It would be logical if a node that receives mouse events was getting mouse coordinates in its own coordinate space, before transformations are applied. Consider an example: A node that shows a line when the mouse is clicked and dragged over it -- class LineDragger. This class works fine until a transformation is applied to the group that contains it (see code below). The example demonstrates that mouse coordinates are useless for a node that has transformations applied to it or to any of its parents. A more practical example is a control (e.g. scrollbar, tabbed pane) that is created in horizontal mode and then rotated to work in vertical mode.

This issue is related to RT-659, which talks about effects.

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import javafx.scene.CustomNode;
import javafx.scene.Group;
import javafx.scene.input.MouseEvent;
import javafx.scene.Node;
import javafx.scene.paint.Color;
import javafx.scene.Scene;
import javafx.scene.shape.Line;
import javafx.scene.shape.Rectangle;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;

class LineDragger extends CustomNode {


    override function create (): Node {
        var l: Line;
        var r: Rectangle;
        def g: Group = Group {
            content: [
                r = Rectangle {
                    fill: Color.BLUE
                    width: 100
                    height: 100
                }
                l = Line {
                    stroke: Color.WHITE;
                    visible: false
                }
            ]

            onMouseDragged: function(e: MouseEvent) {
                l.startX = e.dragAnchorX - g.boundsInScene.minX;
                l.startY = e.dragAnchorY - g.boundsInScene.minY;
                l.endX = e.dragAnchorX + e.dragX - g.boundsInScene.minX;
                l.endY = e.dragAnchorY + e.dragY - g.boundsInScene.minY;
                l.visible = true;
            }

            onMouseReleased: function(e: MouseEvent) {
                l.visible = false;
            }
        };
        return g
    }
}



Stage {
    width: 200
    height: 200
    scene: Scene {
        var g: Group;
        content: g = Group {
                translateX: 20
                translateY: 20
                content: [LineDragger {}]
                transforms: Rotate {
                    angle: 45
                    pivotX: bind g.boundsInLocal.width / 2
                    pivotY: bind g.boundsInLocal.height / 2
                }
            }
    }
}

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Change the angle from 45 to 0 to make this code work just fine.