Python tkinter canvas events not triggering on scrolled region - python

I am making a python progrem using Tkint GUI and the canvas element. I attached a scrollbar to the canvas element so that the user can scroll to unseen regions of the canvas. I created a dotted grid that would allow the user to hover over the dots and if clicked the program draws a circle over the dot. Also as the mouse enters and leave each dot, and dashed circle is drawn and erased.
I also have a print procedures that shows debugging information of the actions performed:
Everything works on the initially visible portion of the canvas. However, when I scroll down, I noticed that the bounded events of click on hover do work, but the canvas graphics are not being triggered/drawn and nothing appears.
I can't understand why initially the graphics were successfully drawn, the event bounded and also working, but the canvas graphics just won't work. Is there some issue between the scroll bar and canvas? Here is the code for the initialization of the canvas and scroll bars:
def __init__(self, parent, model, settings, *args, **kwargs):
super().__init__(parent, *args, **kwargs)
self.width = 625
self.height = 500
self.canvas = tk.Canvas(self, width=self.width, height=self.height, background='white', cursor='arrow')
self.canvas.grid(row=0, column=0)
self.focusDotImage = -1
print("self.focusDotImage: ", self.focusDotImage)
# configure the scroll region
self.canvas.configure(scrollregion=(0, 0, self.width * 2, self.height * 2))
# create scrollbars and connect to canvas
xScroll = tk.Scrollbar(
self,
command=self.canvas.xview,
orient=tk.HORIZONTAL
)
xScroll.grid(row=1, column=0, sticky='new')
yScroll = tk.Scrollbar(self, command=self.canvas.yview)
yScroll.grid(row=0, column=1, sticky='nsw')
self.canvas.configure(yscrollcommand=yScroll.set)
self.canvas.configure(xscrollcommand=xScroll.set)
# Draw Dotted Grid width
self.space = 25
self.dotRadius= 1
self.nodeRadius = 5
for i in range(0, self.width):
for j in range(0, self.height):
dotItem = self.canvas.create_rectangle(i * self.space-self.dotRadius, j * self.space-self.dotRadius, i * self.space + self.dotRadius,
j * self.space + self.dotRadius, fill='lightgrey')
self.canvas.tag_bind(dotItem, '<Enter>', self._on_dot_enter)
self.canvas.tag_bind(dotItem, '<Leave>', self._on_dot_leave)
self.canvas.bind('<Button-1>', self._on_click)
Per comment request, I built a small runnable demo to showcase the weird effects of the canavas/scrolling issue:
import tkinter as tk
def _on_click(event):
print("On click imagine item...", )
global image_item3
canvas.delete(image_item3)
def _on_click_canvas(e):
print("coord {}, {}".format(e.x, e.y))
canvas.create_oval(e.x, e.y, (e.x+10), (e.y+10), fill='white')
# Create root and canvas
root = tk.Tk()
width = 1024
height = 768
canvas = tk.Canvas(
root, background='black',
width=width, height=height,
)
canvas.grid(row=0, column=0)
image_item = canvas.create_oval((200, 200), (300, 300), fill='white')
image_item2 = canvas.create_oval((300, 300), (400, 400), fill='white')
global image_item3
image_item3 = canvas.create_oval((200, 900), (300, 1000), fill='white')
canvas.tag_bind(image_item3, '<Button-1>', _on_click)
canvas.bind('<Button-1>', _on_click_canvas)
# configure the scroll region
canvas.configure(scrollregion=(0, 0, width * 2, height * 2))
# create scrollbars and connect to canvas
xscroll = tk.Scrollbar(
root,
command=canvas.xview,
orient=tk.HORIZONTAL
)
xscroll.grid(row=1, column=0, sticky='new')
yscroll = tk.Scrollbar(root, command=canvas.yview)
yscroll.grid(row=0, column=1, sticky='nsw')
canvas.configure(yscrollcommand=yscroll.set)
canvas.configure(xscrollcommand=xscroll.set)
root.mainloop()

If the canvas is scrolled to other region, the coordinates of the top-left corner of the canvas is not (0, 0) anymore. However (event.x, event.y) is still relative to the top-left corner of the canvas, so (event.x, event.y) will not be the actual coordinates in the canvas.
To get the correct coordinates, you can use self.canvas.canvasx() and self.canvas.canvasy() to convert the event coordinates to actual canvas coordinates.

Related

Tkinter,Canvas converting/saving details

here is my problem. I'm trying to convert my canvas drew into an image. First of all, I create the postscript of my canvas drew, then I convert it into png. The problem is that I obtain white images w/o changes.
So,there is my class:
class Paint(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent = parent
self.color = "white"
self.brush_size = 5
self.setUI()
def draw(self, event):
self.canv.create_rectangle(event.x - 7, event.y - 7, event.x + 7, event.y + 7,
fill=self.color, outline=self.color)
def setUI(self):
self.pack(fill=BOTH, expand=1)
self.canv = Canvas(self, bg="black")
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
self.canv.grid(padx=5, pady=5, sticky=E + W + S + N)
self.canv.bind("<B1-Motion>", self.draw)
def clear(self):
self.canv.delete(ALL)
def save(self):
self.canv.update()
self.canv.postscript(file="D:\\Новая папка\\test.xps", colormode="color")
im2 = Image.open("D:\\Новая папка\\test.xps")
im2.save("D:\\Новая папка\\test.png", 'png')
My main:
root = Tk()
frame=Canvas(root,height=200,width=300)
root.geometry("500x600")
app = Paint(frame)
frame.create_rectangle(10,10,50,50)
frame.pack()
b3= Button(
text="Apply!",
width=35,
height=1,
bg="white",
fg="black",
command=lambda :[which_button("Activated"),b3_clicked(),app.save()],
font=25
)
b3.pack(side=TOP)
root.mainloop()
When you save the canvas drawings to postscript file, the background color of the canvas is ignored. Since you have used white color as the paint color, so the output drawings are white on white which looks like nothing is drawn.
If you want to have a black background in the output postscript file, use .create_rectangle(..., fill="black") to fill the canvas with black color.
class Paint(Frame):
...
def setUI(self):
# better call pack() outside Paint class
#self.pack(fill=BOTH, expand=1)
self.canv = Canvas(self)
# fill the canvas with black color
# make sure the rectangle is big enough to cover the visible area
self.canv.create_rectangle(0, 0, 1000, 1000, fill="black")
...
Also below is how you should create the Paint class:
root = Tk()
root.geometry("500x600")
app = Paint(root)
app.pack(fill=BOTH, expand=1)
...

Unable To Add Scroll Bars To A Canvas Widget

Using Python 2.7.16 on a iMac.
New to Python and this forum.
I have an application that has a canvas widget which the user can drawn on and I want to add scroll bars to it. I have been trying for the past two days and been having no luck. I have looked at numerous example but I can't get anything to work.
How can I do that?
Below is a screen shot and strip down source code to the essential code.
In the screen shot the scroll bars on the outer window. I want the scroll bars on the drawing canvas which is the black area.
Thanks.
This what my code example produce.
This what my code example produce.
This is what I want with the canvas having scroll bars.
Now it looks like this
#!/usr/bin/python
import Tkinter as tk
WINDOW_SIZE='950x650'
##########
# Size for canvas draring area
##########
MAX_X = 600
MAX_Y = 600
window = tk.Tk()
window.title("Cluster")
window.geometry(WINDOW_SIZE)
# Create a frame parent for the canvas and scrollbar(s).
p_frame = tk.Frame(window)
p_frame.grid(row=3, column=0, sticky=tk.NW)
Canvas_frame = tk.Frame()
Canvas = tk.Canvas(window, bg="black", height = MAX_Y, width = MAX_X)
Canvas.pack();
coord = 10, 50, 240, 210
arc = Canvas.create_arc(coord, start=0, extent=150, fill="red")
line = Canvas.create_line(0, 0, 20, 20, 300, 300, 400, 400, fill="dark violet")
lbl = tk.Label(window, width=15, height=5, borderwidth=2, relief="groove", anchor="center", justify="center", text="fasfdasf")
lbl.pack()
# Create a vertical scrollbar linked to the canvas.
vsbar = tk.Scrollbar(p_frame, orient=tk.VERTICAL, command=Canvas.yview)
vsbar.grid(row=0, column=1, sticky=tk.NS)
Canvas.configure(yscrollcommand=vsbar.set)
# Create a horizontal scrollbar linked to the canvas.
hsbar = tk.Scrollbar(p_frame, orient=tk.HORIZONTAL, command=Canvas.xview)
hsbar.grid(row=1, column=0, sticky=tk.EW)
Canvas.configure(xscrollcommand=hsbar.set)
# Start Tk's event loop
window.mainloop()
You should not put the scrollbars inside the canvas. Typically the canvas and the scrollbars should share a common parent.
If you want the scrollbars to appears as if they are inside the canvas, create a frame with a border and the put the canvas and scrollbars inside the frame.

Canvas.Tag_bind not working with OOP | Python 3 [duplicate]

In my simple code, a red ball is falling down in a straight line (that's working). When I push the right arrow key, I want the ball to also move in right direction. This is not working, however. What am I doing wrong?
from tkinter import *
root = Tk()
canvas = Canvas(root, height=400, width=500, background='black')
canvas.pack()
class Bird:
def __init__(self, canvas, coords):
self.canvas = canvas
self.coords = coords
self.bird = canvas.create_rectangle(coords, fill='red')
def gravity(self):
self.canvas.move(self.bird, 0, 10)
self.canvas.after(200, self.gravity)
def moveRight(self, event):
self.canvas.move(self.bird, 10, 0)
self.canvas.after(200, self.moveRight)
bird = Bird(canvas, (100, 100, 110, 110))
bird.gravity()
canvas.bind('<Right>', bird.moveRight)
root.mainloop()
I have another additional question:
Is it possible to call this "after"-function or a similar function for the whole canvas instead of the two methods separately?
If you see any other flaws with my code plz let me know!
Thanks!
You must bind the right key to the canvas inside the class, and set the focus on the canvas:
from tkinter import *
root = Tk()
canvas = Canvas(root, height=400, width=500, background='black')
canvas.pack()
class Bird:
def __init__(self, canvas, coords):
self.canvas = canvas
self.coords = coords
self.bird = canvas.create_rectangle(coords, fill='red')
self.canvas.bind('<Right>', self.moveRight)
self.canvas.focus_set()
def gravity(self):
self.canvas.move(self.bird, 0, 10)
self.canvas.after(200, self.gravity)
def moveRight(self, event=None):
self.canvas.move(self.bird, 10, 0)
self.canvas.after(200, self.moveRight)
bird = Bird(canvas, (100, 100, 110, 110))
bird.gravity()
root.mainloop()
The problem you are facing is that you are binding keyboard events, but the events can only work if the widget with the bindings has the keyboard focus. You can give the canvas the keyboard focus with focus_set():
canvas = Canvas(root, height=400, width=500, background='black')
canvas.focus_set()
Is it possible to call this "after"-function or a similar function for the whole canvas instead of the two methods separately?
Yes. Your binding can call any function you want. If you expect to have more than one object and you want them all to move at the same time, you can move them all from a function.
First, remove the call to after from moveRight. Next, define a global function that calls moveRight for every object. For example:
def move_them_all():
bird1.moveRight()
bird2.moveRight()
something_else.moveRight()
self.canvas.after(1000, move_them_all)
...
canvas = Canvas(root, height=400, width=500, background='black')
...
canvas.bind('<right>', move_them_all)

How to update what image you open with image.open()

I'm just curious how I would go about updating the image opened with the Zoom function WITHOUT calling the Zoom function again. Also if you know of any easier way to do what I'm doing, which is simply just trying to make a image "Zoom-able" with mouse wheel, then my ears are open lol. Any other comments on the code are appreciated, Thank You!
Specifically this part right here:
pictureVar = StringVar()
pictureVar.set("a.png")
Zoom(root, path=pictureVar.get())
pictureVar.set("b.png")
The picture then gets opened using Image.open() here:
class Zoom(Frame):
''' Simple zoom with mouse wheel '''
def __init__(self, mainframe, path):
''' Initialize the main Frame '''
Frame.__init__(self, master=mainframe)
# 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')
# Open image
self.image = Image.open(path) #<------------------------!!!!!!!!!!!
Here is the entire code though:
import csv
import os
from tkinter import *
from PIL import ImageTk, Image
root = Tk()
class AutoScrollbar(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()
Scrollbar.set(self, lo, hi)
class Zoom(Frame):
''' Simple zoom with mouse wheel '''
def __init__(self, mainframe, path):
''' Initialize the main Frame '''
Frame.__init__(self, master=mainframe)
# 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')
# Open image
self.image = Image.open(path)
# Create canvas and put image on it
self.canvas = Canvas(self.master, highlightthickness=0,
xscrollcommand=hbar.set, yscrollcommand=vbar.set)
self.canvas.grid(row=0, column=0, sticky='nswe')
vbar.configure(command=self.canvas.yview) # bind scrollbars to the canvas
hbar.configure(command=self.canvas.xview)
# Make the canvas expandable
self.master.rowconfigure(0, weight=1)
self.master.columnconfigure(0, weight=1)
# Bind events to the Canvas
self.canvas.bind('<ButtonPress-1>', self.move_from)
self.canvas.bind('<B1-Motion>', self.move_to)
self.canvas.bind('<MouseWheel>', self.wheel)
self.imscale = 0.25
self.imageid = None
self.delta = 0.75
# Text is used to set proper coordinates to the image. You can make it invisible.
self.text = self.canvas.create_text(0, 0, anchor='nw', text='')
self.show_image()
self.canvas.configure(scrollregion=self.canvas.bbox('all'))
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)
def wheel(self, event):
''' Zoom with mouse wheel '''
scale = 1.0
# Respond to Linux (event.num) or Windows (event.delta) wheel event
if event.num == 5 or event.delta == -120:
scale *= self.delta
self.imscale *= self.delta
if event.num == 5 or event.delta == 120:
scale /= self.delta
self.imscale /= self.delta
# Rescale all canvas objects
x = self.canvas.canvasx(event.x)
y = self.canvas.canvasy(event.y)
self.canvas.scale('all', x, y, scale, scale)
self.show_image()
self.canvas.configure(scrollregion=self.canvas.bbox('all'))
def show_image(self):
''' Show image on the Canvas '''
if self.imageid:
self.canvas.delete(self.imageid)
self.imageid = None
self.canvas.imagetk = None # delete previous image from the canvas
width, height = self.image.size
new_size = int(self.imscale * width), int(self.imscale * height)
imagetk = ImageTk.PhotoImage(self.image.resize(new_size))
# Use self.text object to set proper coordinates
self.imageid = self.canvas.create_image(self.canvas.coords(self.text),
anchor='nw', image=imagetk)
self.canvas.lower(self.imageid) # set it into background
self.canvas.imagetk = imagetk # keep an extra reference to prevent garbage-collection
pictureVar = StringVar()
pictureVar.set("a.png")
Zoom(root, path=pictureVar.get())
pictureVar.set("b.png")
mainloop()

Tkinter scrollbar for frame

My objective is to add a vertical scroll bar to a frame which has several labels in it. The scroll bar should automatically enabled as soon as the labels inside the frame exceed the height of the frame. After searching through, I found this useful post. Based on that post I understand that in order to achieve what i want, (correct me if I am wrong, I am a beginner) I have to create a Frame first, then create a Canvas inside that frame and stick the scroll bar to that frame as well. After that, create another frame and put it inside the canvas as a window object. So, I finally come up with this:
from Tkinter import *
def data():
for i in range(50):
Label(frame,text=i).grid(row=i,column=0)
Label(frame,text="my text"+str(i)).grid(row=i,column=1)
Label(frame,text="..........").grid(row=i,column=2)
def myfunction(event):
canvas.configure(scrollregion=canvas.bbox("all"),width=200,height=200)
root=Tk()
sizex = 800
sizey = 600
posx = 100
posy = 100
root.wm_geometry("%dx%d+%d+%d" % (sizex, sizey, posx, posy))
myframe=Frame(root,relief=GROOVE,width=50,height=100,bd=1)
myframe.place(x=10,y=10)
canvas=Canvas(myframe)
frame=Frame(canvas)
myscrollbar=Scrollbar(myframe,orient="vertical",command=canvas.yview)
canvas.configure(yscrollcommand=myscrollbar.set)
myscrollbar.pack(side="right",fill="y")
canvas.pack(side="left")
canvas.create_window((0,0),window=frame,anchor='nw')
frame.bind("<Configure>",myfunction)
data()
root.mainloop()
Am I doing it right? Is there better/smarter way to achieve the output this code gave me?
Why must I use grid method? (I tried place method, but none of the labels appear on the canvas.)
What so special about using anchor='nw' when creating window on canvas?
Please keep your answer simple, as I am a beginner.
Here's example code adapted from the VerticalScrolledFrame page on the now defunct Tkinter Wiki that's been modified to run on Python 2.7 and 3+.
try: # Python 2
import tkinter as tk
import tkinter.ttk as ttk
from tkinter.constants import *
except ImportError: # Python 2
import Tkinter as tk
import ttk
from tkinter.constants import *
# Based on
# https://web.archive.org/web/20170514022131id_/http://tkinter.unpythonic.net/wiki/VerticalScrolledFrame
class VerticalScrolledFrame(ttk.Frame):
"""A pure Tkinter scrollable frame that actually works!
* Use the 'interior' attribute to place widgets inside the scrollable frame.
* Construct and pack/place/grid normally.
* This frame only allows vertical scrolling.
"""
def __init__(self, parent, *args, **kw):
ttk.Frame.__init__(self, parent, *args, **kw)
# Create a canvas object and a vertical scrollbar for scrolling it.
vscrollbar = ttk.Scrollbar(self, orient=VERTICAL)
vscrollbar.pack(fill=Y, side=RIGHT, expand=FALSE)
canvas = tk.Canvas(self, bd=0, highlightthickness=0,
yscrollcommand=vscrollbar.set)
canvas.pack(side=LEFT, fill=BOTH, expand=TRUE)
vscrollbar.config(command=canvas.yview)
# Reset the view
canvas.xview_moveto(0)
canvas.yview_moveto(0)
# Create a frame inside the canvas which will be scrolled with it.
self.interior = interior = ttk.Frame(canvas)
interior_id = canvas.create_window(0, 0, window=interior,
anchor=NW)
# Track changes to the canvas and frame width and sync them,
# also updating the scrollbar.
def _configure_interior(event):
# Update the scrollbars to match the size of the inner frame.
size = (interior.winfo_reqwidth(), interior.winfo_reqheight())
canvas.config(scrollregion="0 0 %s %s" % size)
if interior.winfo_reqwidth() != canvas.winfo_width():
# Update the canvas's width to fit the inner frame.
canvas.config(width=interior.winfo_reqwidth())
interior.bind('<Configure>', _configure_interior)
def _configure_canvas(event):
if interior.winfo_reqwidth() != canvas.winfo_width():
# Update the inner frame's width to fill the canvas.
canvas.itemconfigure(interior_id, width=canvas.winfo_width())
canvas.bind('<Configure>', _configure_canvas)
if __name__ == "__main__":
class SampleApp(tk.Tk):
def __init__(self, *args, **kwargs):
root = tk.Tk.__init__(self, *args, **kwargs)
self.frame = VerticalScrolledFrame(root)
self.frame.pack()
self.label = ttk.Label(self, text="Shrink the window to activate the scrollbar.")
self.label.pack()
buttons = []
for i in range(10):
buttons.append(ttk.Button(self.frame.interior, text="Button " + str(i)))
buttons[-1].pack()
app = SampleApp()
app.mainloop()
It does not yet have the mouse wheel bound to the scrollbar but it is possible. Scrolling with the wheel can get a bit bumpy, though.
edit:
to 1)
IMHO scrolling frames is somewhat tricky in Tkinter and does not seem to be done a lot. It seems there is no elegant way to do it.
One problem with your code is that you have to set the canvas size manually - that's what the example code I posted solves.
to 2)
You are talking about the data function? Place works for me, too. (In general I prefer grid).
to 3)
Well, it positions the window on the canvas.
One thing I noticed is that your example handles mouse wheel scrolling by default while the one I posted does not. Will have to look at that some time.
"Am i doing it right?Is there better/smarter way to achieve the output this code gave me?"
Generally speaking, yes, you're doing it right. Tkinter has no native scrollable container other than the canvas. As you can see, it's really not that difficult to set up. As your example shows, it only takes 5 or 6 lines of code to make it work -- depending on how you count lines.
"Why must i use grid method?(i tried place method, but none of the labels appear on the canvas?)"
You ask about why you must use grid. There is no requirement to use grid. Place, grid and pack can all be used. It's simply that some are more naturally suited to particular types of problems. In this case it looks like you're creating an actual grid -- rows and columns of labels -- so grid is the natural choice.
"What so special about using anchor='nw' when creating window on canvas?"
The anchor tells you what part of the window is positioned at the coordinates you give. By default, the center of the window will be placed at the coordinate. In the case of your code above, you want the upper left ("northwest") corner to be at the coordinate.
Please see my class that is a scrollable frame. It's vertical scrollbar is binded to <Mousewheel> event as well. So, all you have to do is to create a frame, fill it with widgets the way you like, and then make this frame a child of my ScrolledWindow.scrollwindow. Feel free to ask if something is unclear.
Used a lot from # Brayan Oakley answers to close to this questions
class ScrolledWindow(tk.Frame):
"""
1. Master widget gets scrollbars and a canvas. Scrollbars are connected
to canvas scrollregion.
2. self.scrollwindow is created and inserted into canvas
Usage Guideline:
Assign any widgets as children of <ScrolledWindow instance>.scrollwindow
to get them inserted into canvas
__init__(self, parent, canv_w = 400, canv_h = 400, *args, **kwargs)
docstring:
Parent = master of scrolled window
canv_w - width of canvas
canv_h - height of canvas
"""
def __init__(self, parent, canv_w = 400, canv_h = 400, *args, **kwargs):
"""Parent = master of scrolled window
canv_w - width of canvas
canv_h - height of canvas
"""
super().__init__(parent, *args, **kwargs)
self.parent = parent
# creating a scrollbars
self.xscrlbr = ttk.Scrollbar(self.parent, orient = 'horizontal')
self.xscrlbr.grid(column = 0, row = 1, sticky = 'ew', columnspan = 2)
self.yscrlbr = ttk.Scrollbar(self.parent)
self.yscrlbr.grid(column = 1, row = 0, sticky = 'ns')
# creating a canvas
self.canv = tk.Canvas(self.parent)
self.canv.config(relief = 'flat',
width = 10,
heigh = 10, bd = 2)
# placing a canvas into frame
self.canv.grid(column = 0, row = 0, sticky = 'nsew')
# accociating scrollbar comands to canvas scroling
self.xscrlbr.config(command = self.canv.xview)
self.yscrlbr.config(command = self.canv.yview)
# creating a frame to inserto to canvas
self.scrollwindow = ttk.Frame(self.parent)
self.canv.create_window(0, 0, window = self.scrollwindow, anchor = 'nw')
self.canv.config(xscrollcommand = self.xscrlbr.set,
yscrollcommand = self.yscrlbr.set,
scrollregion = (0, 0, 100, 100))
self.yscrlbr.lift(self.scrollwindow)
self.xscrlbr.lift(self.scrollwindow)
self.scrollwindow.bind('<Configure>', self._configure_window)
self.scrollwindow.bind('<Enter>', self._bound_to_mousewheel)
self.scrollwindow.bind('<Leave>', self._unbound_to_mousewheel)
return
def _bound_to_mousewheel(self, event):
self.canv.bind_all("<MouseWheel>", self._on_mousewheel)
def _unbound_to_mousewheel(self, event):
self.canv.unbind_all("<MouseWheel>")
def _on_mousewheel(self, event):
self.canv.yview_scroll(int(-1*(event.delta/120)), "units")
def _configure_window(self, event):
# update the scrollbars to match the size of the inner frame
size = (self.scrollwindow.winfo_reqwidth(), self.scrollwindow.winfo_reqheight())
self.canv.config(scrollregion='0 0 %s %s' % size)
if self.scrollwindow.winfo_reqwidth() != self.canv.winfo_width():
# update the canvas's width to fit the inner frame
self.canv.config(width = self.scrollwindow.winfo_reqwidth())
if self.scrollwindow.winfo_reqheight() != self.canv.winfo_height():
# update the canvas's width to fit the inner frame
self.canv.config(height = self.scrollwindow.winfo_reqheight())
For anyone who stumbles across this (as it did when looking for my own gist) I maintain a gist for exactly this purpose at https://gist.github.com/mp035/9f2027c3ef9172264532fcd6262f3b01 It has scrollwheel support for various operating systems, is commented, and has a built-in demo in the file.
We can add scroll bar even without using Canvas. I have read it in many other post we can't add vertical scroll bar in frame directly etc etc. But after doing many experiment found out way to add vertical as well as horizontal scroll bar :). Please find below code which is used to create scroll bar in treeView and frame.
f = Tkinter.Frame(self.master,width=3)
f.grid(row=2, column=0, columnspan=8, rowspan=10, pady=30, padx=30)
f.config(width=5)
self.tree = ttk.Treeview(f, selectmode="extended")
scbHDirSel =tk.Scrollbar(f, orient=Tkinter.HORIZONTAL, command=self.tree.xview)
scbVDirSel =tk.Scrollbar(f, orient=Tkinter.VERTICAL, command=self.tree.yview)
self.tree.configure(yscrollcommand=scbVDirSel.set, xscrollcommand=scbHDirSel.set)
self.tree["columns"] = (self.columnListOutput)
self.tree.column("#0", width=40)
self.tree.heading("#0", text='SrNo', anchor='w')
self.tree.grid(row=2, column=0, sticky=Tkinter.NSEW,in_=f, columnspan=10, rowspan=10)
scbVDirSel.grid(row=2, column=10, rowspan=10, sticky=Tkinter.NS, in_=f)
scbHDirSel.grid(row=14, column=0, rowspan=2, sticky=Tkinter.EW,in_=f)
f.rowconfigure(0, weight=1)
f.columnconfigure(0, weight=1)
It is nessesery to configure Scrollbar in case of using with Canvas
by sending to Canvas xscrollcommand attribute Scrollbar.set method and
to Scrollbar command attribute Canvas.yview (xview) method.
Canvas.yview method after scrollbar was moved recieve *args in next formatting:
tuple('move_to', '<some_absolute_float_value_of_top_of_scrollbar_region>')
In case of implementing scrollability to widget,
Recieving region and translating scrollbar_region (whith element viewable and whith not) features must be created.
Region is `tuple(float, float)' representing open to see part of all elements.
Not ideal bechavior showed in this solution (without using tk.Canvas)
import tkinter as tk
from tkinter import ttk
class ItemizeFrame(ttk.Frame, list):
def __init__(self,
*args,
scroll_upd_callback = lambda x: x,
visible_els: int = 10,
**kwargs):
list.__init__(self)
ttk.Frame.__init__(self, *args, **kwargs)
ttk.Style().configure('Small.TButton', background='red', width=2, height=2, padx=3, pady=3)
ttk.Style().configure('Sep.TFrame', padx=3, pady=3)
self.scroll_upd_callback = scroll_upd_callback
self.visible_els = visible_els
self.visible_st_idx = 0
self.pseudo_scroll_element_cursor_line = 0.5*1/visible_els
def append(self, item: ttk.Widget, **kw):
e = item(self, **kw)
super().append(e)
e.pack(fill='x')
self._update_visible_els()
def _update_visable_id_callback(self):
for id_, entry_ in enumerate(self):
entry_.set_id(id_)
def pop(self, index=None):
e = super().pop(index)
e.destroy()
self._update_visible_els()
def __getitem__(self, idx) -> ttk.Widget:
return list.__getitem__(self, idx)
# indicators computing and application
#property
def visible_end_idx(self):
return self.visible_st_idx + self.visible_els -1
#property
def visible_area_ratio(self) -> tuple[float, float]:
total = len(self)
st_val = 0.0
end_val = 1.0
if total > self.visible_els:
end_val = 1.0 - (total-self.visible_end_idx)/total
st_val = self.visible_st_idx / total
st_val = st_val + self.pseudo_scroll_element_cursor_line
end_val = end_val + self.pseudo_scroll_element_cursor_line
return (st_val, end_val)
def _update_scroll_widget(self):
self.scroll_upd_callback(*self.visible_area_ratio)
def set_yview(self, move_to_ratio):
base_pseudo_ratio = 0.5*1/self.visible_els
total = len(self)
max_ratio = (total - self.visible_els)/total+base_pseudo_ratio
if move_to_ratio < 0:
possible_st_el_pseudo_part = base_pseudo_ratio
possible_st_el_idx = 0
if max_ratio < move_to_ratio:
possible_st_el_idx = total - self.visible_els
possible_st_el_pseudo_part = base_pseudo_ratio
else :
el_idx_raw = move_to_ratio * total
el_idx_round = round(el_idx_raw)
el_idx_pseudo = (el_idx_raw - el_idx_round)*1/self.visible_els
possible_st_el_idx = el_idx_round
possible_st_el_pseudo_part = el_idx_pseudo
self.visible_st_idx = possible_st_el_idx
self.pseudo_scroll_element_cursor_line = possible_st_el_pseudo_part
self._update_visible_els()
def _update_visible_els(self):
for el in self:
el.pack_forget()
for num, el in enumerate(self):
if self.visible_st_idx <= num and num <= self.visible_end_idx:
el.pack()
self._update_scroll_widget()
class ScrollableFrame(ttk.Frame):
def __init__(self, *args, **kwargs):
kw = dict(width=400, height=300)
kw.update(kwargs)
super().__init__(*args, **kw)
self.scroll = ttk.Scrollbar(self, command=self.on_scroll)
self.scroll.pack(expand=True, fill='y', side='right')
self.view = ItemizeFrame(
self,
scroll_upd_callback=self.scroll.set,
**kwargs
)
self.view.pack(expand=True, fill='both')#, side='left')
def on_scroll(self, *args, **kwargs):
value_raw = float(args[1])
self.view.set_yview(value_raw)
Usecase
class App(tk.Tk):
def __init__(self):
super().__init__()
self.frame = ScrollableFrame(self)
self.frame.pack()
def test_fill(self):
for i in range(15):
self.frame.view.append(ttk.Entry)
class Test:
#staticmethod
def v2():
app = App()
app.test_fill()
app.mainloop()
Test.v2()
After I watching many answers, I got it:
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
def onFrameConfigure(canvas):
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
'''When window size change, canvas size will change,
use this line to change its item size (width).'''
canvas.itemconfigure(wrapFrame, width=canvas.winfo_width())
canvas = tk.Canvas(root, highlightthickness=0)
frame = tk.Frame(canvas, background="#FFFFFF")
vsb = tk.Scrollbar(root, orient="vertical", command=canvas.yview)
canvas.configure(yscrollcommand=vsb.set)
vsb.pack(side="right", fill="y")
canvas.pack(fill="both", expand=1, anchor="nw") #canvas size is relative to window size.
wrapFrame = canvas.create_window((0,0), window=frame, anchor="nw")
# When the window size change, it will call this function
canvas.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
L1 = tk.Label(frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame)
input.pack()
root.mainloop()
Specifies the size of the scrollable frame by changing canvas and scrollbar position and size.
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
def onFrameConfigure(canvas):
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
canvas.itemconfigure(wrapFrame, width=canvas.winfo_width())
canvas = tk.Canvas(root, highlightthickness=0)
frame = tk.Frame(canvas, background="#FFFFFF")
vsb = tk.Scrollbar(root, orient="vertical", command=canvas.yview)
canvas.configure(yscrollcommand=vsb.set)
vsb.place(relx=0.9, y=0, relwidth=0.1, relheight=0.5)
canvas.place(x=0, y=0, relwidth=0.9, relheight=0.5)
wrapFrame = canvas.create_window((0,0), window=frame, anchor="nw")
canvas.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
L1 = tk.Label(frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame)
input.pack()
root.mainloop()
Specifies the size of the scrollable frame by writing them to outerFrame.
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
def onFrameConfigure(canvas):
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
canvas.itemconfigure(wrapFrame, width=canvas.winfo_width())
outerFrame = tk.Frame(root)
canvas = tk.Canvas(outerFrame, highlightthickness=0)
frame = tk.Frame(canvas, background="#FFFFFF")
vsb = tk.Scrollbar(outerFrame, orient="vertical", command=canvas.yview)
canvas.config(yscrollcommand=vsb.set)
outerFrame.place(relx=0.25, rely=0.1, relwidth=0.5, relheight=0.5)
vsb.pack(side="right", fill="y")
canvas.pack(fill="both", expand=1, anchor="nw")
wrapFrame = canvas.create_window((0,0), window=frame, anchor="nw")
canvas.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
L1 = tk.Label(frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame)
input.pack()
root.mainloop()
The items inner the frame can use pack or grid (only choose one), but place cannot be used alone. If you want to use place, you need to expand the layout(height) with pack or grid first.
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
def onFrameConfigure(canvas):
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
canvas.itemconfigure(wrapFrame, width=canvas.winfo_width())
canvas = tk.Canvas(root, highlightthickness=0)
frame = tk.Frame(canvas, background="#FFFFFF")
vsb = tk.Scrollbar(root, orient="vertical", command=canvas.yview)
canvas.configure(yscrollcommand=vsb.set)
vsb.pack(side="right", fill="y")
canvas.pack(fill="both", expand=1, anchor="nw")
wrapFrame = canvas.create_window((0,0), window=frame, anchor="nw")
canvas.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
L1 = tk.Label(frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame)
input.pack()
L1 = tk.Label(frame, text="我是Label")
L1.place(x=0, rely=0.5)
root.mainloop()
Use mouse wheel:
tkinter: binding mousewheel to scrollbar
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
def onFrameConfigure(canvas):
canvas.configure(scrollregion=canvas.bbox("all"))
canvas.itemconfigure(wrapFrame, width=canvas.winfo_width())
def on_mouse_wheel(event, scale=3):
#only care event.delta is - or +, scroll down or up
if event.delta<0:
canvas.yview_scroll(scale, "units")
else:
canvas.yview_scroll(-scale, "units")
canvas = tk.Canvas(root, highlightthickness=0)
frame = tk.Frame(canvas, background="#FFFFFF")
vsb = tk.Scrollbar(root, orient="vertical", command=canvas.yview)
canvas.configure(yscrollcommand=vsb.set)
vsb.pack(side="right", fill="y")
canvas.pack(fill="both", expand=1, anchor="nw")
wrapFrame = canvas.create_window((0,0), window=frame, anchor="nw")
canvas.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
canvas.bind("<Enter>", lambda event: canvas.bind_all("<MouseWheel>", on_mouse_wheel)) # on mouse enter
canvas.bind("<Leave>", lambda event: canvas.unbind_all("<MouseWheel>")) # on mouse leave
L1 = tk.Label(frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame)
input.pack()
root.mainloop()
Export to class:
import tkinter as tk
root = tk.Tk()
root.title("音樂編輯器")
root.geometry("600x480")
class scrollFrame():
def __init__(self, **options):
outerFrame = tk.Frame(root)
canvas = tk.Canvas(outerFrame, highlightthickness=0)
vsb = tk.Scrollbar(outerFrame, orient="vertical", command=canvas.yview)
vsb.pack(side="right", fill="y")
canvas.pack(fill="both", expand=1, anchor="nw")
frame = tk.Frame(canvas, **options)
wrapFrameId = canvas.create_window((0,0), window=frame, anchor="nw")
canvas.config(yscrollcommand=vsb.set)
canvas.bind("<Configure>", lambda event: self.onFrameConfigure())
canvas.bind("<Enter>", lambda event: canvas.bind_all("<MouseWheel>", self.on_mouse_wheel)) # on mouse enter
canvas.bind("<Leave>", lambda event: canvas.unbind_all("<MouseWheel>")) # on mouse leave
self.outerFrame, self.canvas, self.vsb, self.frame, self.wrapFrameId = outerFrame, canvas, vsb, frame, wrapFrameId
def onFrameConfigure(self):
canvas = self.canvas
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
canvas.itemconfigure(self.wrapFrameId, width=canvas.winfo_width())
def on_mouse_wheel(self, event, scale=3):
canvas = self.canvas
#only care event.delta is - or +, scroll down or up
if event.delta<0:
canvas.yview_scroll(scale, "units")
else:
canvas.yview_scroll(-scale, "units")
frame = scrollFrame(background="#FFFFFF")
frame.outerFrame.place(relx=0.15, rely=0.1, relwidth=0.7, relheight=0.8)
L1 = tk.Label(frame.frame, text="音樂編輯器", bg="#556644", font=("",25))
L1.pack(anchor="n")
for i in range(100):
input = tk.Entry(frame.frame)
input.pack()
root.mainloop()
According:
https://stackoverflow.com/a/3092341/19470749
https://stackoverflow.com/a/16198198/19470749
https://anzeljg.github.io/rin2/book2/2405/docs/tkinter/create_window.html
Not 100% sure if this solution is on topic (since it explicitely asks for a scrollable FRAME), but the text widget is basically a scrollable Frame.
From documentation of the Text widget:
"Like canvas widgets, text widgets can contain images and any other Tk widgets (including frames containing many other widgets). In a sense, this allows the text widget to work as a geometry manager in its own right. "
Text widgets are very easy to use, and can be made scrollable. So instead of using a special Class like the Scrollable Frame, I think the Text widget is a great option.
Below my code, for a basic example of a scrollable text widget holding 100 buttons:
from tkinter import Tk, Button, Text,Scrollbar
class test:
def __init__(self):
self.win = Tk()
text = Text(self.win, width=40, height=10, wrap = "none")
ys = Scrollbar(self.win, orient = 'vertical', command = text.yview)
text['yscrollcommand'] = ys.set
text.grid(column = 0, row = 0, sticky = 'nwes')
ys.grid(column = 1, row = 0, sticky = 'ns')
for x in range(1,100):
b = Button(text, text='Push Me')
text.window_create("end", window=b)
text.insert("end",'\n')
self.win.mainloop()
test = test()
This is at least the method I am going to use for my scrollable frames. Not sure if there is a better solution then the newline insertion to make the widgets organised vertically. But it works.

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