hi::v1::widget Class Reference

Inheritance diagram for hi::v1::widget:

Public Types
using	callback_token = notifier<void()>::callback_token
using	awaiter_type = notifier<void()>::awaiter_type

Public Member Functions
	widget (widget *parent) noexcept
	widget (widget const &)=delete
	widget (widget &&)=delete
widget &	operator= (widget &&)=delete
widget &	operator= (widget const &)=delete
virtual generator< widget const & >	children (bool include_invisible) const noexcept
	Get a list of child widgets.
generator< widget & >	children (bool include_invisible) noexcept
virtual hitbox	hitbox_test (point2i position) const noexcept
	Find the widget that is under the mouse cursor.
virtual hitbox	hitbox_test_from_parent (point2i position) const noexcept
	Call hitbox_test from a parent widget.
virtual hitbox	hitbox_test_from_parent (point2i position, hitbox sibling_hitbox) const noexcept
	Call hitbox_test from a parent widget.
virtual bool	accepts_keyboard_focus (keyboard_focus_group group) const noexcept
	Check if the widget will accept keyboard focus.
void	reset_layout (gui_window *new_window, gfx_surface *new_surface, float new_scale) noexcept
	Reset the layout.
virtual box_constraints	update_constraints () noexcept
	Update the constraints of the widget.
virtual void	set_layout (widget_layout const &context) noexcept
	Update the internal layout of the widget.
virtual void	draw (widget_draw_context const &context) noexcept
	Draw the widget.
virtual sub_theme_selector_type	sub_theme_selector () const noexcept
virtual bool	process_event (gui_event const &event) const noexcept
virtual void	request_redraw () const noexcept
	Request the widget to be redrawn on the next frame.
virtual bool	handle_event (gui_event const &event) noexcept
	Handle command.
virtual bool	handle_event_recursive (gui_event const &event, std::vector< widget_id > const &reject_list=std::vector< widget_id >{}) noexcept
	Handle command recursive.
virtual widget_id	find_next_widget (widget_id current_keyboard_widget, keyboard_focus_group group, keyboard_focus_direction direction) const noexcept
	Find the next widget that handles keyboard focus.
widget_id	find_first_widget (keyboard_focus_group group) const noexcept
widget_id	find_last_widget (keyboard_focus_group group) const noexcept
bool	is_first (keyboard_focus_group group) const noexcept
bool	is_last (keyboard_focus_group group) const noexcept
virtual void	scroll_to_show (hi::aarectanglei rectangle) noexcept
	Scroll to show the given rectangle on the window.
std::vector< widget_id >	parent_chain () const noexcept
	Get a list of parents of a given widget.
virtual bool	is_tab_button () const noexcept
	Check if this widget is a tab-button.
template<forward_of< void()> Callback>
callback_token	subscribe (Callback &&callback, callback_flags flags=callback_flags::synchronous) const noexcept
awaiter_type	operator co_await () const noexcept

Data Fields
widget_id	id = {}
	The numeric identifier of a widget.
widget *	parent = nullptr
	Pointer to the parent widget.
gui_window *	window = nullptr
	The window this widget is on.
gfx_surface *	surface = nullptr
	The surface this widget is drawn on.
observer< widget_mode >	mode = widget_mode::enabled
	The widget mode.
observer< bool >	hover = false
	Mouse cursor is hovering over the widget.
observer< bool >	clicked = false
	The widget is being clicked by the mouse.
observer< bool >	focus = false
	The widget has keyboard focus.
observer< widget_state >	state = widget_state::off
	The state of the widget.
size_t	semantic_layer = 0_uz
	The draw layer of the widget.
observer< extent2i >	minimum = extent2i{}
	The minimum size this widget is allowed to be.
observer< extent2i >	maximum = extent2i::large()
	The maximum size this widget is allowed to be.
widget_layout	layout

Member Function Documentation

accepts_keyboard_focus()

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

inlinevirtualnoexcept

Check if the widget will accept keyboard focus.

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >.

children()

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

inlinevirtualnoexcept

Get a list of child widgets.

Reimplemented in hi::v1::spacer_widget.

draw()

virtual void hi::v1::widget::draw ( widget_draw_context const & context )

inlinevirtualnoexcept

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.

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >, and hi::v1::spacer_widget.

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

inlinevirtualnoexcept

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.

handle_event()

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

inlinevirtualnoexcept

Handle command.

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

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >.

handle_event_recursive()

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

inlinevirtualnoexcept

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.

hitbox_test()

virtual hitbox hi::v1::widget::hitbox_test ( point2i position ) const

inlinevirtualnoexcept

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.

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >, and hi::v1::spacer_widget.

hitbox_test_from_parent() [1/2]

virtual hitbox hi::v1::widget::hitbox_test_from_parent ( point2i position ) const

inlinevirtualnoexcept

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 ( point2i position, hitbox sibling_hitbox ) const

inlinevirtualnoexcept

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.

is_tab_button()

virtual bool hi::v1::widget::is_tab_button ( ) const

inlinevirtualnoexcept

Check if this widget is a tab-button.

Used by the toolbar to determine if it will draw a focus line underneath the toolbar.

parent_chain()

std::vector< widget_id > hi::v1::widget::parent_chain ( ) const

inlinenoexcept

Get a list of parents of a given widget.

The chain includes the given widget.

request_redraw()

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

inlinevirtualnoexcept

Request the widget to be redrawn on the next frame.

Reimplemented in hi::v1::toolbar_tab_button_widget< Name >.

reset_layout()

void hi::v1::widget::reset_layout ( gui_window * new_window, gfx_surface * new_surface, float new_scale )

inlinenoexcept

Reset the layout.

Parameters

new_scale

The scaling factor from this point forward.

scroll_to_show()

virtual void hi::v1::widget::scroll_to_show ( hi::aarectanglei rectangle )

inlinevirtualnoexcept

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.

set_layout()

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

inlinevirtualnoexcept

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.

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >, and hi::v1::spacer_widget.

update_constraints()

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

inlinevirtualnoexcept

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().

Reimplemented in hi::v1::scroll_bar_widget< Axis, Name >, and hi::v1::spacer_widget.

Field Documentation

clicked

observer<bool> hi::v1::widget::clicked = false

The widget is being clicked by the mouse.

focus

observer<bool> hi::v1::widget::focus = false

The widget has keyboard focus.

hover

observer<bool> hi::v1::widget::hover = false

Mouse cursor is hovering over the widget.

id

widget_id hi::v1::widget::id = {}

The numeric identifier of a widget.

Note

This is a uint32_t equal to the operating system's accessibility identifier.

maximum

observer<extent2i> hi::v1::widget::maximum = extent2i::large()

The maximum size this widget is allowed to be.

minimum

observer<extent2i> hi::v1::widget::minimum = extent2i{}

The minimum size this widget is allowed to be.

mode

observer<widget_mode> hi::v1::widget::mode = widget_mode::enabled

The widget mode.

The current visibility and interactivity of a widget.

parent

widget* hi::v1::widget::parent = nullptr

Pointer to the parent widget.

May be a nullptr only when this is the top level widget.

semantic_layer

size_t hi::v1::widget::semantic_layer = 0_uz

The draw layer of the widget.

The semantic layer is used mostly by the draw() function for selecting colors from the theme, to denote nesting widgets inside other widgets.

Semantic layers start at 0 for the window-widget and for any pop-up widgets.

The semantic layer is increased by one, whenever a user of the user-interface would understand the next layer to begin.

In most cases it would mean that a container widget that does not draw itself will not increase the semantic_layer number.

state

observer<widget_state> hi::v1::widget::state = widget_state::off

The state of the widget.

surface

gfx_surface* hi::v1::widget::surface = nullptr

The surface this widget is drawn on.

window

gui_window* hi::v1::widget::window = nullptr

The window this widget is on.

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

• hikogui/src/hikogui/GUI/widget.hpp