CS21: Using the Graphics Library

	from graphics import *

	 win = GraphWin("My GUI Program", 500, 500)   # creates new GraphWin object, 500x500 pixels in size

	 circ = Circle(Point(50,50), 20)    # creates a new Circle object centered at 50,50 with a radius of 20 pixels
	 circ.setFill("red")     # invoke the setFill method of the Circle object refered to by circ 
	 circ.draw(win)          # draw the circ object to the GraphWin win

class GraphWin
--------------

        GraphWin(title, width, height)

        close()
        flush()  # update drawing to graphics window

        getHeight()
        getWidth()

        getMouse() # wait for mouse click and return Point obj representing click location

        setBackground(color)

        setMouseHandler(func)  # func will be executed on mouse click

class Point
------------

     Point(x, y)

     clone()    # create a new Point object that is an exact copy of this one
     getX()
     getY()

     ----------------------- Methods commone to all Graphics Object classes:

     draw(graphwin):    # Draw the object in graphwin, which should be a 
                        # GraphWin object.  A GraphicsObject may only be drawn 
                        # into one window. 
     move(dx, dy):      # move object dx units in x and dy units in y direction
     setFill(color):    # Set interior color to color
     setOutline(color): # Set outline color to color
     setWidth(width):   # Set line weight to width
     undraw():          # Undraw the object (i.e. hide it). 


class Line
----------

     Line(p1, p2)

     clone()
     setArrow(option)   
     getCenter()
     getP1()
     getP2()

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)

class Rectangle
---------------

     Rectangle( p1, p2)  # p1 and p2 are points for upper left lower rt

     clone()
     getCenter()
     getP1()
     getP2()

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)
     undraw()


class Circle
----------
		 Circle(p1, radius)       # p1 is the center of the circle

     clone()
     getCenter()
     getRadius()
     getP1()		# returns a clone of the corresponding corner of the
     getP2()	  # circle's bounding box (opposite corners of bounding square)

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)
     undraw()


class Oval
----------
     Oval(p1, p2)       # p1 and p2 are opposite corners of bounding rectangle 

     clone()
     getCenter()
     getP1()
     getP2()

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)

class Polygon
-------------

     Polygon()
        # ex. triangle: Polygon ([Point(10,20), Point(30,40), Point(10,60)])

     getPoints()  # return a list of Points in the polygon
     clone()

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)
     undraw()


class Text
----------
     Text(p, text)  # p is center point and text is string
    
     clone()
     getText()
     setText(text)
     setTextColor(color)
     setFace(family)     # set font face, ex. "arial" "courier"
     setSize(size)       # set font size (5-36 are legal)    
     setStyle(style)     # set font style  ex.  "bold" "italic"

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)
     undraw()


class Entry: GUI object into which user can type text
------------

     Entry(pt, width)     # pt is anchor Point (center)

     getAnchor()          # returns the center Point
     getText()            # returns the current text
     setText(string)      # sets the text to string
     setSize(point)       # sets the found size (5-36 are legal)
     setStyle(style)      # sets the font style
     setTextColor(color)  # sets the text color

     draw(graphwin)
     move(dx, dy)
     setFill(color)
     setOutline(color)
     setWidth(width)
     undraw()