Only create config directory when saving

Previously, if the user had no settings dir, starting the program would
create it, but nothing would be read.  If the user did not change their
settings, it would just leave an empty directory!

1 files changed, 30 insertions, 32 deletions

diff --git a/src/main/java/sevenUnitsGUI/Presenter.java b/src/main/java/sevenUnitsGUI/Presenter.java
index e471b01..0b5247d 100644
--- a/src/main/java/sevenUnitsGUI/Presenter.java
+++ b/src/main/java/sevenUnitsGUI/Presenter.java
@@ -57,8 +57,11 @@ import sevenUnits.utils.UncertainDouble;
  * @since 2021-12-15
  */
 public final class Presenter {
-	/** The place where settings are stored. */
-	private static final Optional<Path> CONFIG_FILE = getConfigPath();
+	/**
+	 * The place where settings are stored.
+	 * Both this path and its parent directory may not exist.
+	 */
+	private static final Path CONFIG_FILE = userConfigDir().resolve("SevenUnits").resolve("config.txt");
 	/** The default place where units are stored. */
 	private static final String DEFAULT_UNITS_FILEPATH = "/unitsfile.txt";
 	/** The default place where dimensions are stored. */
@@ -66,43 +69,27 @@ public final class Presenter {
 	/** The default place where exceptions are stored. */
 	private static final String DEFAULT_EXCEPTIONS_FILEPATH = "/metric_exceptions.txt";
 	
-	/** Gets the configuration file, creating the directory if needed. */
-	private static final Optional<Path> getConfigPath() {
-		final Path configDir;
+	private static final Path userConfigDir() {
 		if (System.getProperty("os.name").startsWith("Windows")) {
 			final String envFolder = System.getenv("LOCALAPPDATA");
 			if (envFolder == null || "".equals(envFolder)) {
-				configDir = Path.of(System.getenv("USERPROFILE"), "AppData", "Local", "SevenUnits");
+				return Path.of(System.getenv("USERPROFILE"), "AppData", "Local");
 			} else {
-				configDir = Path.of(envFolder, "SevenUnits");
+				return Path.of(envFolder);
 			}
 		} else {
 			final String envFolder = System.getenv("XDG_CONFIG_HOME");
 			if (envFolder == null || "".equals(envFolder)) {
-				configDir = Path.of(System.getenv("HOME"), ".config", "SevenUnits");
+				return Path.of(System.getenv("HOME"), ".config");
 			} else {
-				configDir = Path.of(envFolder, "SevenUnits");
-			}
-		}
-
-		// try to create config directory
-		if (!Files.exists(configDir)) {
-			try {
-				Files.createDirectory(configDir);
-			} catch (IOException e) {
-				e.printStackTrace();
-				return Optional.empty();
+				return Path.of(envFolder);
 			}
 		}
-
-		return Optional.of(configDir.resolve("config.txt"));
 	}
 
 	/** Gets a Path from a pathname in the config file. */
 	private static Path pathFromConfig(String pathname) {
-		return CONFIG_FILE.map(configFile ->
-			configFile.getParent().resolve(pathname)
-		).orElse(Path.of(pathname));
+		return CONFIG_FILE.getParent().resolve(pathname);
 	}
 
 	/**
@@ -305,9 +292,9 @@ public final class Presenter {
 		}
 		
 		// set default settings temporarily
-		CONFIG_FILE.ifPresentOrElse(this::loadSettings, () -> {
-			this.view.showErrorMessage("Config Loading Error", "Could not load config file - using default settings.");
-		});
+		if (Files.exists(CONFIG_FILE)) {
+			this.loadSettings(CONFIG_FILE);
+		}
 		
 		// a Predicate that returns true iff the argument is a full base unit
 		final Predicate<Unit> isFullBase = unit -> unit instanceof LinearUnit
@@ -710,14 +697,23 @@ public final class Presenter {
 	}
 	
 	/**
-	 * Saves the presenter's current settings to its default filepath.
+	 * Saves the presenter's current settings to the config file,
+	 * creating it if it doesn't exist.
 	 * 
-	 * @return true iff this operation succeeded
+	 * @return false iff the presenter could not write to the file
 	 * @since 2022-04-19
 	 */
 	public boolean saveSettings() {
-		CONFIG_FILE.ifPresent(this::saveSettings);
-		return CONFIG_FILE.isPresent();
+		final Path configDir = CONFIG_FILE.getParent();
+		if (!Files.exists(configDir)) {
+			try {
+				Files.createDirectories(configDir);
+			} catch (IOException e) {
+				return false;
+			}
+		}
+
+		return this.writeSettings(CONFIG_FILE);
 	}
 	
 	/**
@@ -726,7 +722,7 @@ public final class Presenter {
 	 * @param settingsFile file settings should be saved to
 	 * @since 2021-12-15
 	 */
-	void saveSettings(Path settingsFile) {
+	boolean writeSettings(Path settingsFile) {
 		try (BufferedWriter writer = Files.newBufferedWriter(settingsFile)) {
 			writer.write(String.format("number_display_rule=%s\n",
 					this.numberDisplayRule));
@@ -738,11 +734,13 @@ public final class Presenter {
 					String.format("include_duplicates=%s\n", this.showDuplicates));
 			writer.write(
 					String.format("search_prefix_rule=%s\n", this.searchRule));
+			return true;
 		} catch (final IOException e) {
 			e.printStackTrace();
 			this.view.showErrorMessage("I/O Error",
 					"Error occurred while saving settings: "
 							+ e.getLocalizedMessage());
+			return false;
 		}
 	}