Custom Node painting in JavaFX - user-interface

Question

In PySide you can override the paintEvent() method of a QWidget to control how the widget is painted on the screen. Is there an equivalent for Node in JavaFX?
In context: I'm in need of a way to display a custom image format on the screen. Constantly converting my format and JavaFX's Image so I can display it in an ImageView is too slow for me, in addition to being messier.
I've taken a look at ImageView.java and Canvas.java, but no luck. ImageView is using css, and Canvas appears to be doing something with the deprecated impl_ methods, for which I've found no documentation on.
Thanks!

Answer 1

Generally, the paint mechanisms in JavaFX changed towards a more event-based approach. To follow the JavaFX way, you should probably look at Timeline or AnimationTimer and only update the display when the actual image data changes.
However, you could use the old Swing way in JavaFX, if you like:
public class MyPane extends Pane {
private final Canvas canvas;
public MyPane() {
canvas = new Canvas(getWidth(), getHeight());
getChildren().add(canvas);
widthProperty().addListener(e -> canvas.setWidth(getWidth()));
heightProperty().addListener(e -> canvas.setHeight(getHeight()));
}
#Override
protected void layoutChildren() {
super.layoutChildren();
GraphicsContext gc = canvas.getGraphicsContext2D();
gc.clearRect(0, 0, getWidth(), getHeight());
gc.setFill(Color.RED);
gc.fillRect(10, 10, getWidth() - 20, getHeight() - 20);
// Paint your custom image here:
gc.drawImage(someImage, 0, 0);
}
}
The above code would be the equivalence of this Swing code:
public class MyPanel extends JPanel {
private static final long serialVersionUID = -969772195113348076L;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.clearRect(0, 0, getWidth(), getHeight());
g.setColor(java.awt.Color.RED);
g.fillRect(10, 10, getWidth() - 20, getHeight() - 20);
// Paint your custom image here:
g.drawImage(someImage, 0, 0, null);
}
}