QApplication

QApplication is the root object for the entire application. It manages app level settings.

This class is a JS wrapper around Qt's QApplication class

The QApplication class manages the GUI application's control flow and main settings. In NodeGui you will never create an instance of it manually. NodeGui's internal runtime Qode does it for you on app start. You can access the initialised QApplication though if needed.

Example

const { QApplication } = require("@nodegui/nodegui");

const qApp = QApplication.instance();
qApp.quit();

Hierarchy

↳ QObject‹QApplicationSignals›

↳ QApplication

Index

Constructors

• constructor

Properties

• native

Methods

• _id
• addEventListener
• children
• delete
• deleteLater
• devicePixelRatio
• dumpObjectInfo
• dumpObjectTree
• eventProcessed
• exec
• exit
• inherits
• killTimer
• objectName
• palette
• parent
• processEvents
• property
• quit
• quitOnLastWindowClosed
• removeEventListener
• setEventProcessed
• setObjectName
• setParent
• setProperty
• setQuitOnLastWindowClosed
• setStyleSheet
• startTimer
• applicationDisplayName
• clipboard
• desktopFileName
• desktopSettingsAware
• instance
• platformName
• primaryScreen
• screens
• setApplicationDisplayName
• setDesktopFileName
• setDesktopSettingsAware
• setStyle
• setWindowIcon
• style
• windowIcon

Constructors

constructor

+ new QApplication(arg?: QObject | NativeElement): QApplication

Overrides QObject.constructor

Parameters:

Returns: QApplication

Properties

native

• native: NativeElement | null

Inherited from Component.native

Methods

_id

▸ _id(): number

Inherited from QObject._id

Get an ID identifying the underlying C++ object.

This can be useful when debugging memory problems with help from setLogCreateQObject() and setLogDestroyQObject(). The number is hash of the memory address of the C++ object.

Returns: number

a unique number which is valid for the lifetime of the C++ object.

addEventListener

▸ addEventListener‹SignalType›(signalType: SignalType, callback: QApplicationSignals[SignalType], options?: EventListenerOptions): void

Inherited from EventWidget.addEventListener

Type parameters:

▪ SignalType: keyof QApplicationSignals

Parameters:

Returns: void

void

For example in the case of QPushButton:

const button = new QPushButton();
button.addEventListener('clicked',(checked)=>console.log("clicked"));
// here clicked is a value from QPushButtonSignals interface

▸ addEventListener(eventType: WidgetEventTypes, callback: function, options?: EventListenerOptions): void

Inherited from EventWidget.addEventListener

Parameters:

▪ eventType: WidgetEventTypes

▪ callback: function

▸ (event?: NativeRawPointer‹"QEvent"›): void

Parameters:

▪Optional options: EventListenerOptions

Extra optional options controlling how this event listener is added.

For example in the case of QPushButton:

const button = new QPushButton();
button.addEventListener(WidgetEventTypes.HoverEnter,()=>console.log("hovered"));

Returns: void

children

▸ children(): QObject[]

Inherited from QObject.children

Returns: QObject[]

delete

▸ delete(): void

Inherited from QObject.delete

Returns: void

deleteLater

▸ deleteLater(): void

Inherited from QObject.deleteLater

Returns: void

devicePixelRatio

▸ devicePixelRatio(): number

Returns: number

dumpObjectInfo

▸ dumpObjectInfo(): void

Inherited from QObject.dumpObjectInfo

Returns: void

dumpObjectTree

▸ dumpObjectTree(): void

Inherited from QObject.dumpObjectTree

Returns: void

eventProcessed

▸ eventProcessed(): boolean

Inherited from EventWidget.eventProcessed

Get the state of the event processed flag

See setEventProcessed().

Returns: boolean

boolean True if the current event is flagged as processed.

exec

▸ exec(): number

Returns: number

exit

▸ exit(exitCode: number): number

Parameters:

Returns: number

inherits

▸ inherits(className: string): boolean

Inherited from QObject.inherits

Parameters:

Returns: boolean

killTimer

▸ killTimer(timerId: number): void

Inherited from QObject.killTimer

Parameters:

Returns: void

objectName

▸ objectName(): string

Inherited from QObject.objectName

Returns: string

palette

▸ palette(): QPalette

Returns: QPalette

parent

▸ parent(): QObject

Inherited from QObject.parent

Returns: QObject

processEvents

▸ processEvents(): void

Returns: void

property

▸ property(name: string): QVariant

Inherited from QObject.property

Parameters:

Returns: QVariant

quit

▸ quit(): number

Returns: number

quitOnLastWindowClosed

▸ quitOnLastWindowClosed(): boolean

Returns: boolean

removeEventListener

▸ removeEventListener‹SignalType›(signalType: SignalType, callback: QApplicationSignals[SignalType], options?: EventListenerOptions): void

Inherited from EventWidget.removeEventListener

Type parameters:

▪ SignalType: keyof QApplicationSignals

Parameters:

Returns: void

▸ removeEventListener(eventType: WidgetEventTypes, callback: function, options?: EventListenerOptions): void

Inherited from EventWidget.removeEventListener

Parameters:

▪ eventType: WidgetEventTypes

▪ callback: function

▸ (event?: NativeRawPointer‹"QEvent"›): void

Parameters:

▪Optional options: EventListenerOptions

Returns: void

setEventProcessed

▸ setEventProcessed(isProcessed: boolean): void

Inherited from EventWidget.setEventProcessed

Mark the current event as having been processed

This method is used to indicate that the currently dispatched event has been processed and no further processing by superclasses is required. It only makes sense to call this method from an event handler.

When set, this flag will cause NodeGui's QObject::event() method to return true and not call the superclass event(), effectively preventing any further processing on this event.

Parameters:

Returns: void

setObjectName

▸ setObjectName(objectName: string): void

Inherited from QObject.setObjectName

Parameters:

Returns: void

setParent

▸ setParent(parent: QObject): void

Inherited from QObject.setParent

Parameters:

Returns: void

setProperty

▸ setProperty(name: string, value: QVariantType): boolean

Inherited from QObject.setProperty

Parameters:

Returns: boolean

setQuitOnLastWindowClosed

▸ setQuitOnLastWindowClosed(quit: boolean): void

Parameters:

Returns: void

setStyleSheet

▸ setStyleSheet(styleSheet: string, postprocess: boolean): void

Parameters:

Returns: void

startTimer

▸ startTimer(intervalMS: number, timerType: TimerType): number

Inherited from QObject.startTimer

Parameters:

Returns: number

Static applicationDisplayName

▸ applicationDisplayName(): string

Returns: string

Static clipboard

▸ clipboard(): QClipboard | null

Returns: QClipboard | null

Static desktopFileName

▸ desktopFileName(): string

Returns: string

Static desktopSettingsAware

▸ desktopSettingsAware(): boolean

Returns: boolean

Static instance

▸ instance(): QApplication

Returns: QApplication

Static platformName

▸ platformName(): string

Returns: string

Static primaryScreen

▸ primaryScreen(): QScreen | null

Returns: QScreen | null

Static screens

▸ screens(): QScreen[]

Returns: QScreen[]

Static setApplicationDisplayName

▸ setApplicationDisplayName(name: string): void

Parameters:

Returns: void

Static setDesktopFileName

▸ setDesktopFileName(name: string): void

Parameters:

Returns: void

Static setDesktopSettingsAware

▸ setDesktopSettingsAware(on: boolean): void

Parameters:

Returns: void

Static setStyle

▸ setStyle(style: QStyle): void

Parameters:

Returns: void

Static setWindowIcon

▸ setWindowIcon(icon: QIcon): void

Parameters:

Returns: void

Static style

▸ style(): QStyle

Returns: QStyle

Static windowIcon

▸ windowIcon(): QIcon

Returns: QIcon