CODEWITHSUNDEEP
pythoncanvastkintertkinter-canvas
Martin Pavelka
Martin Pavelka

Reputation: 59

How to move object on tkinter canvas knowing only its coordinates?

for i in range(random.randint(1,4)):
    xos=[150,200,250,300,350,400,450,500,550,600,650,700,750,800,850]
    yos=[150,200,250,300,350,400,450,500,550,600,650]
    xos_=random.choice(xos)
    yos_=random.choice(yos)
    object=canvas.create_image(xos_,yos_,image=postava)
    read_=read.replace("[","").replace("]","").replace("'","").replace("\\n","").replace("\\","")
    loot.write(read_+"\n")

I am creating images on canvas in FOR and i want to remove them when I need, but only the last one has the tag (name) object so when I type: canvas.delete(object) it deletes only the last one. So I want to know if it is possible to delete an object which is at certain position (without a name or tag).

Upvotes: 1

Views: 2995

Answers (2)

Sun Bear
Sun Bear

Reputation: 8234

Sure. Scenario (A) Let's say we use the mouse left button to identify the canvas object when clicked and delete the object when mouse left button is released.

Step 1: Include these commands to the callback/method that you use to bind to Button-1 to delete an object.

mx = canvas.canvasx(event.x) #Translate mouse x screen coordinate to canvas coordinate
my = canvas.canvasy(event.y) #Translate mouse y screen coordinate to canvas coordinate
self.canvasobject = canvas.find_closest(mx, my, halo=5) # get canvas object ID of where mouse pointer is 
print(self.canvasobject) #For you to visualize the canvas object number

Step 2: Include these commands to the callback/method that you use to bind to ButtonRelease-1 to delete an object.

canvas.delete(self.canvasobject) #delete the selected canvas object

Scenario (B): Assume you already know the object canvas x,y coordinates, you can issue a single command to delete the canvas object:

canvas.delete(canvas.find_closest(x, y, halo=5))

See this webpage for explanation on the canvas methods that I have used and for other canvas methods.

Upvotes: 1

Khristos
Khristos

Reputation: 983

It is possible to delete an object on the canvas if you know the coordinates (coord). Use item = canvas.find_overlapping(coord) to find the object at that location, then delete it using canvas.delete(item)

See sample code below:

Note: if you know just a single point on the object, then use canvas.find_overlapping(x, y, x, y) instead of canvas.find_overlapping(x1, y1, x2, y2)

import Tkinter as tk
import random


root = tk.Tk()
canvas = tk.Canvas(root, width=550, height=500, borderwidth=0)
canvas.pack(expand=True, fill="both")

coord_list=[]

for i in range(random.randint(1,4)):
    xos=[150,200,250,300,350,400,450,500]
    yos=[150,200,250,300,350,400,450]
    xos_=random.choice(xos)
    yos_=random.choice(yos)

    coord = (xos_,yos_,xos_+50,yos_+50)
    coord_list.append(coord)
    objectt=canvas.create_rectangle(coord, fill="blue")
canvas.create_rectangle(25, 15, 50, 40, fill="red")

# Delete red rectangle
def delete1(event):
    item = canvas.find_overlapping(25, 15, 50, 40)
    canvas.delete(item)

# Delete blue rectangles
def delete2(event):
    for coord in coord_list:
        item = canvas.find_overlapping(*coord)
        canvas.delete(item)

#Click on the canvas to delete objects at the coordinates
canvas.bind("<Button-1>", delete1) # change function to delete blue rectangles
root.mainloop()

Upvotes: 1

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