Screen

EventTarget is a DOM interface implemented by objects that can receive events and may have listeners for them.

Property	Modifier	Type	Default value	Description
`className`	`public`	`string`	`''`	-
`height`	`readonly`	`number`	`undefined`	The height of the screen in CSS pixels. See https://developer.mozilla.org/docs/Web/API/Screen/height
`width`	`readonly`	`number`	`undefined`	The width of the screen in CSS pixels. See https://developer.mozilla.org/docs/Web/API/Screen/width

Accessors

availHeight

get availHeight(): number

MDN Reference

availWidth

get availWidth(): number

MDN Reference

colorDepth

get colorDepth(): number

MDN Reference

offsetHeight

get offsetHeight(): number

offsetLeft

get offsetLeft(): number

offsetWidth

get offsetWidth(): number

orientation

get orientation(): ScreenOrientation

MDN Reference

pixelDepth

get pixelDepth(): number

MDN Reference

Methods

addEventListener()

addEventListener(type, listener, options)

addEventListener(type, listener, options?): void

Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

Parameters

Parameter	Type
`type`	`"touchend"` \| `"touchmove"` \| `"touchstart"`
`listener`	(`ev`) => `any`
`options`?	`boolean` \| `AddEventListenerOptions`

Returns

void

Overrides

EventTarget.addEventListener

See

https://developer.mozilla.org/docs/Web/API/EventTarget/addEventListener

addEventListener(type, listener, options)

addEventListener(type, listener, options?): void

Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

Parameters

Parameter	Type
`type`	`string`
`listener`	`EventListenerOrEventListenerObject`
`options`?	`boolean` \| `AddEventListenerOptions`

Returns

void

Overrides

EventTarget.addEventListener

See

https://developer.mozilla.org/docs/Web/API/EventTarget/addEventListener

dispatchEvent()

dispatchEvent(event): boolean

Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

Parameters

Parameter	Type
`event`	`Event`

Returns

boolean

Inherited from

EventTarget.dispatchEvent

See

https://developer.mozilla.org/docs/Web/API/EventTarget/dispatchEvent

getAttribute()

getAttribute(name): null | string

Parameters

Parameter	Type
`name`	`string`

Returns

null | string

getContext()

getContext(contextId)

getContext(contextId): CanvasRenderingContext2D

Parameters

Parameter	Type
`contextId`	`"2d"`

Returns

CanvasRenderingContext2D

getContext(contextId)

getContext(contextId): null

Parameters

Parameter	Type
`contextId`	`string`

Parameter	Type
`type`	`string`
`callback`	`null` \| `EventListenerOrEventListenerObject`<`any`>
`options`?	`boolean` \| `EventListenerOptions`

Parameter	Type
`name`	`string`
`value`	`string` \| `number`

Parameter	Type	Default value	Description
`callback`	(`blob`) => `void`	`undefined`	A callback function with the resulting Blob object as a single argument. `null` may be passed if the image cannot be created for any reason.
`type`	`string`	`'image/png'`	A string indicating the image format. The default type is `image/png`. This image format will be also used if the specified type is not supported.
`quality`	`number`	`0.8`	A number between `0` and `1` indicating the image quality to be used when creating images using file formats that support lossy compression (such as `image/jpeg`). A user agent will use its default quality value if this option is not specified, or if the number is outside the allowed range.

Returns

void

Example

screen.toBlob(blob => {
  blob.arrayBuffer().then(buffer => {
    Switch.writeFileSync('out.png', buffer);
  });
});

toDataURL()

toDataURL(type, quality): void

Returns a data: URL containing a representation of the image in the format specified by the type parameter.

Parameters

Parameter	Type	Default value	Description
`type`	`string`	`'image/png'`	A string indicating the image format. The default type is `image/png`. This image format will be also used if the specified type is not supported.
`quality`	`number`	`0.8`	A number between `0` and `1` indicating the image quality to be used when creating images using file formats that support lossy compression (such as `image/jpeg`). The default quality value will be used if this option is not specified, or if the number is outside the allowed range.

Returns

void

Example

const url = screen.toDataURL();
fetch(url)
  .then(res => res.arrayBuffer())
  .then(buffer => {
    Switch.writeFileSync('out.png', buffer);
  });

See

https://developer.mozilla.org/docs/Web/API/HTMLCanvasElement/toDataURL

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