I am trying to create dynamically a certain amount of widgets, and then be able to modify them.
For example, I need some Checkboxes :
# Class level lists to store the CheckButtons and their values
self.checkbutton_list = []
self.checkbutton_values_list = []
# With self.amount_of_widgets an integer
for i in range(0, self.amount_of_widgets):
# We create the value of the current CheckButton, default is 0
self.checkbutton_values_list.append(IntVar())
# We create the CheckButton and append it to our list
self.checkbutton_list.append(Checkbutton(self.canvasR,
text="rtest : " + str(i),
variable=self.checkbutton_values_list[i],
onvalue=1,
offvalue=0,
height=1,
width=10))
# As there is a lot of CheckButtons, they have to be browsable inside the canvas
# named canvasR, which has a scrollbar. To browse the created CheckButtons in the
# canva, we need to use the create_window function :
self.canvasR.create_window(x, y, window=self.comp_checkbutton_list[i])
y = y + 100
This generation works well, and I am able, to create all the desired widgets at their desired positions, and have them stored into the dedicated lists. For example I do something similar to create blank images ( I want to update those images later ) :
for i in range(0, self.amount_of_widgets):
# With default photo a PhotoImage object stored at class level
self.photo_list.append(self.default_photo)
self.photo_area_list.append(self.canvasR.create_image(x, y,
image=self.photo_list[i],
anchor=NW))
y = y + 100
The issue is I fail to update the created widgets, if I try to call .itemconfig() like in the following code, I am getting a _tkinter.TclError: invalid boolean operator in tag search expression :
for i in range(0, self.max_image_displayed):
self.canvasR.itemconfig(self.checkbutton_list[i], fill='black', text='')
I understand that it may not work because each widget does not specifically exist for the main class, because they have not been explicitly created inside the class. Only the list storing them does exist in this scope.
But I am not going to declare thousands of CheckBoxes or Images fields, one by one, by hand in my code like :
self.area1 = self.canvasR.create_image(0, 0, image=self.photoimage1, anchor=NW)
self.area_list.append(self.area1)
self.area2 = self.canvasR.create_image(0, 100, image=self.photoimage2, anchor=NW)
self.area_list.append(self.area2)
# ...
self.area9999 = self.canvasR.create_image(0, 0, image=self.photoimage999, anchor=NW)
self.area_list.append(self.area9999)
What could I do?
The issue is I fail to update the created widgets, if I try to call .itemconfig() like in the following code, i am getting a _tkinter.TclError: invalid boolean operator in tag search expression
When you call self.canvasR.itemconfig, the first argument needs to be identifier of an individual item on the canvas, or a tag. However, you're passing in self.defaultPhoto which is definitely not an item identifier or a tag.
In other words, what you pass to itemconfig should be the same as what is returned by self.canvasR.create_image(...) rather than the image itself, if your goal is to modify the canvas item created by create_image.
Related
I have a window in Tkinter that looks like this:
When i click on a button in the first row, it stays. However, when i click on a button in the second row, it unselects the one i chose above.
I want it to be able to only select one option per row. Is there something I'm missing? When it's done, I want to be able to iterate over the rows and get the value of the boxes, but I'm not sure how to do that either.
The code for that section is:
for i in studentList:
Label(left,text=i[0][::]+' ' + i[1][::],fg='black',bg='#dbdbdb',font=('Arial',11,'bold')).grid(row=counter,column=0,pady=13,sticky='news')
P = Radiobutton(right,text='Present',bg='#56ab32',fg='black',value='P'+str(counter),indicatoron = 0,font=('Arial',12,'bold'))
P.grid(row=counter,column=0,pady=10,padx=20,sticky='news')
L = Radiobutton(right,text='Leave',bg='#e6a800',fg='white',indicatoron = 0,value='L'+str(counter),font=('Arial',12,'bold'))
L.grid(row=counter,column=1,pady=10,padx=20,sticky='news')
Radiobutton(right,text='Absent',bg='#bd2900',fg='white',indicatoron = 0,value='A'+str(counter),font=('Arial',12,'bold')).grid(row=counter,column=2,pady=10,padx=20,sticky='news')
counter+=1
Radiobuttons work by assigning two or more radiobuttons the same instance of one of tkinter's special variable objects -- usuallyStringVar or IntVar. This sharing of a variable is what makes a group of radiobuttons work as a set, since the variable can only hold a single value.
Because you aren't assigning a variable, tkinter is using a default variable which is the same for every button. Thus, all buttons are acting as a single set.
To make your code work, each row needs to use it's own instance of StringVar. It would look something like this:
vars = []
for i in studentList:
var = StringVar()
vars.append(var)
...
Radiobutton(right, variable=var, ...)
Radiobutton(right, variable=var, ...)
Radiobutton(right, variable=var, ...)
...
With the above, you can get the choice of each row by getting the value of the variable for that row. For example, the first row would be vars[0].get(), the second row would be vars[1].get() and so on.
At the moment each option menu box replaces the previous one so if write ent1.get() i dont get the value within any box, how can i distinguish betweeen each optionmenu and therefor retrieve each value distinctly? Ideally calling them all by a different name decided by their position in the grid.
for x in range (xval):#creating the matrix
for y in range (yval):
variable = StringVar(root)
ent1 = OptionMenu(root, variable, *inputvalues)#creating the dropdown menus
ent1.config(width=3)
ent1.grid(row=(y+1), column=x)
Not sure if I understand correctly but if you are trying to create different StringVar's in a single loop, you could use the variable.format() method to make sure each StringVar is saved as a unique variable.
Thus the following loop will create StringVar's that are saved into variables ent1, ent2, ent3, etc. This will allow you to call them separately later on..
for x in range (xval):#creating the matrix
for y in range (yval):
variable = StringVar(root)
ent["ent{0}"].format(y+1) = OptionMenu(root, variable, *inputvalues)#creating the dropdown menus
ent["ent{0}"].format(y+1).config(width=3)
ent["ent{0}"].format(y+1).grid(row=(y+1), column=x)
Use a dictionary to keep track of the widgets and variables.
entries = {}
vars = {}
for x in range (xval):#creating the matrix
for y in range (yval):
variable = StringVar(root)
entry = OptionMenu(root, variable, *inputvalues)
entry.config(width=3)
entry.grid(row=(y+1), column=x)
entries[(x,y)] = entry
vars[(x,y)] = variable
I have 20 entries in my Tkinter GUI created using for-loop (there might be more of them in the future and I really don't want to have 50 lines of code just for deifining the entries). I need to collect entries values to create a numpy array out of them. As a shot in the dark I have tried this:
master = Tk()
R=StringVar()
namR = []
for ii in range(0,20):
namR.append(Entry(master), textvariable=R[ii])
namR[ii].grid(row=2+ii, column=3)
which obviously does not work (StringVar instance has no attribute '__getitem__'), but I think the goal is clear.
Any suggestions to make this work, please?
You should include your textvariable within the Entry() call, not after it (append(Entry(master, textvariable=xyz)) rather than append(Entry(master), textvariable=xyz)). append() won't know what to do with the second argument. Next, you can create a list for the StringVar objects and refer to them with something like Entry(master, stringvariable=svars[ii]). However, this is only necessary if you want to do things like variable tracing. If you just want to retrieve the text in an entry object, you can do it with my_entry.get().
master = Tk()
namR = []
for ii in range(0,20):
namR.append(Entry(master))
namR[ii].grid(row=2+ii, column=3)
[e.get() for e in namR] will then be a list of all the entry contents.
I have to implement 5 to 6 checkbuttons next to each other at run time. The checkboxes are generating but when i deselect any one of them, the rest get deselected too. Also, another thing if i want is , if the text attribute of a checkbutton is repeated, it should line up at the same place as where it was and not create a new checkbutton.
the only code i have for the checkbutton is this
option2 = Checkbutton(self.controls,text = name,
variable = self.variable,command lambda:display_temperature(self.variable,name))
option2.pack(side = 'left', anchor = 'sw', pady = 10, padx = 10)
self.controls.pack()
If all the checkbuttons have the same name and are attached to the same variable, python won't be able to distinguish between them.
So I know how to retrieve the text from a single entry widget using the get function but now I am trying to create multiple entry widgets at the same time using a for loop. How can I go back and retrieve the text from anyone of the entry widgets once the user types in them?
rows=11
for line in range(10):
rows=rows+1
widget = Tk.Entry(self.frame)
widget.grid(row=rows, column=5)
The problem is that all of your widget objects are being assigned to a reference, and with each next iteration of the loop are being unreferenced. A way to fix this is to create a list and add these widgets to the list:
entries = []
for line in range(10):
rows = rows + 1
widget = Tk.Entry(self.name)
widget.grid(row = rows, column = 5)
entries.append(widget) # Add this line to your code
Now, to access a specific entrybox, you just find it in the array. So, for example, the second box will be found at entries[1] (because it is 0-based).
The fundamental problem you're having is that you don't have any sort of data structure. Are you familiar with the list type?
rows=11
entries = [Tk.Entry(self.frame) for item in range(10)]
for item in entries:
rows=rows+1
item.grid(row=row, column=5)
This creates a list of Entry widgets, then goes through that list and grids each one into a row (starting with 12). You can access list items by index, e.g. entries[0] for the first Entry.
widgets = []
for i in range(11, 23):
widgets.append(Tk.Entry(self.frame))
widget[i-11].grid(row = i, column = 5)
To answer your question directly, you need the get() method, which is available to the Entry class. To get the value of your widget object, the code would look something like this:
myValue = widget.get()
Please note that, as others have mentioned, your "for" loop does not actually create 10 Entry objects. Since you keep reassigning your new Entry objects to the variable "widget", the old Entry object you created gets de-referenced. Instead of assigning each new Entry object to the variable "widget", append them to a list instead.