Table of Contents

Atomic edits and selection

A transaction validates its candidate state before publication. A failed callback leaves the live document unchanged. Sequential builder operations address the result of preceding operations.

using RichEdit.Core;

var snapshot = editor.Document.CurrentSnapshot;
var paragraph = snapshot.Get<RichStory>(snapshot.Body).Blocks[0];
var point = new RichTextPoint(snapshot.Body, paragraph, 0);

editor.Edit(edit =>
{
    edit.ReplaceText(point, 0, "Welcome ");
    edit.SetCharacterFormat(point, 7, new RichCharacterStyle { Bold = true });
}, new RichEditOptions(Description: "Insert greeting"));

This example starts with a paragraph as the first body block. General tools should inspect node types and use selection/structural commands.

Rich selections

RichSelection distinguishes RichTextSelection, RichTextSelectionSet, RichObjectSelection, RichCellSelection, RichBlockSelection, and RichBoundarySelection. Text points contain story, paragraph, local UTF-16 offset, and affinity.

editor.Selection = new RichEdit.Core.RichTextSelection(point, point with { Offset = 7 });
editor.ReplaceSelection("Hello");

A RichTextSelectionSet supplies stable selection IDs and one primary selection. Typing, deletion, paste, and history use the whole set. The native control owns primary selection and touch handles; secondary carets use native geometry.

Cell selections expand to include whole merged cells. Replacing selected cell content preserves the grid. Delete or Backspace removes the table when every cell is selected; with a partial cell selection, it clears the selected cells. Use ClearCells to empty a whole table while keeping its grid. Row, column, and block commands provide explicit structural operations. Text replacement does not flatten partially selected table boundaries.

Deleting text across list items or separate lists in the same text container joins the remaining prefix and suffix. Unselected text keeps its character formatting, and trailing list items retain their numbering. Fully selected lists and intervening blocks are removed. Deleting the first item's leading paragraph break joins its text to the preceding paragraph. Backspace at the start of the first item removes its list membership; if the paragraph is empty, another Backspace removes the remaining line. Undo restores both text and list membership.

Source selections and batches

CodeEditor.Selections is a TextSelectionSet; SelectedRange and SelectionState address its primary selection. AddCaret, ClearSecondarySelections, and ReplaceSelections provide common commands. Selection sets normalize duplicate carets and intersecting ranges while preserving primary identity.

CodeDocument.Edit uses sequential coordinates. CodeEditor.TryApplyEdits accepts nonoverlapping replacements in the captured snapshot's original coordinates and validates DocumentRevision. Same-position insertions retain caller order. An optional selection generation rejects a completion after the user moves the caret without changing text.

Low-level ranges are exact UTF-16 spans. User navigation and deletion use native geometry and grapheme-aware boundaries; callers of raw replacement APIs must choose their intended range.

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