Want to resize shapes(Rectangle) by cursor using Tkinter

user_15427340 0
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I successfully drawn the rectangle by mouse but fail to resize that. I've tried multiple ways using event by calling function but fail.

New to python so struggling.

Thanks

tkinter-canvas tkinter python
2 Answers

few errors self.current = self.create_rectangle(*self.start, *self.start, width=5) should be self.canvas.create_rectangle(*self.start, *self.start, width=5)

similarly self.tag_bind should be self.canvas.tag_bind

remove self.canvas.bind("<B1-Motion>", self.on_click) and self.__init__(filename) from openFile method

Also, don't forget to import partial (from functools import partial)

user_121985020

You can do the resize on callbacks bound on self.canvas, don't need to bind on the rectangle item.

Below is an simplified example:

import tkinter as tk

class ExampleApp(tk.Tk):
    def __init__(self):
        super().__init__()
        self.canvas = tk.Canvas(self, width=512, height=512, cursor="cross")
        self.canvas.pack(fill="both", expand=1)
        self.canvas.bind("<Button-1>", self.on_button_press)
        self.canvas.bind("<B1-Motion>", self.on_move_press)

    def on_button_press(self, event):
        # find rectangle items under mouse cursor
        items = [x for x in self.canvas.find_withtag("current") if self.canvas.type(x) == "rectangle"]
        if items:
            # item found, use it as the "current" item
            self.start = self.canvas.coords(items[0])[:2]
            self.current = items[0]
        else:
            # no item found, create new "current" rectangle item
            self.start = event.x, event.y
            self.current = self.canvas.create_rectangle(*self.start, *self.start, width=5)

    def on_move_press(self, event):
        # resize the "current" item
        self.canvas.coords(self.current, *self.start, event.x, event.y)

ExampleApp().mainloop()
user_53174030
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