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In Tkinter is there any way to make a widget not visible?
I have a label looks like:
Lab = Label(text = "Update ID")
Lab.pack(side = LEFT)
I want this label invisible but would like to make it visible when particular button is clicked.
I have a button looks like:
Button1 = Button(buttons, text = "Update Item", command = self.Update_item)
Button6.pack(side = LEFT, padx = 5, pady = 3)
I want the label invisible but would like to make it visible when 'Button1' is clicked.
Any feedbacks would be appreciated.
There are a couple ways to accomplish this. For one, you can use the lift and lower attributes to change the stacking order. For example, if the label is a child of a frame and y ou lower it, it will go "behind" the frame and thus become invisible. T
A second option is to completely remove the label from the display. You can use grid_remove if you are using the grid geometry manager. The nice thing about this method is that grid remembers where the widget was, so to restore it you can call widget.grid() and all of the previous options (sticky, row, column, etc) will be used.
There is also pack_forget() and grid_forget(), but they have the disadvantage of truly forgetting about the widget. It is removed from the display and the information about where it was placed is forgotten. This means you must re-apply all of the proper options to get the widget to appear in the same place.
Related
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Adding a scrollbar to a group of widgets in Tkinter
(3 answers)
Closed 4 years ago.
My code is working well in itself, but doesn't scroll through the Labels (which is what i'm trying to achieve).
I don't want to use canvas or listbox or anything.
import tkinter as tk
master = tk.Tk()
scrollbar = tk.Scrollbar(master).pack(side=tk.RIGHT, fill=tk.Y,command=tk.yview)
label = tk.Label(text="llklkl")
label.place(x=100,y=500)
label2 = tk.Label(text="llklkl")
label2.place(x=1000,y=5000)
tk.mainloop()
Hello and welcome to SO.
The tkinter Scrollbar widget sadly can not be used on a _tkinter.tkapp object, i.e. your main window called master. From effbot.org:
This widget is used to implement scrolled listboxes, canvases, and text fields.
and
The Scrollbar widget is almost always used in conjunction with a Listbox, Canvas, or Text widget. Horizontal scrollbars can also be used with the Entry widget.
That means that you absolutely HAVE to create some widget inside your main window in order to be able to scroll anything, you can`t just scroll the window itself.
That being said, if you wanted to add a Scrollbar to, let's say, a Listbox, that's how you would do it (also taken from the above mentioned website, you should really check it out):
First of all, you have to set the widget’s yscrollcommand callbacks to the set method of the scrollbar.
Secondly, you have to set the scrollbar’s command to the yview method of the widget, much like you did already, but like name_of_object.yview, not tk.yview.
import tkinter as tk
master = tk.Tk()
scrollbar = tk.Scrollbar(master)
scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
listbox = tk.Listbox(master, yscrollcommand=scrollbar.set)
for i in range(20):
listbox.insert(tk.END, str(i))
listbox.pack(side=tk.LEFT, fill=tk.BOTH)
scrollbar.config(command=listbox.yview)
master.mainloop()
Also, pack the scrollbar in a seperate line. This will produce a window with numbers from 1 to 50 in a scrollable Listbox widget. If i get you right, you want to be able to scroll between your labels? well, i guess you'll have to use some kind of wrapping widget for that, i would recommend a Canvas. But that's really up to you and i'm sure you'll figure it out yourself. If you need any more help, let me know - but please read the docs before asking ;-)
Tkinter Requirements
So I am relatively new to using tkinter and I am struggling with a very specific doubt here. I tried finding solutions to this but as much as I find it obvious, the solution to this doesn't seem to be easy to understand. So if you can see the image above, I am trying to create a GUI for a particular project which requires multi-layer (I am calling it 3D array based) widgets.
Let's say the variables used for this pointer system are i, j, and k.
I am creating individual layer widgets using for loop:
for n in range(i):
frame_x[i] = Frame(root).grid(row = 1, column = i)
entry_x[i] = Entry(frame_x[i]).grid(row = 2, column = i)
button_x[i] = Button(frame_x[i]).grid(row=3, column = i)
Please note this is not a functional code, I have tried to keep it to the point just to give an idea of the method I am using. (Let me know if you want a more detailed code block.)
Now coming to the problem. I am able to do the basic part of this. But the problem is that I want it to work dynamically.
Let's say if the user enters j = 4 first. 4 blocks will be created.
Later if he changes the value to j = 2 and the presses the button, ideally it should make the widgets at block j= 3 and 4 disappear. But I guess tkinter works on overlapping basis and doesn't change a grid element until something is specifically overlapped over it. How do I do that. I tried destroying the entire frame just after entering the for loop, but that doesn't work as for the first time no widget is created before destroying and python throws NameError saying I can't use a variable before assignment.
Anyways, please let me know how do I do this efficiently.
And also in general, if there is a better way to go about the whole thing. Please refer the image above and let me know if it doesn't make sense.
I am not very comfortable with classes in general. I prefer the inefficient way by only using functions to do everything I have to. So it would be great if you can share me a framework without using classes. But its okay if you use them. I know I should start working with classes at some point.
First off, I want to address this part of the question:
I guess tkinter works on overlapping basis and doesn't change a grid element until something is specifically overlapped over it.
I'm not entirely sure what you mean by that, but if it means what I think it means, it is a false statement. tkinter doesn't "work on an overlapping basis". If you destroy a widget, it is destroyed. It doesn't matter if it's overlapped or not.
Based on the tiny bit of code you posted, the main problem is that you aren't putting the entry and button in the frame. Because of that, they are not destroyed when you destroy the frame.
The reason you aren't putting the widgets into the frame is because of this line:
frame_x[i] = Frame(root).grid(row = 1, column = i)
In python, when you do x=y().z(), x has the value of z(). Thus, when you do frame_x[i] = Frame(...).grid(...), frame_x[i] has the value of .grid(...), and .grid(...) always returns None. Thus, frame_x[i] will be None.
When you next do entry_x[i] = Entry(frame_x[i]).grid(...), it's the same as doing entry_x[i] = Entry(None).grid(...). Because the master of the Entry is None, it becomes a child of the root window.
So, the first step is to separate the creation of the widget from the layout of the widget.
frame_x[i] = Frame(root)
frame_x[i].grid(row = 1, column = i)
Once you do that, the Entry and Button widgets will become a child of the frame, and you can remove widgets you don't want by destroying the frame (eg: frame_x[i].destroy()), since destroying a widget will also cause all children of the widget to be destroyed.
Once you have that in place, you can destroy unwanted widgets by simply calling .destroy() on the frame. For example, if you have previously created 10 groups and now need only 5, you can destroy the others and then remove them from the list like this:
# assume 'num' contains the number of frames that we want,
# and that it is smaller than the number of items in frames_x
for frame in frames_x[num:]:
frame.destroy()
frames_x = frames_x[:num]
Here is a complete working program to illustrate. Enter a number and click the button. It will create that many frame+entry+button combinations. Enter a new number that is larger or smaller and it will either add or remove widgets.
This would be easier if you used classes, but you specifically asked for a solution that doesn't use classes. In your real code you probably need to also save the entry widgets in an array so that you can reference them later, but this example is focuses on the creation of the widgets rather than writing your whole program for you.
import tkinter as tk
frames_x = [] def create_widgets():
global frames_x
num = int(num_widgets.get())
# if the number is less than the previous number of
# widgets, delete the widgets we no longer want
for frame in frames_x[num:]:
frame.destroy()
frames_x = frames_x[:num]
# if the number is greater than the previous number of
# widgets, create additional widgets
for i in range(len(frames_x), num):
# create new widget
frame = tk.Frame(root, bd=1, relief="raised")
entry = tk.Entry(frame)
button = tk.Button(frame, text="click me")
# pack entry and button in frame
button.pack(side="right")
entry.pack(side="left", fill="x", expand=True)
# grid the frame in the parent
frame.grid(row=i+1, column=0, columnspan=2)
# save the new frame in the array
frames_x.append(frame)
root = tk.Tk() num_widgets = tk.Entry(root) button = tk.Button(root, text="Create widgets", command=create_widgets)
button.grid(row=0, column=1) num_widgets.grid(row=0, column=0, sticky="ew")
root.mainloop()
I'm currently learning how to use the Tkinter library on python to create a GUI that takes in longitude and latitude points and outputing that into a file. Basically I'm trying to automate the process of having to copy the correct format of line of points to another file.
So I created a Entry and button field to see how many long/lat points are needed to generate a 'shape'. Using this integer input from user, I have a for loop to populate the GUI with multiple widgets asking for the long/lat points. I have that working properly, but now I am trying to have a clear button, which would allow the user to clear all these long/lat points and give them the ability to repopulate the field with the amount of points the other shape requires.
So far I have:
def clearGrid():
coordAmount = int(pointText.get())
latLabel.grid_forget()
longLabel.grid_forget()
.....(contains code that populates the GUI)
#creating clear site Button
clearButton = Button(main_gui, text="Clear Sites!",command=clearGrid)
clearButton.grid(row=lastRow+1, column=5, pady=10)
However, the problem that I am running into is that when the clear button is clicked, it only clears the latest instance of the widgets not all of them. So in a for loop that creates 5 instances/iteration of widgets, it will remove only the 5th instance/iteration of widgets.
I'm trying to have the clear button functionality be able to delete all 5 instances of these widgets.
So here is a shortened code of how I am populating the GUI with widgets
def generatePoints():
for x in range(0,3):
degLong_label = Label(main_gui, text="Degree:", height=2)
degLong_label.grid(row=y,column=6,sticky=E)
degLong = Entry(main_gui, width=4)
degLong.grid(row=y,column=7,sticky=W)
#minute
minLong_Label = Label(main_gui,text="Minutes:", height=2)
minLong_Label.grid(row=y,column=8,sticky=W)
minLong = Entry(main_gui,width=3)
minLong.grid(row=y,column=8,sticky=E)
#seconds
secLong_Label= Label(main_gui,text="Sec:",height=2)
secLong_Label.grid(row=y,column=9,sticky=W,padx=20)
secLong = Entry(main_gui,width=3)
secLong.grid(row=y,column=9,sticky=E,padx=20)
#direction
dirLong_Label = Label(main_gui,text="Direction:",padx=5,height=2)
dirLong_Label.grid(row=y,column=12,sticky=W)
dirLong = Entry(main_gui,width=3)
dirLong.grid(row=y,column=13)
You need to hold on to references to all those widgets, usually via a list. Try initializing a list (list_of_widgets) before your loop, then every time you create a widget, append it to that list. When you clear, you can iterate through that list of widgets and destroy each one. Once you're done clearing them, you can clear the list so you don't try to destroy a widget twice (Tkinter will error at that point).
def generatePoints():
list_of_widgets = [] # or take the list as a parameter
for x in range(3):
degLong_label = Label(...)
degLong_label.grid(...)
list_of_widgets.append(degLong_label)
degLong = Entry(...)
degLong.grid(...)
list_of_widgets.append(degLong)
# et al.
def clearGrid(list_of_widgets):
for widget in list_of_widgets:
widget.destroy()
Note that you probably want to actually destroy the widgets if you aren't planning on showing that specific widget again (initializing a new one doesn't count).
I'm using Python and Tkinter to create a GUI for a program I'm writing, and I'm having a couple of problems.
I have three objects descended from LabelFrame in an object descended from Frame. One of the LabelFrame descendants is two columns of corresponding Label and Entry objects.
The problem is that there are a varying number of Label and Entry pairs, and there can be more than fit on the screen. I need a way to make a scrollbar for this LabelFrame so that everything fits on the screen. I've tried various ways of making a Scrollbar object, but nothing seems to work. How can I bind a scrollbar to this frame?
Also, I need to be able to refresh or reload this LabelFrame when the load_message() method is called, but it just redisplays the new pairs on top of the old ones (so when there are less pairs in the new set, the old set is still visible at the bottom). I've tried using grid_forget() but either nothing changes or the whole frame doesn't display. How can I forget this display and then redisplay it?
Here is the code for this class:
class freq_frame(LabelFrame):
def __init__(self, master = None, text = 'Substitutions'):
LabelFrame.__init__(self, master, text = text)
self.grid()
def load_message(self):
self.frequency = get_freq(message)
self.create_widgets()
def create_widgets(self):
self.label_list = [Label(self, text = get_label(char, self.frequency[char]), justify = LEFT) for char in self.frequency.keys()]
self.entry_list = [Entry(self, width = 1) for char in self.frequency.keys()]
for n in range(len(self.label_list)):
self.label_list[n].grid(column = 0, row = n)
for n in range(len(self.entry_list)):
self.entry_list[n].grid(column = 1, row = n)
If anyone can help with either of these problems, I'd appreciate it.
Also, this question seems like it might be a little thin, but I don't know what to add. Don't hesitate to ask for more information (but be specific).
Thanks!
Labelframes don't support scrolling. So the short answer to your question is "you can't". It sounds obvious, but if the documentation for a widget doesn't say it supports scrolling, it doesn't support scrolling.
However, there is a simple solution. First, add a canvas as a child to the labelframe and pack it so that it fills the labelframe. Attach scrollbars to the canvas and add them to the labelframe too. Then embed a frame within the canvas, add your widgets to that inner frame, and then adjust the scrollregion of the canvas to match the size of the frame after you've added all the inner labels and entries.
It sounds complicated, but it's really very straight-forward.
As for re-creating the widgets when you call load_message, calling grid_forget only removes them from view, it doesn't actually destroy the widgets. Over time you could potentially end up with hundreds of non-visible widgets which is almost certainly not what you want.
Instead, you want to first destroy all the existing widgets. That's pretty easy if they all are in the same parent, since you can ask the parent for a list of all its children. Just iterate over that list to delete each child, then add any new children. An even easier solution is to destroy and recreate that inner frame that contains the labels and entries. When you delete a widget, all child widgets get automatically destroyed. So, delete that inner frame, create a new one, and add your labels and entries again.
Is it possible to create a multi-line label with word wrap that resizes in sync with the width of its parent? In other words the wordwrap behavior of Notepad as you change the width of the NotePad window.
The use case is a dialog that needs to present a block of multi-line text (instructions) in its entirety without having the text clipped or resorting to scrollbars. The parent container will have enough vertical space to accomodate narrow widths.
I've been experimenting with Tkinter Label and Message widgets and the ttk Label widget without success. It seems that I need to hard code a pixel wraplength value vs. have these controls auto wordwrap when their text reaches the right edge of their containers. Certainly Tkinters geometry managers can help me auto-resize my labels and update their wraplength values accordingly?
Should I be looking at the Text widget instead? If so, is it possible to hide the border of a Text widget so I can use it as a multi-line label with wordwrap?
Here's a prototype of how one might do what I described above. It was inspired by Bryan Oakley's tip to use the Text widget and the following post on Stackoverflow:
In python's tkinter, how can I make a Label such that you can select the text with the mouse?
from Tkinter import *
master = Tk()
text = """
If tkinter is 8.5 or above you'll want the selection background to appear like it does when the widget is activated. Comment this out for older versions of Tkinter.
This is even more text.
The final line of our auto-wrapping label that supports clipboard copy.
""".strip()
frameLabel = Frame( master, padx=20, pady=20 )
frameLabel.pack()
w = Text( frameLabel, wrap='word', font='Arial 12 italic' )
w.insert( 1.0, text )
w.pack()
# - have selection background appear like it does when the widget is activated (Tkinter 8.5+)
# - have label background color match its parent background color via .cget('bg')
# - set relief='flat' to hide Text control borders
# - set state='disabled' to block changes to text (while still allowing selection/clipboard copy)
w.configure( bg=master.cget('bg'), relief='flat', state='disabled' )
mainloop()
Use Message widget:
The Message widget is a variant of the Label, designed to display multiline messages. The message widget can wrap text, and adjust its width to maintain a given aspect ratio.
No, there is no feature built-in to Tk to auto-word-wrap labels. However, it's doable by binding to the <Configure> event of the label and adjusting the wrap length then. This binding will fire every time the label widget is resized.
The other option, as you suggest, is to use a text widget. It is possible to entirely turn off the border if you so desire. This has always been my choice when I want word-wrapped instructional text.
Here is the code:
entry = Label(self, text=text,
anchor=NW, justify=LEFT,
relief=RIDGE, bd=2)
def y(event, entry=entry):
# FIXME: make this a global method, to prevent function object creation
# for every label.
pad = 0
pad += int(str(entry['bd']))
pad += int(str(entry['padx']))
pad *= 2
entry.configure(wraplength = event.width - pad)
entry.bind("<Configure>", y )
The tkinter.Message widget suggested by some people does NOT use TTK styling, which means that it's gonna look like garbage inside a TTK (themed) interface.
You could manually apply the background and foreground colors from your TTK theme to the tkinter.Message (by instantiating ttk.Style() and requesting the active themes' TLabel foreground and background colors from that style object), but it's not worth it... because the ancient Message widget has ZERO advantages over TTK's regular ttk.Label.
The tkinter.Message widget has an "aspect ratio" property that defines how many pixels until it wraps.
The ttk.Label instead has a wraplength= property which determines how many pixels until the words wrap. You should also use its anchor= and justify= properties to customize it to your exact desires. With these properties you can make your Label behave as the old Message widget did.
Example: ttk.Label(root, text="foo", wraplength=220, anchor=tkinter.NW, justify=tkinter.LEFT). Creates a beautifully styled label which permanently wraps its text after 220 pixels wide.
As for automatically updating the wraplength? Well, you should attach to the <Configure> event as people have said... However, if you have a completely fluid window (which resizes itself to fit all content), or a grid/frame that is fluid and contains the label, then you can't automatically calculate it that way, because the parent WINDOW/CONTAINER itself will EXPAND whenever the label grows too wide. Which means that the label will always resize itself to the maximum width it would need to fit all text. So, updating wraplength automatically is only possible if the label itself has some constraints on how wide it can grow (either via its parent container being a fixed size/maxsize, or itself being a fixed size/maxsize). In that case, sure, you can use configure to calculate new wrapping numbers to make sure the text always wraps... However, the example code by t7ko is broken and not valid anymore, just fyi.