Placing child window relative to parent in Tkinter python

coordinates, python, tkinter, window

Solution

The short answer is, use `winfo_rootx` and `winfo_rooty` to get the coordinates relative to the screen. And yes, `wm_geometry` is the way to place a toplevel window precisely.

For example:

    x = parentWgdt.winfo_rootx()
    y = parentWgdt.winfo_rooty()
    height = parentWgdt.winfo_height()
    geom = "+%d+%d" % (x,y+height)

As a bit of friendly advice, I recommend against abbrev var nms. It makes the code hard to read, especially when the abbreviation is wrong (Wgdt should at least be Wdgt). The difference in code size between `geom` and `geometry`, and `Wgdt` and `Widget` are tiny, but the difference in readability is huge.

Problem

I have a parent widget which contains a button. When the button is pressed I would like to open a borderless (i.e. no Windows decoration buttons) window directly underneath the parent widget aligned to the left hand side of it. I'm puzzled that the only way (it seems) of setting the position of a window is using `.geometry()` but worse, I can't seem to get the absolute coordinates of the parent widget - which I need for `.geometry()`, only the offsets from the parent's parent. So far my code is: ``` # This is the child which appears when the button is pressed. class ChildPopUpWindow(Frame): def __init__(self, parentWgdt): win = Toplevel(parentWgdt) geom = str(parentWgdt.winfo_x()) + '+' + str(parentWgdt.winfo_y() + parentWgdt.winfo_height()) win.overrideredirect(1) # No win decoration. win.bd = 10 win.relief = GROOVE win.geometry( geom ) Frame.__init__(self, win) # etc. etc. # ... and this is the handler for the button being pressed. def onDropDown(self): popUp = ChildPopUpWindow(self) ``` This does pop up a window but relative to the desktop, not to the parent widget. It also seems to take no account of the border thickness and relief as far as I can see. Can anyone offer a way that this can be done? Is `.geometry()` the way to go or are there better ways?

Original source