CANVAS IN TKINTER


In this tutorial, we are going to learn about the canvas in Tkinter and what we can do with it followed by a handy example





What is Canvas in Tkinter ?

The canvas widget is used to add graphics in the python application. We can draw different graphics and shapes. You can easily declare canvas and later add different features to it.

canvas_tk = Canvas( window, features)

Discover how to create visually stunning and feature-rich applications by using Python’s built-in Tkinter GUI toolkit

Canvas features and properties are:

1 bd bd displays the border width
2 bg bg displays the background color of the canvas

It represents the background color of the canvas.

3 confine This property doesn’t let you scroll outside the scroll region.
4 cursor You can use the cursor as different shapes on the screen as circle, dot etc.
5 height Displays the size of the canvas as in the Y dimension.
6 highlightcolor Displays the highlighted color in focus
7 relief This displays different types of borders like SUNKEN, RAISED, GROOVE, and RIDGE.
8 scrollregion Allows how much the area can be scrolledin TOP, RIGHT, LEFT and BOTTOM poistions.
9 width Sets the width of the canvas
10 xscrollincrement If the value of set to a positive value then the canvas will only be placed to the multiple of that value horizontally
11 xscrollcommand If you have a scrollable canvas, then xscrollcommand will be used as a .set() method for the horizontal scrollbar
12 yscrollincrement If the value of set to a positive value then the canvas will only be placed to the multiple of that value vertically
13 yscrollcommand If you have a scrollable canvas, then yscrollcommand will be used as a .set() method for the vertical scrollbar




Creating Your First Canvas in Tkinter

import tkinter as tk
screen = tk.Tk()
#Screen size
screen.geometry('300x300')
#Drawing your canvas
canvas_tk = tk.Canvas(screen, bg='yellow', width=250, height=250)
 
canvas_tk.pack()
screen.mainloop()

Output:

Canvas in Tkinter

Coordinates in Canvas

We use pixels on canvas in terms of using x,y coordinates. But there is a slight difference between using coordinates in canvas tkinter and using coordinates in plain geometry. The axis goes down in positive number instead of going up which makes the left corner of the canvas to be the starting point.

Canvas in Tkinter

Courtesy: Carnegie Mellon University

Creating an Oval on Your Canvas

We are going to create an oval where (50,50,100,100) is going to be our coordinates (50,50) being the starting point and 100,100 being the ending point of the shape.

oval = canvas_tk.create_oval(50,50,100,100, fill='red')

Output:

You can create different shapes on your canvas like arc and lines by using coordinates.