31. Mouse Click

The method setOnMouseClicked on the scene is used to listen for mouse clicks.

The coordinates of the point clicked is printed on the canvas.

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package ex31;

import javafx.application.Application;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.Group;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;

public class Ex31 extends Application 
{
    public static void main(String[] args) 
    {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) 
    {
        primaryStage.setTitle( "Example 31. Mouse Click" );

        Group root = new Group();
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);

        Canvas canvas = new Canvas(500, 200);
        GraphicsContext gc = canvas.getGraphicsContext2D();

        Font font = Font.font( "Georgia", FontWeight.BOLD, 32 );
        gc.setFont(font);
        gc.setStroke(Color.BLUE);
        gc.setFill(Color.GREEN);
        gc.fillRect(0,0, 512,512);
        gc.strokeText("Please Click!", 100, 100 );
        root.getChildren().add( canvas );

        scene.setOnMouseClicked ( e -> {
            double x = e.getX();
            double y = e.getY();
            gc.fillRect(0,0, 512,512);
            gc.setFill(Color.GREEN);
            String pointText = "Point: (" + x + ", " + y + ")";
            gc.strokeText( pointText, 100, 100 );
        });
        
        primaryStage.show();
    }
}

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This is the output after clicking at the upper-left corner:

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