ClientChatroom.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.ListView?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>

<BorderPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="assignment7.ClientChatroomController">
   <center>
      <ListView fx:id="chatText" prefHeight="333.0" prefWidth="400.0" BorderPane.alignment="CENTER" />
   </center>
   <right>
      <ListView fx:id="chatClients" prefHeight="200.0" prefWidth="200.0" BorderPane.alignment="CENTER" />
   </right>
   <bottom>
      <GridPane BorderPane.alignment="CENTER_RIGHT">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <padding>
            <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
         </padding>
         <children>
            <TextField fx:id="messageField" />
         </children>
      </GridPane>
   </bottom>
</BorderPane>