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

â–¸ _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:

â–ª 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

â–¸ addEventListener(eventType: WidgetEventTypes, callback: function, options?: EventListenerOptions): void

Inherited from EventWidget.addEventListener

Parameters:

â–ª eventType: WidgetEventTypes

â–ª callback: function

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

Parameters:

NameType
event?NativeRawPointer‹"QEvent"›

â–ªOptional 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

â–¸ children(): QObject[]

Inherited from QObject.children

Returns: QObject[]


delete

â–¸ delete(): void

Inherited from QObject.delete

Returns: void


deleteLater

â–¸ deleteLater(): void

Inherited from QObject.deleteLater

Returns: void


devicePixelRatio

â–¸ devicePixelRatio(): number

Returns: number


dumpObjectInfo

â–¸ dumpObjectInfo(): void

Inherited from QObject.dumpObjectInfo

Returns: void


dumpObjectTree

â–¸ dumpObjectTree(): void

Inherited from QObject.dumpObjectTree

Returns: void


eventProcessed

â–¸ 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

â–¸ exec(): number

Returns: number


exit

â–¸ exit(exitCode: number): number

Parameters:

NameType
exitCodenumber

Returns: number


inherits

â–¸ inherits(className: string): boolean

Inherited from QObject.inherits

Parameters:

NameType
classNamestring

Returns: boolean


killTimer

â–¸ killTimer(timerId: number): void

Inherited from QObject.killTimer

Parameters:

NameType
timerIdnumber

Returns: void


objectName

â–¸ objectName(): string

Inherited from QObject.objectName

Returns: string


palette

â–¸ palette(): QPalette

Returns: QPalette


parent

â–¸ parent(): QObject

Inherited from QObject.parent

Returns: QObject


processEvents

â–¸ processEvents(): void

Returns: void


property

â–¸ property(name: string): QVariant

Inherited from QObject.property

Parameters:

NameType
namestring

Returns: QVariant


quit

â–¸ quit(): number

Returns: number


quitOnLastWindowClosed

â–¸ quitOnLastWindowClosed(): boolean

Returns: boolean


removeEventListener

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

Inherited from EventWidget.removeEventListener

Type parameters:

â–ª SignalType: keyof QApplicationSignals

Parameters:

NameType
signalTypeSignalType
callbackQApplicationSignals[SignalType]
options?EventListenerOptions

Returns: void

â–¸ removeEventListener(eventType: WidgetEventTypes, callback: function, options?: EventListenerOptions): void

Inherited from EventWidget.removeEventListener

Parameters:

â–ª eventType: WidgetEventTypes

â–ª callback: function

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

Parameters:

NameType
event?NativeRawPointer‹"QEvent"›

â–ªOptional options: EventListenerOptions

Returns: void


setEventProcessed

â–¸ 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

â–¸ setObjectName(objectName: string): void

Inherited from QObject.setObjectName

Parameters:

NameType
objectNamestring

Returns: void


setParent

â–¸ setParent(parent: QObject): void

Inherited from QObject.setParent

Parameters:

NameType
parentQObject

Returns: void


setProperty

â–¸ setProperty(name: string, value: QVariantType): boolean

Inherited from QObject.setProperty

Parameters:

NameType
namestring
valueQVariantType

Returns: boolean


setQuitOnLastWindowClosed

â–¸ setQuitOnLastWindowClosed(quit: boolean): void

Parameters:

NameType
quitboolean

Returns: void


setStyleSheet

â–¸ setStyleSheet(styleSheet: string, postprocess: boolean): void

Parameters:

NameTypeDefault
styleSheetstring-
postprocessbooleantrue

Returns: void


startTimer

â–¸ startTimer(intervalMS: number, timerType: TimerType): number

Inherited from QObject.startTimer

Parameters:

NameTypeDefault
intervalMSnumber-
timerTypeTimerTypeTimerType.CoarseTimer

Returns: number


Static applicationDisplayName

â–¸ applicationDisplayName(): string

Returns: string


Static clipboard

â–¸ clipboard(): QClipboard | null

Returns: QClipboard | null


Static desktopFileName

â–¸ desktopFileName(): string

Returns: string


Static desktopSettingsAware

â–¸ desktopSettingsAware(): boolean

Returns: boolean


Static instance

â–¸ instance(): QApplication

Returns: QApplication


Static platformName

â–¸ platformName(): string

Returns: string


Static primaryScreen

â–¸ primaryScreen(): QScreen | null

Returns: QScreen | null


Static screens

â–¸ screens(): QScreen[]

Returns: QScreen[]


Static setApplicationDisplayName

â–¸ setApplicationDisplayName(name: string): void

Parameters:

NameType
namestring

Returns: void


Static setDesktopFileName

â–¸ setDesktopFileName(name: string): void

Parameters:

NameType
namestring

Returns: void


Static setDesktopSettingsAware

â–¸ setDesktopSettingsAware(on: boolean): void

Parameters:

NameType
onboolean

Returns: void


Static setStyle

â–¸ setStyle(style: QStyle): void

Parameters:

NameType
styleQStyle

Returns: void


Static setWindowIcon

â–¸ setWindowIcon(icon: QIcon): void

Parameters:

NameType
iconQIcon

Returns: void


Static style

â–¸ style(): QStyle

Returns: QStyle


Static windowIcon

â–¸ windowIcon(): QIcon

Returns: QIcon