Dropdown

#include <Dropdown.hpp>

Inherits: Widget

A focusable widget that shows a popup list of options when opened.

Public Methods

Return	Name	Description
	`Dropdown` `explicit`
`void`	`setOptions` `inline`	Sets the list of options to display.
`void`	`setOnChange` `inline`	Sets the callback invoked when an option is selected.
`void`	`setPopupStyle` `inline`	Sets the style for the dropdown’s popup list.
`void`	`setPopupFocusedStyle` `inline`	Sets the style for the dropdown’s popup list when focused.
`int`	`selectedIndex` `const` `inline`
`const std::string &`	`selectedValue` `const` `inline`
`int`	`getWidth` `const` `inline`	Gets the current width of the dropdown.
`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.
`void`	`layout` `virtual`	Positions and sizes this widget and its children.

explicit

explicit Dropdown(std::vector< Option > options)

setOptions

inline

inline void setOptions(std::vector< Option > opts)

Sets the list of options to display.

Parameters

opts The new list of options

setOnChange

inline

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

Sets the callback invoked when an option is selected.

Parameters

cb The function to call when an option is selected

setPopupStyle

inline

inline void setPopupStyle(const core::Style & s)

Sets the style for the dropdown’s popup list.

Parameters

s The style to apply to the popup

setPopupFocusedStyle

inline

inline void setPopupFocusedStyle(const core::Style & s)

Sets the style for the dropdown’s popup list when focused.

Parameters

s The style to apply to the popup when focused

selectedIndex

const inline

inline int selectedIndex() const

selectedValue

const inline

inline const std::string & selectedValue() const

getWidth

const inline

inline int getWidth() const

Gets the current width of the dropdown.

Returns

the width in columns

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

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

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

layout

virtual

virtual void layout(int x, int y, int width, int height)

Positions and sizes this widget and its children.

Called after measurement to actually place the widget at a specific location. If your widget has children, you must call their layout() methods here.

Parameters

x The X coordinate for this widget
y The Y coordinate for this widget
width The width allocated to this widget
height The height allocated to this widget

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::vector< Option >`	`options`
`int`	`selected`
`bool`	`open`
`core::Style`	`popupStyle`
`core::Style`	`popupFocusedStyle`
`std::function< void(int, const std::string &)>`	`onChange`

options

std::vector< Option > options

selected

int selected = 0

open

bool open = false

popupStyle

core::Style popupStyle

popupFocusedStyle

core::Style popupFocusedStyle

onChange

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

Private Methods

Return	Name	Description
`void`	`openPopup`
`void`	`closePopup`

openPopup

void openPopup()

closePopup

void closePopup()