TextArea

TextArea

#include <TextArea.hpp>

Inherits: Widget

A multiline text input widget.

TextArea supports editing text across multiple lines with cursor movement, insertion, deletion, and vertical/horizontal scrolling.

Public Methods

Return	Name	Description
	TextArea inline explicit	Creates a TextArea with optional placeholder text.
void	setText	Set the text of the TextArea.
const std::string &	getText const inline	Get the current text of the TextArea.
void	setPlaceholder inline	Set the placeholder text shown when the TextArea is empty.
void	setFlowMode inline	Set the text flow mode, which determines how the TextArea handles overflow.
TextFlowMode	getFlowMode const inline	Get the current text flow mode.
void	setOnChange inline	Set what happens when the text changes. The callback is called with the new text whenever it changes.
bool	isFocusable virtual const inline	Returns whether this widget can receive keyboard focus.
core::Size	measure virtual	Measures how much space this widget needs.
bool	onEvent virtual	Handles an input event.

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TextArea

inline explicit

inline explicit TextArea(const std::string & placeholder)

Creates a TextArea with optional placeholder text.

Parameters

• placeholder The text to show when the TextArea is empty (default: empty

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setText

void setText(const std::string & t)

Set the text of the TextArea.

Parameters

• t The new text content

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getText

const inline

inline const std::string & getText() const

Get the current text of the TextArea.

Returns

The current text content

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setPlaceholder

inline

inline void setPlaceholder(const std::string & p)

Set the placeholder text shown when the TextArea is empty.

Parameters

• p The new placeholder text

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setFlowMode

inline

inline void setFlowMode(TextFlowMode mode)

Set the text flow mode, which determines how the TextArea handles overflow.

Parameters

• mode The new TextFlowMode (default: Scroll)

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getFlowMode

const inline

inline TextFlowMode getFlowMode() const

Get the current text flow mode.

Returns

The current flow mode

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setOnChange

inline

inline void setOnChange(std::function< void(const std::string &)> cb)

Set what happens when the text changes. The callback is called with the new text whenever it changes.

Parameters

• cb The callback function to call on text change

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isFocusable

virtual const inline

virtual inline bool isFocusable() const

Returns whether this widget can receive keyboard focus.

Widgets like Button and Input return true; containers return false.

Returns

True if this widget can be focused, false otherwise

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measure

virtual

virtual core::Size measure(int availW, int availH)

Measures how much space this widget needs.

Called during the measurement pass to determine widget size requirements. Should return the preferred size based on available space.

Parameters

• availW Maximum available width (may be ignored by widget)

• availH Maximum available height (may be ignored by widget)

Returns

The Size this widget wants, or needs at minimum

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onEvent

virtual

virtual bool onEvent(const core::events::Event & event)

Handles an input event.

Called by the framework to deliver an event to this widget. The default implementation runs any listeners registered via addEventListener(), then returns false. Subclasses (Button, Input, etc.) override this to add built-in behavior, and should call Widget::onEvent(event) first to give user listeners a chance to handle the event before the widget’s own logic.

Return true if the event was handled, false to let it bubble to the parent widget.

Parameters

• event The input event

Returns

True if this widget (or one of its listeners) handled the event

Protected Methods

Return	Name	Description
void	drawContent virtual	Draws this widget’s content.

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drawContent

virtual

virtual void drawContent(backend::Buffer & buf, core::Rect inner)

Draws this widget’s content.

Called by render() after background and borders are drawn. This is where you should draw your widget’s actual content. The inner rectangle accounts for borders and padding.

Parameters

• buf The buffer to draw to

• inner The inner rectangle (excluding border/padding)

Private Attributes

Return	Name	Description
std::string	text
std::string	placeholder
int	cursor
int	preferredColumn
int	scrollX
int	scrollY
TextFlowMode	flowMode
std::function< void(const std::string &)>	onChange

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text

std::string text

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placeholder

std::string placeholder

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cursor

int cursor = 0

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preferredColumn

int preferredColumn = -1

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scrollX

int scrollX = 0

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scrollY

int scrollY = 0

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flowMode

TextFlowMode flowMode = TextFlowMode::Scroll

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onChange

std::function< void(const std::string &)> onChange

Private Methods

Return	Name	Description
void	insertChar
void	insertNewline
void	deleteBack
void	deleteForward
void	moveCursorHorizontal
void	moveCursorVertical
void	moveToLineBoundary
void	updateScroll

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insertChar

void insertChar(char c)

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insertNewline

void insertNewline()

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deleteBack

void deleteBack()

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deleteForward

void deleteForward()

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moveCursorHorizontal

void moveCursorHorizontal(int delta)

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moveCursorVertical

void moveCursorVertical(int delta)

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moveToLineBoundary

void moveToLineBoundary(bool endOfLine)

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updateScroll

void updateScroll()