introduced functionality to center the unlock screen within the main application window

src/main/java/org/cryptomator/ui/unlock/UnlockWorkflow.java

@@ -11,6 +11,7 @@ import org.cryptomator.ui.common.FxmlFile;
 import org.cryptomator.ui.common.FxmlScene;
 import org.cryptomator.ui.common.VaultService;
 import org.cryptomator.ui.fxapp.FxApplicationWindows;
+import org.cryptomator.ui.fxapp.PrimaryStage;
 import org.cryptomator.ui.keyloading.KeyLoadingStrategy;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -21,6 +22,7 @@ import javafx.beans.property.ObjectProperty;
 import javafx.concurrent.Task;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
+import javafx.stage.Window;
 import java.io.IOException;
 
 /**
@@ -33,6 +35,7 @@ public class UnlockWorkflow extends Task<Void> {
 
 	private static final Logger LOG = LoggerFactory.getLogger(UnlockWorkflow.class);
 
+	private final Stage mainWindow;
 	private final Stage window;
 	private final Vault vault;
 	private final VaultService vaultService;
@@ -44,7 +47,8 @@ public class UnlockWorkflow extends Task<Void> {
 	private final ObjectProperty<IllegalMountPointException> illegalMountPointException;
 
 	@Inject
-	UnlockWorkflow(@UnlockWindow Stage window, //
+	UnlockWorkflow(@PrimaryStage Stage mainWindow, //
+				   @UnlockWindow Stage window, //
 				   @UnlockWindow Vault vault, //
 				   VaultService vaultService, //
 				   @FxmlScene(FxmlFile.UNLOCK_SUCCESS) Lazy<Scene> successScene, //
@@ -53,6 +57,7 @@ public class UnlockWorkflow extends Task<Void> {
 				   FxApplicationWindows appWindows, //
 				   @UnlockWindow KeyLoadingStrategy keyLoadingStrategy, //
 				   @UnlockWindow ObjectProperty<IllegalMountPointException> illegalMountPointException) {
+		this.mainWindow = mainWindow;
 		this.window = window;
 		this.vault = vault;
 		this.vaultService = vaultService;
@@ -99,6 +104,13 @@ public class UnlockWorkflow extends Task<Void> {
 		appWindows.showErrorWindow(e, window, null);
 	}
 
+	private void centerOnPrimaryStage(Window window){
+		double centerXPosition = mainWindow.getX() + (mainWindow.getWidth() - window.getWidth()) / 2;
+		double centerYPosition = mainWindow.getY() + (mainWindow.getHeight() - window.getHeight()) / 2;
+		window.setX(centerXPosition);
+		window.setY(centerYPosition);
+	}
+
 	@Override
 	protected void succeeded() {
 		LOG.info("Unlock of '{}' succeeded.", vault.getDisplayName());
@@ -107,6 +119,7 @@ public class UnlockWorkflow extends Task<Void> {
 			case ASK -> Platform.runLater(() -> {
 				window.setScene(successScene.get());
 				window.show();
+				centerOnPrimaryStage(window);
 			});
 			case REVEAL -> {
 				Platform.runLater(window::close);