Module kas::layout

Layout utilities

For documentation of layout resolution, see the Layout trait.

Size units are physical (real) pixels. This applies to most of KAS.

Data types

SizeRules is the “heart” of widget layout, used to specify a widget’s size requirements. It provides various methods to compute derived rules and SizeRules::solve_seq, the “muscle” of the layout engine.

AxisInfo, Margins and Stretch are auxilliary data types.

Solvers

The RulesSolver and RulesSetter traits define interfaces for layout engines:

• SingleSolver and SingleSetter are trivial implementations for single-child parents
• RowSolver and RowSetter set out a row or column of children. These are parametrised over S: RowStorage allowing both efficient operation on a small fixed number of children with FixedRowStorage and operation on a over a Vec with DynRowStorage.
• GridSolver and GridSetter set out children assigned to grid cells with optional cell-spans. This is the most powerful and flexible layout engine.

RowPositionSolver may be used with widgets set out by RowSetter to quickly locate children from a coord or rect.

Structs

• AlignHints
  Partial alignment information provided by the parent
• AlignPair
  Provides alignment information on both axes along with ideal size
• AxisInfo
  Information on which axis is being resized
• DynGridStorage
  Variable-length grid storage
• DynRowStorage
  Variable-length row storage
• FixedGridStorage
  Fixed-length grid storage
• FixedRowStorage
  Fixed-length row storage
• FrameRules
  Frame size rules
• FrameStorage
  Layout storage for frame layout
• GridChildInfo
  Per-child information
• GridDimensions
  Grid dimensions
• GridSetter
  A RulesSetter for grids supporting cell-spans
• GridSolver
  A RulesSolver for grids supporting cell-spans
• LogicalSize
  Logical (pre-scaling) pixel size
• Margins
  Margin sizes
• PackStorage
  Layout storage for alignment
• PixmapScaling
  Control over scaling
• RowPositionSolver
  Allows efficient implementations of draw / event handlers based on the layout representation.
• RowSetter
  A RulesSetter for rows (and, without loss of generality, for columns).
• RowSolver
  A RulesSolver for rows (and, without loss of generality, for columns).
• SingleSetter
  RulesSetter implementation for a fixed single-child layout
• SingleSolver
  RulesSolver implementation for a fixed single-child layout
• SizeRules
  Widget sizing information
• SolveCache
  Size solver

Enums

• Align
  Alignment of contents
• Stretch
  Priority for stretching widgets beyond ideal size

Traits

• AutoLayout
  Implementation generated by use of layout = .. property of #[widget]
• DefaultWithLen
  Bound on GridSolver type parameters
• GridStorage
  Requirements of grid solver storage type
• RowStorage
  Requirements of row solver storage type
• RowTemp
  Temporary storage type.
• RulesSetter
  Resolves a RulesSolver solution for each child
• RulesSolver
  A SizeRules solver for layouts

Functions

• solve_size_rules
  Solve size rules for a widget