8. tk Listbox

See: https://www.geeksforgeeks.org/-tkinter-listbox-widget/

8.1. Usage

The tkinter.Listbox widget provides a list from which the user can select one or more items.
To create a listbox widget, the general syntax is (assuming import via "import tkinter as tk"):
listbox_widget = tk.Listbox(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.
e.g. listbox_widget = tk.Listbox(root, height=10, width=50)

8.2. Using a listbox widget

../_images/listbox.png

This code creates a simple Tkinter GUI application that allows a user to select from a list.

import tkinter as tk  # Import the tkinter module for GUI creation.

root = tk.Tk()  # Create the main root.
root.geometry("400x400")  # Set window size.
root.title("Listbox Example")  # Set window title.

def get_selection():  # Define a function to get selected items from the listbox.
    selected_indices = listbox.curselection()  # Get indices of selected items.
    selected_items = [listbox.get(i) for i in selected_indices]  # Retrieve selected items.
    output_label.config(text=f"Selected items:\n{', '.join(selected_items)}")  # Display selected items in the label.

listbox = tk.Listbox(root, selectmode=tk.MULTIPLE, font=('calibre', 14, 'normal'), width=30, height=7)  # Create a listbox widget.
listbox.pack(pady=10)  # Add padding to the top of the listbox.

items = ["Item 1", "Item 2", "Item 3", "Item 4", "Item 5"]  # Define items to add to the listbox.
for item in items:
    listbox.insert(tk.END, item)  # Insert items into the listbox.

submit_button = tk.Button(root, text="Submit", font=('calibre', 14, 'normal'), command=get_selection)  # Create a button to trigger the get_selection function.
submit_button.pack(pady=10)  # Add padding to the button.

output_label = tk.Label(root, text="", font=('calibre', 14, 'normal'), width=50, height=3,
                         bd=2, highlightthickness=2 highlightbackground="gray")  # Create a label to display the output.
output_label.pack(pady=10, padx=10)  # Add padding around the label.

root.mainloop()  # Run the main event loop.

8.3. Listbox methods

Tkinter's Listbox widget provides several methods to help you work with selected items. Here are some key methods:

  1. curselection(): Returns a tuple of indices of the selected items.

    selected_indices = listbox.curselection()

  2. get(index): Retrieves the item at the specified index.

    item = listbox.get(index)

  3. selection_set(first, last=None): Selects items from the first index to the last index. If last is not specified, only the item at first is selected.

    listbox.selection_set(0, 2) # Selects items from index 0 to 2

  4. selection_clear(first, last=None): Deselects items from the first index to the last index. If last is not specified, only the item at first is deselected.

    listbox.selection_clear(0, 2) # Deselects items from index 0 to 2

  5. selection_includes(index): Returns True if the item at the specified index is selected.

    is_selected = listbox.selection_includes(index)

  6. size(): Returns the number of items in the listbox.

    num_items = listbox.size()

  7. activate(index): Sets the active item to the specified index.

    listbox.activate(index)

  8. see(index): Scrolls the listbox to make the item at the specified index visible.

    listbox.see(index)

8.4. Option details

listbox_widget = tk.Listbox(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.

Parameters:

activestyle
Syntax: listbox_widget = tk.Listbox(parent, activestyle="underline")
Description: Sets the style of the active item.
Default: underline
Example: listbox_widget = tk.Listbox(root, activestyle="underline")
background
bg
Syntax: listbox_widget = tk.Listbox(parent, bg="color")
Description: Sets the background color of the listbox.
Default: SystemWindow
Example: listbox_widget = tk.Listbox(root, bg="SystemWindow")
bd
borderwidth
Syntax: listbox_widget = tk.Listbox(parent, bd=value)
Description: Sets the border width of the listbox.
Default: 1
Example: listbox_widget = tk.Listbox(root, bd=1)
cursor
Syntax: listbox_widget = tk.Listbox(parent, cursor="cursor_type")
Description: Sets the cursor that appears when the mouse is over the listbox.
Default: None
Example: listbox_widget = tk.Listbox(root, cursor="arrow")
disabledforeground
Syntax: listbox_widget = tk.Listbox(parent, disabledforeground="color")
Description: Sets the foreground color of the listbox when it is disabled.
Default: SystemDisabledText
Example: listbox_widget = tk.Listbox(root, disabledforeground="SystemDisabledText")
exportselection
Syntax: listbox_widget = tk.Listbox(parent, exportselection=value)
Description: Controls whether the selection is exported to the clipboard.
Default: 1
Example: listbox_widget = tk.Listbox(root, exportselection=1)
fg
foreground
Syntax: listbox_widget = tk.Listbox(parent, fg="color")
Description: Sets the foreground color of the listbox.
Default: SystemButtonText
Example: listbox_widget = tk.Listbox(root, fg="SystemButtonText")
font
Syntax: listbox_widget = tk.Listbox(parent, font="font")
Description: Sets the font of the listbox text.
Default: TkDefaultFont
Example: listbox_widget = tk.Listbox(root, font="TkDefaultFont")
height
Syntax: listbox_widget = tk.Listbox(parent, height=value)
Description: Sets the height of the listbox in number of lines.
Default: 10
Example: listbox_widget = tk.Listbox(root, height=10)
highlightbackground
Syntax: listbox_widget = tk.Listbox(parent, highlightbackground="color")
Description: Sets the color of the focus highlight when the listbox does not have focus.
Default: SystemButtonFace
Example: listbox_widget = tk.Listbox(root, highlightbackground="SystemButtonFace")
highlightcolor
Syntax: listbox_widget = tk.Listbox(parent, highlightcolor="color")
Description: Sets the color of the focus highlight when the listbox has focus.
Default: SystemWindowFrame
Example: listbox_widget = tk.Listbox(root, highlightcolor="SystemWindowFrame")
highlightthickness
Syntax: listbox_widget = tk.Listbox(parent, highlightthickness=value)
Description: Sets the thickness of the focus highlight.
Default: 1
Example: listbox_widget = tk.Listbox(root, highlightthickness=1)
justify
Syntax: listbox_widget = tk.Listbox(parent, justify="left")
Description: Sets the justification of the text within the listbox.
Default: left
Example: listbox_widget = tk.Listbox(root, justify="left")
relief
Syntax: listbox_widget = tk.Listbox(parent, relief="style")
Description: Sets the 3D effect of the listbox border.
Default: sunken
Example: listbox_widget = tk.Listbox(root, relief="sunken")
selectbackground
Syntax: listbox_widget = tk.Listbox(parent, selectbackground="color")
Description: Sets the background color of selected items.
Default: SystemHighlight
Example: listbox_widget = tk.Listbox(root, selectbackground="SystemHighlight")
selectborderwidth
Syntax: listbox_widget = tk.Listbox(parent, selectborderwidth=value)
Description: Sets the width of the border around selected items.
Default: 0
Example: listbox_widget = tk.Listbox(root, selectborderwidth=0)
selectforeground
Syntax: listbox_widget = tk.Listbox(parent, selectforeground="color")
Description: Sets the foreground color of selected items.
Default: SystemHighlightText
Example: listbox_widget = tk.Listbox(root, selectforeground="SystemHighlightText")
selectmode
Syntax: listbox_widget = tk.Listbox(parent, selectmode="mode")
Description: Sets the selection mode of the listbox.
Default: browse
Example: listbox_widget = tk.Listbox(root, selectmode="browse")
setgrid
Syntax: listbox_widget = tk.Listbox(parent, setgrid=value)
Description: Controls whether the listbox is gridded.
Default: 0
Example: listbox_widget = tk.Listbox(root, setgrid=0)
state
Syntax: listbox_widget = tk.Listbox(parent, state="state")
Description: Sets the state of the listbox (normal or disabled).
Default: normal
Example: listbox_widget = tk.Listbox(root, state="normal")
takefocus
Syntax: listbox_widget = tk.Listbox(parent, takefocus=value)
Description: Controls whether the listbox accepts focus.
Default: None
Example: listbox_widget = tk.Listbox(root, takefocus=1)
width
Syntax: listbox_widget = tk.Listbox(parent, width=value)
Description: Sets the width of the listbox in number of characters.
Default: 20
Example: listbox_widget = tk.Listbox(root, width=20)
xscrollcommand
Syntax: listbox_widget = tk.Listbox(parent, xscrollcommand=callback)
Description: Sets the horizontal scroll command.
Default: None
Example: listbox_widget = tk.Listbox(root, xscrollcommand=scrollbar.set)
yscrollcommand
Syntax: listbox_widget = tk.Listbox(parent, yscrollcommand=callback)
Description: Sets the vertical scroll command.
Default: None
Example: listbox_widget = tk.Listbox(root, yscrollcommand=scrollbar.set)
listvariable
Syntax: listbox_widget = tk.Listbox(parent, listvariable=variable)
Description: Sets the variable associated with the listbox.
Default: None
Example: listbox_widget = tk.Listbox(root, listvariable=my_var)