Window

import introcs.turtle

A window is a GUI canvas that supports turtle (Turtle or Pen) graphics. You construct a window before adding the turtle or pen. A window can have as many turtles or pens as you want at the same time. It can also have no turtles or pens.

While windows may be resized, your should take great care when resizing them while drawing. Since the origin is typically the center of the window, resizing a window will shift the drawing implements (Turtle and Pen objects) to a new position. For the most part, this should preserve coordinates, but round-off error may be an issue.

Because of the overhead, this class is not included in the top level of the introcs module. It must be imported separately as part of the introcs.turtle module.

Constructor

class introcs.turtle.Window(x=50, y=50, width=700, height=700, scale=1)

An instance is a GUI windows that support turtle graphics

You should construct a Window object before constructing a Turtle or Pen. While you should only need one Window object at any given time, you may have as many as you want. Deleteing a Window object will close the window, making the associated turtles and pens invalid.

Parameters

  • x (int >= 0) – initial x coordinate (default 50)

  • y (int >= 0) – initial y coordinate (default 50)

  • width (int > 0) – initial window width (default 700)

  • height (int > 0) – initial window height (default 700)

  • scale (float > 0) – initial window scale (INGORED)

Mutable Attributes

Window.x

The x coordinate for top left corner of window

Screen coordinates have their origin in the top left corner, with y increasing downwards.

invariant: x must be an int >= 0

Window.y

The y coordinate for top left corner of window

Screen coordinates have their origin in the top left corner, with y increasing downwards.

invariant: y must be an int >= 0

Window.width

The width of the drawing canvas in pixels

The width specified is the width of the internal drawing canvas. The width does not include the border or window frame (title, close buttons, etc.)

invariant: width must be an int > 0

Window.height

The height of the drawing canvas in pixels

The height specified is the height of the internal drawing canvas. The height does not include the border or window frame (title, close buttons, etc.)

invariant: height must be an int > 0

Window.title

The title displayed at top of window bar

invariant: title must be a str

Window.resizable

Whether or not the Window supports user resizing

invariant: resizable must be a bool

Immutable Attributes

These attributes may be read (e.g. used in an expression), but not altered.

Window.turtles

The tuple of all turtles attached to this Window

This attribute may not be altered directly

Window.pens

The tuple of all pens attached to this Window.

This attribute may not be altered directly

Methods

All of these methods modify the underlying window object.

Window.setPosition(x, y)

Sets the position of this Window

Screen coordinates have their origin in the top left corner, with y increasing downwards.

Parameters

  • x – the left edge of the window

  • y – the top edge of the window

Window.setSize(width, height)

Sets the size for this Window

The size specified is the actual the size of the internal drawing canvas. The size does not include the border or window frame (title, close buttons, etc.)

Parameters

  • width (int > 0) – the window width

  • height (int > 0) – the height width

Window.setMaxSize(width, height)

Sets the maximum size for this Window

The size specified is the maximum the size of the internal drawing canvas. The size does not include the border or window frame (title, close buttons, etc.)

Any attempt to resize a dimension beyond the maximum size will fail.

Parameters

  • width (int > 0) – the maximum Window width

  • height (int > 0) – the maximum Window height

Window.setMinSize(width, height)

Sets the minimum size for this window

The size specified is the minimum the size of the internal drawing canvas. The size does not include the border or window frame (title, close buttons, etc.)

Any attempt to resize a dimension below the minimum size will fail.

Parameters

  • width (int > 0) – the minimum Window width

  • height (int > 0) – the minimum Window height

Window.iconify()

Shrinks the Window down to an icon, effectively hiding it

Window.deiconify()

Expands the Window from an icon so that it is visible

Window.flush()

Displays any pending drawing commands on the screen.

This command is necessary when Turtle or Pen speed is set to 0. When that happens, the drawing tool will not force a refresh until this command is executed.

Window.clear()

Erases the contents of this Window

All Turtles and Pens are eliminated from the Window. Any attempt to use a previously created Turtle or Pen will fail.

Window.dispose()

Closes the graphics Window, deleting all assets.

Window.beep()

Plays an OS specific alert sound

Errors

class introcs.turtle.window.AttachmentError

Instance is an error for an illegal drawing operation.

This error is used to prevent drawing tools from using commands when they are unhooked from their window.