После прочтения этого поста:
Tkinter canvas zoom + move / pan
Я хотел попытаться получить положение курсора / пикселя, но не могувыяснить, как это сделать.
Например, я хочу, чтобы при увеличении / уменьшении масштаба и нажатии на ту же точку изображения я получал те же координаты x, y на изображении:
Я пытался поиграть с self.imscale, связать щелчок мышью с помощью функции canvasx(evt.x), но ничего не работает!
# -*- coding: utf-8 -*-
# Advanced zoom example. Like in Google Maps.
# It zooms only a tile, but not the whole image. So the zoomed tile occupies
# constant memory and not crams it with a huge resized image for the large zooms.
import random
import tkinter as tk
from tkinter import ttk
from PIL import Image, ImageTk
class AutoScrollbar(ttk.Scrollbar):
''' A scrollbar that hides itself if it's not needed.
Works only if you use the grid geometry manager '''
def set(self, lo, hi):
if float(lo) <= 0.0 and float(hi) >= 1.0:
self.grid_remove()
else:
self.grid()
ttk.Scrollbar.set(self, lo, hi)
def pack(self, **kw):
raise tk.TclError('Cannot use pack with this widget')
def place(self, **kw):
raise tk.TclError('Cannot use place with this widget')
class Zoom_Advanced(ttk.Frame):
''' Advanced zoom of the image '''
def __init__(self, mainframe, path):
''' Initialize the main Frame '''
ttk.Frame.__init__(self, master=mainframe)
self.master.title('Zoom with mouse wheel')
# Vertical and horizontal scrollbars for canvas
vbar = AutoScrollbar(self.master, orient='vertical')
hbar = AutoScrollbar(self.master, orient='horizontal')
vbar.grid(row=0, column=1, sticky='ns')
hbar.grid(row=1, column=0, sticky='we')
# Create canvas and put image on it
self.canvas = tk.Canvas(self.master, highlightthickness=0,
xscrollcommand=hbar.set, yscrollcommand=vbar.set)
self.canvas.grid(row=0, column=0, sticky='nswe')
self.canvas.update() # wait till canvas is created
vbar.configure(command=self.scroll_y) # bind scrollbars to the canvas
hbar.configure(command=self.scroll_x)
# Make the canvas expandable
self.master.rowconfigure(0, weight=1)
self.master.columnconfigure(0, weight=1)
# Bind events to the Canvas
self.canvas.bind('<Configure>', self.show_image) # canvas is resized
self.canvas.bind('<ButtonPress-1>', self.move_from)
self.canvas.bind('<B1-Motion>', self.move_to)
self.canvas.bind('<MouseWheel>', self.wheel) # with Windows and MacOS, but not Linux
self.canvas.bind('<Button-5>', self.wheel) # only with Linux, wheel scroll down
self.canvas.bind('<Button-4>', self.wheel) # only with Linux, wheel scroll up
self.canvas.bind('<Button-3>', self.pix_pos)
self.image = Image.open(path) # open image
self.width, self.height = self.image.size
self.imscale = 1.0 # scale for the canvaas image
self.delta = 1.3 # zoom magnitude
# Put image into container rectangle and use it to set proper coordinates to the image
self.container = self.canvas.create_rectangle(0, 0, self.width, self.height, width=0)
# Plot some optional random rectangles for the test purposes
minsize, maxsize, number = 5, 20, 10
for n in range(number):
x0 = random.randint(0, self.width - maxsize)
y0 = random.randint(0, self.height - maxsize)
x1 = x0 + random.randint(minsize, maxsize)
y1 = y0 + random.randint(minsize, maxsize)
color = ('red', 'orange', 'yellow', 'green', 'blue')[random.randint(0, 4)]
self.canvas.create_rectangle(x0, y0, x1, y1, fill=color, activefill='black')
self.show_image()
def pix_pos(self, evt=None):
bbox = self.canvas.bbox(self.container)
print("x: " + str(bbox[0]) + ", y: " + str(bbox[1]))
x = self.canvas.canvasx(evt.x)# / self.imscale
y = self.canvas.canvasy(evt.y)# / self.imscale
print(str(evt.x) + ", " + str(evt.y))
print("x: " + str(evt.x - bbox[0]) + "y: " + str(evt.y - bbox[1]))
print("imgscale:" + str(self.imscale) + " x: " + str(x) + " y: " + str(y))
def scroll_y(self, *args, **kwargs):
''' Scroll canvas vertically and redraw the image '''
self.canvas.yview(*args, **kwargs) # scroll vertically
self.show_image() # redraw the image
def scroll_x(self, *args, **kwargs):
''' Scroll canvas horizontally and redraw the image '''
self.canvas.xview(*args, **kwargs) # scroll horizontally
self.show_image() # redraw the image
def move_from(self, event):
''' Remember previous coordinates for scrolling with the mouse '''
self.canvas.scan_mark(event.x, event.y)
def move_to(self, event):
''' Drag (move) canvas to the new position '''
self.canvas.scan_dragto(event.x, event.y, gain=1)
self.show_image() # redraw the image
def wheel(self, event):
''' Zoom with mouse wheel '''
x = self.canvas.canvasx(event.x)
y = self.canvas.canvasy(event.y)
bbox = self.canvas.bbox(self.container) # get image area
if bbox[0] < x < bbox[2] and bbox[1] < y < bbox[3]: pass # Ok! Inside the image
else: return # zoom only inside image area
scale = 1.0
# Respond to Linux (event.num) or Windows (event.delta) wheel event
if event.num == 5 or event.delta == -120: # scroll down
i = min(self.width, self.height)
if int(i * self.imscale) < 30: return # image is less than 30 pixels
self.imscale /= self.delta
scale /= self.delta
if event.num == 4 or event.delta == 120: # scroll up
i = min(self.canvas.winfo_width(), self.canvas.winfo_height())
if i < self.imscale: return # 1 pixel is bigger than the visible area
self.imscale *= self.delta
scale *= self.delta
self.canvas.scale('all', x, y, scale, scale) # rescale all canvas objects
self.show_image()
def show_image(self, event=None):
''' Show image on the Canvas '''
bbox1 = self.canvas.bbox(self.container) # get image area
# Remove 1 pixel shift at the sides of the bbox1
bbox1 = (bbox1[0] + 1, bbox1[1] + 1, bbox1[2] - 1, bbox1[3] - 1)
bbox2 = (self.canvas.canvasx(0), # get visible area of the canvas
self.canvas.canvasy(0),
self.canvas.canvasx(self.canvas.winfo_width()),
self.canvas.canvasy(self.canvas.winfo_height()))
bbox = [min(bbox1[0], bbox2[0]), min(bbox1[1], bbox2[1]), # get scroll region box
max(bbox1[2], bbox2[2]), max(bbox1[3], bbox2[3])]
if bbox[0] == bbox2[0] and bbox[2] == bbox2[2]: # whole image in the visible area
bbox[0] = bbox1[0]
bbox[2] = bbox1[2]
if bbox[1] == bbox2[1] and bbox[3] == bbox2[3]: # whole image in the visible area
bbox[1] = bbox1[1]
bbox[3] = bbox1[3]
self.canvas.configure(scrollregion=bbox) # set scroll region
x1 = max(bbox2[0] - bbox1[0], 0) # get coordinates (x1,y1,x2,y2) of the image tile
y1 = max(bbox2[1] - bbox1[1], 0)
x2 = min(bbox2[2], bbox1[2]) - bbox1[0]
y2 = min(bbox2[3], bbox1[3]) - bbox1[1]
if int(x2 - x1) > 0 and int(y2 - y1) > 0: # show image if it in the visible area
x = min(int(x2 / self.imscale), self.width) # sometimes it is larger on 1 pixel...
y = min(int(y2 / self.imscale), self.height) # ...and sometimes not
image = self.image.crop((int(x1 / self.imscale), int(y1 / self.imscale), x, y))
imagetk = ImageTk.PhotoImage(image.resize((int(x2 - x1), int(y2 - y1))))
imageid = self.canvas.create_image(max(bbox2[0], bbox1[0]), max(bbox2[1], bbox1[1]),
anchor='nw', image=imagetk)
self.canvas.lower(imageid) # set image into background
self.canvas.imagetk = imagetk # keep an extra reference to prevent garbage-collection
path = 'doge.jpg' # place path to your image here
root = tk.Tk()
app = Zoom_Advanced(root, path=path)
root.mainloop()