#
# draw_polylines.py
#
#  CREATED:  2023.04.19  ABS  written by ChatGPT
# MODIFIED:  2023.04.19  ABS  tweaked, added menu code
# MODIFIED:  2023.04.20  ABS  tweaked, got Save working (.vect format), button 2
# MODIFIED:  2023.04.21  ABS  debugged button 2 (right click); added buggy Clear
# MODIFIED:  2023.04.26  ABS  debugged Clear; added clumsy clipping
#
# prompt:
#
# Write a program in Python 2.7 to create a GUI with a drawing canvas where
# the user can draw a polyline by clicking points in rubber band mode.
#
# ChatGPT:
#
# I'm sorry, but as a language model, I don't have the capability to create a
# GUI with a drawing canvas on my own. However, I can provide you with some
# guidance on how to create a GUI with a drawing canvas in Python 2.7.
# 
# One way to create a GUI with a drawing canvas in Python 2.7 is to use the
# Tkinter module. Here's an example program that creates a canvas and allows
# the user to draw a polyline by clicking points in rubber band mode: [code]
#
# ToDo: get menus working:
#       [X] Save
#       [X] Clear
#
#       [_] New
#       [_] Open
#       [_] Save as...
#       [_] Close

from Tkinter import *

class RubberBandCanvas(Canvas):
    def __init__(self, master=None, **kwargs):
        Canvas.__init__(self, master, width=512, height=512, **kwargs)
        self.bind("<Motion>", self.on_move)
        self.bind("<Button-1>", self.on_button1_press)
        self.bind("<ButtonRelease-1>", self.on_button1_release)
        self.bind("<Button-2>", self.on_button2_press)
        self.bind("<ButtonRelease-2>", self.on_button2_release)
        self.line = None

    def on_move(self, event):
        global ClearFlag
        global pline
        if (ClearFlag):
            pline = []
            pline.append((event.x, event.y))
            ClearFlag = False
            print "# checkpoint 2"
        self.delete(self.line)
        # clipping
        if (event.x >= 0 and event.x < 512 and event.y >= 0 and event.y < 512):
            self.line = self.create_line(pline + [(event.x, event.y)], fill="black")
            print "drawing", event.x,event.y
        else:
            self.line = self.create_line(pline, fill="red")
            print "clipping", event.x,event.y

    def on_button1_press(self, event):
        global pline
        pline.append((event.x, event.y))

    def on_button1_release(self, event):
        global pline
        self.delete(self.line)
        self.create_line(pline + [(event.x, event.y)], fill="green")

    def on_button2_press(self, event):
        global pline
        pline.pop()

    def on_button2_release(self, event):
        global pline
        self.delete('all')
        # self.create_line(pline + [(event.x, event.y)], fill="black")
        self.create_line(pline, fill="blue")

class Application(Frame):
    def create_widgets(self):
        self.canvas = RubberBandCanvas(self)
        self.canvas.config(bg = "cyan")
        self.canvas.pack(fill=BOTH, expand=YES)
        # self.canvas.focus_set()

    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()
        self.create_widgets()

def donothing():
    filewin = Toplevel(root)
    button = Button(filewin, text="Do nothing button")
    button.pack()

def save_points():
    global pline
    print len(pline) - 1
    for i_point in range(0, len(pline) - 1):
        print pline[i_point][0], pline[i_point][1], 0,
        print pline[i_point + 1][0], pline[i_point + 1][1], 0

def clear_points():
    global ClearFlag
    global pline
    app.canvas.delete('all')
    pline = []
    # pline.append((event.x, event.y))
    ClearFlag = True
    print "# checkpoint 3"

# START main

pline = []
ClearFlag = False
print "# checkpoint 1"

root = Tk()
menubar = Menu(root)
filemenu = Menu(menubar, tearoff=0)
print "# checkpoint X"
filemenu.add_command(label="New", command=donothing)
print "# checkpoint Y"
filemenu.add_command(label="Open", command=donothing)
print "# checkpoint Z"
filemenu.add_command(label="Save", command=save_points)
filemenu.add_command(label="Save as...", command=donothing)
filemenu.add_command(label="Close", command=donothing)

filemenu.add_separator()

filemenu.add_command(label="Exit", command=root.quit)
menubar.add_cascade(label="File", menu=filemenu)
editmenu = Menu(menubar, tearoff=0)

editmenu.add_separator()

editmenu.add_command(label="Clear", command=clear_points)

menubar.add_cascade(label="Edit", menu=editmenu)
helpmenu = Menu(menubar, tearoff=0)

root.config(menu=menubar)

app = Application()
app.master.title("Draw Polylines in Rubber Band Mode")
app.mainloop()
root.mainloop()

# END main