hi::v1::widget Class Reference

#include <hikogui/widgets/widget.hpp>

Inheritance diagram for hi::v1::widget:

Public Member Functions
	widget () noexcept
	Constructor for creating sub views.
	widget (const widget &)=delete
widget &	operator= (const widget &)=delete
	widget (widget &&)=delete
widget &	operator= (widget &&)=delete
generator< widget_intf & >	children (bool include_invisible) noexcept override
	Get a list of child widgets.
hitbox	hitbox_test (point2 position) const noexcept override
	Find the widget that is under the mouse cursor.
virtual hitbox	hitbox_test_from_parent (point2 position) const noexcept
	Call hitbox_test from a parent widget.
virtual hitbox	hitbox_test_from_parent (point2 position, hitbox sibling_hitbox) const noexcept
	Call hitbox_test from a parent widget.
bool	accepts_keyboard_focus (keyboard_focus_group group) const noexcept override
	Check if the widget will accept keyboard focus.
box_constraints	update_constraints () noexcept override
	Update the constraints of the widget.
void	set_layout (widget_layout const &context) noexcept override
	Update the internal layout of the widget.
void	draw (draw_context const &context) noexcept override
	Draw the widget.
bool	process_event (gui_event const &event) const noexcept override
	Send a event to the window.
void	request_redraw () const noexcept override
	Request the widget to be redrawn on the next frame.
bool	handle_event (gui_event const &event) noexcept override
	Handle command.
bool	handle_event_recursive (gui_event const &event, std::vector< widget_id > const &reject_list=std::vector< widget_id >{}) noexcept override
	Handle command recursive.
virtual widget_id	find_next_widget (widget_id current_keyboard_widget, keyboard_focus_group group, keyboard_focus_direction direction) const noexcept override
	Find the next widget that handles keyboard focus.
void	scroll_to_show (hi::aarectangle rectangle) noexcept override
	Scroll to show the given rectangle on the window.
hi::theme const &	theme () const noexcept
gfx_surface const *	surface () const noexcept
virtual color	background_color () const noexcept
virtual color	foreground_color () const noexcept
virtual color	focus_color () const noexcept
virtual color	accent_color () const noexcept
virtual generator< widget_intf const & >	children (bool include_invisible=true) const noexcept final
	Get a list of child widgets.
void	scroll_to_show () noexcept
	Scroll to show the important part of the widget.
Public Member Functions inherited from hi::v1::widget_intf
widget_intf *	parent () const noexcept
	Pointer to the parent widget.
virtual void	set_parent (widget_intf *new_parent) noexcept
	Set the parent widget.
template<forward_of< void()> Func>
callback< void()>	subscribe (Func &&func, callback_flags flags=callback_flags::synchronous) noexcept
	Subscribe a callback to be called when an action is completed by the widget.
auto	operator co_await () const noexcept
	Await until an action is completed by the widget.
size_t	layer () const noexcept
void	set_layer (size_t new_layer) noexcept
widget_mode	mode () const noexcept
void	set_mode (widget_mode new_mode) noexcept
widget_value	value () const noexcept
void	set_value (widget_value new_value) noexcept
widget_phase	phase () const noexcept
void	set_pressed (bool pressed) noexcept
void	set_hover (bool hover) noexcept
void	set_active (bool active) noexcept
bool	focus () const noexcept
void	set_focus (bool new_focus) noexcept
widget_layout const &	layout () const noexcept
	Get the current layout for this widget.
std::vector< widget_id >	parent_chain () const noexcept
	Get a list of parents of a given widget.
void	scroll_to_show () noexcept
	Scroll to show the important part of the widget.

Data Fields
observer< extent2 >	minimum = extent2{}
	The minimum size this widget is allowed to be.
observer< extent2 >	maximum = extent2::large()
	The maximum size this widget is allowed to be.
Data Fields inherited from hi::v1::widget_intf
widget_id	id = {}
	The numeric identifier of a widget.
hi::style	style = {}
	The style of this widget.
gui_window *	window = nullptr
notifier< void()>	notifier
	Notifier which is called after an action is completed by a widget.
observer< widget_state >	state
	The current state of the widget.

Detailed Description

An interactive graphical object as part of the user-interface.

Rendering is done in three distinct phases:

1. Updating Constraints: widget::update_constraints()
2. Updating Layout: widget::set_layout()
3. Drawing: widget::draw()

Constructor & Destructor Documentation

widget()

hi::v1::widget::widget ( )

inlineexplicitnoexcept

Constructor for creating sub views.

Member Function Documentation

accepts_keyboard_focus()

bool hi::v1::widget::accepts_keyboard_focus ( keyboard_focus_group group ) const

inlinenodiscardoverridevirtualnoexcept

Check if the widget will accept keyboard focus.

Implements hi::v1::widget_intf.

children() [1/2]

generator< widget_intf & > hi::v1::widget::children ( bool include_invisible )

inlinenodiscardoverridevirtualnoexcept

Get a list of child widgets.

Implements hi::v1::widget_intf.

children() [2/2]

virtual generator< widget_intf const & > hi::v1::widget_intf::children ( bool include_invisible = true ) const

inlinenodiscardfinalvirtualnoexcept

Get a list of child widgets.

Reimplemented from hi::v1::widget_intf.

draw()

void hi::v1::widget::draw ( draw_context const & context )

inlineoverridevirtualnoexcept

Draw the widget.

This function is called by the window (optionally) on every frame. It should recursively call this function on every visible child. This function is only called when updateLayout() has returned true.

The overriding function should call the base class's draw(), the place where the call this function will determine the order of the vertices into each buffer. This is important when needing to do the painters algorithm for alpha-compositing. However the pipelines are always drawn in the same order.

Parameters

context

The context to where the widget will draw.

Implements hi::v1::widget_intf.

find_next_widget()

virtual widget_id hi::v1::widget::find_next_widget ( widget_id current_keyboard_widget, keyboard_focus_group group, keyboard_focus_direction direction ) const

inlinenodiscardoverridevirtualnoexcept

Find the next widget that handles keyboard focus.

This recursively looks for the current keyboard widget, then returns the next (or previous) widget that returns true from accepts_keyboard_focus().

Parameters

current_keyboard_widget	The widget that currently has focus; or nullptr to get the first widget that accepts focus.
group	The group to which the widget must belong.
direction	The direction in which to walk the widget tree.

Returns

A pointer to the next widget.

Return values

current_keyboard_widget	When current_keyboard_widget was found but no next widget that accepts keyboard focus was found.
nullptr	When current_keyboard_widget is not found in this widget.

Implements hi::v1::widget_intf.

handle_event()

bool hi::v1::widget::handle_event ( gui_event const & event )

inlineoverridevirtualnoexcept

Handle command.

If a widget does not fully handle a command it should pass the command to the super class' handle_event().

Implements hi::v1::widget_intf.

handle_event_recursive()

bool hi::v1::widget::handle_event_recursive ( gui_event const & event, std::vector< widget_id > const & reject_list = std::vector< widget_id >{} )

inlineoverridevirtualnoexcept

Handle command recursive.

Handle a command and pass it to each child.

Parameters

event	The command to handle by this widget.
reject_list	The widgets that should ignore this command

Returns

True when the command was handled by this widget or recursed child.

Implements hi::v1::widget_intf.

hitbox_test()

hitbox hi::v1::widget::hitbox_test ( point2 position ) const

inlinenodiscardoverridevirtualnoexcept

Find the widget that is under the mouse cursor.

This function will recursively test with visual child widgets, when widgets overlap on the screen the hitbox object with the highest elevation is returned.

Parameters

position

The coordinate of the mouse local to the widget.

Returns

A hit_box object with the cursor-type and a reference to the widget.

Implements hi::v1::widget_intf.

hitbox_test_from_parent() [1/2]

virtual hitbox hi::v1::widget::hitbox_test_from_parent ( point2 position ) const

inlinenodiscardvirtualnoexcept

Call hitbox_test from a parent widget.

This function will transform the position from parent coordinates to local coordinates.

Parameters

position

The coordinate of the mouse local to the parent widget.

hitbox_test_from_parent() [2/2]

virtual hitbox hi::v1::widget::hitbox_test_from_parent ( point2 position, hitbox sibling_hitbox ) const

inlinenodiscardvirtualnoexcept

Call hitbox_test from a parent widget.

This function will transform the position from parent coordinates to local coordinates.

Parameters

position	The coordinate of the mouse local to the parent widget.
sibling_hitbox	The hitbox of a sibling to combine with the hitbox of this widget.

process_event()

bool hi::v1::widget::process_event ( gui_event const & event ) const

inlineoverridevirtualnoexcept

Send a event to the window.

Implements hi::v1::widget_intf.

request_redraw()

void hi::v1::widget::request_redraw ( ) const

inlineoverridevirtualnoexcept

Request the widget to be redrawn on the next frame.

Implements hi::v1::widget_intf.

scroll_to_show() [1/2]

void hi::v1::widget_intf::scroll_to_show ( )

inlinenoexcept

Scroll to show the important part of the widget.

scroll_to_show() [2/2]

void hi::v1::widget::scroll_to_show ( hi::aarectangle rectangle )

inlineoverridevirtualnoexcept

Scroll to show the given rectangle on the window.

This will call parents, until all parents have scrolled the rectangle to be shown on the window.

Parameters

rectangle

The rectangle in window coordinates.

Implements hi::v1::widget_intf.

set_layout()

void hi::v1::widget::set_layout ( widget_layout const & context )

inlineoverridevirtualnoexcept

Update the internal layout of the widget.

This function is called when the size of this widget must change, or if any of the widget request a re-layout.

This function may be used for expensive calculations, such as geometry calculations, which should only be done when the data or sizes change; it should cache these calculations.

Postcondition

This function will change what is returned by widget::size() and the transformation matrices.

Parameters

context

The layout for this child.

Implements hi::v1::widget_intf.

update_constraints()

box_constraints hi::v1::widget::update_constraints ( )

inlinenodiscardoverridevirtualnoexcept

Update the constraints of the widget.

Typically the implementation of this function starts with recursively calling update_constraints() on its children.

If the container, due to a change in constraints, wants the window to resize to the minimum size it should call request_resize().

Postcondition

This function will change what is returned by widget::minimum_size(), widget::preferred_size() and widget::maximum_size().

Implements hi::v1::widget_intf.

Field Documentation

maximum

observer<extent2> hi::v1::widget::maximum = extent2::large()

The maximum size this widget is allowed to be.

minimum

observer<extent2> hi::v1::widget::minimum = extent2{}

The minimum size this widget is allowed to be.

---

The documentation for this class was generated from the following file:

• hikogui/src/hikogui/widgets/widget.hpp