The Layout Structure

The Layout struct is the primary type used to define how controls are positioned and sized within their parent containers in AppCUI. It serves as a wrapper around layout format information and provides the main interface for specifying control layouts.

The Layout struct provides several methods that can be used to quickly create a layout (for the most common use cases).

• absolute(...) - The control is positioned using explicit coordinates (x, y) for the top-left corner and fixed dimensions (width, height).

  #![allow(unused)]
  fn main() {
  use appcui::prelude::*;
  
  // Creates a control positioned at (8, 5) with a size of 33x6 characters.
  let layout = Layout::absolute(8, 5, 33, 6);
  }

• pivot(...) - The control is positioned relative to a reference point (x, y) and a [Pivot] value, which determines which part of the control attaches to that point (e.g., top-left, center, bottom-right).

  #![allow(unused)]
  fn main() {
  use appcui::prelude::*;
  
  // Creates a control centered around the point (10, 10) 
  // with a size of 6x6 characters. The control will start from
  // the point (7,7), where 7 = 10 - 6/2, and will expand until
  // the point (13,13), where 13 = 10 + 6/2.
  let layout = Layout::pivot(10, 10, 6, 6, Pivot::Center);
  }

• fill()
  The control automatically resizes to completely fill its parent container.

  #![allow(unused)]
  fn main() {
  use appcui::prelude::*;
  
  // Creates a layout that occupies the entire parent container.
  let layout = Layout::fill();
  }

• aligned(...)
  The control is aligned relative to the parent using an [Alignment] value (e.g., top-left, center, bottom-right). Its size remains fixed.

  #![allow(unused)]
  fn main() {
  use appcui::prelude::*;
  
  // Creates a control aligned to the bottom-right corner of 
  // the parent with a fixed size of 20x5 characters.
  let layout = Layout::aligned(Alignment::BottomRight, 20, 5);
  }

Remarks:

• while the Layout can work with percentage values, the methods from the Layout struct only support absolute values. If percentages are needed use LayoutBuilder instead.
• not all possible layouts can be created with the methods from the Layout struct. For example, using various anchors or different dock method are not possible. In this case, use LayoutBuilder or the layout! proc-macro instead.