Screen
EventTarget is a DOM interface implemented by objects that can receive events and may have listeners for them.
See
https://developer.mozilla.org/docs/Web/API/EventTarget
Extends
Implements
Properties
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
Returns
number
Implementation of
globalThis.Screen.availHeight
availWidth
get
availWidth(): number
Returns
number
Implementation of
globalThis.Screen.availWidth
colorDepth
get
colorDepth(): number
Returns
number
Implementation of
globalThis.Screen.colorDepth
nodeName
get
nodeName(): string
Returns
string
nodeType
get
nodeType(): number
Returns
number
offsetHeight
get
offsetHeight(): number
Returns
number
offsetLeft
get
offsetLeft(): number
Returns
number
offsetTop
get
offsetTop(): number
Returns
number
offsetWidth
get
offsetWidth(): number
Returns
number
orientation
get
orientation(): ScreenOrientation
Returns
Implementation of
globalThis.Screen.orientation
pixelDepth
get
pixelDepth(): number
Returns
number
Implementation of
globalThis.Screen.pixelDepth
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
See
https://developer.mozilla.org/docs/Web/API/EventTarget/addEventListener
addEventListener(type, listener, options)
addEventListener(type
, listener
, options
?): void
Parameters
Parameter | Type |
---|---|
type | string |
listener | EventListenerOrEventListenerObject |
options ? | boolean | AddEventListenerOptions |
Returns
void
Overrides
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
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
getContext(contextId)
getContext(contextId
): null
Parameters
Parameter | Type |
---|---|
contextId | string |
Returns
null
removeEventListener()
removeEventListener(type
, callback
, options
?): void
Removes the event listener in target's event listener list with the same type, callback, and options.
Parameters
Parameter | Type |
---|---|
type | string |
callback | null | EventListenerOrEventListenerObject <any > |
options ? | boolean | EventListenerOptions |
Returns
void
Inherited from
EventTarget
.removeEventListener
See
https://developer.mozilla.org/docs/Web/API/EventTarget/removeEventListener
setAttribute()
setAttribute(name
, value
): void
Parameters
Parameter | Type |
---|---|
name | string |
value | string | number |
Returns
void
toBlob()
toBlob(callback
, type
, quality
): void
Creates a Blob object representing the image contained on the screen.
Parameters
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
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
See
https://developer.mozilla.org/docs/Web/API/HTMLCanvasElement/toDataURL