In the last section, we used the to_parent()
method (line 66) to translate the coordinates relative to the DrawingSpace
to its parent.
Note
Please note, that we were inside DraggableWidget
and the coordinates we received were relative to the parent (DrawingSpace
).
These coordinates are convenient for DraggableWidget
because we position it in the parent's coordinates. It allows us to use the coordinates in the parent's collide_point
. This is no longer convenient when we want to check the coordinates on the parent's parent space or when we need to draw something directly on the canvas of a Widget
.
Before studying more examples, let's summarize the theory.You learned that RelativeLayout
is very useful because it is easier to think inside of a constraint space to localize our objects. The problems start when we need to translate the coordinates to other Widget
area. Let us consider the following screenshot of a Kivy program: