The display/vault name is now constrained:

* should not be empty
* is stripped of leading & trailing whitespaces
* is truncated to 50 characters

main/ui/src/main/java/org/cryptomator/ui/vaultoptions/GeneralVaultOptionsController.java

@@ -1,20 +1,26 @@
 package org.cryptomator.ui.vaultoptions;
 
+import com.google.common.base.Strings;
 import org.cryptomator.common.settings.WhenUnlocked;
 import org.cryptomator.common.vaults.Vault;
 import org.cryptomator.ui.common.FxController;
 
 import javax.inject.Inject;
+import javafx.beans.Observable;
 import javafx.fxml.FXML;
 import javafx.scene.control.CheckBox;
 import javafx.scene.control.ChoiceBox;
 import javafx.scene.control.TextField;
+import javafx.stage.Stage;
 import javafx.util.StringConverter;
 import java.util.ResourceBundle;
 
 @VaultOptionsScoped
 public class GeneralVaultOptionsController implements FxController {
 
+	private static final int VAULTNAME_TRUNCATE_THRESHOLD = 50;
+
+	private final Stage window;
 	private final Vault vault;
 	private final ResourceBundle resourceBundle;
 
@@ -23,20 +29,37 @@ public class GeneralVaultOptionsController implements FxController {
 	public ChoiceBox<WhenUnlocked> actionAfterUnlockChoiceBox;
 
 	@Inject
-	GeneralVaultOptionsController(@VaultOptionsWindow Vault vault, ResourceBundle resourceBundle) {
+	GeneralVaultOptionsController(@VaultOptionsWindow Stage window, @VaultOptionsWindow Vault vault, ResourceBundle resourceBundle) {
+		this.window = window;
 		this.vault = vault;
 		this.resourceBundle = resourceBundle;
 	}
 
 	@FXML
 	public void initialize() {
-		vaultName.textProperty().bindBidirectional(vault.getVaultSettings().displayName());
+		vaultName.textProperty().set(vault.getVaultSettings().displayName().get());
+		vaultName.focusedProperty().addListener(this::checkTrimAndTuncateVaultName);
 		unlockOnStartupCheckbox.selectedProperty().bindBidirectional(vault.getVaultSettings().unlockAfterStartup());
 		actionAfterUnlockChoiceBox.getItems().addAll(WhenUnlocked.values());
 		actionAfterUnlockChoiceBox.valueProperty().bindBidirectional(vault.getVaultSettings().actionAfterUnlock());
 		actionAfterUnlockChoiceBox.setConverter(new WhenUnlockedConverter(resourceBundle));
 	}
 
+	private void checkTrimAndTuncateVaultName(Observable observable, Boolean oldValue, Boolean newValue) {
+		if (!vaultName.isFocused()) { //only check if TextField loses focus
+			String currentContent = vaultName.getText().trim();
+			if (!Strings.isNullOrEmpty(currentContent)) {
+				if (currentContent.length() > 50) {
+					currentContent = currentContent.substring(0, VAULTNAME_TRUNCATE_THRESHOLD);
+				}
+				vaultName.textProperty().set(currentContent);
+				vault.getVaultSettings().displayName().setValue(currentContent);
+			} else {
+				vaultName.textProperty().set(vault.getVaultSettings().displayName().get());
+			}
+		}
+	}
+
 	private static class WhenUnlockedConverter extends StringConverter<WhenUnlocked> {
 
 		private final ResourceBundle resourceBundle;