'''
    typeablewindow.py
    Jeff Ondich, updated 3 November 2018

    The TypeableWindow class demonstrates how to handle keyboard events
    in the context of John Zelle's graphics library.

    TypeableWindow uses the Tkinter "bind_all" mechanism to trap
    keyboard events and respond to them appropriately.

    The discussion of Events and Bindings in the Tkinter library at
    http://www.pythonware.com/library/tkinter/introduction/events-and-bindings.htm
    describes more things you can do to handle keyboard events.
'''

from graphics import *

class TypeableWindow(GraphWin):
    def __init__(self, title, width, height):
        GraphWin.__init__(self, title, width, height)
        self.setBackground(color_rgb(255, 255, 255))
        self.circle = Circle(Point(width // 2, height // 2), min(width, height) // 4)
        self.circle.setFill(color_rgb(180, 50, 50))
        self.circle.draw(self)

        self.bind_all('<Key>', self.key_handler)
        self.bind_all('<Up>', self.up_handler)
        self.bind_all('<Down>', self.down_handler)
        self.bind_all('<Left>', self.left_handler)
        self.bind_all('<Right>', self.right_handler)

    def key_handler(self, event):
        if event.char == 'r':
            self.circle.setFill(color_rgb(180, 50, 50))
        elif event.char == 'g':
            self.circle.setFill(color_rgb(50, 180, 50))
        elif event.char == 'b':
            self.circle.setFill(color_rgb(50, 50, 180))

    def up_handler(self, event):
        self.circle.move(0, -10)

    def down_handler(self, event):
        self.circle.move(0, 10)

    def right_handler(self, event):
        self.circle.move(10, 0)

    def left_handler(self, event):
        self.circle.move(-10, 0)

if __name__ == '__main__':
    print('Use the arrow keys to move the circle around.')
    print('Type r, g, or b to change its color.')

    window = TypeableWindow('Keyboard Test', 1000, 600)
    while window.winfo_exists():
        window.update()