Small projectElementary20 XPExercise 1/8

A tuft of grass

Task

Make a program with a 700 × 500 canvas. A left mouse click draws a tuft of grass where you click: at least 5 green lines (blades) that start at the click and end at most 30 points to the left or right and at most 50 points above it. The right button erases the whole picture.

The blades may have a random direction and length.

The program runs in a tkinter simulation right in your browser - after Run you see the window and can click it. The tests click and check what was drawn on the canvas.

Examples

Call

from tkinter import _mente as okno


def v_poriadku(ciara, x, y):
    zaciatok = (round(ciara.coords[0]), round(ciara.coords[1]))
    koniec = (round(ciara.coords[-2]), round(ciara.coords[-1]))
    if koniec == (x, y):
        zaciatok, koniec = koniec, zaciatok
    return zaciatok == (x, y) and abs(koniec[0] - x) <= 30 and 0 <= y - koniec[1] <= 50


okno.check("platno 700x500", okno.size() == (700, 500), f"rozmer je {okno.size()}")
okno.click(350, 250)
steble = okno.items("line")
okno.check("klik nakreslil trs", len(steble) >= 5, f"pocet ciar: {len(steble)}")
okno.check("steble su v povolenom rozsahu", steble and all(v_poriadku(c, 350, 250) for c in steble))
okno.check("trava je zelena", steble and all(okno.greenish(c.fill) for c in steble))

Expected output

platno 700x500: OK
klik nakreslil trs: OK
steble su v povolenom rozsahu: OK
trava je zelena: OK

Call

from tkinter import _mente as okno

okno.click(100, 400)
okno.click(600, 100)
okno.check("dva trsy", len(okno.items("line")) >= 10)
okno.click(300, 300, button=3)
okno.check("prave tlacidlo zmaze obrazok", len(okno.items()) == 0, f"na platne ostalo {len(okno.items())}")

Expected output

dva trsy: OK
prave tlacidlo zmaze obrazok: OK

After you submit, 1 hidden test will also check your solution: a click somewhere else.

Python starts the first time you run code.

import tkinter
import random
canvas = tkinter.Canvas(width=700, height=500)
canvas.pack()
def trava(event):
    # nakresli trs trávy v bode (event.x, event.y)
    pass
def zmaz(event):
    pass
canvas.bind("<Button-1>", trava)
canvas.bind("<Button-3>", zmaz)
tkinter.mainloop()

Ctrl+Enter runs the program. Tab indents. Press Esc, then Tab, to leave the editor.

Input (stdin)

Each line = one call to input().

Output

Hints

Try it yourself first. Each hint reveals a little more - and lowers the reward a little.

Signed out, hints are free - but no XP is awarded either.

Solution

The solution unlocks after the last hint.