+    public Vector<AddonArgs> getAddons() {
+        return addons;
+    }
+
     public static void printArgs() {
         System.out.print(
             "    -help|-h              Print help.\n" +
@@ -137,7 +145,8 @@ public static void printArgs() {
             "    -stats                Print instruction statistics.\n" +
             "    -text colsxrows       Show and resize textual screen.\n" +
             "    -graph colsxrows[@hz] Show and resize graphical screen.\n" +
-            "    -keyb address         Show and set keyboard address.\n");
+            "    -keyb address         Show and set keyboard address.\n" +
+            "    -a path[@params]      Load addon.\n");
     }
 
     int parseFreq(String s) {
@@ -179,6 +188,17 @@ void parseKeyb(String s){
         }
     }
 
+    void parseAddon(String s) {
+        int i = s.indexOf('@');
+        String path = s;
+        String params = null;
+        if (i != -1) {
+            path = s.substring(0, i);
+            params = s.substring(i + 1);
+        }
+        addons.add(new AddonArgs(path, params));
+    }
+
     void processArgs(String[] args) {
         // options
         int last = 0;
@@ -213,6 +233,9 @@ void processArgs(String[] args) {
                     keyb = true;
                     parseKeyb(args[++last]);
                     break;
+                case "-a":
+                    parseAddon(args[++last]);
+                    break;
             }
             if (!arg.startsWith("-") || arg.equals("--")) break;
             last++;
@@ -229,4 +252,13 @@ public Args(String[] args) {
         processArgs(args);
     }
 
-}
+    public class AddonArgs {
+        public String path;
+        public String pars;
+
+        public AddonArgs(String path, String pars) {
+            this.path = path;
+            this.pars = pars;
+        }
+    }
+}

src/sic/sim/MainView.java

@@ -14,6 +14,7 @@
 import sic.sim.addons.Keyboard;
 import sic.sim.addons.TextualScreen;
 import sic.sim.views.*;
+import sic.sim.addons.Addon;
 
 import javax.swing.*;
 import javax.swing.filechooser.FileNameExtensionFilter;
@@ -22,6 +23,7 @@
 import java.io.*;
 import java.util.Timer;
 import java.util.TimerTask;
+import java.util.Vector;
 
 /**
  * TODO: write a short description
@@ -47,6 +49,11 @@ public class MainView {
 
     private File lastLoadedFile;
 
+    private Vector<Addon.MenuEntry> menuEntries = new Vector<Addon.MenuEntry>();
+    private Vector<Addon.SettingsPanel> settingsPanels = new Vector<Addon.SettingsPanel>();
+    private Vector<TimerTask> timerTasks = new Vector<TimerTask>();
+
+    private Timer timer;
 
     public MainView(final Executor executor, Disassembler disassembler, Args arg) {
         this.executor = executor;
@@ -96,7 +103,7 @@ public MainView(final Executor executor, Disassembler disassembler, Args arg) {
             keyboard.toggleView();
         }
 
-        Timer timer = new Timer();
+        timer = new Timer();
         TimerTask timerTask = new TimerTask() {
             public void run() {
                 if (mainFrame.isVisible() && executor.hasChanged()) {
@@ -125,6 +132,47 @@ public void updateView() {
         watchView.updateView();
     }
 
+    public void addMenuEntries(Vector<Addon.MenuEntry> entries) {
+        if (entries == null) {
+            return;
+        }
+        menuEntries.addAll(entries);
+    }
+
+    public void addSettingsPanels(Vector<Addon.SettingsPanel> panels) {
+        if (panels == null) {
+            return;
+        }
+        settingsPanels.addAll(panels);
+    }
+
+    public void addAddonMenu() {
+        if (menuEntries.size() <= 0) {
+            return;
+        }
+        JMenuBar mb = mainFrame.getJMenuBar();
+        JMenu menu = new JMenu("Addons");
+
+        for (Addon.MenuEntry e : menuEntries) {
+            GUI.addMenuItem(menu, e.name, e.keyEvent, e.keyStroke, e.actionListener);
+        }
+        mb.add(menu);
+    }
+
+    public void addTimerTasks(Vector<TimerTask> tasks) {
+        if (tasks == null) {
+            return;
+        }
+        timerTasks.addAll(tasks);
+    }
+
+    public void updateTimerTasks() {
+        for (TimerTask t : timerTasks) {
+            System.out.println("scheduling a task");
+            timer.schedule(t, 0, 50);
+        }
+    }
+
     private JMenuBar createMenuBar() {
         JMenuBar mb = new JMenuBar();
 
@@ -326,7 +374,7 @@ public void loadObj(File file) {
             Loader.loadSection(executor.machine, reader);
             lastLoadedFile = file;
             mainFrame.setTitle(file.getName());
-			updateView();
+            updateView();
         } catch (FileNotFoundException e1) {
             JOptionPane.showMessageDialog(mainFrame, "Error loading object file.");
             updateView();
@@ -392,6 +440,9 @@ private void showSettingsView() {
         tabs.addTab("Textual screen", null, textScreen.createSettingsPane(), null);
         tabs.addTab("Graphical screen", null, graphScreen.createSettingsPane(), null);
         tabs.addTab("Keyboard", null, keyboard.createSettingsPane(), null);
+        for (Addon.SettingsPanel panel : settingsPanels) {
+            tabs.addTab(panel.title, null, panel.panel, null);
+        }
         GUI.showInJFrame("Settings", tabs, 0, 0);
     }