chrome.system.display

Description
Use the system.display API to query display metadata.
Permissions
system.display

Summary

Types
Bounds
DisplayLayout
DisplayMode
DisplayProperties
DisplayUnitInfo
Edid
GetInfoFlags
Insets
LayoutPosition
MirrorMode
MirrorModeInfo
Point
TouchCalibrationPair
TouchCalibrationPairQuad
Methods
clearTouchCalibration
completeCustomTouchCalibration
enableUnifiedDesktop
getDisplayLayout
getInfo
overscanCalibrationAdjust
overscanCalibrationComplete
overscanCalibrationReset
overscanCalibrationStart
setDisplayLayout
setDisplayProperties
setMirrorMode
showNativeTouchCalibration
startCustomTouchCalibration
Events
onDisplayChanged

Types

Bounds

Properties

height
number
The height of the display in pixels.
left
number
The x-coordinate of the upper-left corner.
top
number
The y-coordinate of the upper-left corner.
width
number
The width of the display in pixels.

DisplayLayout

Chrome 53+

Properties

id
string
The unique identifier of the display.
offset
number
The offset of the display along the connected edge. 0 indicates that the topmost or leftmost corners are aligned.
parentId
string
The unique identifier of the parent display. Empty if this is the root.
position
LayoutPosition
The layout position of this display relative to the parent. This will be ignored for the root.

DisplayMode

Chrome 52+

Properties

deviceScaleFactor
number
The display mode device scale factor.
height
number
The display mode height in device independent (user visible) pixels.
heightInNativePixels
number
The display mode height in native pixels.
isInterlaced
boolean optional
Chrome 74+
True if this mode is interlaced, false if not provided.
isNative
boolean
True if the mode is the display's native mode.
isSelected
boolean
True if the display mode is currently selected.
refreshRate
number
Chrome 67+
The display mode refresh rate in hertz.
uiScale
number optional
Deprecated since Chrome 70
Use displayZoomFactor
The display mode UI scale factor.
width
number
The display mode width in device independent (user visible) pixels.
widthInNativePixels
number
The display mode width in native pixels.

DisplayProperties

Properties

boundsOriginX
number optional
If set, updates the display's logical bounds origin along the x-axis. Applied together with boundsOriginY. Defaults to the current value if not set and boundsOriginY is set. Note that when updating the display origin, some constraints will be applied, so the final bounds origin may be different than the one set. The final bounds can be retrieved using getInfo. The bounds origin cannot be changed on the primary display.
boundsOriginY
number optional
If set, updates the display's logical bounds origin along the y-axis. See documentation for boundsOriginX parameter.
displayMode
DisplayMode optional
Chrome 52+
If set, updates the display mode to the mode matching this value. If other parameters are invalid, this will not be applied. If the display mode is invalid, it will not be applied and an error will be set, but other properties will still be applied.
displayZoomFactor
number optional
Chrome 65+
If set, updates the zoom associated with the display. This zoom performs re-layout and repaint thus resulting in a better quality zoom than just performing a pixel by pixel stretch enlargement.
isPrimary
boolean optional
If set to true, makes the display primary. No-op if set to false. Note: If set, the display is considered primary for all other properties (i.e. isUnified may be set and bounds origin may not).
isUnified
boolean optional
Chrome 59+
Chrome OS only. If set to true, changes the display mode to unified desktop (see enableUnifiedDesktop for details). If set to false, unified desktop mode will be disabled. This is only valid for the primary display. If provided, mirroringSourceId must not be provided and other properties will be ignored. This is has no effect if not provided.
mirroringSourceId
string optional
Deprecated since Chrome 68
Use setMirrorMode.
Chrome OS only. If set and not empty, enables mirroring for this display only. Otherwise disables mirroring for all displays. This value should indicate the id of the source display to mirror, which must not be the same as the id passed to setDisplayProperties. If set, no other property may be set.
overscan
Insets optional
If set, sets the display's overscan insets to the provided values. Note that overscan values may not be negative or larger than a half of the screen's size. Overscan cannot be changed on the internal monitor.
rotation
number optional
If set, updates the display's rotation. Legal values are [0, 90, 180, 270]. The rotation is set clockwise, relative to the display's vertical position.

DisplayUnitInfo

Properties

availableDisplayZoomFactors
number[]
Chrome 67+
A list of zoom factor values that can be set for the display.
bounds
Bounds
The display's logical bounds.
displayZoomFactor
number
Chrome 65+
The ratio between the display's current and default zoom. For example, value 1 is equivalent to 100% zoom, and value 1.5 is equivalent to 150% zoom.
dpiX
number
The number of pixels per inch along the x-axis.
dpiY
number
The number of pixels per inch along the y-axis.
edid
Edid optional
Chrome 67+
NOTE: This is only available to Chrome OS Kiosk apps and Web UI.
hasTouchSupport
boolean
Chrome 57+
True if this display has a touch input device associated with it.
id
string
The unique identifier of the display.
isEnabled
boolean
True if this display is enabled.
isPrimary
boolean
True if this is the primary display.
isUnified
boolean
Chrome 59+
True for all displays when in unified desktop mode. See documentation for enableUnifiedDesktop.
mirroringDestinationIds
string[]
Chrome 64+
Chrome OS only. Identifiers of the displays to which the source display is being mirrored. Empty if no displays are being mirrored. This will be set to the same value for all displays. This must not include mirroringSourceId.
mirroringSourceId
string
Chrome OS only. Identifier of the display that is being mirrored if mirroring is enabled, otherwise empty. This will be set for all displays (including the display being mirrored).
modes
DisplayMode[]
Chrome 52+
The list of available display modes. The current mode will have isSelected=true. Only available on Chrome OS. Will be set to an empty array on other platforms.
name
string
The user-friendly name (e.g. "HP LCD monitor").
overscan
Insets
The display's insets within its screen's bounds. Currently exposed only on ChromeOS. Will be set to empty insets on other platforms.
rotation
number
The display's clockwise rotation in degrees relative to the vertical position. Currently exposed only on ChromeOS. Will be set to 0 on other platforms. A value of -1 will be interpreted as auto-rotate when the device is in a physical tablet state.
workArea
Bounds
The usable work area of the display within the display bounds. The work area excludes areas of the display reserved for OS, for example taskbar and launcher.

Edid

Chrome 67+

Properties

manufacturerId
string
3 character manufacturer code. See Sec. 3.4.1 page 21. Required in v1.4.
productId
string
2 byte manufacturer-assigned code, Sec. 3.4.2 page 21. Required in v1.4.
yearOfManufacture
number
Year of manufacturer, Sec. 3.4.4 page 22. Required in v1.4.

GetInfoFlags

Chrome 59+

Properties

singleUnified
boolean optional
If set to true, only a single DisplayUnitInfo will be returned by getInfo when in unified desktop mode (see enableUnifiedDesktop). Defaults to false.

Insets

Properties

bottom
number
The y-axis distance from the bottom bound.
left
number
The x-axis distance from the left bound.
right
number
The x-axis distance from the right bound.
top
number
The y-axis distance from the top bound.

LayoutPosition

Chrome 53+

Layout position, i.e. edge of parent that the display is attached to.

Type

"top"

"right"

"bottom"

, or

"left"

MirrorMode

Chrome 65+

Mirror mode, i.e. different ways of how a display is mirrored to other displays.

Type

"off"

"normal"

, or

"mixed"

MirrorModeInfo

Chrome 65+

Properties

mirroringDestinationIds
string[] optional
The ids of the mirroring destination displays. This is only valid for 'mixed'.
mirroringSourceId
string optional
The id of the mirroring source display. This is only valid for 'mixed'.
mode
MirrorMode
The mirror mode that should be set.

Point

Chrome 57+

Properties

x
number
The x-coordinate of the point.
y
number
The y-coordinate of the point.

TouchCalibrationPair

Chrome 57+

Properties

displayPoint
Point
The coordinates of the display point.
touchPoint
Point
The coordinates of the touch point corresponding to the display point.

TouchCalibrationPairQuad

Chrome 57+

Properties

pair1
TouchCalibrationPair
First pair of touch and display point required for touch calibration.
pair2
TouchCalibrationPair
Second pair of touch and display point required for touch calibration.
pair3
TouchCalibrationPair
Third pair of touch and display point required for touch calibration.
pair4
TouchCalibrationPair
Fourth pair of touch and display point required for touch calibration.

Methods

clearTouchCalibration

chrome.system.display.clearTouchCalibration(
  id: string,
)

Chrome 57+

Resets the touch calibration for the display and brings it back to its default state by clearing any touch calibration data associated with the display.

Parameters

id
string
The display's unique identifier.

completeCustomTouchCalibration

chrome.system.display.completeCustomTouchCalibration(
  pairs: TouchCalibrationPairQuad,
  bounds: Bounds,
)

Chrome 57+

Sets the touch calibration pairs for a display. These pairs would be used to calibrate the touch screen for display with id called in startCustomTouchCalibration(). Always call startCustomTouchCalibration before calling this method. If another touch calibration is already in progress this will throw an error.

Parameters

pairs
TouchCalibrationPairQuad
The pairs of point used to calibrate the display.
bounds
Bounds
Bounds of the display when the touch calibration was performed. bounds.left and bounds.top values are ignored.

enableUnifiedDesktop

chrome.system.display.enableUnifiedDesktop(
  enabled: boolean,
)

Chrome 46+

Enables/disables the unified desktop feature. If enabled while mirroring is active, the desktop mode will not change until mirroring is turned off. Otherwise, the desktop mode will switch to unified immediately. NOTE: This is only available to Chrome OS Kiosk apps and Web UI.

Parameters

enabled
boolean
True if unified desktop should be enabled.

getDisplayLayout

chrome.system.display.getDisplayLayout(
  callback?: function,
)

Promise Chrome 53+

Requests the layout info for all displays. NOTE: This is only available to Chrome OS Kiosk apps and Web UI.

Parameters

callback
function optional
The callback parameter looks like: (layouts: DisplayLayout[]) => void
- layouts
  DisplayLayout[]

Returns

Promise<DisplayLayout[]>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

getInfo

chrome.system.display.getInfo(
  flags?: GetInfoFlags,
  callback?: function,
)

Promise

Requests the information for all attached display devices.

Parameters

flags
GetInfoFlags optional
Chrome 59+
Options affecting how the information is returned.
callback
function optional
The callback parameter looks like: (displayInfo: DisplayUnitInfo[]) => void
- displayInfo
  DisplayUnitInfo[]

Returns

Promise<DisplayUnitInfo[]>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

overscanCalibrationAdjust

chrome.system.display.overscanCalibrationAdjust(
  id: string,
  delta: Insets,
)

Chrome 53+

Adjusts the current overscan insets for a display. Typically this should either move the display along an axis (e.g. left+right have the same value) or scale it along an axis (e.g. top+bottom have opposite values). Each Adjust call is cumulative with previous calls since Start.

Parameters

id
string
The display's unique identifier.
delta
Insets
The amount to change the overscan insets.

overscanCalibrationComplete

chrome.system.display.overscanCalibrationComplete(
  id: string,
)

Chrome 53+

Complete overscan adjustments for a display by saving the current values and hiding the overlay.

Parameters

id
string
The display's unique identifier.

overscanCalibrationReset

chrome.system.display.overscanCalibrationReset(
  id: string,
)

Chrome 53+

Resets the overscan insets for a display to the last saved value (i.e before Start was called).

Parameters

id
string
The display's unique identifier.

overscanCalibrationStart

chrome.system.display.overscanCalibrationStart(
  id: string,
)

Chrome 53+

Starts overscan calibration for a display. This will show an overlay on the screen indicating the current overscan insets. If overscan calibration for display id is in progress this will reset calibration.

Parameters

id
string
The display's unique identifier.

setDisplayLayout

chrome.system.display.setDisplayLayout(
  layouts: DisplayLayout[],
  callback?: function,
)

Promise Chrome 53+

Set the layout for all displays. Any display not included will use the default layout. If a layout would overlap or be otherwise invalid it will be adjusted to a valid layout. After layout is resolved, an onDisplayChanged event will be triggered. NOTE: This is only available to Chrome OS Kiosk apps and Web UI.

Parameters

layouts
DisplayLayout[]
The layout information, required for all displays except the primary display.
callback
function optional
The callback parameter looks like: () => void

Returns

Promise<void>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

setDisplayProperties

chrome.system.display.setDisplayProperties(
  id: string,
  info: DisplayProperties,
  callback?: function,
)

Promise

Updates the properties for the display specified by id, according to the information provided in info. On failure, runtime.lastError will be set. NOTE: This is only available to Chrome OS Kiosk apps and Web UI.

Parameters

id
string
The display's unique identifier.
info
DisplayProperties
The information about display properties that should be changed. A property will be changed only if a new value for it is specified in info.
callback
function optional
The callback parameter looks like: () => void

Returns

Promise<void>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

setMirrorMode

chrome.system.display.setMirrorMode(
  info: MirrorModeInfo,
  callback?: function,
)

Promise Chrome 65+

Sets the display mode to the specified mirror mode. Each call resets the state from previous calls. Calling setDisplayProperties() will fail for the mirroring destination displays. NOTE: This is only available to Chrome OS Kiosk apps and Web UI.

Parameters

info
MirrorModeInfo
The information of the mirror mode that should be applied to the display mode.
callback
function optional
The callback parameter looks like: () => void

Returns

Promise<void>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

showNativeTouchCalibration

chrome.system.display.showNativeTouchCalibration(
  id: string,
  callback?: function,
)

Promise Chrome 57+

Displays the native touch calibration UX for the display with id as display id. This will show an overlay on the screen with required instructions on how to proceed. The callback will be invoked in case of successful calibration only. If the calibration fails, this will throw an error.

Parameters

id
string
The display's unique identifier.
callback
function optional
The callback parameter looks like: (success: boolean) => void
- success
  boolean

Returns

Promise<boolean>
Pending
This only returns a Promise when the callback parameter is not specified, and with MV3+. The type inside the Promise is the same as the 1st argument to callback.

startCustomTouchCalibration

chrome.system.display.startCustomTouchCalibration(
  id: string,
)

Chrome 57+

Starts custom touch calibration for a display. This should be called when using a custom UX for collecting calibration data. If another touch calibration is already in progress this will throw an error.

Parameters

id
string
The display's unique identifier.

Events

onDisplayChanged

chrome.system.display.onDisplayChanged.addListener(
  callback: function,
)

Fired when anything changes to the display configuration.

Parameters

callback
function
The callback parameter looks like: () => void