Fix page title not updating

src/main/java/edu/kit/typicalc/presenter/Presenter.java

@@ -2,7 +2,6 @@ package edu.kit.typicalc.presenter;
 
 import java.util.Map;
 
-import com.vaadin.flow.component.UI;
 import edu.kit.typicalc.model.Model;
 import edu.kit.typicalc.model.TypeInfererInterface;
 import edu.kit.typicalc.model.parser.ParseError;
@@ -31,11 +30,6 @@ public class Presenter implements MainViewListener {
 
     @Override
     public void typeInferLambdaString(String lambdaTerm, Map<String, String> typeAssumptions) {
-        if (lambdaTerm.isBlank()) {
-            UI.getCurrent().getPage().setTitle(UI.getCurrent().getTranslation("root.typicalc"));
-        } else {
-            UI.getCurrent().getPage().setTitle(UI.getCurrent().getTranslation("root.typicalc") + " - " + lambdaTerm);
-        }
         Result<TypeInfererInterface, ParseError> result = model.getTypeInferer(lambdaTerm, typeAssumptions);
         if (result.isError()) {
             view.displayError(result.unwrapError());

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

@@ -36,7 +36,6 @@ public class StartPageView extends VerticalLayout implements ControlPanelView, L
     private static final String CONTROL_PANEL_ID = "controlPanel";
     private static final String START_PAGE_ID = "startPage";
     private static final String SLIDE_SHOW_ID = "slideShow";
-    private static final String FOOTER_ID = "startpage-footer";
 
     private static final String DOT = ".";
 

src/main/java/edu/kit/typicalc/view/content/typeinferencecontent/TypeInferenceView.java

@@ -10,11 +10,18 @@ import com.vaadin.flow.component.html.Footer;
 import com.vaadin.flow.component.orderedlayout.VerticalLayout;
 import com.vaadin.flow.i18n.LocaleChangeEvent;
 import com.vaadin.flow.i18n.LocaleChangeObserver;
+import com.vaadin.flow.router.BeforeEnterEvent;
+import com.vaadin.flow.router.BeforeEnterObserver;
+import com.vaadin.flow.router.HasDynamicTitle;
+import com.vaadin.flow.router.Route;
 import edu.kit.typicalc.model.TypeInfererInterface;
 import edu.kit.typicalc.view.content.ControlPanel;
 import edu.kit.typicalc.view.content.ControlPanelView;
 import edu.kit.typicalc.view.content.typeinferencecontent.latexcreator.LatexCreator;
+import edu.kit.typicalc.view.main.MainViewImpl;
 
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Locale;
 
@@ -27,8 +34,10 @@ import java.util.Locale;
  */
 @CssImport("./styles/view/type-inference.css")
 @JavaScript("./src/key-shortcuts.js")
+@Route(value = TypeInferenceView.ROUTE + "/:term", layout = MainViewImpl.class)
 public class TypeInferenceView extends VerticalLayout
-        implements ControlPanelView, ComponentEventListener<AttachEvent>, LocaleChangeObserver {
+        implements ControlPanelView, ComponentEventListener<AttachEvent>, LocaleChangeObserver, HasDynamicTitle,
+        BeforeEnterObserver {
     /**
      * Route of this view.
      */
@@ -47,6 +56,15 @@ public class TypeInferenceView extends VerticalLayout
     private final transient TypeInfererInterface typeInferer;
     private final Div content;
     private final ControlPanel controlPanel;
+    private String term = "?";
+
+    // used by Spring
+    public TypeInferenceView() {
+        this.typeInferer = null;
+        this.content = null;
+        this.controlPanel = null;
+        this.treeNumbers = null;
+    }
 
     /**
      * Initializes the component. When initialization is complete, the first step of the type
@@ -138,6 +156,7 @@ public class TypeInferenceView extends VerticalLayout
 
     @Override
     public void localeChange(LocaleChangeEvent localeChangeEvent) {
+        if (typeInferer != null) {
             lc = new LatexCreator(typeInferer,
                     error -> getTranslation("root." + error.toString().toLowerCase(Locale.ENGLISH)));
             unification = new MathjaxUnification(lc.getUnification());
@@ -145,4 +164,23 @@ public class TypeInferenceView extends VerticalLayout
             content.add(unification, tree);
             refreshElements();
         }
+    }
+
+    @Override
+    public void beforeEnter(BeforeEnterEvent event) {
+        if (event.getLocation().getPath().matches(ROUTE + "/.*")) {
+            term = URLDecoder.decode(
+                    event.getRouteParameters().get("term")
+                            .orElseThrow(IllegalStateException::new),
+                    StandardCharsets.UTF_8);
+        }
+    }
+
+    @Override
+    public String getPageTitle() {
+        if (typeInferer != null) {
+            return typeInferer.getFirstInferenceStep().getConclusion().getLambdaTerm().toString();
+        }
+        return UI.getCurrent().getTranslation("root.typicalc") + " - " + term;
+    }
 }

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

@@ -16,11 +16,12 @@ import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 
 import javax.servlet.http.HttpServletResponse;
+import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
+import java.util.TreeMap;
 import java.util.stream.Collectors;
 
 /**
@@ -34,9 +35,8 @@ import java.util.stream.Collectors;
 @CssImport(value = "./styles/view/main/app-layout.css", themeFor = "vaadin-app-layout")
 @JavaScript("./src/svg-pan-zoom.min.js")
 @JavaScript("./src/tex-svg-full.js")
-@Route(TypeInferenceView.ROUTE + "/:term")
 public class MainViewImpl extends AppLayout
-        implements MainView, BeforeEnterObserver, HasErrorParameter<NotFoundException> {
+        implements MainView, HasErrorParameter<NotFoundException>, AfterNavigationObserver {
     private static final long serialVersionUID = -2411433187835906976L;
 
     /**
@@ -45,7 +45,6 @@ public class MainViewImpl extends AppLayout
     public static final String PAGE_TITLE = "Typicalc";
 
     private final UpperBar upperBar;
-    private transient Optional<TypeInferenceView> tiv = Optional.empty();
 
     /**
      * Creates a new MainViewImpl.
@@ -53,15 +52,14 @@ public class MainViewImpl extends AppLayout
     public MainViewImpl() {
         setDrawerOpened(false);
         MainViewListener presenter = new Presenter(new ModelImpl(), this);
-        upperBar = new UpperBar(presenter, this::setTermInURL);
+        upperBar = new UpperBar(presenter, this::processInput);
         addToNavbar(upperBar);
         addToDrawer(new DrawerContent());
     }
 
     @Override
     public void setTypeInferenceView(TypeInfererInterface typeInferer) {
-        tiv = Optional.of(new TypeInferenceView(typeInferer));
+        setContent(new TypeInferenceView(typeInferer));
-        setContent(tiv.get());
     }
 
     @Override
@@ -70,56 +68,41 @@ public class MainViewImpl extends AppLayout
     }
 
     @Override
-    public void beforeEnter(BeforeEnterEvent event) {
+    public void afterNavigation(AfterNavigationEvent event) {
-        tiv = Optional.empty();
+        this.handleLocation(event.getLocation());
-        if (event.getLocation().getPath().matches(TypeInferenceView.ROUTE + "/.*")) {
+    }
-            Location url = event.getLocation();
+
+    private void handleLocation(Location url) {
+        if (url.getPath().matches(TypeInferenceView.ROUTE + "/.*")) {
             List<String> segments = url.getSegments();
             String term = segments.get(segments.size() - 1);
             Map<String, String> types = url.getQueryParameters().getParameters().entrySet().stream().map(entry ->
                     Pair.of(entry.getKey(), entry.getValue().get(0))
             ).collect(Collectors.toMap(Pair::getLeft, Pair::getRight));
             upperBar.inferTerm(decodeURL(term), types);
-        } else if (event.getLocation().getPath().equals(TypeInferenceView.ROUTE)) {
+        } else if (url.getPath().equals(TypeInferenceView.ROUTE)) {
             setContent(new StartPageView());
             upperBar.inferTerm(StringUtils.EMPTY, Collections.emptyMap());
-        } else if (event.getLocation().getPath().equals(StringUtils.EMPTY)) {
+        } else if (url.getPath().equals(StringUtils.EMPTY)) {
             setContent(new StartPageView());
         }
     }
 
-    @Override
+    private void processInput(Pair<String, Map<String, String>> lambdaTermAndAssumptions) {
-    protected void afterNavigation() {
-        // this method ensures that the content is visible after navigation
-        tiv.ifPresent(this::setContent);
-    }
-
-    private void setTermInURL(Pair<String, Map<String, String>> lambdaTermAndAssumptions) {
         String lambdaTerm = lambdaTermAndAssumptions.getLeft();
-        if ("".equals(lambdaTerm)) {
+        if (lambdaTerm.isBlank()) {
-            UI.getCurrent().getPage().getHistory().pushState(null, "./");
+            UI.getCurrent().navigate("./");
-            setContent(new StartPageView());
             return;
         }
-        StringBuilder types = new StringBuilder();
+        QueryParameters qp = new QueryParameters(lambdaTermAndAssumptions.getRight().entrySet().stream().map(entry ->
-        for (Map.Entry<String, String> type : lambdaTermAndAssumptions.getRight().entrySet()) {
+                Pair.of(entry.getKey(), List.of(entry.getValue()))
-            if (types.length() > 0) {
+        ).collect(Collectors.toMap(Pair::getLeft, Pair::getRight,
-                types.append('&');
+                (existing, replacement) -> existing, TreeMap::new)));
-            }
+        UI.getCurrent().navigate(TypeInferenceView.ROUTE + "/" + lambdaTerm, qp);
-            types.append(type.getKey());
-            types.append('=');
-            types.append(type.getValue());
-        }
-        String typeAssumptions = "";
-        if (types.length() > 0) {
-            typeAssumptions = "?" + types.toString();
-        }
-        UI.getCurrent().getPage().getHistory().pushState(null,
-                new Location(TypeInferenceView.ROUTE + "/" + lambdaTerm + typeAssumptions));
     }
 
     private String decodeURL(String encodedUrl) {
-        return java.net.URLDecoder.decode(encodedUrl, StandardCharsets.UTF_8);
+        return URLDecoder.decode(encodedUrl, StandardCharsets.UTF_8);
     }
 
     @Override

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

@@ -3,7 +3,6 @@ package edu.kit.typicalc.view.main;
 import com.vaadin.flow.component.applayout.DrawerToggle;
 import com.vaadin.flow.component.button.Button;
 import com.vaadin.flow.component.dependency.CssImport;
-import com.vaadin.flow.component.dialog.Dialog;
 import com.vaadin.flow.component.html.Anchor;
 import com.vaadin.flow.component.html.H1;
 import com.vaadin.flow.component.icon.Icon;
@@ -41,18 +40,18 @@ public class UpperBar extends HorizontalLayout implements LocaleChangeObserver {
     private final Button helpButton;
 
     private final transient MainViewListener presenter;
-    private final transient Consumer<Pair<String, Map<String, String>>> setTermInURL;
+    private final transient Consumer<Pair<String, Map<String, String>>> inputConsumer;
 
     /**
      * Initializes a new UpperBar with the provided mainViewListener.
      *
      * @param presenter    the listener used to communicate with the model
-     * @param setTermInURL function to set the term into the URL
+     * @param inputConsumer function to handle user input
      */
-    protected UpperBar(MainViewListener presenter, Consumer<Pair<String, Map<String, String>>> setTermInURL) {
+    protected UpperBar(MainViewListener presenter, Consumer<Pair<String, Map<String, String>>> inputConsumer) {
 
         this.presenter = presenter;
-        this.setTermInURL = setTermInURL;
+        this.inputConsumer = inputConsumer;
 
         toggle = new DrawerToggle();
         H1 viewTitle = new H1(new Anchor("/", getTranslation("root.typicalc")));
@@ -60,7 +59,7 @@ public class UpperBar extends HorizontalLayout implements LocaleChangeObserver {
         this.inputBar = new InputBar(this::typeInfer);
         inputBar.setId(INPUT_BAR_ID);
         helpButton = new Button(new Icon(VaadinIcon.QUESTION_CIRCLE));
-        helpButton.addClickListener(event -> onHelpIconClick());
+        helpButton.addClickListener(event -> new HelpDialog().open());
         helpButton.setId(HELP_ICON_ID);
 
         add(toggle, viewTitle, inputBar, helpButton);
@@ -76,10 +75,7 @@ public class UpperBar extends HorizontalLayout implements LocaleChangeObserver {
      * @param termAndAssumptions the lambda term to be type-inferred and the type assumptions to use
      */
     protected void typeInfer(Pair<String, Map<String, String>> termAndAssumptions) {
-        setTermInURL.accept(termAndAssumptions);
+        inputConsumer.accept(termAndAssumptions);
-        if (!"".equals(termAndAssumptions.getLeft())) {
-            startInfer(termAndAssumptions.getLeft(), termAndAssumptions.getRight());
-        }
     }
 
     private void startInfer(String term, Map<String, String> typeAssumptions) {
@@ -98,11 +94,6 @@ public class UpperBar extends HorizontalLayout implements LocaleChangeObserver {
         startInfer(term, typeAssumptions);
     }
 
-    private void onHelpIconClick() {
-        Dialog helpDialog = new HelpDialog();
-        helpDialog.open();
-    }
-
     @Override
     public void localeChange(LocaleChangeEvent event) {
         toggle.getElement().setAttribute("title", getTranslation("root.drawerToggleTooltip"));