A retained widget. A new widget is visible, enabled, content-sized, not draggable and not a drop target. More...

#include <backend.hpp>

Inheritance diagram for morph::ui::Widget:

Public Member Functions
	Widget (Widget const &)=delete
Widget &	operator= (Widget const &)=delete
	Widget (Widget &&)=delete
Widget &	operator= (Widget &&)=delete
virtual void	setVisible (bool visible)=0
	Shows or hides the widget and everything inside it.
virtual void	setEnabled (bool enabled)=0
	Enables or disables input on the widget and everything inside it.
virtual void	setLayout (LayoutHints const &hints)=0
	Sets the size request.
virtual void	setDragKey (std::optional< Key > const &key)=0
	Makes the widget draggable, carrying `key`, or not draggable.
virtual void	setDropHandler (std::function< bool(Key const &)> accepts, std::function< void(Key)> onDrop)=0
	Makes the widget a drop target.
virtual void	setAccessibleName (std::string_view name)=0
	Sets the name assistive technology reads for the widget.
virtual void	setAccessibleRole (std::string_view role)=0
	Sets the role assistive technology announces for the widget.
virtual void	setTestId (std::string_view testId)=0
	Sets the stable identifier an automated test finds the widget by.
virtual void	setTooltip (std::string_view text)=0
	Sets the text shown while the pointer rests on the widget.
virtual void	setSurface (std::string_view surface)=0
	Styles the widget and everything inside it with a named token set of the theme.
virtual void	setKeys (std::vector< std::string > const &chords, std::function< void(std::string)> onChord)=0
	Declares the keyboard chords the widget handles while focus is inside it.
virtual void	focus ()=0
	Moves keyboard focus to the widget.
virtual void	setOnHover (std::function< void()> onHover)
	Calls `onHover` each time the pointer comes to rest over the widget. A backend without a pointer, or one that does not report hovering, keeps the default, which never calls it: hovering is a hint, such as a prefetch, never something a widget relies on.

Detailed Description

A retained widget. A new widget is visible, enabled, content-sized, not draggable and not a drop target.

Its destructor detaches it from its parent and frees its native resources; no handler of the widget runs after the destructor returns. A handler may destroy its own widget: the backend keeps the handler alive until that call returns, for example by calling a copy. A backend may assume a handler, a drop's accepts predicate included, never throws: the mount catches and reports what one throws. Every setter takes UTF-8.

A setter called with the value the widget already shows changes nothing: a text input keeps its cursor, its selection and an input method's composition. Input widgets are controlled: a user's action changes what the widget shows, as the toolkit does, and reports the request through the handler; the mount then shows what the application's slot says, in a turn posted after the request's flush, so a refused request snaps back.

Definition at line 34 of file backend.hpp.

Member Function Documentation

◆ setVisible()

virtual void morph::ui::Widget::setVisible ( bool visible )

pure virtual

Shows or hides the widget and everything inside it.

Parameters

visible Whether it is shown.

◆ setEnabled()

virtual void morph::ui::Widget::setEnabled ( bool enabled )

pure virtual

Enables or disables input on the widget and everything inside it.

Parameters

enabled Whether it accepts input.

◆ setLayout()

virtual void morph::ui::Widget::setLayout ( LayoutHints const & hints )

pure virtual

Sets the size request.

Parameters

hints The request in both dimensions.

◆ setDragKey()

virtual void morph::ui::Widget::setDragKey ( std::optional< Key > const & key )

pure virtual

Makes the widget draggable, carrying key, or not draggable.

Parameters

key	Engaged: the key a drop delivers. nullopt: not draggable.

◆ setDropHandler()

virtual void morph::ui::Widget::setDropHandler	(	std::function< bool(Key const &)>	accepts,
		std::function< void(Key)>	onDrop )

pure virtual

Makes the widget a drop target.

Parameters

accepts	Whether a dragged key may be dropped here; the backend asks before highlighting.
onDrop	Called with the key on a drop that accepts allowed.

◆ setAccessibleName()

virtual void morph::ui::Widget::setAccessibleName ( std::string_view name )

pure virtual

Sets the name assistive technology reads for the widget.

Parameters

name	The accessible name; empty leaves the widget's own text as its name.

◆ setAccessibleRole()

virtual void morph::ui::Widget::setAccessibleRole ( std::string_view role )

pure virtual

Sets the role assistive technology announces for the widget.

Parameters

role	The role, such as "heading"; empty leaves the kind's own role.

◆ setTestId()

virtual void morph::ui::Widget::setTestId ( std::string_view testId )

pure virtual

Sets the stable identifier an automated test finds the widget by.

Parameters

testId The identifier; empty means none.

◆ setTooltip()

virtual void morph::ui::Widget::setTooltip ( std::string_view text )

pure virtual

Sets the text shown while the pointer rests on the widget.

Parameters

text	The tooltip; empty shows none.

◆ setSurface()

virtual void morph::ui::Widget::setSurface ( std::string_view surface )

pure virtual

Styles the widget and everything inside it with a named token set of the theme.

Parameters

surface The surface's name; empty is the theme's default.

◆ setKeys()

virtual void morph::ui::Widget::setKeys	(	std::vector< std::string > const &	chords,
		std::function< void(std::string)>	onChord )

pure virtual

Declares the keyboard chords the widget handles while focus is inside it.

A chord pressed while focus is inside several widgets that declare it goes to the innermost of them only.

Parameters

chords	The chords, each modifiers joined to a key name, such as "Ctrl+S".
onChord	Called with the chord that was pressed.

◆ focus()

virtual void morph::ui::Widget::focus ( )

pure virtual

Moves keyboard focus to the widget.

◆ setOnHover()

virtual void morph::ui::Widget::setOnHover ( std::function< void()> onHover )

inlinevirtual

Calls onHover each time the pointer comes to rest over the widget. A backend without a pointer, or one that does not report hovering, keeps the default, which never calls it: hovering is a hint, such as a prefetch, never something a widget relies on.

Parameters

onHover The handler; empty stops calling one.

Definition at line 99 of file backend.hpp.

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

morph/ui/backend.hpp

Public Member Functions

Detailed Description

Member Function Documentation

◆ setVisible()

◆ setEnabled()

◆ setLayout()

◆ setDragKey()

◆ setDropHandler()

◆ setAccessibleName()

◆ setAccessibleRole()

◆ setTestId()

◆ setTooltip()

◆ setSurface()

◆ setKeys()

◆ focus()

◆ setOnHover()