Creating a versatile drawing program with Python and tkinter

Python Tkinter Canvas and Graphics: Exercise-7 with Solution

Write a Python program that creates a drawing program with Tkinter that supports freehand drawing, shapes, and text annotations on the Canvas.

Sample Solution:

Python Code:

import tkinter as tk
from tkinter import ttk

class DrawingApp:
    def __init__(self, root):
        self.root = root
        self.root.title("Drawing App")

        # Create a canvas
        self.canvas = tk.Canvas(root, bg="white")
        self.canvas.pack(fill=tk.BOTH, expand=True)

        # Create a toolbar
        self.toolbar = ttk.Frame(root)
        self.toolbar.pack(side=tk.TOP, fill=tk.X)

        # Create drawing tools buttons
        self.pen_button = ttk.Button(self.toolbar, text="Pen", command=self.use_pen)
        self.pen_button.grid(row=0, column=0)

        self.line_button = ttk.Button(self.toolbar, text="Line", command=self.use_line)
        self.line_button.grid(row=0, column=1)

        self.rectangle_button = ttk.Button(self.toolbar, text="Rectangle", command=self.use_rectangle)
        self.rectangle_button.grid(row=0, column=2)

        self.text_button = ttk.Button(self.toolbar, text="Text", command=self.use_text)
        self.text_button.grid(row=0, column=3)

        # Initialize drawing mode
        self.drawing_mode = "pen"

        # Binding mouse events
        self.canvas.bind("<Button-1>", self.start_drawing)
        self.canvas.bind("<B1-Motion>", self.draw)
        self.canvas.bind("<ButtonRelease-1>", self.stop_drawing)

        # Variables for drawing
        self.start_x, self.start_y = None, None
        self.current_object = None

    def use_pen(self):
        self.drawing_mode = "pen"

    def use_line(self):
        self.drawing_mode = "line"

    def use_rectangle(self):
        self.drawing_mode = "rectangle"

    def use_text(self):
        self.drawing_mode = "text"

    def start_drawing(self, event):
        self.start_x, self.start_y = event.x, event.y
        if self.drawing_mode == "pen":
            self.current_object = self.canvas.create_line(event.x, event.y, event.x, event.y, fill="black", width=2)
        elif self.drawing_mode == "text":
            text = input("Enter text: ")
            self.current_object = self.canvas.create_text(event.x, event.y, text=text, font=("Arial", 12))
        else:
            self.start_x, self.start_y = event.x, event.y

    def draw(self, event):
        if self.drawing_mode == "pen":
            x, y = event.x, event.y
            self.canvas.create_line(self.start_x, self.start_y, x, y, fill="black", width=2)
            self.start_x, self.start_y = x, y
        elif self.drawing_mode == "line":
            if self.current_object:
                self.canvas.delete(self.current_object)
            self.current_object = self.canvas.create_line(self.start_x, self.start_y, event.x, event.y, fill="black", width=2)
        elif self.drawing_mode == "rectangle":
            if self.current_object:
                self.canvas.delete(self.current_object)
            self.current_object = self.canvas.create_rectangle(self.start_x, self.start_y, event.x, event.y, outline="black", width=2)
        else:
            pass

    def stop_drawing(self, event):
        self.current_object = None

if __name__ == "__main__":
    root = tk.Tk()
    app = DrawingApp(root)
    root.mainloop()

The above exercise creates a basic drawing application with four drawing tools: pen, line, rectangle, and text. We can switch between drawing tools using the toolbar buttons and use the left mouse button to draw on the canvas. In this program, the user is shown how to handle different drawing modes and create various objects on the canvas.

Output:

Flowchart:

Python Code Editor:

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