JavaFX Right Coordinate of a CustomMenuItem - javafx

Question

I have a Class that extends the CustomMenuItem. This MenuItems are added to a ContextMenu. Now i need to get the X-Coordinates from the right side of the CustomMenuItem.
The Problem is, that I have no idea how I can get the Coordinates.
The CustMenuItem has no function for getting the Coordinates like getX() or getY().
So how can I solve this problem?
This thing I would like to get:
Here we can see a Sample for a Context Menu (red lines). In the Context Menu are a lot of different CustomMenuItems implemented. Now I would like to get the right top corner Coordinate of the CustomMenuItem.
Thank you for your very nice help.

Answer 1

Before dealing with menu items, let's start saying that a ContextMenu is a popup window, so it has Windowproperties. You can ask for (x,y) left, top origin, and for (w,h).
But you have to take into account the effects, since by default it includes a dropshadow. And when it does, there's an extra space added of 24x24 pixels to the right and bottom.
.context-menu {
-fx-effect: dropshadow( gaussian , rgba(0,0,0,0.2) , 12, 0.0 , 0 , 8 );
}
Since this default dropshadow has a radius of 12px, and Y-offset to the bottom of 8px, the right and bottom coordinates of the context menu, including the 24x24 area, are given by:
X=t.getX()+cm.getWidth()-12-24;
Y=t.getY()+cm.getHeight()-(12-8)-24;
where t could be a MouseEvent relative to the scene, and values are hardcoded for simplicity.
Let's see this over an example. Since you don't say how your custom menu items are implemented, I'll just create a simple Menu Item with graphic and text:
private final Label labX = new Label("X: ");
private final Label labY = new Label("Y: ");
#Override
public void start(Stage primaryStage) {
final ContextMenu cm = new ContextMenu();
MenuItem cmItem1 = createMenuItem("mNext", "Next Long Option",t->System.out.println("next"));
MenuItem cmItem2 = createMenuItem("mBack", "Go Back", t->System.out.println("back"));
SeparatorMenuItem sm = new SeparatorMenuItem();
cm.getItems().addAll(cmItem1,cmItem2);
VBox root = new VBox(10,labX,labY);
Scene scene = new Scene(root, 300, 250);
scene.setOnMouseClicked(t->{
if(t.getButton()==MouseButton.SECONDARY || t.isControlDown()){
// t.getX,Y->scene based coordinates
cm.show(scene.getWindow(),t.getX()+scene.getWindow().getX()+scene.getX(),
t.getY()+scene.getWindow().getY()+scene.getY());
labX.setText("Right X: "+(t.getX()+cm.getWidth()-12-24));
labY.setText("Bottom Y: "+(t.getY()+cm.getHeight()-4-24));
}
});
scene.getStylesheets().add(getClass().getResource("root.css").toExternalForm());
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.setTitle("Scene: "+scene.getWidth()+"x"+scene.getHeight());
}
private MenuItem createMenuItem(String symbol, String text, EventHandler<ActionEvent> t){
MenuItem m=new MenuItem(text);
StackPane g=new StackPane();
g.setPrefSize(24, 24);
g.setId(symbol);
m.setGraphic(g);
m.setOnAction(t);
return m;
}
If you remove the effect:
.context-menu {
-fx-effect: null;
}
then these coordinates are:
X=t.getX()+cm.getWidth();
Y=t.getY()+cm.getHeight();
Now that we have the window, let's go into the items.
MenuItem skin is derived from a (private) ContextMenuContent.MenuItemContainer class, which is a Region where the graphic and text are layed out.
When the context menu is built, all the items are wrapped in a VBox, and all are equally resized, as you can see if you set the border for the item:
.menu-item {
-fx-border-color: black;
-fx-border-width: 1;
}
This is how it looks like:
So the X coordinates of every item on the custom context menu are the same X from their parent (see above, with or without effect), minus 1 pixel of padding (by default).
Note that you could also go via private methods to get dimensions for the items:
ContextMenuContent cmc= (ContextMenuContent)cm.getSkin().getNode();
System.out.println("cmc: "+cmc.getItemsContainer().getBoundsInParent());
Though this is not recommended since private API can change in the future.
EDIT
By request, this is the same code removing lambdas and css.
private final Label labX = new Label("X: ");
private final Label labY = new Label("Y: ");
#Override
public void start(Stage primaryStage) {
final ContextMenu cm = new ContextMenu();
MenuItem cmItem1 = createMenuItem("mNext", "Next Long Option",action);
MenuItem cmItem2 = createMenuItem("mBack", "Go Back", action);
SeparatorMenuItem sm = new SeparatorMenuItem();
cm.getItems().addAll(cmItem1,cmItem2);
VBox root = new VBox(10,labX,labY);
Scene scene = new Scene(root, 300, 250);
scene.setOnMouseClicked(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent t) {
if(t.getButton()==MouseButton.SECONDARY || t.isControlDown()){
// t.getX,Y->scene based coordinates
cm.show(scene.getWindow(),t.getX()+scene.getWindow().getX()+scene.getX(),
t.getY()+scene.getWindow().getY()+scene.getY());
labX.setText("Right X: "+(t.getX()+cm.getWidth()-12-24));
labY.setText("Bottom Y: "+(t.getY()+cm.getHeight()-4-24));
}
}
});
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.setTitle("Scene: "+scene.getWidth()+"x"+scene.getHeight());
}
private MenuItem createMenuItem(String symbol, String text, EventHandler<ActionEvent> t){
MenuItem m=new MenuItem(text);
StackPane g=new StackPane();
g.setPrefSize(24, 24);
g.setId(symbol);
SVGPath svg = new SVGPath();
svg.setContent("M0,5H2L4,8L8,0H10L5,10H3Z");
m.setGraphic(svg);
m.setOnAction(t);
return m;
}
private final EventHandler<ActionEvent> action = new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
System.out.println("action");
}
};