Resolves #31 Enhance MenuItem methods for setting icons

Author: javier-godoy

src/main/java/com/flowingcode/addons/applayout/menu/MenuItem.java

@@ -25,6 +25,7 @@
 import java.util.Arrays;
 import java.util.List;
 
+import com.vaadin.flow.component.icon.VaadinIcon;
 import com.vaadin.flow.server.Command;
 
 /**
@@ -64,6 +65,14 @@ public MenuItem(String label, String icon, Command command) {
 		this.icon = icon;
 	}
 
+	public MenuItem(String label, VaadinIcon icon, Command command) {
+		this(label, getIconName(icon), command);
+	}
+	
+	private static String getIconName(VaadinIcon icon) {
+		return icon.create().getElement().getAttribute("icon");
+	}
+
 	public String getLabel() {
 		return label;
 	}

src/test/java/com/flowingcode/addons/applayout/DemoView.java

@@ -25,7 +25,6 @@
 import java.io.InputStreamReader;
 import java.util.stream.Collectors;
 
-
 import com.flowingcode.addons.applayout.menu.MenuItem;
 import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.button.Button;
@@ -38,6 +37,7 @@
 import com.vaadin.flow.component.html.H5;
 import com.vaadin.flow.component.html.Image;
 import com.vaadin.flow.component.html.Span;
+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.component.orderedlayout.VerticalLayout;
@@ -177,7 +177,7 @@ private MenuItem[] createMenuItems() {
 		toggleSettings.getCommand().execute();
 
 		return new MenuItem[] {
-				new MenuItem("Content", "vaadin:book", () -> showHamletContent()),
+				new MenuItem("Content", VaadinIcon.BOOK, () -> showHamletContent()),
 				toggleSettings,
 				mi,
 				new MenuItem("About", "cloud", () -> showContent("About")),