Skip to content

PackFrame

PackFrame is a layout container with simplified pack-based layout management.

It extends the bootstack Frame with automatic pack-based layout management, including support for direction, gap spacing, and default fill/expand behavior. Use PackFrame when you want a flex-like layout experience without manually managing pack options.

Children simply call the standard pack() method and automatically receive the frame's default layout options.

Quick start

import bootstack as bs

app = bs.App()

# Vertical stack with gap
stack = bs.PackFrame(app, direction="vertical", gap=10, padding=20)
stack.pack(fill="both", expand=True)

# Add widgets using standard pack()
bs.Button(stack, text="First").pack()
bs.Button(stack, text="Second").pack()
bs.Button(stack, text="Third").pack()

app.mainloop()

When to use

Use PackFrame when:

  • you want a simple vertical or horizontal stack of widgets
  • you need consistent gap spacing between children
  • you want to set default fill/expand behavior for all children
  • you want standard pack() calls to work with managed defaults

Consider a different control when:

  • you need a 2D grid layout -> use GridFrame
  • you just need a container without layout management -> use Frame
  • you need a labeled container -> use LabelFrame

Appearance

Styling

PackFrame inherits all styling options from Frame. Use accent for semantic tokens.

bs.PackFrame(app, accent="secondary", padding=20)

Design System

For theming details and color tokens, see Design System.

Examples & patterns

direction

Controls the layout direction. Options: "vertical", "horizontal", "row", "column", "row-reverse", "column-reverse".

# Vertical stack (top to bottom)
bs.PackFrame(app, direction="vertical")

# Horizontal row (left to right)
bs.PackFrame(app, direction="horizontal")

# Reverse order (bottom to top)
bs.PackFrame(app, direction="column-reverse")

gap

Spacing between children in pixels.

bs.PackFrame(app, direction="vertical", gap=12)

fill_items / expand_items

Default fill and expand behavior for all children.

# All children fill horizontally
stack = bs.PackFrame(app, direction="vertical", fill_items="x")

# All children expand to fill available space
stack = bs.PackFrame(app, direction="vertical", expand_items=True)

anchor_items

Default anchor for children.

bs.PackFrame(app, direction="vertical", anchor_items="w")

propagate

Control whether the frame resizes to fit its contents.

# Fixed size frame
stack = bs.PackFrame(app, width=300, height=400, propagate=False)

Adding widgets

Children use standard pack() to add themselves. The frame automatically applies its defaults.

stack = bs.PackFrame(app, direction="vertical", gap=8, fill_items="x")

# These all use the frame's defaults (fill="x", gap spacing)
bs.Button(stack, text="Button 1").pack()
bs.Button(stack, text="Button 2").pack()
bs.Button(stack, text="Button 3").pack()

# Override defaults for specific widgets
bs.Label(stack, text="Centered").pack(fill="none", anchor="center")

Method chaining

The pack() method returns the widget for chaining:

btn = bs.Button(stack, text="Click").pack()
btn.configure(command=my_callback)

# Or chain further
bs.Entry(stack).pack().focus()

Insertion order

Use before and after to control widget placement:

stack = bs.PackFrame(app, direction="vertical", gap=10)

first = bs.Label(stack, text="First").pack()
last = bs.Label(stack, text="Last").pack()

# Insert between existing widgets
bs.Label(stack, text="Middle").pack(after=first)

Removing widgets

Use standard pack_forget() to remove widgets:

btn = bs.Button(stack, text="Removable").pack()

# Later, remove it
btn.pack_forget()

Behavior

  • Widgets are managed in order; gaps are applied automatically between consecutive widgets.

  • The pack() method returns the widget for fluent/chaining patterns.

  • Removing widgets automatically adjusts gap spacing for remaining widgets.

  • Per-widget options in pack() override container defaults.

  • PackFrame extends Frame, so all Frame options (color, padding, etc.) are available.

  • Standard tkinter pack options (before, after, fill, expand, anchor, etc.) work as expected.

Additional resources

Framework concepts

API reference