13. tk PanedWindow

See: https://docs.python.org/3/library/tkinter.html#tkinter.PanedWindow

13.1. Usage

The tkinter.PanedWindow widget is a container that allows the user to resize child widgets by dragging a separator (sash).
It is useful for creating layouts where the user controls the relative size of sections of the window.
Paned windows can be arranged horizontally or vertically.
To create a paned window the general syntax is
(assuming import via "import tkinter as tk"):
panedwindow_widget = tk.PanedWindow(parent, option=value)
parent is the window or frame object.
Options can be passed as parameters separated by commas.
Child widgets are added to a PanedWindow using the add() method.

13.2. Sample PanedWindow

The code below creates a horizontal PanedWindow containing two frames.
The user can drag the divider between the frames to resize them.
import tkinter as tk

root = tk.Tk()
root.title("PanedWindow Example")
root.geometry("500x300")

# Create the PanedWindow
paned = tk.PanedWindow(
    root,
    orient="horizontal",
    sashwidth=5,
    bg="lightgray"
)

paned.pack(fill="both", expand=True)

# Create child frames
left_frame = tk.Frame(
    paned,
    bg="lightblue",
    width=200,
    height=200
)

right_frame = tk.Frame(
    paned,
    bg="lightgreen",
    width=200,
    height=200
)

# Add frames to the PanedWindow
paned.add(left_frame)
paned.add(right_frame)

root.mainloop()
../_images/panedwindow.png

Tasks

  1. Modify the code so that it creates a vertical PanedWindow containing three frames.

    • Arrange the frames from top to bottom.

    • Set the top frame background to light blue.

    • Set the middle frame background to light yellow.

    • Set the bottom frame background to light green.

    • Add all three frames to the PanedWindow.

    • Set the minimum size of each pane to 50 pixels.

    ../_images/panedwindow_question.png

Modify the code so that it creates a vertical PanedWindow containing three resizable frames.

import tkinter as tk

# Create the main window
root = tk.Tk()
root.title("PanedWindow Question")
root.geometry("300x310")

# Create the PanedWindow
paned = tk.PanedWindow(
    root,
    orient="vertical",
    sashwidth=5
)

paned.pack(fill="both", expand=True)

# Create three frames
top_frame = tk.Frame(
    paned,
    bg="light blue",
    width=300,
    height=100
)

middle_frame = tk.Frame(
    paned,
    bg="light yellow",
    width=300,
    height=100
)

bottom_frame = tk.Frame(
    paned,
    bg="light green",
    width=300,
    height=100
)

# Add frames to the PanedWindow
paned.add(top_frame, minsize=50)
paned.add(middle_frame, minsize=50)
paned.add(bottom_frame, minsize=50)

# Run the main event loop
root.mainloop()

13.3. Methods

panedwindow_widget.add(child_widget, option=value)
Adds a child widget to the PanedWindow.
The child widget becomes one of the resizable sections.

Example:

paned.add(frame1)
panedwindow_widget.remove(child_widget)
Removes a child widget from the PanedWindow.

Example:

paned.remove(frame1)
panedwindow_widget.forget(child_widget)
Removes a child widget from the PanedWindow.
The widget is removed but not destroyed.

Example:

paned.forget(frame1)
panedwindow_widget.paneconfig(child_widget, option=value)
Changes the configuration options for a child widget inside the PanedWindow.

Example:

paned.paneconfig(frame1, minsize=100)
panedwindow_widget.paneconfigure(child_widget, option=value)
Alternative name for paneconfig().
Updates options for a specific child pane.
panedwindow_widget.panes()
Returns a tuple containing the widgets managed by the PanedWindow.

Example:

print(paned.panes())
panedwindow_widget.sash_coord(index)
Returns the current x and y coordinates of a sash.

Example:

x, y = paned.sash_coord(0)
panedwindow_widget.sash_place(index, x, y)
Moves a sash to a specified position.

Example:

paned.sash_place(0, 150, 0)

13.4. Parameter syntax

The main options are below.
panedwindow_widget = tk.PanedWindow(parent, option=value)

Parameters:

background
bg
Syntax: panedwindow_widget = tk.PanedWindow(parent, bg="color")
Description: Sets the background colour of the PanedWindow.
Default: SystemButtonFace
borderwidth
bd
Syntax: panedwindow_widget = tk.PanedWindow(parent, bd=width)
Description: Sets the width of the border around the PanedWindow.
Default: 2
cursor
Syntax: panedwindow_widget = tk.PanedWindow(parent, cursor="cursor_type")
Description: Sets the mouse cursor when hovering over the PanedWindow.
handlepad
Syntax: panedwindow_widget = tk.PanedWindow(parent, handlepad=value)
Description: Sets the distance between the sash and the resize handle.
Default: 8
handlesize
Syntax: panedwindow_widget = tk.PanedWindow(parent, handlesize=value)
Description: Sets the size of the sash resize handle.
Default: 8
orient
Syntax: panedwindow_widget = tk.PanedWindow(parent, orient="orientation")
Description: Sets the direction of the panes.
Values:

- "horizontal": panes arranged left to right.
- "vertical": panes arranged top to bottom.

Default: horizontal
relief
Syntax: panedwindow_widget = tk.PanedWindow(parent, relief="style")
Description: Sets the border style.
Values include flat, raised, sunken, ridge, solid and groove.
Default: raised
sashcursor
Syntax: panedwindow_widget = tk.PanedWindow(parent, sashcursor="cursor_type")
Description: Sets the cursor displayed over the sash.
Example:

sashcursor="sb_h_double_arrow"
sashpad
Syntax: panedwindow_widget = tk.PanedWindow(parent, sashpad=value)
Description: Sets padding around the sash.
Default: 0
sashrelief
Syntax: panedwindow_widget = tk.PanedWindow(parent, sashrelief="style")
Description: Sets the relief style of the sash.
Default: flat
sashwidth
Syntax: panedwindow_widget = tk.PanedWindow(parent, sashwidth=value)
Description: Sets the width of the sash divider.
Default: 2
showhandle
Syntax: panedwindow_widget = tk.PanedWindow(parent, showhandle=True)
Description: Displays the resize handle on the sash.
Default: False
width
Syntax: panedwindow_widget = tk.PanedWindow(parent, width=value)
Description: Sets the requested width of the PanedWindow.
height
Syntax: panedwindow_widget = tk.PanedWindow(parent, height=value)
Description: Sets the requested height of the PanedWindow.

13.5. Default options

Code to display the default value for each PanedWindow option is shown below.
import tkinter as tk

root = tk.Tk()

widget = tk.PanedWindow(root)

widget_options = widget.keys()

for option in widget_options:
    print(f"{option}: {widget.cget(option)}")