Krypton.Toolkit right-to-left layout

Overview

Issue #2379 extends the Form/Ribbon two-flag RTL contract to Toolkit visual bases and the remaining control chrome (spin buttons, lists, split/group). Ribbon RTL is #2382. Workspace RTL is a separate branch (#2383).

Contract

Flag Meaning
Control.RightToLeft = Yes Reading order; renderer Near/Far content (AccurateText, RenderStandard.RightToLeftIndex). ComboBox drop glyph follows this for WinForms parity.
RightToLeftLayout = true Layout mirroring when also RightToLeft.Yes.

Gate: CommonHelper.IsRightToLeftLayout(control) (both flags).

Named to match WinForms Form.RightToLeftLayout (bool). Distinct from the Toolkit RightToLeftLayout enum used by dialog routing.

Where the layout flag lives

  • VisualControlBase — ComboBox, TextBox, NUD, ListBox, SplitContainer (VisualControlContainment), GroupBox, HeaderGroup, DateTimePicker, TreeView, ListView, MonthCalendar (VisualSimpleBase), Ribbon override.
  • VisualPanel — KryptonPanel (does not inherit VisualControlBase).
  • VisualContainerControlBase — container visuals that do not inherit VisualControlBase.
  • VisualPopup, KryptonForm — existing bool flags.

CommonHelper.GetRightToLeftLayout fast-paths those types, then reflects for WinForms Form / ListView / TreeView.

Docker double-flip rule

ViewLayoutDocker.CalculateDock and ViewDrawDocker.CalculateDock swap Left/Right when IsRightToLeftLayout is true, unless IgnoreRightToLeftLayout is set.

  • Rely on docker for ButtonSpecs (Near→Left, then docker flips) and GroupBox/HeaderGroup Left/Right captions.
  • Or set IgnoreRightToLeftLayout and assign docks yourself (KryptonDateTimePicker, CheckBox/RadioButton UpdateForOrientation).

Never both.

Helpers

ToolkitRtlLayout (Krypton.Toolkit/General/ToolkitRtlLayout.cs): IsRtl, MirrorDock, ApplyTo (copy both flags onto a hosted control), FlipHorizontal, MapNearFar.

Per-control notes

  • NumericUpDown / DomainUpDown: UpDownAlign Left when both flags, Right otherwise.
  • ListBox / CheckedListBox: inner native RightToLeft only (WinForms ListBox has no layout bool). Scrollbar moves with native RTL.
  • RichTextBox: inner RightToLeft. Paragraph SelectionAlignment is unchanged (Left remains Left).
  • ComboBox drop: still keys off RightToLeft alone (WinForms combo parity). ButtonSpecs use docker + layout flag.
  • CheckBox / RadioButton: glyph side from RightToLeft; docker Ignore so both flags do not invert twice.
  • KryptonHScrollBar / KryptonVScrollBar: no thumb reversal; list RTL is native VScroll-on-the-left.
  • Context menu: Show copies both flags from the caller onto VisualContextMenu. Item docks rely on docker flip (do not also MirrorDock). Submenus use ShowHorz = Before; Left/Right keys swap; split hit-test uses the separator side; chevron is flipped. Horizontal ViewLayoutStack reverses column order.
  • TaskDialog: owner flags copy onto the dialog form; element TableLayoutPanels set RightToLeft only when both flags are on (so icon/text/footer columns reverse). Heading Near/Far maps through MapNearFar.
  • PropertyGrid: host RightToLeft is forwarded to InternalPropertyGrid and its children. Native category UI is not rewritten.
  • CommandLink: docker packs the arrow to the start edge; CommandLinkArrowHelper.GetDefaultArrowImage(..., rightToLeft: true) supplies a mirrored arrow when both flags are set.
  • MonthCalendar: both flags pack the day-name row and date grid from the start edge (first weekday on the right). Do not also reverse the day index. Prev/Next ButtonSpecs stay Near/Far Left/Right and rely on docker flip.