Screen - Web APIs 编辑

The Screen interface represents a screen, usually the one on which the current window is being rendered, and is obtained using window.screen.

Note that browsers determine which screen to report as current by detecting which screen has the center of the browser window.

Properties

Screen.availTop 

Specifies the y-coordinate of the first pixel that is not allocated to permanent or semipermanent user interface features.

Screen.availLeft 

Returns the first available pixel available from the left side of the screen.

Screen.availHeight

Specifies the height of the screen, in pixels, minus permanent or semipermanent user interface features displayed by the operating system, such as the Taskbar on Windows.

Screen.availWidth

Returns the amount of horizontal space in pixels available to the window.

Screen.colorDepth

Returns the color depth of the screen.

Screen.height

Returns the height of the screen in pixels.

Screen.left 

Returns the distance in pixels from the left side of the main screen to the left side of the current screen.

Screen.orientation

Returns the ScreenOrientation instance associated with this screen.

Screen.pixelDepth

Gets the bit depth of the screen.

Screen.top 

Returns the distance in pixels from the top side of the current screen.

Screen.width

Returns the width of the screen.

Screen.mozEnabled  

Boolean. Setting to false will turn off the device's screen.

Screen.mozBrightness  

Controls the brightness of a device's screen. A double between 0 and 1.0 is expected.

Events handler

Screen.onorientationchange

A handler for the orientationchange event.

Methods

Screen.lockOrientation

Lock the screen orientation (only works in fullscreen or for installed apps)

Screen.unlockOrientation

Unlock the screen orientation (only works in fullscreen or for installed apps)

Methods inherited from EventTarget:

EventTarget.addEventListener()

Registers an event handler of a specific event type on the EventTarget.

EventTarget.removeEventListener()

Removes an event listener from the EventTarget.

EventTarget.dispatchEvent()

Dispatches an event to this EventTarget.

Additional methods in Mozilla chrome codebase

Mozilla includes a couple of extensions for use by JS-implemented event targets to implement onevent properties.

See also WebIDL bindings.

• void setEventHandler(DOMString type, EventHandler handler)
• EventHandler getEventHandler(DOMString type)

Example

if (screen.pixelDepth < 8) {
  // use low-color version of page
} else {
  // use regular, colorful page
}

Specifications

Browser compatibility

BCD tables only load in the browser