GraphWin Objects

A GraphWin object represents a window on the screen where graphical images may be drawn. A program may define any number of GraphWins. A GraphWin understands the following methods:

GraphWin(title, width, height, autoflush)

Constructs a new graphics window for drawing on the screen. The parameters are optional, the default title is ``Graphics Window,'' and the default size is 200 x 200. The autoflush parameter, if True causes the window to be immediately updated after every drawing operation. The default value is False, allowing operations to ``batch up'' for better efficiency.

plot(x, y, color)

Draws the pixel at $(x,y)$ in the window. Color is optional, black is the default. Note: pixel-level operations are very inefficient and this method should be avoided.

plotPixel(x, y, Color)

Draws the pixel at the ``raw'' position $(x,y)$ ignoring any coordinate transformations set up by setCoords. Note: pixel-level operations are very inefficient and this method should be avoided.

setBackground(color)

Sets the window background to the given color. The initial background is gray. See Section 5.8.5 for information on specifying colors.

close()

Closes the on-screen window. Once a window is closed, further operations on the window will raise a GraphicsError exception.

isClosed()

Returns a Boolean indicating if the window has been closed either by an explicit call to close or a click on its close box.

getMouse()

Pauses for the user to click in the window and returns where the mouse was clicked as a Point object. Raises GraphicsError if the window is closed while getMouse is in progress.

setCoords(xll, yll, xur, yur)

Sets the coordinate system of the window. The lower left corner is $(xll, yll)$ and the upper right corner is $(xur, yur)$. All subsequent drawing will be done with respect to the altered coordinate system (except for plotPixel).

update()

Causes any pending window operations to be performed. Normally, this will happen automatically during idle periods. Explicit update() calls may be useful for animations.