#include <ttauri/widgets/widget.hpp>

Inheritance diagram for tt::widget:

Public Member Functions
	widget (gui_window &window, std::shared_ptr< abstract_container_widget > parent) noexcept

	widget (const widget &)=delete

widget &	operator= (const widget &)=delete

	widget (widget &&)=delete

widget &	operator= (widget &&)=delete

virtual void	init () noexcept
	Should be called right after allocating and constructing a widget.

float	margin () const noexcept
	Get the margin around the Widget.

float	draw_layer () const noexcept
	The first drawing layer of the widget.

int	logical_layer () const noexcept
	The logical layer of the widget.

int	semantic_layer () const noexcept
	The semantic layer of the widget.

ranged_int< 3 >	width_resistance () const noexcept
	Get the resistance in width.

ranged_int< 3 >	height_resistance () const noexcept
	Get the resistance in height.

interval_extent2	preferred_size () const noexcept
	Get the size-range of the widget.

void	set_layout_parameters (geo::transformer auto const &local_to_parent, extent2 size, aarectangle const &clipping_rectangle) noexcept
	Set the location and size of the widget inside the window.

void	set_layout_parameters_from_parent (aarectangle child_rectangle, aarectangle parent_clipping_rectangle, float draw_layer_delta) noexcept

void	set_layout_parameters_from_parent (aarectangle child_rectangle) noexcept

matrix3	parent_to_local () const noexcept

matrix3	local_to_parent () const noexcept

matrix3	window_to_local () const noexcept

matrix3	local_to_window () const noexcept

extent2	size () const noexcept

float	width () const noexcept

float	height () const noexcept

aarectangle	rectangle () const noexcept
	Get the rectangle in local coordinates.

virtual float	base_line () const noexcept
	Return the base-line where the text should be located.

aarectangle	clipping_rectangle () const noexcept

gui_device *	device () const noexcept

virtual hit_box	hitbox_test (point2 position) const noexcept
	Find the widget that is under the mouse cursor.

virtual bool	accepts_keyboard_focus (keyboard_focus_group group) const noexcept
	Check if the widget will accept keyboard focus.

virtual bool	update_constraints (hires_utc_clock::time_point display_time_point, bool need_reconstrain) noexcept
	Update the constraints of the widget.

virtual void	update_layout (hires_utc_clock::time_point display_time_point, bool need_layout) noexcept
	Update the internal layout of the widget.

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 color	label_color () const noexcept

virtual void	draw (draw_context context, hires_utc_clock::time_point display_time_point) noexcept
	Draw the widget.

virtual void	request_redraw () const noexcept

virtual bool	handle_event (command command) noexcept
	Handle command.

virtual bool	handle_event (std::vector< command > const &commands) noexcept

virtual bool	handle_command_recursive (command command, std::vector< std::shared_ptr< widget > > const &reject_list) noexcept
	Handle command recursive.

virtual bool	handle_event (mouse_event const &event) noexcept

virtual bool	handle_event (keyboard_event const &event) noexcept
	Handle keyboard event.

virtual std::shared_ptr< widget >	find_next_widget (std::shared_ptr< widget > const &current_keyboard_widget, keyboard_focus_group group, keyboard_focus_direction direction) const noexcept
	Find the next widget that handles keyboard focus.

std::shared_ptr< abstract_container_widget const >	shared_parent () const noexcept
	Get a shared_ptr to the parent.

std::shared_ptr< abstract_container_widget >	shared_parent () noexcept
	Get a shared_ptr to the parent.

abstract_container_widget const &	parent () const noexcept
	Get a reference to the parent.

abstract_container_widget &	parent () noexcept
	Get a reference to the parent.

bool	is_first (keyboard_focus_group group) const noexcept
	Is this widget the first widget in the parent container.

bool	is_last (keyboard_focus_group group) const noexcept
	Is this widget the last widget in the parent container.

Public Member Functions inherited from std::enable_shared_from_this< widget >
T	enable_shared_from_this (T... args)

T	operator= (T... args)

T	shared_from_this (T... args)

T	~enable_shared_from_this (T... args)

Static Public Member Functions
static std::vector< std::shared_ptr< widget > >	parent_chain (std::shared_ptr< tt::widget > const &child_widget) noexcept
	Get a list of parents of a given widget.

Data Fields
gui_window &	window
	Convenient reference to the Window.

observable< bool >	enabled = true
	The widget is enabled.

Detailed Description

View of a widget. A view contains the dynamic data for a Widget. It is often accompanied with a Backing which contains that static data of an Widget and the drawing code. Backings are shared between Views.

All methods should make sure the mutex is locked by the current thread.

Rendering is done in three distinct phases:

Updating Constraints
Updating Layout
Drawing (optional phase)

Each of these phases is executed to completion for all widget belonging to a window before the next phases is executed.

Updating Constraints

In this phases the widget will update the constraints to determine the position and size of the widget inside the window.

The updateConstraints() function will be called on each widget recursively. You should minimize the cost of this function as much as possible.

Since this function is called on each frame, the widget should first check if constraint changes are needed.

A widget should return true if any of the constraints has changed.

Updating Layout

A widget may update its internal (expensive) layout calculations from the updateLayout() function.

Since this function is called on each frame, the widget should first check if layout calculations are needed. If a constraint has changed (the window size is also a constraint) then the forceLayout flag is set.

A widget should return true if the window needs to be redrawn.

Drawing (optional)

A widget can draw itself when the draw() function is called. This phase is only entered when one of the widget's layout was changed. But if this phase is entered then all the widgets' draw() functions are called.

Constructor & Destructor Documentation

◆ widget()

tt::widget::widget	(	gui_window &	window,
		std::shared_ptr< abstract_container_widget >	parent )

noexcept

Constructor for creating sub views.

Member Function Documentation

◆ accepts_keyboard_focus()

virtual bool tt::widget::accepts_keyboard_focus ( keyboard_focus_group group ) const

inlinevirtualnoexcept

Check if the widget will accept keyboard focus.

Precondition: mutex must be locked by current thread.

Reimplemented in tt::abstract_button_widget< T >, tt::abstract_button_widget< bool >, tt::abstract_button_widget< value_type >, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::selection_widget< T >, tt::text_field_widget< T >, and tt::toolbar_tab_button_widget< T >.

◆ base_line()

virtual float tt::widget::base_line ( ) const

inlinevirtualnoexcept

Return the base-line where the text should be located.

Returns: Number of pixels from the bottom of the widget where the base-line is located.

◆ draw()

virtual void tt::widget::draw	(	draw_context	context,
		hires_utc_clock::time_point	display_time_point )

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.

Precondition: mutex must be locked by current thread.

Parameters

context	The context to where the widget will draw.
display_time_point	The time point when the widget will be shown on the screen.

Reimplemented in tt::abstract_container_widget, tt::toolbar_widget, tt::button_widget< T >, tt::checkbox_widget< T >, tt::checkbox_widget< bool >, tt::label_widget, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, tt::overlay_view_widget, tt::radio_button_widget< T >, tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::selection_widget< T >, tt::system_menu_widget, tt::tab_view_widget< T >, tt::text_field_widget< T >, tt::toggle_widget, tt::toolbar_tab_button_widget< T >, and tt::window_traffic_lights_widget.

◆ draw_layer()

float tt::widget::draw_layer ( ) const

inlinenoexcept

The first drawing layer of the widget.

Drawing layers start at 0.0 and go up to 100.0.

Each child widget that has drawing to do increases the layer by 1.0.

The widget should draw within 0.0 and 1.0 of its drawing layer. The toWindowTransfer and the DrawingContext will already include the draw_layer.

An overlay widget such as popups will increase the layer by 25.0, to make sure the overlay will draw above other widgets in the window.

Precondition: mutex must be locked by current thread.

Returns: The draw layer of this widget.

◆ find_next_widget()

virtual std::shared_ptr< widget > tt::widget::find_next_widget	(	std::shared_ptr< widget > const &	current_keyboard_widget,
		keyboard_focus_group	group,
		keyboard_focus_direction	direction ) const

virtualnoexcept

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 empty 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

currentKeyboardWidget	when currentKeyboardWidget was found but no next widget was found.
empty	when currentKeyboardWidget is not found in this Widget.

Reimplemented in tt::abstract_container_widget, tt::selection_widget< T >, and tt::tab_view_widget< T >.

◆ handle_command_recursive()

virtual bool tt::widget::handle_command_recursive	(	command	command,
		std::vector< std::shared_ptr< widget > > const &	reject_list )

virtualnoexcept

Handle command recursive.

Handle a command and pass it to each child.

Parameters

command	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.

Reimplemented in tt::abstract_container_widget.

◆ handle_event() [1/3]

virtual bool tt::widget::handle_event ( command command )

virtualnoexcept

Handle command.

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

Reimplemented in tt::abstract_button_widget< T >, tt::abstract_button_widget< bool >, tt::abstract_button_widget< value_type >, tt::selection_widget< T >, tt::text_field_widget< T >, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, and tt::toolbar_tab_button_widget< T >.

◆ handle_event() [2/3]

virtual bool tt::widget::handle_event ( keyboard_event const & event )

virtualnoexcept

Handle keyboard event.

Called by the operating system when editing text, or entering special keys

Parameters

event The keyboard event.

Returns: If this widget has handled the keyboard event.

Reimplemented in tt::text_field_widget< T >.

◆ handle_event() [3/3]

virtual bool tt::widget::handle_event ( mouse_event const & event )

virtualnoexcept

Handle mouse event. Called by the operating system to show the position and button state of the mouse. This is called very often so it must be made efficient. This function is also used to determine the mouse cursor.

In most cased overriding methods should call the super's handle_event() at the start of the function, to detect hover.

When this method does not handle the event the window will call handle_event() on the widget's parent.

Parameters

event The mouse event, positions are in window coordinates.

Returns: If this widget has handled the mouse event.

Reimplemented in tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::abstract_button_widget< T >, tt::abstract_button_widget< bool >, tt::abstract_button_widget< value_type >, tt::scroll_view_widget< CanScrollHorizontally, CanScrollVertically, ControlsWindow >, tt::selection_widget< T >, tt::text_field_widget< T >, and tt::window_traffic_lights_widget.

◆ height_resistance()

ranged_int< 3 > tt::widget::height_resistance ( ) const

inlinenoexcept

Get the resistance in height.

The amount of resistance the widget has for resizing to larger than the minimum size.

Precondition: mutex must be locked by current thread.

Returns: The amount of resistance to vertical resize.

Return values

0	Greedy: Widget will try to become the largest.
1	Normal: Widget will share the space with others.
2	Resist: Widget will try to maintain minimum size.

◆ hitbox_test()

virtual hit_box tt::widget::hitbox_test ( point2 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 tt::toolbar_widget, tt::abstract_button_widget< T >, tt::abstract_button_widget< bool >, tt::abstract_button_widget< value_type >, tt::abstract_container_widget, tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::scroll_view_widget< CanScrollHorizontally, CanScrollVertically, ControlsWindow >, tt::selection_widget< T >, tt::system_menu_widget, tt::tab_view_widget< T >, tt::text_field_widget< T >, tt::window_traffic_lights_widget, and tt::window_widget.

◆ init()

virtual void tt::widget::init ( )

inlinevirtualnoexcept

Should be called right after allocating and constructing a widget.

Reimplemented in tt::button_widget< T >, tt::checkbox_widget< T >, tt::checkbox_widget< bool >, tt::grid_layout_widget, tt::label_widget, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, tt::radio_button_widget< T >, tt::scroll_view_widget< CanScrollHorizontally, CanScrollVertically, ControlsWindow >, tt::selection_widget< T >, tt::toolbar_tab_button_widget< T >, and tt::window_widget.

◆ is_first()

bool tt::widget::is_first ( keyboard_focus_group group ) const

noexcept

Is this widget the first widget in the parent container.

◆ is_last()

bool tt::widget::is_last ( keyboard_focus_group group ) const

noexcept

Is this widget the last widget in the parent container.

◆ logical_layer()

int tt::widget::logical_layer ( ) const

inlinenoexcept

The logical layer of the widget.

The logical layer can be used to determine how for away from the window-widget (root) the current widget is.

Logical layers start at 0 for the window-widget. Each child widget increases the logical layer by 1.

Precondition: mutex must be locked by current thread.

Returns: The draw layer of this widget.

◆ margin()

float tt::widget::margin ( ) const

inlinenoexcept

Get the margin around the Widget.

A container widget should layout the children in such a way that the maximum margin of neighbouring widgets is maintained.

Precondition: mutex must be locked by current thread.

Returns: The margin for this widget.

◆ parent() [1/2]

abstract_container_widget const & tt::widget::parent ( ) const

noexcept

Get a reference to the parent.

It is undefined behavior to call this function when the widget does not have a parent.

◆ parent() [2/2]

abstract_container_widget & tt::widget::parent ( )

noexcept

Get a reference to the parent.

It is undefined behavior to call this function when the widget does not have a parent.

◆ parent_chain()

static std::vector< std::shared_ptr< widget > > tt::widget::parent_chain ( std::shared_ptr< tt::widget > const & child_widget )

staticnoexcept

Get a list of parents of a given widget.

The chain includes the given widget.

◆ preferred_size()

interval_extent2 tt::widget::preferred_size ( ) const

inlinenoexcept

Get the size-range of the widget.

This size-range is used to determine the size of container widgets and eventually the size of the window.

Precondition: mutex must be locked by current thread.; updateConstraint() must be called first.

Returns: The minimum and maximum size as an interval of a 2D vector.

◆ rectangle()

aarectangle tt::widget::rectangle ( ) const

inlinenoexcept

Get the rectangle in local coordinates.

Precondition: mutex must be locked by current thread.

◆ semantic_layer()

int tt::widget::semantic_layer ( ) const

inlinenoexcept

The semantic 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.

Precondition: mutex must be locked by current thread.

Returns: The draw layer of this widget.

◆ set_layout_parameters()

void tt::widget::set_layout_parameters	(	geo::transformer auto const &	local_to_parent,
		extent2	size,
		aarectangle const &	clipping_rectangle )

inlinenoexcept

Set the location and size of the widget inside the window.

The parent should call this set_layout_paramters() before this updateLayout().

If the parent's layout did not change, it does not need to call this set_layout_parameters(). This way the parent does not need to keep a cache, recalculate or query the client for these layout parameters for each frame.

Precondition: mutex must be locked by current thread.

◆ shared_parent() [1/2]

std::shared_ptr< abstract_container_widget const > tt::widget::shared_parent ( ) const

noexcept

Get a shared_ptr to the parent.

◆ shared_parent() [2/2]

std::shared_ptr< abstract_container_widget > tt::widget::shared_parent ( )

noexcept

Get a shared_ptr to the parent.

◆ update_constraints()

virtual bool tt::widget::update_constraints	(	hires_utc_clock::time_point	display_time_point,
		bool	need_reconstrain )

virtualnoexcept

Update the constraints of the widget.

This function is called on each vertical sync, even if no drawing is to be done. It should recursively call updateConstraints() on each of the visible children, so they get a chance to update.

This function may be used for expensive calculations, such as text-shaping, which should only be done when the data changes. Because this function is called on every vertical sync it should cache these calculations.

Subclasses should call updateConstraints() on its base-class to check if the constraints where changed. Widget::update_constraints() will check if requestConstraints was set. Container::update_constraints() will check if any of the children changed constraints.

If the container, due to a change in constraints, wants the window to resize to the minimum size it should set window.requestResize to true.

This function will change what is returned by preferred_size() and preferred_base_line().

Precondition: mutex must be locked by current thread.

Parameters

display_time_point	The time point when the widget will be shown on the screen.
need_reconstrain	Force the widget to re-constrain.

Returns: True if its or any children's constraints has changed.

Reimplemented in tt::abstract_container_widget, tt::row_column_layout_widget< Arrangement >, tt::toolbar_widget, tt::button_widget< T >, tt::checkbox_widget< T >, tt::checkbox_widget< bool >, tt::grid_layout_widget, tt::label_widget, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, tt::overlay_view_widget, tt::radio_button_widget< T >, tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::scroll_view_widget< CanScrollHorizontally, CanScrollVertically, ControlsWindow >, tt::selection_widget< T >, tt::system_menu_widget, tt::tab_view_widget< T >, tt::text_field_widget< T >, tt::toggle_widget, tt::toolbar_tab_button_widget< T >, tt::window_traffic_lights_widget, and tt::window_widget.

◆ update_layout()

virtual void tt::widget::update_layout	(	hires_utc_clock::time_point	display_time_point,
		bool	need_layout )

virtualnoexcept

Update the internal layout of the widget.

This function is called on each vertical sync, even if no drawing is to be done. It should recursively call updateLayout() on each of the visible children, so they get a chance to update.

This function may be used for expensive calculations, such as geometry calculations, which should only be done when the data or sizes change. Because this function is called on every vertical sync it should cache these calculations.

This function will likely call set_layout_parameters() on its children.

Subclasses should call updateLayout() on its children, call updateLayout() on its base class with forceLayout argument to the result of layoutRequest.exchange(false).

Precondition: mutex must be locked by current thread.

Parameters

display_time_point	The time point when the widget will be shown on the screen.
need_layout	Force the widget to layout

Reimplemented in tt::abstract_container_widget, tt::menu_item_widget< T >, tt::menu_item_widget< value_type >, tt::row_column_layout_widget< Arrangement >, tt::toolbar_widget, tt::window_widget, tt::grid_layout_widget, tt::overlay_view_widget, tt::radio_button_widget< T >, tt::scroll_bar_widget< IsVertical >, tt::scroll_bar_widget< false >, tt::scroll_bar_widget< true >, tt::scroll_view_widget< CanScrollHorizontally, CanScrollVertically, ControlsWindow >, tt::selection_widget< T >, tt::system_menu_widget, tt::tab_view_widget< T >, tt::text_field_widget< T >, tt::toggle_widget, tt::toolbar_tab_button_widget< T >, tt::window_traffic_lights_widget, tt::button_widget< T >, tt::checkbox_widget< T >, tt::checkbox_widget< bool >, and tt::label_widget.

◆ width_resistance()

ranged_int< 3 > tt::widget::width_resistance ( ) const

inlinenoexcept

Get the resistance in width.

The amount of resistance the widget has for resizing to larger than the minimum size.

Precondition: mutex must be locked by current thread.

Returns: The amount of resistance to horizontal resize.

Return values

0	Greedy: Widget will try to become the largest.
1	Normal: Widget will share the space with others.
2	Resist: Widget will try to maintain minimum size.

Field Documentation

◆ enabled

observable<bool> tt::widget::enabled = true

The widget is enabled.

◆ window

gui_window& tt::widget::window

Convenient reference to the Window.

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

hikogui/src/ttauri/widgets/widget.hpp

Public Member Functions

Static Public Member Functions

Data Fields

Detailed Description

Updating Constraints

Updating Layout

Drawing (optional)

Constructor & Destructor Documentation

◆ widget()

Member Function Documentation

◆ accepts_keyboard_focus()

◆ base_line()

◆ draw()

◆ draw_layer()

◆ find_next_widget()

◆ handle_command_recursive()

◆ handle_event() [1/3]

◆ handle_event() [2/3]

◆ handle_event() [3/3]

◆ height_resistance()

◆ hitbox_test()

◆ init()

◆ is_first()

◆ is_last()

◆ logical_layer()

◆ margin()

◆ parent() [1/2]

◆ parent() [2/2]

◆ parent_chain()

◆ preferred_size()

◆ rectangle()

◆ semantic_layer()

◆ set_layout_parameters()

◆ shared_parent() [1/2]

◆ shared_parent() [2/2]

◆ update_constraints()

◆ update_layout()

◆ width_resistance()

Field Documentation

◆ enabled

◆ window