Drawing rectangle using mouse events in Tkinter
Question: This is with respect to [Draw rectangle on mouse click
[Python]](http://stackoverflow.com/questions/12837575/draw-rectangle-on-mouse-
click-python). I tried out the first solution and it works perfectly. Can
someone please tell me, what to do if I want to see the rectangle being drawn
and the rectangle gets fixed once the mouse button is released as I can only
see the drawn rectangle once the button is released.

Any kind of help will be appreciated.


Answer: I amended the code from the referenced question. Now it shows the rectangle
when mouse is being dragged on the canvas. The canvas displays Lena image.

    
    
    import tkinter as tk # this is in python 3.4. For python 2.x import Tkinter
    from PIL import Image, ImageTk
    
    
    
    class ExampleApp(tk.Tk):
        def __init__(self):
            tk.Tk.__init__(self)
            self.x = self.y = 0
            self.canvas = tk.Canvas(self, width=512, height=512, cursor="cross")
            self.canvas.pack(side="top", fill="both", expand=True)
            self.canvas.bind("<ButtonPress-1>", self.on_button_press)
            self.canvas.bind("<B1-Motion>", self.on_move_press)
            self.canvas.bind("<ButtonRelease-1>", self.on_button_release)
    
            self.rect = None
    
            self.start_x = None
            self.start_y = None
    
    
            self._draw_image()
    
    
        def _draw_image(self):
             self.im = Image.open('./resource/lena.jpg')
             self.tk_im = ImageTk.PhotoImage(self.im)
             self.canvas.create_image(0,0,anchor="nw",image=self.tk_im)
    
    
    
        def on_button_press(self, event):
            # save mouse drag start position
            self.start_x = event.x
            self.start_y = event.y
    
            # create rectangle if not yet exist
            #if not self.rect:
            self.rect = self.canvas.create_rectangle(self.x, self.y, 1, 1, fill="black")
    
        def on_move_press(self, event):
            curX, curY = (event.x, event.y)
    
            # expand rectangle as you drag the mouse
            self.canvas.coords(self.rect, self.start_x, self.start_y, curX, curY)
    
    
    
        def on_button_release(self, event):
            pass
    
    
    if __name__ == "__main__":
        app = ExampleApp()
        app.mainloop()
    

![enter image description here](http://i.stack.imgur.com/Vw3WJ.jpg)

The black square is drawn on top of the image. Hope this helps.

