refactor(startup): replace custom JavaFX splash with JVM -splash

Use Java native splash for consistent behavior across OS and Flatpak.\n\n- remove custom StartupSplashController/Widget module\n- wire -splash for run, jar/shadowJar, jpackage, and Flatpak launcher\n- close native splash after primary stage show\n- add startup splash PNG and keep SVG source asset

Author: remiceres

build.gradle.kts

@@ -174,6 +174,11 @@ val jpackageExecutable = packagingJavaHome.map { javaHome ->
     file("$javaHome/bin/$executable").absolutePath
 }
 
+val startupSplashImage = file("src/main/resources/images/startup-splash-primer-dark.png")
+val startupSplashEnabled = startupSplashImage.exists()
+val startupSplashJvmOption = "-splash:${startupSplashImage.absolutePath}"
+val startupSplashPackagedJvmOption = "-splash:\$APPDIR/${startupSplashImage.name}"
+
 /*
  * Per-platform icon resolution for jpackage.
  * Keep jpackage icons under packaging/.
@@ -248,7 +253,12 @@ javafx {
 
 application {
     mainClass.set(Meta.mainClass)
-    applicationDefaultJvmArgs = listOf(Meta.nativeAccessOption)
+    applicationDefaultJvmArgs = buildList {
+        add(Meta.nativeAccessOption)
+        if (startupSplashEnabled) {
+            add(startupSplashJvmOption)
+        }
+    }
 }
 
 /*
@@ -332,6 +342,9 @@ tasks.named<Jar>("jar") {
     manifest {
         attributes["Main-Class"] = Meta.mainClass
         attributes["Implementation-Version"] = project.version.toString()
+        if (startupSplashEnabled) {
+            attributes["SplashScreen-Image"] = "images/${startupSplashImage.name}"
+        }
     }
 }
 
@@ -348,6 +361,9 @@ tasks.named<ShadowJar>("shadowJar") {
     manifest {
         attributes["Main-Class"] = Meta.mainClass
         attributes["Implementation-Version"] = project.version.toString()
+        if (startupSplashEnabled) {
+            attributes["SplashScreen-Image"] = "images/${startupSplashImage.name}"
+        }
     }
 }
 
@@ -408,6 +424,11 @@ tasks.register<Exec>("jpackageCurrentPlatform") {
             "--java-options", Meta.nativeAccessOption
         )
 
+        if (startupSplashEnabled) {
+            args("--app-content", startupSplashImage.absolutePath)
+            args("--java-options", startupSplashPackagedJvmOption)
+        }
+
         if (jpackageIcon.exists()) {
             args("--icon", jpackageIcon.absolutePath)
         } else {
@@ -464,6 +485,11 @@ if (hostOs == "windows") {
                 "--java-options", Meta.nativeAccessOption
             )
 
+            if (startupSplashEnabled) {
+                args("--app-content", startupSplashImage.absolutePath)
+                args("--java-options", startupSplashPackagedJvmOption)
+            }
+
             if (jpackageIcon.exists()) {
                 args("--icon", jpackageIcon.absolutePath)
             } else {

packaging/flatpak/fr.inria.corese.CoreseGui.yml

@@ -31,6 +31,7 @@ modules:
     build-commands:
       - install -Dm644 corese-gui-standalone.jar /app/bin/corese-gui-standalone.jar
       - install -Dm755 packaging/flatpak/scripts/run.sh /app/bin/corese-gui
+      - install -Dm644 src/main/resources/images/startup-splash-primer-dark.png /app/share/corese-gui/startup-splash-primer-dark.png
       - install -Dm644 packaging/flatpak/appdata/${FLATPAK_ID}.appdata.xml /app/share/metainfo/${FLATPAK_ID}.appdata.xml
       - install -Dm644 packaging/flatpak/appdata/${FLATPAK_ID}.desktop /app/share/applications/${FLATPAK_ID}.desktop
       - install -Dm644 packaging/assets/logo/${FLATPAK_ID}.svg /app/share/icons/hicolor/scalable/apps/${FLATPAK_ID}.svg

packaging/flatpak/scripts/run.sh

@@ -5,5 +5,6 @@ export GDK_BACKEND=x11
 
 exec /app/jre/bin/java \
   --enable-native-access=ALL-UNNAMED \
+  -splash:/app/share/corese-gui/startup-splash-primer-dark.png \
   -jar /app/bin/corese-gui-standalone.jar \
   "$@"

src/main/java/fr/inria/corese/gui/App.java

@@ -8,19 +8,17 @@
 import fr.inria.corese.gui.feature.main.MainView;
 import fr.inria.corese.gui.feature.main.ViewManager;
 import fr.inria.corese.gui.feature.main.navigation.NavigationBarController;
-import fr.inria.corese.gui.feature.startup.splash.StartupSplashController;
 import fr.inria.corese.gui.utils.AppExecutors;
 import fr.inria.corese.gui.utils.fx.SvgImageLoader;
+import java.awt.SplashScreen;
 import java.util.Objects;
-import javafx.animation.PauseTransition;
 import javafx.application.Application;
 import javafx.application.Platform;
 import javafx.geometry.Rectangle2D;
 import javafx.scene.Scene;
 import javafx.scene.image.Image;
 import javafx.stage.Screen;
 import javafx.stage.Stage;
-import javafx.util.Duration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -42,17 +40,7 @@ public final class App extends Application {
 	public void start(Stage primaryStage) {
 		Platform.setImplicitExit(true);
 		ThemeManager themeManager = ThemeManager.getInstance();
-
-		StartupSplashController splashController = createStartupSplashController(themeManager);
-		if (splashController != null) {
-			splashController.show();
-		}
-
-		long startupStartNanos = System.nanoTime();
-		PauseTransition initializeDelay = new PauseTransition(Duration.millis(StartupSplashController.RENDER_GUARD_MS));
-		initializeDelay.setOnFinished(
-				event -> initializeAndShowMainStage(primaryStage, splashController, startupStartNanos, themeManager));
-		initializeDelay.play();
+		initializeAndShowMainStage(primaryStage, themeManager);
 	}
 
 	@Override
@@ -69,8 +57,7 @@ public static void main(String[] args) {
 		System.exit(0);
 	}
 
-	private static void initializeAndShowMainStage(Stage primaryStage, StartupSplashController splashController,
-			long startupStartNanos, ThemeManager themeManager) {
+	private static void initializeAndShowMainStage(Stage primaryStage, ThemeManager themeManager) {
 		try {
 			MainView mainView = new MainView();
 			NavigationBarController navigationController = new NavigationBarController();
@@ -91,44 +78,22 @@ private static void initializeAndShowMainStage(Stage primaryStage, StartupSplash
 			applyInitialWindowSize(primaryStage);
 			primaryStage.setOnCloseRequest(event -> Platform.exit());
 
-			schedulePrimaryStageShow(primaryStage, splashController, startupStartNanos);
+			primaryStage.show();
+			closeNativeSplashIfPresent();
 		} catch (RuntimeException e) {
-			closeSplashStage(splashController);
+			closeNativeSplashIfPresent();
 			throw e;
 		}
 	}
 
-	private static void schedulePrimaryStageShow(Stage primaryStage, StartupSplashController splashController,
-			long startupStartNanos) {
-		double elapsedMs = (System.nanoTime() - startupStartNanos) / 1_000_000.0;
-		double remainingMs = StartupSplashController.MIN_DISPLAY_MS - elapsedMs;
-		if (splashController == null || remainingMs <= 0) {
-			showPrimaryStageAndCloseSplash(primaryStage, splashController);
-			return;
-		}
-		PauseTransition delay = new PauseTransition(Duration.millis(remainingMs));
-		delay.setOnFinished(event -> showPrimaryStageAndCloseSplash(primaryStage, splashController));
-		delay.play();
-	}
-
-	private static void showPrimaryStageAndCloseSplash(Stage primaryStage, StartupSplashController splashController) {
-		primaryStage.show();
-		closeSplashStage(splashController);
-	}
-
-	private static void closeSplashStage(StartupSplashController splashController) {
-		if (splashController == null) {
-			return;
-		}
-		splashController.close();
-	}
-
-	private static StartupSplashController createStartupSplashController(ThemeManager themeManager) {
+	private static void closeNativeSplashIfPresent() {
 		try {
-			return new StartupSplashController(themeManager);
-		} catch (RuntimeException e) {
-			LOGGER.warn("Unable to create startup splash", e);
-			return null;
+			SplashScreen splash = SplashScreen.getSplashScreen();
+			if (splash != null) {
+				splash.close();
+			}
+		} catch (UnsupportedOperationException _) {
+			// No native splash active.
 		}
 	}
 
@@ -140,8 +105,8 @@ private static void applyApplicationIcon(Stage stage) {
 				return;
 			}
 
-			Image pngIcon = new Image(
-					Objects.requireNonNull(App.class.getResourceAsStream(APP_LOGO_PNG_RESOURCE), "Application icon not found"));
+			Image pngIcon = new Image(Objects.requireNonNull(App.class.getResourceAsStream(APP_LOGO_PNG_RESOURCE),
+					"Application icon not found"));
 			stage.getIcons().add(pngIcon);
 		} catch (Exception e) {
 			LOGGER.warn("Failed to load application icon", e);