Consider a case for creating a GUI application such that when we click on the window with a mouse button, it stores the coordinates and creates a line between two given points. Tkinter provides events that allow the user to bind the keys or buttons with the functions.
To draw a line between two points, we can follow these general steps,
Create a canvas widget and pack it to display in the window.
Define a function draw_line() that works as the event when the user does the click event.
Create a global variable that counts the number of clicks in the canvas.
If the count becomes two, then draw a line between the first and second coordinates.
Bind the Mouse button with the callback function to get full control over the function.
# Import the required libraries from tkinter import * from tkinter import ttk # Create an instance of tkinter frame or window win=Tk() # Set the size of the window win.geometry("700x350") # Define a function to draw the line between two points def draw_line(event): global click_num global x1,y1 if click_num==0: x1=event.x y1=event.y click_num=1 else: x2=event.x y2=event.y # Draw the line in the given co-ordinates canvas.create_line(x1,y1,x2,y2, fill="green", width=10) # Create a canvas widget canvas=Canvas(win, width=700, height=350, background="white") canvas.grid(row=0, column=0) canvas.bind('<Button-1>', draw_line) click_num=0 win.mainloop()
Run the above code to display a window. If we click on the canvas widget twice anywhere, it will draw a line in the canvas.