grid

Application.java

import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.stage.Stage;

import java.io.IOException;

public class Application extends javafx.application.Application {
    @Override
    public void start(Stage stage) throws IOException {
        FXMLLoader fxmlLoader = new FXMLLoader(Application.class.getResource("hello-view.fxml"));
        Scene scene = new Scene(fxmlLoader.load());
        stage.setTitle("Hello!");
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch();
    }
}

Component.java

import javafx.scene.shape.Rectangle;

public class Component {

    private Rectangle rectangle;
    private int startPositionX;
    private int startPositionY;

    public Component(int size, int startPositionX, int startPositionY) {
        this.startPositionX = startPositionX;
        this.startPositionY = startPositionY;
        rectangle = new Rectangle(startPositionX, startPositionY, size, size);
    }

    public Rectangle getRectangle() {
        return rectangle;
    }

    public int getStartPositionX() {
        return startPositionX;
    }

    public int getStartPositionY() {
        return startPositionY;
    }
}

Controller.java

import com.example.gridbaseddraggable.grid.*;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.layout.AnchorPane;

import java.net.URL;
import java.util.ResourceBundle;

public class Controller implements Initializable {

    private int gridSize = 50;

    @FXML
    private AnchorPane pane;

    private GridHandler backgroundGridHandler;
    private DraggableMakerGrid draggableMakerGrid;
    private DraggableMaker draggableMaker = new DraggableMaker();
    private DraggableMakerGrid2 gridMaker2;

    @Override
    public void initialize(URL url, ResourceBundle resourceBundle) {

        draggableMakerGrid = new DraggableMakerGrid(pane.getPrefWidth(), pane.getPrefHeight(), gridSize, pane);
        gridMaker2 = new DraggableMakerGrid2(pane.getPrefWidth(), pane.getPrefHeight(), gridSize, pane);

        backgroundGridHandler = new GridHandler(pane.getPrefWidth(), pane.getPrefHeight(), gridSize, pane);
        backgroundGridHandler.updateGrid();

        Component component = new Component(gridSize, 100, 100);
        pane.getChildren().add(component.getRectangle());

        //draggableMakerGrid.makeDraggable(component);
        draggableMaker.makeDraggable(component.getRectangle());
    }
}

DraggableMaker.java

import javafx.scene.Node;

public class DraggableMaker {

    private double mouseAnchorX;
    private double mouseAnchorY;

    public void makeDraggable(Node node){
        node.setOnMousePressed(mouseEvent -> {
            mouseAnchorX = mouseEvent.getX();
            mouseAnchorY = mouseEvent.getY();
        });

        node.setOnMouseDragged(mouseEvent -> {
            node.setLayoutX(mouseEvent.getSceneX() - mouseAnchorX);
            node.setLayoutY(mouseEvent.getSceneY() - mouseAnchorY);
        });
    }
}

DraggableMakerGrid.java

import javafx.scene.Node;
import javafx.scene.layout.AnchorPane;

public class DraggableMakerGrid extends GridBase{

    private double mouseAnchorX;
    private double mouseAnchorY;

    public DraggableMakerGrid(double planeWidth, double planeHeight, int gridSize, AnchorPane anchorPane) {
        super(planeWidth, planeHeight, gridSize, anchorPane);
    }

    public void makeDraggable(Node node){
        node.setOnMouseReleased(mouseEvent -> {
            mouseAnchorX = mouseEvent.getSceneX();
            mouseAnchorY = mouseEvent.getSceneY();

            int x = (int) ((mouseAnchorX/getGridSize()) % getTilesAcross()) * getGridSize();
            int y = (int) ((mouseAnchorY/getGridSize()) % getTilesDown()) * getGridSize();

            node.setLayoutX(x);
            node.setLayoutY(y);
        });
    }

    public void makeDraggable(Component component){
        Node node = component.getRectangle();
        node.setOnMouseDragged(mouseEvent -> {
            mouseAnchorX = mouseEvent.getSceneX();
            mouseAnchorY = mouseEvent.getSceneY();

            int x = (int) ((mouseAnchorX/getGridSize()) % getTilesAcross()) * getGridSize();
            int y = (int) ((mouseAnchorY/getGridSize()) % getTilesDown()) * getGridSize();

            node.setLayoutX(x - component.getStartPositionX());
            node.setLayoutY(y - component.getStartPositionY());
        });
    }
}

GridBase.java

import javafx.scene.layout.AnchorPane;

public abstract class GridBase {

    private double planeWidth;
    private double planeHeight;
    private int tilesAcross;
    private int tileAmount;
    private int gridSize;
    private int tilesDown;
    private AnchorPane anchorPane;

    public GridBase(double planeWidth, double planeHeight, int gridSize, AnchorPane anchorPane) {
        this.planeWidth = planeWidth;
        this.planeHeight = planeHeight;
        this.gridSize = gridSize;
        this.anchorPane = anchorPane;

        tilesAcross = (int) (planeWidth / gridSize);
        tileAmount = (int) ((planeWidth /gridSize) * (planeHeight /gridSize));
        tilesDown = tileAmount/tilesAcross;
    }

    public double getPlaneWidth() {
        return planeWidth;
    }

    public double getPlaneHeight() {
        return planeHeight;
    }

    public int getTilesAcross() {
        return tilesAcross;
    }

    public int getTileAmount() {
        return tileAmount;
    }

    public int getGridSize() {
        return gridSize;
    }

    public int getTilesDown() {
        return tilesDown;
    }

    public AnchorPane getAnchorPane() {
        return anchorPane;
    }
}

GridHandler.java

import javafx.scene.layout.AnchorPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;

public class GridHandler extends GridBase {

    Color backgroundColor1 = Color.WHITE;
    Color backgroundColor2 = Color.color(0.82,0.82,0.82);

    public GridHandler(double planeWidth, double planeHeight, int gridSize, AnchorPane anchorPane) {
        super(planeWidth, planeHeight, gridSize, anchorPane);
    }

    public void updateGrid() {
        for(int i = 0; i < getTileAmount(); i++){
            int x = (i % getTilesAcross());
            int y = (i / getTilesAcross());

            Rectangle rectangle = new Rectangle(x * getGridSize(),y * getGridSize(),getGridSize(),getGridSize());

            if((x + y) % 2 == 0){
                rectangle.setFill(backgroundColor1);
            } else {
                rectangle.setFill(backgroundColor2);
            }
            getAnchorPane().getChildren().add(rectangle);
        }
    }
}

hello-view.fxml

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

<?import javafx.scene.layout.AnchorPane?>


<AnchorPane fx:id="pane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/15.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.example.gridbaseddraggable.Controller" />

I'm interested in the fxml file, could you possibly post it here?

The DraggableMakerGrid2 is missing