Added JavaFX login dialog scene

src/main/java/envoy/client/ui/LoginDialog.fxml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.control.Button?>
+<?import javafx.scene.control.CheckBox?>
+<?import javafx.scene.control.Label?>
+<?import javafx.scene.control.PasswordField?>
+<?import javafx.scene.control.TextField?>
+<?import javafx.scene.layout.ColumnConstraints?>
+<?import javafx.scene.layout.GridPane?>
+<?import javafx.scene.layout.HBox?>
+<?import javafx.scene.layout.RowConstraints?>
+<?import javafx.scene.layout.VBox?>
+<?import javafx.scene.text.Font?>
+
+<VBox maxHeight="-Infinity" maxWidth="-Infinity"
+	minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0"
+	prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1"
+	xmlns:fx="http://javafx.com/fxml/1"
+	fx:controller="envoy.client.ui.LoginDialogController">
+	<children>
+		<Label text="User Login">
+			<font>
+				<Font size="26.0" />
+			</font>
+		</Label>
+		<GridPane>
+			<columnConstraints>
+				<ColumnConstraints hgrow="SOMETIMES"
+					minWidth="10.0" percentWidth="40.0" prefWidth="100.0" />
+				<ColumnConstraints hgrow="SOMETIMES"
+					minWidth="10.0" prefWidth="100.0" />
+			</columnConstraints>
+			<rowConstraints>
+				<RowConstraints minHeight="10.0" prefHeight="30.0"
+					vgrow="SOMETIMES" />
+				<RowConstraints minHeight="10.0" prefHeight="30.0"
+					vgrow="SOMETIMES" />
+				<RowConstraints minHeight="10.0" prefHeight="30.0"
+					vgrow="SOMETIMES" />
+			</rowConstraints>
+			<children>
+				<Label text="User Name:" />
+				<Label text="Password" GridPane.rowIndex="1" />
+				<Label text="Repeat Password:" visible="false"
+					GridPane.rowIndex="2" fx:id="repeatPasswordLabel" />
+				<TextField GridPane.columnIndex="1" />
+				<PasswordField GridPane.columnIndex="1"
+					GridPane.rowIndex="1" fx:id="repeatPasswordField"/>
+				<PasswordField visible="false"
+					GridPane.columnIndex="1" GridPane.rowIndex="2" fx:id="repeatPasswordField"/>
+			</children>
+		</GridPane>
+		<CheckBox mnemonicParsing="false" text="Register" fx:id="registerCheckBox" onAction="#registerCheckboxChanged"/>
+		<HBox prefHeight="100.0" prefWidth="200.0">
+			<children>
+				<Button cancelButton="true" mnemonicParsing="false"
+					text="Cancel" onAction="#cancelButtonClicked"/>
+				<Button defaultButton="true" mnemonicParsing="false"
+					text="Submit" disable="true" onAction="#submitButtonClicked"/>
+			</children>
+		</HBox>
+	</children>
+</VBox>

src/main/java/envoy/client/ui/LoginDialogController.java

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+package envoy.client.ui;
+
+import javafx.event.ActionEvent;
+import javafx.fxml.FXML;
+import javafx.scene.Node;
+import javafx.scene.control.CheckBox;
+import javafx.scene.control.Label;
+import javafx.scene.control.PasswordField;
+import javafx.stage.Stage;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>LoginDialogController.java</strong><br>
+ * Created: <strong>03.04.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.1-beta
+ */
+public final class LoginDialogController {
+
+	@FXML
+	private PasswordField passwordField;
+
+	@FXML
+	private PasswordField repeatPasswordField;
+
+	@FXML
+	private Label repeatPasswordLabel;
+
+	@FXML
+	private CheckBox registerCheckBox;
+
+	@FXML
+	private void registerCheckboxChanged() {
+
+		// Make repeat password field and label visible / invisible
+		repeatPasswordField.setVisible(registerCheckBox.isSelected());
+		repeatPasswordLabel.setVisible(registerCheckBox.isSelected());
+
+		// Clear repeat password field if registration cancelled
+		if (!registerCheckBox.isSelected()) repeatPasswordField.clear();
+	}
+
+	@FXML
+	private void submitButtonClicked() {
+
+	}
+
+	@FXML
+	private void cancelButtonClicked(ActionEvent e) { closeStage(e); }
+
+	private void closeStage(ActionEvent e) { ((Stage) ((Node) e.getSource()).getScene().getWindow()).close(); }
+}