Allow default datafile to be disabled

If this option is deselected, the default unit, prefix, dimension and
metric exception data will not be loaded, and only custom data and the
few units that are not provided by files will be available.

The main rationale for this change is so that the data can be localized
by custom unit files.

5 files changed, 110 insertions, 21 deletions

diff --git a/src/main/java/sevenUnitsGUI/Presenter.java b/src/main/java/sevenUnitsGUI/Presenter.java
index 6467f03..ba600e3 100644
--- a/src/main/java/sevenUnitsGUI/Presenter.java
+++ b/src/main/java/sevenUnitsGUI/Presenter.java
@@ -347,6 +347,19 @@ public final class Presenter {
 	 * unit view in views that show units as a list to choose from.
 	 */
 	private boolean showDuplicates = false;
+	
+	/**
+	 * The default unit, prefix, dimension and exception data will only be loaded
+	 * if this variable is true.
+	 */
+	private boolean useDefaultDatafiles = true;
+	
+	/** Custom unit datafiles that will be loaded by {@link #reloadData} */
+	private final Set<Path> customUnitFiles = new HashSet<>();
+	/** Custom dimension datafiles that will be loaded by {@link #reloadData} */
+	private final Set<Path> customDimensionFiles = new HashSet<>();
+	/** Custom exception datafiles that will be loaded by {@link #reloadData} */
+	private final Set<Path> customExceptionFiles = new HashSet<>();
 
 	/**
 	 * Creates a Presenter
@@ -357,8 +370,45 @@ public final class Presenter {
 	public Presenter(View view) {
 		this.view = view;
 		this.database = new UnitDatabase();
-		addDefaults(this.database);
+		this.metricExceptions = new HashSet<>();
+
+		this.locales = this.loadLocales();
+		this.userLocale = DEFAULT_LOCALE;
+
+		// set default settings temporarily
+		if (Files.exists(CONFIG_FILE)) {
+			this.loadSettings(CONFIG_FILE);
+		}
 
+		this.reloadData();
+
+		// print out unit counts
+		System.out.println(this.loadStatMsg());
+	}
+	
+	/**
+	 * Clears then reloads all unit, prefix, dimension and exception data.
+	 */
+	public void reloadData() {
+		this.database.clear();
+		this.metricExceptions.clear();
+		addDefaults(this.database);
+		
+		if (this.useDefaultDatafiles) {
+			this.loadDefaultData();
+		}
+		
+		this.customUnitFiles.forEach(
+				path -> this.handleLoadErrors(this.database.loadUnitsFile(path)));
+		this.customDimensionFiles.forEach(
+				path -> this.handleLoadErrors(this.database.loadDimensionFile(path)));
+		this.customExceptionFiles.forEach(this::loadExceptionFile);
+	}
+	
+	/**
+	 * Load units, prefixes and dimensions from the default files.
+	 */
+	private void loadDefaultData() {
 		// load units and prefixes
 		try (final var units = inputStream(DEFAULT_UNITS_FILEPATH)) {
 			this.handleLoadErrors(this.database.loadUnitsFromStream(units));
@@ -377,7 +427,6 @@ public final class Presenter {
 
 		// load metric exceptions
 		try {
-			this.metricExceptions = new HashSet<>();
 			try (var exceptions = inputStream(DEFAULT_EXCEPTIONS_FILEPATH);
 					var scanner = new Scanner(exceptions)) {
 				while (scanner.hasNextLine()) {
@@ -392,17 +441,6 @@ public final class Presenter {
 			throw new AssertionError("Loading of metric_exceptions.txt failed.",
 					e);
 		}
-
-		this.locales = this.loadLocales();
-		this.userLocale = DEFAULT_LOCALE;
-
-		// set default settings temporarily
-		if (Files.exists(CONFIG_FILE)) {
-			this.loadSettings(CONFIG_FILE);
-		}
-
-		// print out unit counts
-		System.out.println(this.loadStatMsg());
 	}
 
 	/**
@@ -962,6 +1000,10 @@ public final class Presenter {
 	 * @since 2021-12-15
 	 */
 	void loadSettings(Path settingsFile) {
+		this.customDimensionFiles.clear();
+		this.customExceptionFiles.clear();
+		this.customUnitFiles.clear();
+
 		for (final Map.Entry<String, String> setting : this
 				.settingsFromFile(settingsFile)) {
 			final var value = setting.getValue();
@@ -970,15 +1012,13 @@ public final class Presenter {
 			// set manually to avoid the unnecessary saving of the non-manual
 			// methods
 			case "custom_dimension_file":
-				this.handleLoadErrors(
-						this.database.loadDimensionFile(pathFromConfig(value)));
+				this.customDimensionFiles.add(pathFromConfig(value));
 				break;
 			case "custom_exception_file":
-				this.loadExceptionFile(pathFromConfig(value));
+				this.customExceptionFiles.add(pathFromConfig(value));
 				break;
 			case "custom_unit_file":
-				this.handleLoadErrors(
-						this.database.loadUnitsFile(pathFromConfig(value)));
+				this.customUnitFiles.add(pathFromConfig(value));
 				break;
 			case "number_display_rule":
 				this.setDisplayRuleFromString(value);
@@ -1204,6 +1244,16 @@ public final class Presenter {
 			return null;
 		}
 	}
+	
+	/**
+	 * Sets whether or not the default datafiles will be loaded.
+	 * This method automatically updates the view's units.
+	 */
+	public void setUseDefaultDatafiles(boolean useDefaultDatafiles) {
+		this.useDefaultDatafiles = useDefaultDatafiles;
+		this.reloadData();
+		this.updateView();
+	}
 
 	/**
 	 * Sets the user's locale, updating the view.
@@ -1304,6 +1354,13 @@ public final class Presenter {
 			ucview.setToUnitNames(toNames);
 		}
 	}
+	
+	/**
+	 * @return true iff the default datafiles are being used
+	 */
+	public boolean usingDefaultDatafiles() {
+		return this.useDefaultDatafiles;
+	}
 
 	/**
 	 * @param message message to add
diff --git a/src/main/java/sevenUnitsGUI/TabbedView.java b/src/main/java/sevenUnitsGUI/TabbedView.java
index ca9f23c..40ed0a7 100644
--- a/src/main/java/sevenUnitsGUI/TabbedView.java
+++ b/src/main/java/sevenUnitsGUI/TabbedView.java
@@ -662,10 +662,22 @@ final class TabbedView implements ExpressionConversionView, UnitConversionView {
 			miscPanel.add(showAllVariations, new GridBagBuilder(0, 1, 2, 1)
 					.setAnchor(GridBagConstraints.LINE_START).build());
 			
+			final JCheckBox useDefaultFiles = new JCheckBox();
+			this.localizedTextSetters.put("tv.settings.use_default_files", 
+					useDefaultFiles::setText);
+			useDefaultFiles.setSelected(this.presenter.usingDefaultDatafiles());
+			useDefaultFiles.addItemListener(e -> {
+				this.presenter
+						.setUseDefaultDatafiles(e.getStateChange() == ItemEvent.SELECTED);
+				this.presenter.saveSettings();
+			});
+			miscPanel.add(useDefaultFiles, new GridBagBuilder(0, 2, 2, 1)
+					.setAnchor(GridBagConstraints.LINE_START).build());
+			
 			final JLabel localeLabel = new JLabel();
 			this.localizedTextSetters.put("tv.settings.locale", 
 					localeLabel::setText);
-			miscPanel.add(localeLabel, new GridBagBuilder(0, 2, 1, 1)
+			miscPanel.add(localeLabel, new GridBagBuilder(0, 3, 1, 1)
 					.setAnchor(GridBagConstraints.LINE_START).build());
 			
 			this.presenter.getAvailableLocales().stream().sorted()
@@ -675,14 +687,14 @@ final class TabbedView implements ExpressionConversionView, UnitConversionView {
 				this.presenter.setUserLocale((String) e.getItem());
 				this.presenter.saveSettings();
 			});
-			miscPanel.add(localeSelector, new GridBagBuilder(1, 2, 1, 1)
+			miscPanel.add(localeSelector, new GridBagBuilder(1, 3, 1, 1)
 					.setAnchor(GridBagConstraints.LINE_END).build());
 			
 			final JButton unitFileButton = new JButton();
 			this.localizedTextSetters.put("tv.settings.unitfiles.button", 
 					unitFileButton::setText);
 			unitFileButton.setEnabled(false);
-			miscPanel.add(unitFileButton, new GridBagBuilder(0, 3, 2, 1)
+			miscPanel.add(unitFileButton, new GridBagBuilder(0, 4, 2, 1)
 					.setAnchor(GridBagConstraints.LINE_START).build());
 		}
 		
diff --git a/src/main/resources/locales/en.txt b/src/main/resources/locales/en.txt
index 19ed781..5173cf3 100644
--- a/src/main/resources/locales/en.txt
+++ b/src/main/resources/locales/en.txt
@@ -25,5 +25,6 @@ tv.settings.search.common_prefixes=Include Common Prefixes
 tv.settings.search.all_prefixes=Include All Single Prefixes
 tv.settings.oneway=Convert One Way Only
 tv.settings.show_duplicate=Show Duplicate Units & Prefixes
+tv.settings.use_default_files=Use Default Datafiles
 tv.settings.locale=🌐 Locale:
 tv.settings.unitfiles.button=Manage Unit Data Files
diff --git a/src/main/resources/locales/fr.txt b/src/main/resources/locales/fr.txt
index d25e2b0..e8b7138 100644
--- a/src/main/resources/locales/fr.txt
+++ b/src/main/resources/locales/fr.txt
@@ -25,5 +25,6 @@ tv.settings.search.common_prefixes=Inclure préfixes fréquents
 tv.settings.search.all_prefixes=Inclure tous préfixes seuls
 tv.settings.oneway=Convertir Seulement en un Direction
 tv.settings.show_duplicate=Montrer unités et préfixes doubles
+tv.settings.use_default_files=Utilise donées par défaut
 tv.settings.locale=🌐 Locale:
 tv.settings.unitfiles.button=Gérer donées d’unités
diff --git a/src/test/java/sevenUnitsGUI/PresenterTest.java b/src/test/java/sevenUnitsGUI/PresenterTest.java
index 9e25a08..8b16365 100644
--- a/src/test/java/sevenUnitsGUI/PresenterTest.java
+++ b/src/test/java/sevenUnitsGUI/PresenterTest.java
@@ -17,6 +17,7 @@
 package sevenUnitsGUI;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assumptions.assumeTrue;
 
@@ -154,6 +155,23 @@ public final class PresenterTest {
 				expectedOutput.getValue().toString(false, RoundingMode.HALF_EVEN));
 		assertEquals(List.of(expectedUC), viewBot.unitConversionList());
 	}
+	
+	/**
+	 * Ensures that the default unitfile can be disabled.
+	 * 
+	 * @since v1.0.0
+	 * @since 2025-02-23
+	 */
+	@Test
+	void testDisableDefault() {
+		final var viewBot = new ViewBot();
+		final var presenter = new Presenter(viewBot);
+		assumeTrue(presenter.database.containsUnitName("joule"),
+				"Attempted to test disabling default on unit not in default file.");
+		presenter.setUseDefaultDatafiles(false);
+		assertFalse(presenter.database.containsUnitName("joule"),
+				"Presenter disabled default datafiles, but still contains the joule.");
+	}
 
 	/**
 	 * Tests that duplicate units are successfully removed, if that is asked for