Class _Screen

Lib/turtle.py:3817–3943

    return Turtle._screen

class _Screen(TurtleScreen):

    _root = None
    _canvas = None
    _title = _CFG["title"]

    def __init__(self):
        if _Screen._root is None:
            _Screen._root = self._root = _Root()
            self._root.title(_Screen._title)
            self._root.ondestroy(self._destroy)
        if _Screen._canvas is None:
            width = _CFG["width"]
            height = _CFG["height"]
            canvwidth = _CFG["canvwidth"]
            canvheight = _CFG["canvheight"]
            leftright = _CFG["leftright"]
            topbottom = _CFG["topbottom"]
            self._root.setupcanvas(width, height, canvwidth, canvheight)
            _Screen._canvas = self._root._getcanvas()
            TurtleScreen.__init__(self, _Screen._canvas)
            self.setup(width, height, leftright, topbottom)

    def setup(self, width=_CFG["width"], height=_CFG["height"],
              startx=_CFG["leftright"], starty=_CFG["topbottom"]):
        """ Set the size and position of the main window.

        Arguments:
        width: as integer a size in pixels, as float a fraction of the screen.
          Default is 50% of screen.
        height: as integer the height in pixels, as float a fraction of the
          screen. Default is 75% of screen.
        startx: if positive, starting position in pixels from the left
          edge of the screen, if negative from the right edge
          Default, startx=None is to center window horizontally.
        starty: if positive, starting position in pixels from the top
          edge of the screen, if negative from the bottom edge
          Default, starty=None is to center window vertically.

        Examples (for a Screen instance named screen):
        >>> screen.setup (width=200, height=200, startx=0, starty=0)

        sets window to 200x200 pixels, in upper left of screen

        >>> screen.setup(width=.75, height=0.5, startx=None, starty=None)

        sets window to 75% of screen by 50% of screen and centers
        """
        if not hasattr(self._root, "set_geometry"):
            return
        sw = self._root.win_width()
        sh = self._root.win_height()
        if isinstance(width, float) and 0 <= width <= 1:
            width = sw*width
        if startx is None:
            startx = (sw - width) / 2
        if isinstance(height, float) and 0 <= height <= 1:
            height = sh*height