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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​

Properties​

Methods​

Constructors​

constructor​

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

Overrides QObject.constructor

Parameters:

NameType
arg?QObject | NativeElement

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:

NameTypeDescription
signalTypeSignalTypeSignalType is a signal from the widgets signals interface.
callbackQApplicationSignals[SignalType]Corresponding callback for the signal as mentioned in the widget's signal interface
options?EventListenerOptionsExtra optional options controlling how this event listener is added.

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:

NameType
event?NativeRawPointer‹"QEvent"›

▪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:

NameType
exitCodenumber

Returns: number

inherits​

▸ inherits(className: string): boolean

Inherited from QObject.inherits

Parameters:

NameType
classNamestring

Returns: boolean

killTimer​

▸ killTimer(timerId: number): void

Inherited from QObject.killTimer

Parameters:

NameType
timerIdnumber

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:

NameType
namestring

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:

NameType
signalTypeSignalType
callbackQApplicationSignals[SignalType]
options?EventListenerOptions

Returns: void

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

Inherited from EventWidget.removeEventListener

Parameters:

▪ eventType: WidgetEventTypes

▪ callback: function

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

Parameters:

NameType
event?NativeRawPointer‹"QEvent"›

▪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:

NameTypeDescription
isProcessedbooleantrue if the event has been processed.

Returns: void

setObjectName​

▸ setObjectName(objectName: string): void

Inherited from QObject.setObjectName

Parameters:

NameType
objectNamestring

Returns: void

setParent​

▸ setParent(parent: QObject): void

Inherited from QObject.setParent

Parameters:

NameType
parentQObject

Returns: void

setProperty​

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

Inherited from QObject.setProperty

Parameters:

NameType
namestring
valueQVariantType

Returns: boolean

setQuitOnLastWindowClosed​

▸ setQuitOnLastWindowClosed(quit: boolean): void

Parameters:

NameType
quitboolean

Returns: void

setStyleSheet​

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

Parameters:

NameTypeDefault
styleSheetstring-
postprocessbooleantrue

Returns: void

startTimer​

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

Inherited from QObject.startTimer

Parameters:

NameTypeDefault
intervalMSnumber-
timerTypeTimerTypeTimerType.CoarseTimer

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:

NameType
namestring

Returns: void

Static setDesktopFileName​

▸ setDesktopFileName(name: string): void

Parameters:

NameType
namestring

Returns: void

Static setDesktopSettingsAware​

▸ setDesktopSettingsAware(on: boolean): void

Parameters:

NameType
onboolean

Returns: void

Static setStyle​

▸ setStyle(style: QStyle): void

Parameters:

NameType
styleQStyle

Returns: void

Static setWindowIcon​

▸ setWindowIcon(icon: QIcon): void

Parameters:

NameType
iconQIcon

Returns: void

Static style​

▸ style(): QStyle

Returns: QStyle

Static windowIcon​

▸ windowIcon(): QIcon

Returns: QIcon