jsdom-browser.screen

The implementation of the Screen API for jsdom-browser.

jsdom-browser is a simulator of a Web browser with JSDOM.

This module is implemented along the CSSOM View Module W3C Working Draft, 17 March 2016. This specification may become older than the latest version.

Install

$ npm install jsdom-browser.screen

Usage

Creates a ScreenConfig object

const { ScreenConfig } = require('jsdom-browser.screen')
 
const screenConfig = new ScreenConfig({
  width: 1280,
  height: 800,
  availTop: 23,
  availLeft: 0,
  availRight: 0,
  availBottom: 0,
  deviceAngle: -90,
})

Configures a Screen object

const { JSDOM } = require('jsdom')
const window = new JSDOM().window
screenConfig.configure(window.screen)
 
window.screen.width  // => 1280
window.screen.height  // => 800
window.screen.availTop // => 23
window.screen.availLeft // => 0
window.screen.availWidth // => 1280
window.screen.availHeight // => 777
 
screenConfig.width  // => 1280
screenConfig.height  // => 800
screenConfig.availTop  // => 23
screenConfig.availLeft  // => 0
screenConfig.availRight  // => 0
screenConfig.availBottom  // => 0
screenConfig.deviceAngle  // => -90
screenConfig.screenAngle  // => 90  // calculates negative value of device angle to 90 * n (n = 0〜3)
screenConfig.baseAngle  // => 90   // is initial screen angle

Rotate screen

This function is not described in the specification, but is needed to implement Screen Orientation API.

screenConfig.deviceAngle = -200
 
window.screen.width  // => 800
window.screen.height  // => 1280
window.screen.availTop // => 23
window.screen.availLeft // => 0
window.screen.availWidth // => 800
window.screen.availHeight // => 1257
 
screenConfig.width  // => 1280
screenConfig.height  // => 800
screenConfig.availTop  // => 23
screenConfig.availLeft  // => 0
screenConfig.availRight  // => 0
screenConfig.availBottom  // => 0
screenConfig.deviceAngle  // => -200
screenConfig.screenAngle  // => 180
screenConfig.baseAngle  // => 90

WebIDL

See The Screen interface in CSSOM View Module.

interface Screen {
  readonly attribute long availWidth;
  readonly attribute long availHeight;
  readonly attribute long width;
  readonly attribute long height;
  readonly attribute unsigned long colorDepth;
  readonly attribute unsigned long pixelDepth;
};

API

class Screen

Is the implementation of the Screen API. This class represents information about the screen of the monitor device.

Properties:

Name	Type	Description
width	number	Is the width of the output device, in CSS pixels. (read only)
height	number	Is the height of the output device, in CSS pixels. (read only)
availTop	number	The available top position of the rendering surface of the monitor device, in CSS pixels. This property is not specified in the specification, but is supported by most browsers. (read only)
availLeft	number	The available left position of the rendering surface of the monitor device, in CSS pixels. This property is not specified in the specification, but is supported by most browsers. (read only)
availWidth	number	The available width of the rendering surface of the monitor device, in CSS pixels. (read only)
availHeight	number	The available height of the rendering surface of the monitor device, in CSS pixels. (read only)
colorDepth	number	This value is always 24. This is useless but are included for compatiility. (read only)
pixelDepth	number	This value is always 24. This is useless but are included for compatiility. (read only)

class ScreenConfig

extends ClassConfig

Is the class to configure a Screen object.

Properties:

Name	Type	Description
width	number	Is the full width of the monitor device.
height	number	Is the full height of the monitor device.
availTop	number	Is the top position of available area from top side of the monitor device.
availLeft	number	Is the left position of available area from left side of the monitor device.
availRight	number	Is the right position of available area from right side of the monitor device.
availBottom	number	Is the bottom position of available area from right side of the monitor device.
deviceAngle	number	Is the angle from natural orientation of the monitor device.
screenAngle	number	Is the angle among 0, 90, 180, 270 degrees rounded the opposite direction value of the device angle. (read only)
baseAngle	number	Is the initial screen angle from natural orientation of the monitor device.

constructor (initConfig [, opts]) : ScreenConfig

Creates a new instance of this class.

If initConfig is a ClassConfig object and opts.sharePrivate is true, this instance shares .$private property with initConfig object. This function is for screens of which windows have a same top window.

Parameters:

Parameter	Type	Description
initConfig	object | ScreenConfig	An object to initialize a new instance.
opts	object	True, if sharing .$private of initConfig which is ClassConfig object. (By default, falsy)

License

Copyright (C) 2018 Takayuki Sato

This program is free software under MIT License. See the file LICENSE in this distribution for more details.