Detecting collisions between items

As a continuation of the preceding recipe, we can detect whether a rectangle item overlaps with another one. In fact, this can be achieved, assuming that we are working with shapes contained in rectangular boxes, using the find_overlapping() method from the Canvas class.

Getting ready

This application extends the preceding one by adding four green rectangles to the canvas and highlighting the one that is touched by a blue rectangle moved using the arrow keys:

How to do it...

Since this script has many similarities with the preceding one, we marked the parts of the code that create the four rectangles and invoke the canvas.find_overlapping() method:

import tkinter as tk

class App(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("Detecting collisions between items")

        self.canvas = tk.Canvas(self, bg="white")
        self.canvas.pack()
        self.update()
        self.width = w = self.canvas.winfo_width()
        self.height...