Rewrite the turtledemo makeGraphFrame method (#104224)

Replace `self._canvas` and `self.scanvas`, both bound to `canvas`,
with `self.canvas, which is accessed in other methods.
Replace `_s_` with `screen` and `_s_._canvas` with `canvas`.
Add a comment explaining the unorthodox use of
function turtle.Screen and singleton class turtle._Screen.
This commit is contained in:
Terry Jan Reedy 2023-05-06 11:09:08 -04:00 committed by GitHub
parent e407661e7a
commit 96f95df48e
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1 changed files with 14 additions and 10 deletions

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@ -203,10 +203,10 @@ class DemoWindow(object):
def onResize(self, event):
cwidth = self._canvas.winfo_width()
cheight = self._canvas.winfo_height()
self._canvas.xview_moveto(0.5*(self.canvwidth-cwidth)/self.canvwidth)
self._canvas.yview_moveto(0.5*(self.canvheight-cheight)/self.canvheight)
cwidth = self.canvas.winfo_width()
cheight = self.canvas.winfo_height()
self.canvas.xview_moveto(0.5*(self.canvwidth-cwidth)/self.canvwidth)
self.canvas.yview_moveto(0.5*(self.canvheight-cheight)/self.canvheight)
def makeTextFrame(self, root):
self.text_frame = text_frame = Frame(root)
@ -237,19 +237,23 @@ class DemoWindow(object):
return text_frame
def makeGraphFrame(self, root):
# t._Screen is a singleton class instantiated or retrieved
# by calling Screen. Since tdemo canvas needs a different
# configuration, we manually set class attributes before
# calling Screen and manually call superclass init after.
turtle._Screen._root = root
self.canvwidth = 1000
self.canvheight = 800
turtle._Screen._canvas = self._canvas = canvas = turtle.ScrolledCanvas(
turtle._Screen._canvas = self.canvas = canvas = turtle.ScrolledCanvas(
root, 800, 600, self.canvwidth, self.canvheight)
canvas.adjustScrolls()
canvas._rootwindow.bind('<Configure>', self.onResize)
canvas._canvas['borderwidth'] = 0
self.screen = _s_ = turtle.Screen()
turtle.TurtleScreen.__init__(_s_, _s_._canvas)
self.scanvas = _s_._canvas
turtle.RawTurtle.screens = [_s_]
self.screen = screen = turtle.Screen()
turtle.TurtleScreen.__init__(screen, canvas)
turtle.RawTurtle.screens = [screen]
return canvas
def set_txtsize(self, size):
@ -373,7 +377,7 @@ class DemoWindow(object):
def clearCanvas(self):
self.refreshCanvas()
self.screen._delete("all")
self.scanvas.config(cursor="")
self.canvas.config(cursor="")
self.configGUI(NORMAL, DISABLED, DISABLED)
def stopIt(self):