feat: Persist GUI app settings between executions

app/gui/src/main/java/org/mobilitydata/gtfsvalidator/app/gui/GtfsValidatorApp.java

@@ -25,6 +25,8 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.ResourceBundle;
 import javax.swing.BorderFactory;
 import javax.swing.Box;
@@ -68,6 +70,8 @@ public class GtfsValidatorApp extends JFrame {
   private final ValidationDisplay validationDisplay;
   private final ResourceBundle bundle;
 
+  private final List<Runnable> preValidationCallbacks = new ArrayList<>();
+
   public GtfsValidatorApp(
       MonitoredValidationRunner validationRunner, ValidationDisplay validationDisplay) {
     super("GTFS Schedule Validator");
@@ -80,18 +84,42 @@ public void setGtfsSource(String source) {
     gtfsInputField.setText(source);
   }
 
+  public String getGtfsSource() {
+    return gtfsInputField.getText();
+  }
+
   public void setOutputDirectory(Path outputDirectory) {
     outputDirectoryField.setText(outputDirectory.toString());
   }
 
+  public String getOutputDirectory() {
+    return outputDirectoryField.getText();
+  }
+
   public void setNumThreads(int numThreads) {
     numThreadsSpinner.setValue(numThreads);
   }
 
+  public int getNumThreads() {
+    Object value = numThreadsSpinner.getValue();
+    if (value instanceof Integer) {
+      return (Integer) value;
+    }
+    return 0;
+  }
+
   public void setCountryCode(String countryCode) {
     countryCodeField.setText(countryCode);
   }
 
+  public String getCountryCode() {
+    return countryCodeField.getText();
+  }
+
+  void addPreValidationCallback(Runnable callback) {
+    preValidationCallbacks.add(callback);
+  }
+
   void constructUI() {
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
@@ -255,6 +283,10 @@ private boolean isValidationReadyToRun() {
   }
 
   private void runValidation() {
+    for (Runnable r : preValidationCallbacks) {
+      r.run();
+    }
+
     try {
       ValidationRunnerConfig config = buildConfig();
       validationRunner.run(config, this);

app/gui/src/main/java/org/mobilitydata/gtfsvalidator/app/gui/GtfsValidatorPreferences.java

@@ -0,0 +1,72 @@
+package org.mobilitydata.gtfsvalidator.app.gui;
+
+import java.nio.file.Path;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.prefs.Preferences;
+
+/**
+ * Supports loading and saving application preferences from a persistent {@link Preferences} backend
+ * across application runs.
+ */
+public class GtfsValidatorPreferences {
+
+  private static final String KEY_GTFS_SOURCE = "gtfs_source";
+  private static final String KEY_OUTPUT_DIRECTORY = "output_directory";
+  private static final String KEY_NUM_THREADS = "num_threads";
+  private static final String KEY_COUNTRY_CODE = "country_code";
+
+  private final Preferences prefs;
+
+  public GtfsValidatorPreferences() {
+    this.prefs = Preferences.userNodeForPackage(GtfsValidatorPreferences.class);
+  }
+
+  public void loadPreferences(GtfsValidatorApp app) {
+    loadStringSetting(KEY_GTFS_SOURCE, app::setGtfsSource);
+    loadPathSetting(KEY_OUTPUT_DIRECTORY, app::setOutputDirectory);
+    loadIntSetting(KEY_NUM_THREADS, app::setNumThreads);
+    loadStringSetting(KEY_COUNTRY_CODE, app::setCountryCode);
+  }
+
+  public void savePreferences(GtfsValidatorApp app) {
+    saveStringSetting(app::getGtfsSource, KEY_GTFS_SOURCE);
+    saveStringSetting(app::getOutputDirectory, KEY_OUTPUT_DIRECTORY);
+    saveIntSetting(app::getNumThreads, KEY_NUM_THREADS);
+    saveStringSetting(app::getCountryCode, KEY_COUNTRY_CODE);
+  }
+
+  private void loadStringSetting(String key, Consumer<String> setter) {
+    String value = prefs.get(key, "");
+    if (!value.isBlank()) {
+      setter.accept(value);
+    }
+  }
+
+  private void loadIntSetting(String key, Consumer<Integer> setter) {
+    loadStringSetting(key, (value) -> setter.accept(Integer.parseInt(value)));
+  }
+
+  private void loadPathSetting(String key, Consumer<Path> setter) {
+    loadStringSetting(key, (value) -> setter.accept(Path.of(value)));
+  }
+
+  private void saveStringSetting(Supplier<String> getter, String key) {
+    String value = getter.get();
+    if (!value.isBlank()) {
+      prefs.put(key, value);
+    }
+  }
+
+  private void saveIntSetting(Supplier<Integer> getter, String key) {
+    saveStringSetting(
+        () -> {
+          Integer value = getter.get();
+          if (value == null || value == 0) {
+            return "";
+          }
+          return value.toString();
+        },
+        key);
+  }
+}

app/gui/src/main/java/org/mobilitydata/gtfsvalidator/app/gui/Main.java

@@ -58,12 +58,16 @@ public class Main {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   public static void main(String[] args) {
+    Thread.setDefaultUncaughtExceptionHandler(new LogUncaughtExceptionHandler());
+
     logger.atInfo().log("gtfs-validator: start");
     SwingUtilities.invokeLater(() -> createAndShowGUI(args));
     logger.atInfo().log("gtfs-validator: exit");
   }
 
   private static void createAndShowGUI(String[] args) {
+    Thread.currentThread().setUncaughtExceptionHandler(new LogUncaughtExceptionHandler());
+
     try {
       UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
     } catch (Exception e) {
@@ -76,14 +80,26 @@ private static void createAndShowGUI(String[] args) {
     GtfsValidatorApp app = new GtfsValidatorApp(runner, display);
     app.constructUI();
 
+    GtfsValidatorPreferences prefs = new GtfsValidatorPreferences();
+    prefs.loadPreferences(app);
+    // We save preferences each time validation is run.
+    app.addPreValidationCallback(
+        () -> {
+          prefs.savePreferences(app);
+        });
+
     // On Windows, if you drag a file onto the application shortcut, it will
     // execute the app with the file as the first command-line argument.  This
     // doesn't appear to work on Mac OS.
     if (args.length == 1) {
       app.setGtfsSource(args[0]);
     }
 
-    app.setOutputDirectory(getDefaultOutputDirectory());
+    // We set a default output directory as a fallback if the user didn't
+    // have one previously set.
+    if (app.getOutputDirectory().isBlank()) {
+      app.setOutputDirectory(getDefaultOutputDirectory());
+    }
 
     app.pack();
     // This causes the application window to center in the screen.
@@ -116,4 +132,14 @@ private static Path getDefaultOutputDirectory() {
     }
     return workingDirectory;
   }
+
+  /**
+   * We introduce a catch-all for uncaught exceptions to make sure they make it into our application
+   * logs.
+   */
+  public static class LogUncaughtExceptionHandler implements Thread.UncaughtExceptionHandler {
+    public void uncaughtException(Thread thread, Throwable thrown) {
+      logger.atSevere().withCause(thrown).log("Uncaught application exception");
+    }
+  }
 }

app/gui/src/test/java/org/mobilitydata/gtfsvalidator/app/gui/GtfsValidatorAppTest.java

@@ -82,4 +82,17 @@ public void testValidationConfigWithAdvancedOptions() throws URISyntaxException
     assertThat(config.numThreads()).isEqualTo(5);
     assertThat(config.countryCode().getCountryCode()).isEqualTo("US");
   }
+
+  @Test
+  public void testPreValidationCallback() throws URISyntaxException {
+    app.setGtfsSource("http://transit/gtfs.zip");
+    app.setOutputDirectory(Path.of("/path/to/output"));
+
+    Runnable callback = Mockito.mock(Runnable.class);
+    app.addPreValidationCallback(callback);
+
+    app.getValidateButtonForTesting().doClick();
+
+    verify(callback).run();
+  }
 }

app/gui/src/test/java/org/mobilitydata/gtfsvalidator/app/gui/GtfsValidatorPreferencesTest.java

@@ -0,0 +1,47 @@
+package org.mobilitydata.gtfsvalidator.app.gui;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import java.nio.file.Path;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+import org.mockito.quality.Strictness;
+
+@RunWith(JUnit4.class)
+public class GtfsValidatorPreferencesTest {
+
+  @Rule public MockitoRule rule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
+
+  @Mock private MonitoredValidationRunner runner;
+  @Mock private ValidationDisplay display;
+
+  @Test
+  public void testEndToEnd() {
+    {
+      GtfsValidatorApp source = new GtfsValidatorApp(runner, display);
+      source.setGtfsSource("http://gtfs.org/gtfs.zip");
+      source.setOutputDirectory(Path.of("/tmp/gtfs"));
+      source.setNumThreads(3);
+      source.setCountryCode("CA");
+
+      GtfsValidatorPreferences prefs = new GtfsValidatorPreferences();
+      prefs.savePreferences(source);
+    }
+
+    {
+      GtfsValidatorPreferences prefs = new GtfsValidatorPreferences();
+      GtfsValidatorApp dest = new GtfsValidatorApp(runner, display);
+      prefs.loadPreferences(dest);
+
+      assertThat(dest.getGtfsSource()).isEqualTo("http://gtfs.org/gtfs.zip");
+      assertThat(dest.getOutputDirectory()).isEqualTo("/tmp/gtfs");
+      assertThat(dest.getNumThreads()).isEqualTo(3);
+      assertThat(dest.getCountryCode()).isEqualTo("CA");
+    }
+  }
+}

app/pkg/build.gradle

@@ -52,6 +52,7 @@ extraJavaModuleInfo {
         requires('java.desktop')
         requires('java.logging')
         requires('java.naming')
+        requires('java.prefs')
         requires('java.security.jgss')
         requires('java.sql')
   }