The code below results in a JavaFX Canvas that can be drawn on with the mouse pointer but skips some points, i.e., leaves gaps if one tries to draw a continuous line. The ga
This code from here.
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
/**
* @web http://java-buddy.blogspot.com/
*/
public class JavaFX_DrawOnCanvas extends Application {
@Override
public void start(Stage primaryStage) {
Canvas canvas = new Canvas(400, 400);
final GraphicsContext graphicsContext = canvas.getGraphicsContext2D();
initDraw(graphicsContext);
canvas.addEventHandler(MouseEvent.MOUSE_PRESSED,
new EventHandler(){
@Override
public void handle(MouseEvent event) {
graphicsContext.beginPath();
graphicsContext.moveTo(event.getX(), event.getY());
graphicsContext.stroke();
}
});
canvas.addEventHandler(MouseEvent.MOUSE_DRAGGED,
new EventHandler(){
@Override
public void handle(MouseEvent event) {
graphicsContext.lineTo(event.getX(), event.getY());
graphicsContext.stroke();
}
});
canvas.addEventHandler(MouseEvent.MOUSE_RELEASED,
new EventHandler(){
@Override
public void handle(MouseEvent event) {
}
});
StackPane root = new StackPane();
root.getChildren().add(canvas);
Scene scene = new Scene(root, 400, 400);
primaryStage.setTitle("java-buddy.blogspot.com");
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
private void initDraw(GraphicsContext gc){
double canvasWidth = gc.getCanvas().getWidth();
double canvasHeight = gc.getCanvas().getHeight();
gc.setFill(Color.LIGHTGRAY);
gc.setStroke(Color.BLACK);
gc.setLineWidth(5);
gc.fill();
gc.strokeRect(
0, //x of the upper left corner
0, //y of the upper left corner
canvasWidth, //width of the rectangle
canvasHeight); //height of the rectangle
gc.setFill(Color.RED);
gc.setStroke(Color.BLUE);
gc.setLineWidth(1);
}
}