How to enable drag and drop of objects in tkinter canvas?

Python Help
1

I have this piece of code:

import tkinter as tk
from tkinter import ttk

root = tk.Tk()
frame = tk.Frame(root)
frame.pack()

Bottom = tk.Frame(root)
Bottom.pack(side = tk.BOTTOM)
CanvasArea = ttk.Frame(Bottom)
CanvasArea.pack(side = tk.LEFT)
LeftGrid = tk.Frame(CanvasArea)
LeftGrid.pack(side = tk.LEFT)

def MakeDraggable(widget):
    widget.bind("<Button-1>", OnDragStart)
    widget.bind("<B1-Motion>", OnDragMotion)

def OnDragStart(event):
    widget = event.widget
    widget._drag_start_x = exent.x
    widget._drag_start_y = exent.y

def OnDragMotion(event):
    widget = event.widget
    x = widget.winfo_x() - widget._drag_start_x + event.x
    y = widget.winfo_y() - widget._drag_start_y + event.y
    widget.place(x = x, y = y)

class DragDropMixin:
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        make_draggable(self)

CW = 600
CH = 450
LXM = (CW / 2)
LYM = (CH / 2)
TLX = tk.IntVar()
TLY = tk.IntVar()

TLXInput = ttk.Entry(LeftGrid, textvariable = TLX)
TLXInput.grid(row = 2, column = 1)
TLYInput = ttk.Entry(LeftGrid, textvariable = TLY)
TLYInput.grid(row = 3, column = 1)

MainCanvas = tk.Canvas(CanvasArea, bg = 'white', height = CH, width = CW)
MainCanvas.pack(side = tk.LEFT)

N = 0

ObjectList = [0]

def MakeRect():
    Pum = N
    Rectangle = MainCanvas.create_rectangle((LXM + TLX.get()), (LYM + TLY.get()), (LXM + TLX.get()), (LYM + TLY.get()), fill = 'red', outline = 'black', width = 1, tags = Pum)
    MakeDraggable(Rectangle)
    ObjectList.insert(Pum, Rectangle)
    Pum = N + 1
    return Pum

AddRect = tk.Button(LeftGrid, text = 'Make Rectangle', command = MakeRect)
AddRect.grid(row = 4, column = 1)

I tried to put a drag and drop function solution into the canvas objects. It didn’t work. Error says:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\User\AppData\Local\Programs\Python\Python311\Lib\tkinter\__init__.py", line 1948, in __call__
    return self.func(*args)
           ^^^^^^^^^^^^^^^^
  File "C:/Users/User/AppData/Local/Programs/Python/Python311/PASS/PA/Help.py", line 58, in MakeRect
    MakeDraggable(Rectangle)
  File "C:/Users/User/AppData/Local/Programs/Python/Python311/PASS/PA/Help.py", line 16, in MakeDraggable
    widget.bind("<Button-1>", OnDragStart)
    ^^^^^^^^^^^
AttributeError: 'int' object has no attribute 'bind'

Previously the def and objects part was this:

MainCanvas = tk.Canvas(CanvasArea, bg = 'white', height = CH, width = CW)
MainCanvas.pack(side = tk.LEFT)

N = 0

ObjectList = [0]

def MakeRect():
    Pum = N
    ObjectList.insert(Pum, MainCanvas.create_rectangle(((LXM + TLX.get()) + TSX.get()), ((LYM + TLY.get()) + TSY.get()), (LXM + TLX.get()), (LYM + TLY.get()) -, fill = 'red', outline = 'black', width = 1, tags = Pum))
    Pum = N + 1
    return Pum

Tell me, is it possible to put drag and drop on canvas objects?

2

Please post a short, runnable program that shows the problem, and include any traceback.

4

I have redone it, but instead of the “bad screen” error I was looking for, I got a “int object has no attribute” error. I can give you the file if you want.

Sorry for double.

5

Canvas items are not widgets. Canvas.create_xyq return an int id that you can use to configure.

Read tkinter.dnd doc and see if you can make it work. (I have never used it.)

6

Well, this is interesting. I asked Bing Chat and it gave me this, which works!

import tkinter as tk

def drag_start(event):
    widget = event.widget
    widget._drag_start_x = event.x
    widget._drag_start_y = event.y

def drag_motion(event):
    widget = event.widget
    x = widget.winfo_x() - widget._drag_start_x + event.x
    y = widget.winfo_y() - widget._drag_start_y + event.y
    widget.place(x=x, y=y)

root = tk.Tk()
canvas = tk.Canvas(root, width=400, height=400)
canvas.pack()

rect = canvas.create_rectangle(10, 10, 50, 50, fill="blue")

canvas.tag_bind(rect, "<Button-1>", drag_start)
canvas.tag_bind(rect, "<B1-Motion>", drag_motion)

root.mainloop()