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:

Name	Type
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:

Name	Type	Description
signalType	SignalType	SignalType is a signal from the widgets signals interface.
callback	QApplicationSignals[SignalType]	Corresponding callback for the signal as mentioned in the widget's signal interface
options?	EventListenerOptions	Extra 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:

Name	Type
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:

Name	Type
exitCode	number

Returns: number

---

inherits

▸ inherits(className: string): boolean

Inherited from QObject.inherits

Parameters:

Name	Type
className	string

Returns: boolean

---

killTimer

▸ killTimer(timerId: number): void

Inherited from QObject.killTimer

Parameters:

Name	Type
timerId	number

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:

Name	Type
name	string

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:

Name	Type
signalType	SignalType
callback	QApplicationSignals[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:

Name	Type
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:

Name	Type	Description
isProcessed	boolean	true if the event has been processed.

Returns: void

---

setObjectName

▸ setObjectName(objectName: string): void

Inherited from QObject.setObjectName

Parameters:

Name	Type
objectName	string

Returns: void

---

setParent

▸ setParent(parent: QObject): void

Inherited from QObject.setParent

Parameters:

Name	Type
parent	QObject

Returns: void

---

setProperty

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

Inherited from QObject.setProperty

Parameters:

Name	Type
name	string
value	QVariantType

Returns: boolean

---

setQuitOnLastWindowClosed

▸ setQuitOnLastWindowClosed(quit: boolean): void

Parameters:

Name	Type
quit	boolean

Returns: void

---

setStyleSheet

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

Parameters:

Name	Type	Default
styleSheet	string	-
postprocess	boolean	true

Returns: void

---

startTimer

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

Inherited from QObject.startTimer

Parameters:

Name	Type	Default
intervalMS	number	-
timerType	TimerType	TimerType.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:

Name	Type
name	string

Returns: void

---

Static setDesktopFileName

▸ setDesktopFileName(name: string): void

Parameters:

Name	Type
name	string

Returns: void

---

Static setDesktopSettingsAware

▸ setDesktopSettingsAware(on: boolean): void

Parameters:

Name	Type
on	boolean

Returns: void

---

Static setStyle

▸ setStyle(style: QStyle): void

Parameters:

Name	Type
style	QStyle

Returns: void

---

Static setWindowIcon

▸ setWindowIcon(icon: QIcon): void

Parameters:

Name	Type
icon	QIcon

Returns: void

---

Static style

▸ style(): QStyle

Returns: QStyle

---

Static windowIcon

▸ windowIcon(): QIcon

Returns: QIcon