chrome.system.display

Description

Use the system.display API to query display metadata.

Permissions

system.display

Types

ActiveState

Chrome 117+

An enum to tell if the display is detected and used by the system. The display is considered 'inactive', if it is not detected by the system (maybe disconnected, or considered disconnected due to sleep mode, etc). This state is used to keep existing display when the all displays are disconnected, for example.

Enum

"active"

"inactive"

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

activeState

ActiveState

Chrome 117+

Active if the display is detected and used by the system.
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.

Enum

"top"

"right"

"bottom"

"left"

MirrorMode

Chrome 65+

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

Enum

"off"
Specifies the default mode (extended or unified desktop).

"normal"
Specifies that the default source display will be mirrored to all other displays.

"mixed"
Specifies that the specified source display will be mirrored to the provided destination displays. All other connected displays will be extended.

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 57+

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

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 57+

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

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 46+

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

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()

Promise Chrome 53+

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

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[]>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

getInfo()

Promise

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

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[]>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

overscanCalibrationAdjust()

Chrome 53+

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

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 53+

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

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 53+

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

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 53+

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

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()

Promise Chrome 53+

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

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>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

setDisplayProperties()

Promise

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

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>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

setMirrorMode()

Promise Chrome 65+

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

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>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

showNativeTouchCalibration()

Promise Chrome 57+

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

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>

Chrome 91+

Promises are supported in Manifest V3 and later, but callbacks are provided for backward compatibility. You cannot use both on the same function call. The promise resolves with the same type that is passed to the callback.

startCustomTouchCalibration()

Chrome 57+

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

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
```