Having trouble adding label to GridPane in JavaFX

Question

I have a GridPane in FXML document with id of matrix. And I want to add labels to each cell in the matrix. Here is my controller:

package application.view;

import java.awt.Button;
import java.awt.Insets;
import java.awt.Label;

import javafx.fxml.FXML;
import javafx.scene.Node;
import javafx.scene.layout.GridPane;

public class viewController {

    @FXML
    private GridPane matrix;
    private Label[][] label = new Label[10][10];

    public viewController() {
    }

    @FXML
    private void initialize() {

    }

    @FXML
    private void setMatrix() {
        for (int i = 0; i < label.length; i++) {
            for (int j = 0; j < label[i].length; j++) {
                label[i][j].setText("1");
                matrix.add(label[i][j], i, j);
            }
        }
    }

}

Here is my FXML Document:

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.view.viewController">
   <children>
      <SplitPane dividerPositions="0.8467336683417085" orientation="VERTICAL" prefHeight="200.0" prefWidth="160.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
        <items>
          <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
               <children>
                  <GridPane fx:id="matrix" alignment="CENTER" disable="true" gridLinesVisible="true" layoutX="73.0" layoutY="125.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                    <columnConstraints>
                      <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                        <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" 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 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 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 minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                    </rowConstraints>
                  </GridPane>
               </children>
            </AnchorPane>
          <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="100.0" prefWidth="160.0">
               <children>
                  <HBox alignment="CENTER" prefHeight="65.0" prefWidth="200.0" spacing="10.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                     <children>
                        <Button fx:id="refresh" mnemonicParsing="false" text="Refresh" />
                        <Button fx:id="findBlock" mnemonicParsing="false" text="Find Largest Block" />
                     </children>
                  </HBox>
               </children>
            </AnchorPane>
        </items>
      </SplitPane>
   </children>
</AnchorPane>

As you can see I get the GridPane of id matrix. There I want to add a label in each cell. The label will obviously have a number in it.The only thing that is giving me an error is the matrix.add(). It says can't convert to a node. Please help. Thank you!

Answer 1

Like user4132613 said, import javafx.scene.control.Label instead of java.awt.Label. Actually, never use AWT classes with JavaFX.

And you've created the array of labels, but you haven't instantiated the objects inside the array. Method setMatrix() should be:

@FXML
private void setMatrix() {
    for (int i = 0; i < label.length; i++) {
      for (int j = 0; j < label[i].length; j++) {
            label[i][j] = new Label(); // This is missing in the original code
            label[i][j].setText("1");
            matrix.add(label[i][j], i, j);
        }
    }
}

Answer 2

Try using javafx.scene.control.Label class.