Prose.TextWithCaret

public sealed class Prose.TextWithCaret : IEquatable<Prose.TextWithCaret>

Represents a string with caret location and block selection. This is useful for mimicking text area inputs that are not tied to specific controls.

All positions (Caret, Block and the block bounds) are measured in grapheme clusters, not char code units. The text is segmented into complete grapheme runs (base character plus any combining marks, and whole surrogate pairs) via Prose.Graphemes, so the caret can never land inside a cluster and no edit can split one into invalid UTF-16.

Constructors

TextWithCaret

public TextWithCaret(string text, int caret, int block)

Parameters:

text (string)	The text content.
caret (int)	Caret position, measured in grapheme clusters.
block (int)	Selection length, measured in grapheme clusters (signed, relative to the caret).

TextWithCaret

public TextWithCaret(string text)

Parameters:

text (string)

Properties

Block

public int Block { get; }

Gets the length of the selection block (in grapheme clusters), starting at the caret.

BlockEnd

public int BlockEnd { get; }

Gets the index of the right edge of the block.

BlockStart

public int BlockStart { get; }

Gets the index of the left edge of the block.

Caret

public int Caret { get; }

Gets the position of the caret, measured in grapheme clusters.

Empty

public static Prose.TextWithCaret Empty { get; }

IsEmpty

public bool IsEmpty { get; }

Gets whether the Text field is null or empty.

Length

public int Length { get; }

Gets the number of grapheme clusters in the text.

SelectedText

public string SelectedText { get; }

Gets the currently selected text.

Text

public string Text { get; }

Gets the string inside this instance.

Methods

ControlCaretLeft

public Prose.TextWithCaret ControlCaretLeft()

Perform the default caret+block modification based on a COMMAND+LEFT arrow key press.

ControlCaretRight

public Prose.TextWithCaret ControlCaretRight()

Perform the default caret+block modification based on a COMMAND+Right arrow key press.

DeleteAfter

public Prose.TextWithCaret DeleteAfter()

Delete either the block or, if there is no block, the grapheme after the caret.

DeleteBefore

public Prose.TextWithCaret DeleteBefore()

Delete either the block or, if there is no block, the grapheme before the caret.

DeleteBlock

public Prose.TextWithCaret DeleteBlock()

Delete the block, if any.

Equals

public override bool Equals(object obj)

Parameters:

obj (object)

Overrides: Object.Equals

Equals

public bool Equals(TextWithCaret other)

Parameters:

other (Prose.TextWithCaret)

GetHashCode

public override int GetHashCode()

Overrides: Object.GetHashCode

HandleKeyDown

public Prose.TextWithCaret HandleKeyDown(KeyEventArgs e, out CaretDeparture departure)

Handle a key press, additionally reporting when the key asks to leave this text altogether (see Prose.CaretDeparture). A departing key never edits the text; whether it counts as handled depends on the key: the four editing keys always do - a text context owns them even when it cannot act, and letting them bubble would trigger shortcuts elsewhere - while up and down stay unhandled, so hosts which don't accept the departure keep their existing behaviour.

Parameters:

e (KeyEventArgs)
departure (out Prose.CaretDeparture)

HandleKeyDown

public Prose.TextWithCaret HandleKeyDown(KeyEventArgs e)

Parameters:

e (KeyEventArgs)

Insert

public Prose.TextWithCaret Insert(string segment, bool adjust = true, bool select = false)

Replace the block with a text fragment, or insert the fragment at the caret.

Parameters:

segment (string)	Text to insert.
adjust (bool = true)	If true, the caret is moved to the end of the inserted segment.
select (bool = false)	If true, the selection block covers the inserted segment.

IsCharacterInBlock

public bool IsCharacterInBlock(int characterIndex)

Gets whether the grapheme at the given index is inside the selection.

Parameters:

characterIndex (int)

IsPositionInBlock

public bool IsPositionInBlock(int caretPosition)

Gets whether the given caret position is inside the selection. This is true even if the block length is zero.

Parameters:

caretPosition (int)

MoveCaret

public Prose.TextWithCaret MoveCaret(int steps = 1, bool clearBlock = true)

Move the caret left or right.

Parameters:

steps (int = 1)
clearBlock (bool = true)

MoveCaretLeft

public Prose.TextWithCaret MoveCaretLeft()

Perform the default caret+block modification based on a LEFT arrow key press.

MoveCaretLeft

public Prose.TextWithCaret MoveCaretLeft(Keys modifiers)

Move the caret to the left, with default behaviour based on modifier keys.

Parameters:

modifiers (Keys)

Returns: Modified text or this text if the caret could not be moved.

MoveCaretRight

public Prose.TextWithCaret MoveCaretRight()

Perform the default caret+block modification based on a Right arrow key press.

MoveCaretRight

public Prose.TextWithCaret MoveCaretRight(Keys modifiers)

Move the caret to the right, with default behaviour based on modifier keys.

Parameters:

modifiers (Keys)

Returns: Modified text or this text if the caret could not be moved.

ReplaceBlock

public Prose.TextWithCaret ReplaceBlock(string segment, bool adjust = true, bool select = false)

Replace the contents of the selected block with a different text fragment. If there is no selected block, this method does nothing.

Parameters:

segment (string)	Text to insert.
adjust (bool = true)	If true, the caret is moved to the end of the inserted segment.
select (bool = false)	If true, the selection block covers the inserted segment.

SelectAll

public Prose.TextWithCaret SelectAll(bool caretAtStart)

Select the entire text.

Parameters:

caretAtStart (bool)

SelectWordAt

public Prose.TextWithCaret SelectWordAt(int position)

Select the word surrounding a caret position. A 'word' here is a run of graphemes which all classify the same way (letters and digits, whitespace, symbols), i.e. exactly the runs the by-word caret jumps step over.

The caret ends up at the end of the run, where typing is expected to continue, with the block reaching back to its start.

Parameters:

position (int)

Caret position to expand from, in grapheme clusters.

ShiftCaretLeft

public Prose.TextWithCaret ShiftCaretLeft()

Perform the default caret+block modification based on a LEFT+SHIFT arrow key press.

ShiftCaretRight

public Prose.TextWithCaret ShiftCaretRight()

Perform the default caret+block modification based on a RIGHT+SHIFT arrow key press.

ShiftControlCaretLeft

public Prose.TextWithCaret ShiftControlCaretLeft()

Perform the default caret+block modification based on a LEFT+SHIFT arrow key press.

ShiftControlCaretRight

public Prose.TextWithCaret ShiftControlCaretRight()

Perform the default caret+block modification based on a LEFT+SHIFT arrow key press.

ToString

public override string ToString()

Overrides: Object.ToString

WithBlock

public Prose.TextWithCaret WithBlock(int block = 0)

Modify the block of this text.

Parameters:

block (int = 0)

WithCaret

public Prose.TextWithCaret WithCaret(int caret)

Set the caret of this text.

Parameters:

caret (int)

WithCaretAtEnd

public Prose.TextWithCaret WithCaretAtEnd()

Move the caret to the end of this text.

WithCaretAtStart

public Prose.TextWithCaret WithCaretAtStart()

Move the caret to the start of this text.

Operators

Operation			Result	Description
Prose.TextWithCaret	==	Prose.TextWithCaret	bool
Prose.TextWithCaret	!=	Prose.TextWithCaret	bool