morph::tui::Backend Class Reference

Builds every widget of a mounted view tree as a core::tui::Component on one Screen. More...

#include <backend.hpp>

Inheritance diagram for morph::tui::Backend:

Public Types
using	Clock = std::function<std::chrono::steady_clock::time_point()>
	Reads the current time.

Public Member Functions
	Backend (::core::tui::Screen &screen, Clock now={})
	~Backend () override
	Destroys the backend; every widget it made must already be gone.
	Backend (Backend const &)=delete
Backend &	operator= (Backend const &)=delete
	Backend (Backend &&)=delete
Backend &	operator= (Backend &&)=delete
std::unique_ptr< ui::TextWidget >	createText (ui::ContainerWidget *parent) override
	Makes read-only text.
std::unique_ptr< ui::ButtonWidget >	createButton (ui::ContainerWidget *parent) override
	Makes a push button.
std::unique_ptr< ui::TextInputWidget >	createTextInput (ui::ContainerWidget *parent, ui::TextInputMode mode) override
	Makes a text field.
std::unique_ptr< ui::CheckboxWidget >	createCheckbox (ui::ContainerWidget *parent) override
	Makes a check box.
std::unique_ptr< ui::SelectWidget >	createSelect (ui::ContainerWidget *parent, ui::SelectStyle style) override
	Makes a choice of one option.
std::unique_ptr< ui::MenuWidget >	createMenu (ui::ContainerWidget *parent) override
	Makes a command list.
std::unique_ptr< ui::StackWidget >	createStack (ui::ContainerWidget *parent, ui::Axis axis) override
	Makes a stack.
std::unique_ptr< ui::GridWidget >	createGrid (ui::ContainerWidget *parent) override
	Makes a grid.
std::unique_ptr< ui::SpacerWidget >	createSpacer (ui::ContainerWidget *parent) override
	Makes empty space.
std::unique_ptr< ui::PanelWidget >	createPanel (ui::ContainerWidget *parent) override
	Makes a titled frame.
std::unique_ptr< ui::ScrollWidget >	createScroll (ui::ContainerWidget *parent, ui::Axis axis) override
	Makes a scroll area.
std::unique_ptr< ui::SlotWidget >	createSlot (ui::ContainerWidget *parent) override
	Makes a slot.
std::unique_ptr< ui::TabsWidget >	createTabs (ui::ContainerWidget *parent) override
	Makes a tab bar.
std::unique_ptr< ui::DialogWidget >	createDialog (ui::ContainerWidget *parent) override
	Makes a modal overlay.
std::unique_ptr< ui::ToastWidget >	createToast (ui::ContainerWidget *parent) override
	Makes a transient message.
std::unique_ptr< ui::BusyWidget >	createBusy (ui::ContainerWidget *parent) override
	Makes a progress indicator.
std::unique_ptr< ui::TableWidget >	createTable (ui::ContainerWidget *parent) override
	Makes a table.
std::unique_ptr< ui::DateTimeInputWidget >	createDateTimeInput (ui::ContainerWidget *parent, ui::DateMode mode, int offsetMinutes) override
	Makes a date or date-and-time field.
std::unique_ptr< ui::SliderWidget >	createSlider (ui::ContainerWidget *parent) override
	Makes a slider.
std::unique_ptr< ui::FilePickerWidget >	createFilePicker (ui::ContainerWidget *parent, ui::FilePickerMode mode) override
	Makes a file path field.
std::unique_ptr< ui::BannerWidget >	createBanner (ui::ContainerWidget *parent) override
	Makes a banner.
std::unique_ptr< ui::BadgeWidget >	createBadge (ui::ContainerWidget *parent) override
	Makes a badge.
std::unique_ptr< ui::ProgressWidget >	createProgress (ui::ContainerWidget *parent) override
	Makes a progress bar.
std::unique_ptr< ui::StepsWidget >	createSteps (ui::ContainerWidget *parent) override
	Makes a steps indicator.
std::unique_ptr< ui::KeyValueWidget >	createKeyValue (ui::ContainerWidget *parent) override
	Makes a key-value list.
std::unique_ptr< ui::EmptyStateWidget >	createEmptyState (ui::ContainerWidget *parent) override
	Makes an empty state.
std::unique_ptr< ui::DrawerWidget >	createDrawer (ui::ContainerWidget *parent, ui::Side side) override
	Makes a drawer.
std::unique_ptr< ui::SplitterWidget >	createSplitter (ui::ContainerWidget *parent, ui::Axis axis) override
	Makes a splitter.
std::unique_ptr< ui::CollapsibleWidget >	createCollapsible (ui::ContainerWidget *parent) override
	Makes a collapsible section.
std::unique_ptr< ui::DropZoneWidget >	createDropZone (ui::ContainerWidget *parent) override
	Makes a drop zone.
void	fit ()
	Sizes every root widget to the screen's viewport and centres every open dialog; call before each Screen::draw(), which is how a resize reaches the tree.
void	focusNext ()
	Moves keyboard focus to the next focusable widget — inside the innermost open dialog when one is open, because Screen::focusNext does not know overlays.
void	focusPrev ()
	Moves keyboard focus to the previous focusable widget, with focusNext's dialog rule.
void	focusFirst ()
	Focuses the first focusable widget when nothing has focus yet, or when the focus is on an open dialog's frame (the dialog held nothing focusable when it opened, and has since gained something).
bool	endDrag ()
	Ends the drag-and-drop gesture in progress, if any, with no drop, as Esc does.
bool	animating () const noexcept
	Whether any Busy widget is spinning, so the frontend should keep advancing the animation.
void	advanceAnimation () noexcept
	Moves every spinning Busy to its next frame; the next draw shows it.
Public Member Functions inherited from morph::ui::IViewBackend
	IViewBackend (IViewBackend const &)=delete
IViewBackend &	operator= (IViewBackend const &)=delete
	IViewBackend (IViewBackend &&)=delete
IViewBackend &	operator= (IViewBackend &&)=delete
virtual std::unique_ptr< CustomWidget >	createCustom (ContainerWidget *parent, CustomRequest const &request)
	Loads the component a custom node names, if this backend can. The only factory that may return null: null means "not loaded", and the mount shows the node's fallback instead. A backend that loads no components keeps this default.

Detailed Description

Builds every widget of a mounted view tree as a core::tui::Component on one Screen.

Containers arrange their children in cells when the screen renders them; a Dialog and an open Dropdown are screen overlays; drag-and-drop runs on the mouse with pointer capture. The factories, documented on ui::IViewBackend, run on the screen's thread. Widgets must be destroyed before the backend, and the backend before the screen.

The widgets show no tooltips, so nothing here needs the screen's hover timer (Screen::tickHover). A widget that goes drops the screen's hover target, so a caller that does tick it never reaches a destroyed component.

Definition at line 28 of file backend.hpp.

Member Typedef Documentation

Clock

using morph::tui::Backend::Clock = std::function<std::chrono::steady_clock::time_point()>

Reads the current time.

Definition at line 31 of file backend.hpp.

Constructor & Destructor Documentation

Backend()

morph::tui::Backend::Backend ( ::core::tui::Screen & screen, Clock now = {} )

explicit

Parameters

screen	Where every widget renders. Borrowed: it must outlive the backend.
now	The clock the widgets read the time from (a table telling a double click from two clicks); empty reads std::chrono::steady_clock. A test passes one it advances itself.

Member Function Documentation

createText()

std::unique_ptr< ui::TextWidget > morph::tui::Backend::createText ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes read-only text.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createButton()

std::unique_ptr< ui::ButtonWidget > morph::tui::Backend::createButton ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a push button.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createTextInput()

std::unique_ptr< ui::TextInputWidget > morph::tui::Backend::createTextInput ( ui::ContainerWidget * parent, ui::TextInputMode mode )

nodiscardoverridevirtual

Makes a text field.

Parameters

parent	The container to append to, or null for a root.
mode	Single-line, multiline or password.

Returns

The widget.

Implements morph::ui::IViewBackend.

createCheckbox()

std::unique_ptr< ui::CheckboxWidget > morph::tui::Backend::createCheckbox ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a check box.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSelect()

std::unique_ptr< ui::SelectWidget > morph::tui::Backend::createSelect ( ui::ContainerWidget * parent, ui::SelectStyle style )

nodiscardoverridevirtual

Makes a choice of one option.

Parameters

parent	The container to append to, or null for a root.
style	Dropdown or radio.

Returns

The widget.

Implements morph::ui::IViewBackend.

createMenu()

std::unique_ptr< ui::MenuWidget > morph::tui::Backend::createMenu ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a command list.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createStack()

std::unique_ptr< ui::StackWidget > morph::tui::Backend::createStack ( ui::ContainerWidget * parent, ui::Axis axis )

nodiscardoverridevirtual

Makes a stack.

Parameters

parent	The container to append to, or null for a root.
axis	Vertical (a column) or horizontal (a row).

Returns

The widget.

Implements morph::ui::IViewBackend.

createGrid()

std::unique_ptr< ui::GridWidget > morph::tui::Backend::createGrid ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a grid.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSpacer()

std::unique_ptr< ui::SpacerWidget > morph::tui::Backend::createSpacer ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes empty space.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createPanel()

std::unique_ptr< ui::PanelWidget > morph::tui::Backend::createPanel ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a titled frame.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createScroll()

std::unique_ptr< ui::ScrollWidget > morph::tui::Backend::createScroll ( ui::ContainerWidget * parent, ui::Axis axis )

nodiscardoverridevirtual

Makes a scroll area.

Parameters

parent	The container to append to, or null for a root.
axis	The scroll direction.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSlot()

std::unique_ptr< ui::SlotWidget > morph::tui::Backend::createSlot ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a slot.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createTabs()

std::unique_ptr< ui::TabsWidget > morph::tui::Backend::createTabs ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a tab bar.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createDialog()

std::unique_ptr< ui::DialogWidget > morph::tui::Backend::createDialog ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a modal overlay.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createToast()

std::unique_ptr< ui::ToastWidget > morph::tui::Backend::createToast ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a transient message.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createBusy()

std::unique_ptr< ui::BusyWidget > morph::tui::Backend::createBusy ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a progress indicator.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createTable()

std::unique_ptr< ui::TableWidget > morph::tui::Backend::createTable ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a table.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createDateTimeInput()

std::unique_ptr< ui::DateTimeInputWidget > morph::tui::Backend::createDateTimeInput ( ui::ContainerWidget * parent, ui::DateMode mode, int offsetMinutes )

nodiscardoverridevirtual

Makes a date or date-and-time field.

Parameters

parent	The container to append to, or null for a root.
mode	Date, or date and time.
offsetMinutes	The display zone's offset from UTC.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSlider()

std::unique_ptr< ui::SliderWidget > morph::tui::Backend::createSlider ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a slider.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createFilePicker()

std::unique_ptr< ui::FilePickerWidget > morph::tui::Backend::createFilePicker ( ui::ContainerWidget * parent, ui::FilePickerMode mode )

nodiscardoverridevirtual

Makes a file path field.

Parameters

parent	The container to append to, or null for a root.
mode	Open or save.

Returns

The widget.

Implements morph::ui::IViewBackend.

createBanner()

std::unique_ptr< ui::BannerWidget > morph::tui::Backend::createBanner ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a banner.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createBadge()

std::unique_ptr< ui::BadgeWidget > morph::tui::Backend::createBadge ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a badge.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createProgress()

std::unique_ptr< ui::ProgressWidget > morph::tui::Backend::createProgress ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a progress bar.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSteps()

std::unique_ptr< ui::StepsWidget > morph::tui::Backend::createSteps ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a steps indicator.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createKeyValue()

std::unique_ptr< ui::KeyValueWidget > morph::tui::Backend::createKeyValue ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a key-value list.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createEmptyState()

std::unique_ptr< ui::EmptyStateWidget > morph::tui::Backend::createEmptyState ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes an empty state.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createDrawer()

std::unique_ptr< ui::DrawerWidget > morph::tui::Backend::createDrawer ( ui::ContainerWidget * parent, ui::Side side )

nodiscardoverridevirtual

Makes a drawer.

Parameters

parent	The container to append to, or null for a root.
side	The edge it slides in from.

Returns

The widget.

Implements morph::ui::IViewBackend.

createSplitter()

std::unique_ptr< ui::SplitterWidget > morph::tui::Backend::createSplitter ( ui::ContainerWidget * parent, ui::Axis axis )

nodiscardoverridevirtual

Makes a splitter.

Parameters

parent	The container to append to, or null for a root.
axis	The axis its panes are laid out along.

Returns

The widget.

Implements morph::ui::IViewBackend.

createCollapsible()

std::unique_ptr< ui::CollapsibleWidget > morph::tui::Backend::createCollapsible ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a collapsible section.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

createDropZone()

std::unique_ptr< ui::DropZoneWidget > morph::tui::Backend::createDropZone ( ui::ContainerWidget * parent )

nodiscardoverridevirtual

Makes a drop zone.

Parameters

parent

The container to append to, or null for a root.

Returns

The widget.

Implements morph::ui::IViewBackend.

endDrag()

bool morph::tui::Backend::endDrag

(

)

Ends the drag-and-drop gesture in progress, if any, with no drop, as Esc does.

Esc reaches the gesture through the widget that has the keyboard focus; a frontend calls this for an Esc no widget took, so that a drag ends while nothing is focused too.

Returns

True when a drag was in progress and has ended.

animating()

bool morph::tui::Backend::animating ( ) const

nodiscardnoexcept

Whether any Busy widget is spinning, so the frontend should keep advancing the animation.

Returns

True while at least one Busy is active.

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

• morph/tui/backend.hpp