Add a save and reload button.

src/main/java/org/nwapw/abacus/Abacus.java

@@ -57,7 +57,7 @@ public class Abacus {
      * Creates a new instance of the Abacus calculator.
      */
     public Abacus() {
-        pluginManager = new PluginManager();
+        pluginManager = new PluginManager(this);
         numberReducer = new NumberReducer(this);
         configuration = new Configuration(CONFIG_FILE);
         configuration.saveTo(CONFIG_FILE);

src/main/java/org/nwapw/abacus/config/Configuration.java

@@ -5,6 +5,9 @@ import com.moandjiezana.toml.TomlWriter;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
 
 /**
  * The configuration object that stores
@@ -12,26 +15,38 @@ import java.io.IOException;
  */
 public class Configuration {
 
+    /**
+     * The defaults TOML string.
+     */
+    private static final String DEFAULT_CONFIG =
+            "numberImplementation = \"naive\"\n" +
+            "disabledPlugins = []";
+    /**
+     * The defaults TOML object, parsed from the string.
+     */
+    private static final Toml DEFAULT_TOML = new Toml().read(DEFAULT_CONFIG);
     /**
      * The TOML writer used to write this configuration to a file.
      */
     private static final TomlWriter TOML_WRITER = new TomlWriter();
-    /**
-     * The TOML reader used to load this config from a file.
-     */
-    private static final Toml TOML_READER = new Toml();
 
     /**
      * The implementation of the number that should be used.
      */
-    private String numberImplementation = "naive";
+    private String numberImplementation = "<default>";
+    /**
+     * The list of disabled plugins in this Configuration.
+     */
+    private Set<String> disabledPlugins = new HashSet<>();
 
     /**
      * Creates a new configuration with the given values.
      * @param numberImplementation the number implementation, like "naive" or "precise"
+     * @param disabledPlugins the list of disabled plugins.
      */
-    public Configuration(String numberImplementation){
+    public Configuration(String numberImplementation, String[] disabledPlugins){
         this.numberImplementation = numberImplementation;
+        this.disabledPlugins.addAll(Arrays.asList(disabledPlugins));
     }
 
     /**
@@ -40,7 +55,7 @@ public class Configuration {
      */
     public Configuration(File fromFile){
         if(!fromFile.exists()) return;
-        copyFrom(TOML_READER.read(fromFile).to(Configuration.class));
+        copyFrom(new Toml(DEFAULT_TOML).read(fromFile).to(Configuration.class));
     }
 
     /**
@@ -49,6 +64,7 @@ public class Configuration {
      */
     public void copyFrom(Configuration otherConfiguration){
         this.numberImplementation = otherConfiguration.numberImplementation;
+        this.disabledPlugins.addAll(otherConfiguration.disabledPlugins);
     }
 
     /**
@@ -80,4 +96,13 @@ public class Configuration {
     public void setNumberImplementation(String numberImplementation) {
         this.numberImplementation = numberImplementation;
     }
+
+    /**
+     * Gets the list of disabled plugins.
+     * @return the list of disabled plugins.
+     */
+    public Set<String> getDisabledPlugins() {
+        return disabledPlugins;
+    }
+
 }

src/main/java/org/nwapw/abacus/fx/AbacusController.java

@@ -4,19 +4,39 @@ import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
 import javafx.fxml.FXML;
 import javafx.scene.control.*;
+import javafx.scene.control.cell.CheckBoxListCell;
 import javafx.scene.text.Text;
 import javafx.util.Callback;
+import javafx.util.StringConverter;
 import org.nwapw.abacus.Abacus;
+import org.nwapw.abacus.config.Configuration;
 import org.nwapw.abacus.number.NumberInterface;
+import org.nwapw.abacus.plugin.PluginListener;
+import org.nwapw.abacus.plugin.PluginManager;
 import org.nwapw.abacus.tree.TreeNode;
 
+import java.util.Set;
+
 
 /**
  * The controller for the abacus FX UI, responsible
  * for all the user interaction.
  */
-public class AbacusController {
+public class AbacusController implements PluginListener {
 
+    /**
+     * The title for the apply alert dialog.
+     */
+    private static final String APPLY_MSG_TITLE = "\"Apply\" Needed";
+    /**
+     * The text for the header of the apply alert dialog.
+     */
+    private static final String APPLY_MSG_HEADER = "The settings have not been applied.";
+    /**
+     * The text for the dialog that is shown if settings haven't been applied.
+     */
+    private static final String APPLY_MSG_TEXT = "You have made changes to the configuration, however, you haven't pressed \"Apply\". " +
+                "The changes to the configuration will not be present in the calculator until \"Apply\" is pressed.";
     /**
      * Constant string that is displayed if the text could not be lexed or parsed.
      */
@@ -26,6 +46,12 @@ public class AbacusController {
      */
     private static final String ERR_EVAL = "Evaluation Error";
 
+    @FXML
+    private TabPane coreTabPane;
+    @FXML
+    private Tab calculateTab;
+    @FXML
+    private Tab settingsTab;
     @FXML
     private TableView<HistoryModel> historyTable;
     @FXML
@@ -42,6 +68,8 @@ public class AbacusController {
     private Button inputButton;
     @FXML
     private ComboBox<String> numberImplementationBox;
+    @FXML
+    private ListView<ToggleablePlugin> enabledPluginView;
 
     /**
      * The list of history entries, created by the users.
@@ -54,35 +82,88 @@ public class AbacusController {
      */
     private ObservableList<String> numberImplementationOptions;
 
+    /**
+     * The list of plugin objects that can be toggled on and off,
+     * and, when reloaded, get added to the plugin manager's black list.
+     */
+    private ObservableList<ToggleablePlugin> enabledPlugins;
+
+    /**
+     * The abacus instance used for changing the plugin configuration.
+     */
     private Abacus abacus;
 
+    /**
+     * Boolean which represents whether changes were made to the configuration.
+     */
+    private boolean changesMade;
+    /**
+     * Whether an alert about changes to the configuration was already shown.
+     */
+    private boolean reloadAlertShown;
+    /**
+     * The alert shown when a press to "apply" is needed.
+     */
+    private Alert reloadAlert;
+
+    /**
+     * Alerts the user if the changes they made
+     * have not yet been applied.
+     */
+    private void alertIfApplyNeeded(boolean ignorePrevious){
+        if(changesMade && (!reloadAlertShown || ignorePrevious)) {
+            reloadAlertShown = true;
+            reloadAlert.showAndWait();
+        }
+    }
+
     @FXML
     public void initialize(){
         Callback<TableColumn<HistoryModel, String>, TableCell<HistoryModel, String>> cellFactory =
                 param -> new CopyableCell<>();
+        Callback<ListView<ToggleablePlugin>, ListCell<ToggleablePlugin>> pluginCellFactory =
+                param -> new CheckBoxListCell<>(ToggleablePlugin::enabledProperty, new StringConverter<ToggleablePlugin>() {
+                    @Override
+                    public String toString(ToggleablePlugin object) {
+                        return object.getClassName().substring(object.getClassName().lastIndexOf('.') + 1);
+                    }
+
+                    @Override
+                    public ToggleablePlugin fromString(String string) {
+                        return new ToggleablePlugin(true, string);
+                    }
+                });
 
         historyData = FXCollections.observableArrayList();
         historyTable.setItems(historyData);
         numberImplementationOptions = FXCollections.observableArrayList();
         numberImplementationBox.setItems(numberImplementationOptions);
-        numberImplementationBox.valueProperty().addListener((observable, oldValue, newValue)
-                -> {
-            abacus.getConfiguration().setNumberImplementation(newValue);
-            abacus.getConfiguration().saveTo(Abacus.CONFIG_FILE);
-        });
+        numberImplementationBox.getSelectionModel().selectedIndexProperty().addListener(e -> changesMade = true);
         historyTable.getSelectionModel().setCellSelectionEnabled(true);
+        enabledPlugins = FXCollections.observableArrayList();
+        enabledPluginView.setItems(enabledPlugins);
+        enabledPluginView.setCellFactory(pluginCellFactory);
         inputColumn.setCellFactory(cellFactory);
         inputColumn.setCellValueFactory(cell -> cell.getValue().inputProperty());
         parsedColumn.setCellFactory(cellFactory);
         parsedColumn.setCellValueFactory(cell -> cell.getValue().parsedProperty());
         outputColumn.setCellFactory(cellFactory);
         outputColumn.setCellValueFactory(cell -> cell.getValue().outputProperty());
+        coreTabPane.getSelectionModel().selectedItemProperty().addListener((observable, oldValue, newValue) -> {
+            if(oldValue.equals(settingsTab)) alertIfApplyNeeded(true);
+        });
 
         abacus = new Abacus();
-        numberImplementationOptions.addAll(abacus.getPluginManager().getAllNumbers());
-        String actualImplementation = abacus.getConfiguration().getNumberImplementation();
-        String toSelect = (numberImplementationOptions.contains(actualImplementation)) ? actualImplementation : "naive";
-        numberImplementationBox.getSelectionModel().select(toSelect);
+        abacus.getPluginManager().addListener(this);
+        abacus.getPluginManager().reload();
+
+        changesMade = false;
+        reloadAlertShown = false;
+
+        reloadAlert = new Alert(Alert.AlertType.WARNING);
+        reloadAlert.setTitle(APPLY_MSG_TITLE);
+        reloadAlert.setHeaderText(APPLY_MSG_HEADER);
+        reloadAlert.setContentText(APPLY_MSG_TEXT);
     }
 
     @FXML
@@ -107,4 +188,53 @@ public class AbacusController {
         inputField.setText("");
     }
 
+    @FXML
+    private void performSaveAndReload(){
+        performSave();
+        performReload();
+        changesMade = false;
+        reloadAlertShown = false;
+    }
+
+    @FXML
+    private void performReload(){
+        alertIfApplyNeeded(true);
+        abacus.getPluginManager().reload();
+    }
+
+    @FXML
+    private void performSave(){
+        Configuration configuration = abacus.getConfiguration();
+        configuration.setNumberImplementation(numberImplementationBox.getSelectionModel().getSelectedItem());
+        Set<String> disabledPlugins = configuration.getDisabledPlugins();
+        disabledPlugins.clear();
+        for(ToggleablePlugin pluginEntry : enabledPlugins){
+            if(!pluginEntry.isEnabled()) disabledPlugins.add(pluginEntry.getClassName());
+        }
+        configuration.saveTo(Abacus.CONFIG_FILE);
+        changesMade = false;
+        reloadAlertShown = false;
+    }
+
+    @Override
+    public void onLoad(PluginManager manager) {
+        Configuration configuration = abacus.getConfiguration();
+        Set<String> disabledPlugins = configuration.getDisabledPlugins();
+        numberImplementationOptions.addAll(abacus.getPluginManager().getAllNumbers());
+        String actualImplementation = configuration.getNumberImplementation();
+        String toSelect = (numberImplementationOptions.contains(actualImplementation)) ? actualImplementation : "<default>";
+        numberImplementationBox.getSelectionModel().select(toSelect);
+        for(Class<?> pluginClass : abacus.getPluginManager().getLoadedPluginClasses()){
+            String fullName = pluginClass.getName();
+            ToggleablePlugin plugin = new ToggleablePlugin(!disabledPlugins.contains(fullName), fullName);
+            plugin.enabledProperty().addListener(e -> changesMade = true);
+            enabledPlugins.add(plugin);
+        }
+    }
+
+    @Override
+    public void onUnload(PluginManager manager) {
+        enabledPlugins.clear();
+        numberImplementationOptions.clear();
+    }
 }

src/main/java/org/nwapw/abacus/fx/ToggleablePlugin.java

@@ -0,0 +1,29 @@
+package org.nwapw.abacus.fx;
+
+import javafx.beans.property.BooleanProperty;
+import javafx.beans.property.SimpleBooleanProperty;
+
+public class ToggleablePlugin {
+
+    private final BooleanProperty enabled;
+    private final String className;
+
+    public ToggleablePlugin(boolean enabled, String className){
+        this.enabled = new SimpleBooleanProperty();
+        this.enabled.setValue(enabled);
+        this.className = className;
+    }
+
+    public BooleanProperty enabledProperty() {
+        return enabled;
+    }
+
+    public boolean isEnabled() {
+        return enabled.get();
+    }
+
+    public String getClassName() {
+        return className;
+    }
+
+}

src/main/java/org/nwapw/abacus/parsing/ShuntingYardParser.java

@@ -89,7 +89,7 @@ public class ShuntingYardParser implements Parser<Match<TokenType>>, PluginListe
                     if (!(otherMatchType == TokenType.OP || otherMatchType == TokenType.FUNCTION)) break;
 
                     if (otherMatchType == TokenType.OP) {
-                        int otherPrecedence = precedenceMap.get(match.getContent());
+                        int otherPrecedence = precedenceMap.get(otherMatch.getContent());
                         if (otherPrecedence < precedence ||
                                 (associativity == OperatorAssociativity.RIGHT && otherPrecedence == precedence)) {
                             break;

src/main/java/org/nwapw/abacus/plugin/PluginManager.java

@@ -1,5 +1,6 @@
 package org.nwapw.abacus.plugin;
 
+import org.nwapw.abacus.Abacus;
 import org.nwapw.abacus.function.Function;
 import org.nwapw.abacus.function.Operator;
 import org.nwapw.abacus.number.NumberInterface;
@@ -52,11 +53,17 @@ public class PluginManager {
      * The list of plugin listeners attached to this instance.
      */
     private Set<PluginListener> listeners;
+    /**
+     * The abacus instance used to access other
+     * components of the application.
+     */
+    private Abacus abacus;
 
     /**
      * Creates a new plugin manager.
      */
-    public PluginManager() {
+    public PluginManager(Abacus abacus) {
+        this.abacus = abacus;
         loadedPluginClasses = new HashSet<>();
         plugins = new HashSet<>();
         cachedFunctions = new HashMap<>();
@@ -160,8 +167,13 @@ public class PluginManager {
      * Loads all the plugins in the PluginManager.
      */
     public void load() {
-        for (Plugin plugin : plugins) plugin.enable();
+        Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
         for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            plugin.enable();
+        }
+        for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
             allFunctions.addAll(plugin.providedFunctions());
             allOperators.addAll(plugin.providedOperators());
             allNumbers.addAll(plugin.providedNumbers());
@@ -173,11 +185,18 @@ public class PluginManager {
      * Unloads all the plugins in the PluginManager.
      */
     public void unload() {
-        for (Plugin plugin : plugins) plugin.disable();
+        listeners.forEach(e -> e.onUnload(this));
+        Set<String> disabledPlugins = abacus.getConfiguration().getDisabledPlugins();
+        for (Plugin plugin : plugins) {
+            if(disabledPlugins.contains(plugin.getClass().getName())) continue;
+            plugin.disable();
+        }
+        cachedFunctions.clear();
+        cachedOperators.clear();
+        cachedNumbers.clear();
         allFunctions.clear();
         allOperators.clear();
         allNumbers.clear();
-        listeners.forEach(e -> e.onUnload(this));
     }
 
     /**
@@ -185,7 +204,7 @@ public class PluginManager {
      */
     public void reload() {
         unload();
-        reload();
+        load();
     }
 
     /**
@@ -233,4 +252,12 @@ public class PluginManager {
         listeners.remove(listener);
     }
 
+    /**
+     * Gets a list of all the plugin class files that have been
+     * added to the plugin manager.
+     * @return the list of all the added plugin classes.
+     */
+    public Set<Class<?>> getLoadedPluginClasses() {
+        return loadedPluginClasses;
+    }
 }

src/main/resources/abacus.fxml

@@ -7,12 +7,13 @@
 <?import javafx.scene.text.Text?>
 <?import javafx.scene.layout.HBox?>
 <?import javafx.scene.layout.GridPane?>
+<?import javafx.scene.layout.FlowPane?>
 <BorderPane xmlns="http://javafx.com/javafx"
             xmlns:fx="http://javafx.com/fxml"
             fx:controller="org.nwapw.abacus.fx.AbacusController">
     <center>
-        <TabPane>
-            <Tab text="Calculator" closable="false">
+        <TabPane fx:id="coreTabPane">
+            <Tab fx:id="calculateTab" text="Calculator" closable="false">
                 <BorderPane>
                     <center>
                         <TableView fx:id="historyTable">
@@ -41,11 +42,19 @@
                     </bottom>
                 </BorderPane>
             </Tab>
-            <Tab text="Settings" closable="false">
+            <Tab fx:id="settingsTab" text="Settings" closable="false">
                 <GridPane hgap="10" vgap="10">
                     <padding><Insets left="10" right="10" top="10" bottom="10"/></padding>
                     <Label text="Number Implementation" GridPane.columnIndex="0" GridPane.rowIndex="0"/>
                     <ComboBox fx:id="numberImplementationBox" GridPane.columnIndex="1" GridPane.rowIndex="0"/>
+                    <ListView fx:id="enabledPluginView"
+                              GridPane.rowIndex="1" GridPane.columnIndex="0"
+                              GridPane.columnSpan="2" maxHeight="100"/>
+                    <FlowPane GridPane.columnIndex="0" GridPane.columnSpan="2" GridPane.rowIndex="2" hgap="10" vgap="10">
+                        <Button text="Apply" onAction="#performSave"/>
+                        <Button text="Reload Plugins" onAction="#performReload"/>
+                        <Button text="Apply and Reload" onAction="#performSaveAndReload"/>
+                    </FlowPane>
                 </GridPane>
             </Tab>
         </TabPane>