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Companion Helpers

The companion surface is now split across two packages:

  • Pretext.Layout for platform-neutral wrap and obstacle-layout helpers
  • Pretext.Uno for Uno-specific controls and render scheduling

Pretext.Layout

Pretext.Layout builds on the core Pretext engine without taking any Uno Platform dependency.

Data types

WrapMetrics

Aggregate metrics for a wrapped text block:

  • LineCount
  • Height
  • MaxLineWidth

PositionedLine

Represents one laid-out line placed into a coordinate system:

  • Text
  • X
  • Y
  • Width

Obstacle primitives

  • RectObstacle
  • CircleObstacle
  • Interval

These are the geometric primitives used by the obstacle-aware helpers.

Helper types

PreparedTextMetrics

Utility methods for common wrap calculations:

  • MeasureMaxLineWidth
  • CollectWrapMetrics
  • FindTightWrapMetrics
  • IsEnd

ColumnFlowLayout

Flows prepared text through rectangular columns while respecting rectangular and circular obstacles.

ObstacleLayoutHelper

Lower-level helper methods for carving intervals and selecting usable slots around obstacles.

Pretext.Uno

Pretext.Uno now focuses on the Uno-specific pieces.

StretchScrollHost

A simple page-level container that:

  • wraps content in a ScrollViewer
  • stretches the child width to the host width
  • exposes ContentBackground and ContentPadding
  • can compute local viewport bounds for a target element

This is useful for sample-like pages or long document surfaces that need viewport-relative calculations.

UiRenderScheduler

A small dispatcher-backed scheduler that coalesces repeated render requests into a single DispatcherQueue callback.

Use it when:

  • many UI events can trigger a redraw
  • you want to avoid stacking redundant render passes
  • your custom surface already owns a render action

When to use which package

Use Pretext.Layout when you want the helper patterns from the sample hosts without taking a UI framework dependency. Add Pretext.Uno only when your application already targets Uno and wants the reusable Uno controls as well.

See the dedicated package pages for installation and dependency details: