Button

Button

#include <Button.hpp>

Inherits: Widget

A clickable button widget.

Button displays text and responds to click events. It’s focusable and can be activated via Enter key or mouse click. Use setOnClick() to handle activation.

Example Usage:

auto btn = std::make_shared<Button>("Click me");
btn->setOnClick([](/api/widgets/button) {
  std::cout << "Button clicked!\n";
});

Public Methods

Return	Name	Description
	Button inline explicit	Creates a button with optional label text.
void	setLabel inline	Sets the button’s label text.
const std::string &	getLabel const inline	Gets the button’s label text.
void	setOnClick inline	Sets the callback to invoke when the button is activated. The callback is called when the user presses Enter (if focused) or clicks.
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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Button

inline explicit

inline explicit Button(const std::string & label)

Creates a button with optional label text.

Parameters

• label The text to display on the button (default: empty)

---

setLabel

inline

inline void setLabel(const std::string & l)

Sets the button’s label text.

Parameters

• l The new label text

---

getLabel

const inline

inline const std::string & getLabel() const

Gets the button’s label text.

Returns

The current label

---

setOnClick

inline

inline void setOnClick(std::function< void()> cb)

Sets the callback to invoke when the button is activated. The callback is called when the user presses Enter (if focused) or clicks.

Parameters

• cb The function to call on activation (can be empty)

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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.

---

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	label
std::function< void()>	onClick

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label

std::string label

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onClick

std::function< void()> onClick