setContent for startpage + exception handling

src/main/java/edu/kit/typicalc/view/content/infocontent/StartPageView.java

@@ -13,7 +13,7 @@ import edu.kit.typicalc.view.content.typeinferencecontent.MathjaxUnification;
 import edu.kit.typicalc.view.main.MainViewImpl;
 import edu.kit.typicalc.view.main.MathjaxDisplay;
 
-@Route(value = "home", layout = MainViewImpl.class)
+@Route(value = "", layout = MainViewImpl.class)
 @PageTitle("Typicalc")
 @JsModule("./src/mathjax-setup.js")
 public class StartPageView extends VerticalLayout implements ControlPanelView {

src/main/java/edu/kit/typicalc/view/main/ErrorNotification.java

@@ -0,0 +1,25 @@
+package edu.kit.typicalc.view.main;
+
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.html.Span;
+import com.vaadin.flow.component.notification.Notification;
+import com.vaadin.flow.component.notification.NotificationVariant;
+import com.vaadin.flow.component.orderedlayout.FlexComponent;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+
+public class ErrorNotification extends Notification {
+
+    private static final long serialVersionUID = 1L;
+
+    protected ErrorNotification(final String errorMessage) {
+        final VerticalLayout container = new VerticalLayout();
+        final Span errorSpan = new Span(errorMessage);
+        final Button closeButton = new Button(getTranslation("root.close"), event -> this.close());
+        
+        container.add(errorSpan, closeButton);
+        container.setAlignItems(FlexComponent.Alignment.CENTER);
+        addThemeVariants(NotificationVariant.LUMO_ERROR);
+        add(container);
+        setPosition(Position.MIDDLE);
+    }
+}

src/main/java/edu/kit/typicalc/view/main/InputBar.java

@@ -6,12 +6,15 @@ import java.util.function.Consumer;
 import com.vaadin.flow.component.textfield.TextField;
 
 import org.apache.commons.lang3.StringUtils;
+
+import com.vaadin.flow.component.Key;
 import com.vaadin.flow.component.button.Button;
 import com.vaadin.flow.component.button.ButtonVariant;
 import com.vaadin.flow.component.dependency.CssImport;
 import com.vaadin.flow.component.dialog.Dialog;
 import com.vaadin.flow.component.icon.Icon;
 import com.vaadin.flow.component.icon.VaadinIcon;
+import com.vaadin.flow.component.notification.Notification;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
 import com.vaadin.flow.i18n.LocaleChangeEvent;
 import com.vaadin.flow.i18n.LocaleChangeObserver;
@@ -28,6 +31,8 @@ public class InputBar extends HorizontalLayout implements LocaleChangeObserver {
      */
     private static final String INPUT_FIELD_ID = "inputField";
     private static final String INPUT_BAR_ID = "inputBar";
+    
+    private static final short MAX_INPUT_LENGTH = 1000;
 
     private final Icon infoIcon;
     private final Button exampleButton;
@@ -48,26 +53,35 @@ public class InputBar extends HorizontalLayout implements LocaleChangeObserver {
         inputField = new TextField();
         inputField.setId(INPUT_FIELD_ID);
         inputField.setClearButtonVisible(true);
-        //TODO seems to be the only solution to "immediately" parse backslash
-        inputField.addValueChangeListener(event -> {
-            if (inputField.getOptionalValue().isPresent()) {
-                String value = inputField.getValue();
-                value = value.replace("\\", "λ"); //TODO exchange magic strings
-                inputField.setValue(value);
-            }
-        });
+        inputField.addValueChangeListener(event -> onInputFieldValueChange());
         lambdaButton = new Button(getTranslation("root.lambda"), event -> onlambdaButtonClick());
         exampleButton = new Button(getTranslation("root.examplebutton"), event -> onExampleButtonClick());
         inferTypeButton = new Button(getTranslation("root.typeInfer"), event -> onTypeInferButtonClick(callback));
+        inferTypeButton.addClickShortcut(Key.ENTER).listenOn(this);
         inferTypeButton.addThemeVariants(ButtonVariant.LUMO_PRIMARY);
 
         add(infoIcon, exampleButton, lambdaButton, inputField, inferTypeButton);
         setId(INPUT_BAR_ID);
     }
+    
+    protected void reset() {
+        inputField.clear();
+    }
+    
+    private void onInputFieldValueChange() {
+        inputField.getOptionalValue().ifPresent(value -> inputField
+                .setValue(value.replace(getTranslation("root.backslash"), getTranslation("root.lambda"))));
+    }
 
     private void onTypeInferButtonClick(final Consumer<String> callback) {
-        final Optional<String> currentInput = inputField.getOptionalValue();
-        currentInput.ifPresentOrElse(callback::accept, () -> callback.accept(StringUtils.EMPTY));
+        final String currentInput = inputField.getOptionalValue().orElse(StringUtils.EMPTY);
+        
+        if (currentInput.length() < MAX_INPUT_LENGTH) {
+            callback.accept(currentInput);
+        } else {
+            final Notification errorNotification = new ErrorNotification(getTranslation("root.overlongInput"));
+            errorNotification.open();
+        }
     }
 
     private void onlambdaButtonClick() {

src/main/java/edu/kit/typicalc/view/main/MainViewImpl.java

@@ -2,16 +2,10 @@ package edu.kit.typicalc.view.main;
 
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.applayout.AppLayout;
-import com.vaadin.flow.component.button.Button;
 import com.vaadin.flow.component.dependency.CssImport;
 import com.vaadin.flow.component.dependency.JavaScript;
 import com.vaadin.flow.component.dependency.JsModule;
-import com.vaadin.flow.component.html.Span;
 import com.vaadin.flow.component.notification.Notification;
-import com.vaadin.flow.component.notification.Notification.Position;
-import com.vaadin.flow.component.notification.NotificationVariant;
-import com.vaadin.flow.component.orderedlayout.FlexComponent;
-import com.vaadin.flow.component.orderedlayout.VerticalLayout;
 import com.vaadin.flow.router.Location;
 import edu.kit.typicalc.model.ModelImpl;
 import edu.kit.typicalc.model.TypeInfererInterface;
@@ -41,7 +35,7 @@ public class MainViewImpl extends AppLayout implements MainView {
     public MainViewImpl() {
         setDrawerOpened(false);
         MainViewListener presenter = new Presenter(new ModelImpl(), this);
-        addToNavbar(true, new UpperBar(presenter));
+        addToNavbar(true, new UpperBar(presenter, this::setContent));
         addToDrawer(new DrawerContent());
     }
 
@@ -55,16 +49,7 @@ public class MainViewImpl extends AppLayout implements MainView {
     @Override
     public void displayError(final ParseError error) {
         //TODO add error keys to bundle
-        final VerticalLayout container = new VerticalLayout();
-        final Span errorText = new Span(getTranslation("root." + error.toString()));
-        final Notification errorNotification = new Notification();
-        final Button closeButton = new Button(getTranslation("root.close"), event -> errorNotification.close());
-
-        errorNotification.addThemeVariants(NotificationVariant.LUMO_ERROR);
-        container.add(errorText, closeButton);
-        container.setAlignItems(FlexComponent.Alignment.CENTER);
-        errorNotification.add(container);
-        errorNotification.setPosition(Position.MIDDLE);
+        final Notification errorNotification = new ErrorNotification(getTranslation("root." + error.toString()));
         errorNotification.open();
     }
 }

src/main/java/edu/kit/typicalc/view/main/UpperBar.java

@@ -1,5 +1,7 @@
 package edu.kit.typicalc.view.main;
 
+import com.vaadin.flow.component.Component;
+import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.applayout.DrawerToggle;
 import com.vaadin.flow.component.button.Button;
 import com.vaadin.flow.component.dependency.CssImport;
@@ -8,10 +10,15 @@ import com.vaadin.flow.component.html.H1;
 import com.vaadin.flow.component.icon.Icon;
 import com.vaadin.flow.component.icon.VaadinIcon;
 import com.vaadin.flow.component.orderedlayout.HorizontalLayout;
+
 import edu.kit.typicalc.view.content.infocontent.StartPageView;
 import edu.kit.typicalc.view.main.MainView.MainViewListener;
 
 import java.util.HashMap;
+import java.util.function.Consumer;
+
+import org.apache.commons.lang3.StringUtils;
+
 
 /**
  * Contains all the components constantly shown in the upper part of the webage.
@@ -34,17 +41,20 @@ public class UpperBar extends HorizontalLayout {
     private final Button rules;
 
     private final transient MainViewListener presenter;
-
+    private final Consumer<Component> setContent;
+    
     /**
      * Initializes a new UpperBar with the provided mainViewListener.
      *
      * @param presenter the listener used to communicate with the model
+     * @param setContent function to set the content of the application
      */
-    protected UpperBar(final MainViewListener presenter) {
+    protected UpperBar(final MainViewListener presenter, final Consumer<Component> setContent) {
         this.presenter = presenter;
-
+        this.setContent = setContent;
+        
         this.viewTitle = new H1(getTranslation("root.typicalc"));
-        viewTitle.addClickListener(event -> this.getUI().ifPresent(ui -> ui.navigate(StartPageView.class)));
+        viewTitle.addClickListener(event -> routeToStartPage());
         viewTitle.setId(VIEW_TITLE_ID);
         this.inputBar = new InputBar(this::typeInfer);
         inputBar.setId(INPUT_BAR_ID);
@@ -66,7 +76,17 @@ public class UpperBar extends HorizontalLayout {
      * @param lambdaString the lambda term to be type-inferred
      */
     protected void typeInfer(final String lambdaString) {
-        presenter.typeInferLambdaString(lambdaString, new HashMap<>());
+        inputBar.reset(); //TODO should term remain in input field?
+        if (lambdaString.equals(StringUtils.EMPTY)) {
+            routeToStartPage();
+        } else {
+            presenter.typeInferLambdaString(lambdaString, new HashMap<>());
+        }
+    }
+    
+    private void routeToStartPage() {
+        setContent.accept(new StartPageView());
+        UI.getCurrent().getPage().getHistory().replaceState(null, StringUtils.EMPTY);
     }
 
     private void onHelpIconClick() {

src/main/resources/language/general.properties

@@ -1 +1,3 @@
-root.general=Hallo
+root.backslash=\\
+root.lambda=\u03BB
+root.home=home

src/main/resources/language/translation_de.properties

@@ -1,7 +1,6 @@
 root.close=Schließen
 root.copyLatex=Kopiere Latex-Code
 root.typicalc=Typicalc
-root.lambda=\u03BB
 root.examplebutton=📂
 root.selectExample=Beispiel auswählen:
 root.typeInfer=Typisieren
@@ -9,6 +8,7 @@ root.operatingHelp=Bedienhilfen
 root.inputSyntax=Eingabe Syntax
 root.inferenceRules=Ableitungsregeln
 root.absRule=Abs-Regel
+root.overlongInput=Die maximale Länge der Eingabe beträgt 1000 Zeichen!
 
 abs-rule=\
 \\begin{prooftree}\

src/main/resources/language/translation_en.properties

@@ -1,7 +1,6 @@
 root.close=Close
 root.copyLatex=Copy latex code
 root.typicalc=Typicalc
-root.lambda=\u03BB
 root.examplebutton=📂
 root.selectExample=Select example:
 root.typeInfer=Type