DatumHueEnterprise v0.0.24datumhue.com
Contents

namespaceDisplay Control8 functions, 9 propertiesUI apps only

datumhue.screen

Window dimensions, fullscreen, resolution, stretch/zoom, and monitor information. Scope follows the caller: bootstrap controls the workstation window, while a regular app controls its own root panel. The request_* functions are proposals — bootstrap's apply at the end of the frame (in a browser the page sets the workstation's size, so its request_resolution changes nothing), and an app's are sent to its window manager to answer (see the app_*_request events and the wm namespace).

Returns handles
Image

Fields 9

FieldTypeAccessDescription
keep_awakebooleanread/writeWhether this app asks the host to keep the display awake. While any running app holds true, the host inhibits the machine's screensaver and display sleep; the request is released when the app clears it or exits. Best-effort: where the system offers no way to keep the display awake, the value still reads back as set and nothing else changes.
is_fullscreenbooleanread-onlyRead-only. Whether the workstation window is in full screen, as the window system reports it: it turns true once a full-screen request has landed, a few frames after the call, and false after any exit, including ones the app did not make (the browser's Esc, an OS shortcut, the window manager). A regular app's maximized panel does not count.
fullscreen_availablebooleanread-onlyRead-only. Whether this host can put the workstation in full screen. Always true natively; false in a browser without full-screen support (iPhone Safari) or where the page is not allowed to use it. While this is false the bootstrap's fullscreen raises for a full-screen mode, and leaving full screen does nothing.
zoomnumberread-onlyCurrent end-user comfort zoom multiplier.
widthnumberread-onlyDrawable surface width in UI px — the app's own panel (the whole window for bootstrap).
heightnumberread-onlyDrawable surface height in UI px — the app's own panel (the whole window for bootstrap).
stretch_modescreen.StretchModeread-onlyCurrent stretch mode.
resolutionscreen.Resolutionread-onlyDrawable surface resolution — the app's own panel (the whole window for bootstrap).
design_resolutionscreen.DesignResolutionread-onlyCurrent design resolution.

Functions 8

datumhue.screen.fullscreen

functionUI apps only
datumhue.screen.fullscreen(mode: screen.FullscreenMode | false, monitor_index?: integer)

Enter a full-screen mode, or leave it with "windowed" or false. It raises for true, a non-string or an unknown mode. For the bootstrap this is the workstation window: the change lands a few frames later (read is_fullscreen), on the monitor monitor_index names, 1-based as monitors() lists them (default: the window's current monitor; a browser uses the screen showing the page). The bootstrap's call also raises for "exclusive" in a browser, for a full-screen mode while fullscreen_available is false (leaving does nothing there), and for a monitor_index outside monitors(). In a browser without a recent tap, click or key press (after a gamepad press), the call returns, the workstation shows its "Continue" chip, and full screen starts on that chip's tap, click or key press; is_fullscreen turns true then. A regular app's call asks its window manager to maximize or restore the app's panel instead (app_fullscreen_request).

Example
datumhue.screen.fullscreen("borderless")
datumhue.screen.fullscreen(false)

In the guide: Fit any window size How your app runs

datumhue.screen.request_resolution

functionUI apps only
datumhue.screen.request_resolution(width: number, height: number)

Request a size for the caller's window. The bootstrap's sizes the workstation window while it is windowed; a full-screen mode keeps the monitor's size, and the request applies again on the return to windowed. In a browser the page sets the workstation's size, so the bootstrap's request changes nothing there. A regular app's request goes to the window manager framing it (app_resize_request); without a frame it resizes the app's own root panel.

In the guide: Fit any window size How your app runs

datumhue.screen.monitors

functionUI apps only
datumhue.screen.monitors() -> screen.Monitor[]

List of connected monitors.

returns screen.Monitor record 8 keys

KeyTypeDescription
indexinteger1-based monitor index.
name?stringMonitor name, when the OS reports one.
widthintegerWidth in pixels.
heightintegerHeight in pixels.
scale_factornumberDevice pixel ratio.
refresh_rate_hz?numberRefresh rate in Hz, when known.
is_primarybooleanWhether this is the primary monitor.
is_currentbooleanWhether the window is currently on this monitor.

datumhue.screen.current_monitor

functionUI apps only
datumhue.screen.current_monitor() -> screen.Monitor?

The monitor the window is currently on, or nil.

returns screen.Monitor record 8 keys

KeyTypeDescription
indexinteger1-based monitor index.
name?stringMonitor name, when the OS reports one.
widthintegerWidth in pixels.
heightintegerHeight in pixels.
scale_factornumberDevice pixel ratio.
refresh_rate_hz?numberRefresh rate in Hz, when known.
is_primarybooleanWhether this is the primary monitor.
is_currentbooleanWhether the window is currently on this monitor.

datumhue.screen.screenshot

functionUI apps onlysuspendsneeds screenshot
datumhue.screen.screenshot() -> Image

Capture the whole workstation window.

In the guide: Waiting: suspending calls and handles Permissions and capabilities

datumhue.screen.request_stretch_mode

functionUI apps only
datumhue.screen.request_stretch_mode(mode: screen.StretchMode)

Request how the design canvas fits the window when their sizes differ.

In the guide: Fit any window size

datumhue.screen.request_design_resolution

functionUI apps only
datumhue.screen.request_design_resolution(width: number, height: number)

Request the logical design resolution (0, 0 to clear).

In the guide: Fit any window size

datumhue.screen.request_zoom

functionUI apps only
datumhue.screen.request_zoom(factor: number)

Request a change to the end-user comfort zoom multiplier.

In the guide: Fit any window size

Types 5

screen.DesignResolution

record

record 2 keys

KeyTypeDescription
widthnumberDesign width in points.
heightnumberDesign height in points.

Used by: datumhue.screen.design_resolution

screen.FullscreenMode

enum
ValueDescription
"windowed"Normal decorated window. Also selected by passing false.
"borderless"Borderless window filling the current monitor at its desktop resolution.
"exclusive"Exclusive fullscreen at the monitor's current video mode.

Used by: datumhue.screen.fullscreen

Nested in: events.AppFullscreenRequest

screen.Monitor

record

record 8 keys

KeyTypeDescription
indexinteger1-based monitor index.
name?stringMonitor name, when the OS reports one.
widthintegerWidth in pixels.
heightintegerHeight in pixels.
scale_factornumberDevice pixel ratio.
refresh_rate_hz?numberRefresh rate in Hz, when known.
is_primarybooleanWhether this is the primary monitor.
is_currentbooleanWhether the window is currently on this monitor.

Used by: datumhue.screen.monitors, datumhue.screen.current_monitor

screen.Resolution

record

record 6 keys

KeyTypeDescription
widthnumberWidth in UI px (the value screen.width reads).
heightnumberHeight in UI px (the value screen.height reads).
scale_factornumberDevice pixel ratio (physical / logical).
physical_widthintegerWidth in physical pixels, as the display draws the surface: after the zoom, the stretch mode and the scale factor.
physical_heightintegerHeight in physical pixels, as physical_width.
zoomnumberCurrent zoom factor.

Used by: datumhue.screen.resolution

screen.StretchMode

enum
ValueDescription
"fill"
"letterbox"
"pixel_perfect"

Used by: datumhue.screen.request_stretch_mode, datumhue.screen.stretch_mode

Nested in: events.AppStretchModeRequest

datumhue.com

(c) 2026 Shuusei AB. Quote excerpts of this manual, with attribution to DatumHue, in your own documentation, tutorials, course materials, reviews, and other writing or video. Republishing it in whole or in substantial part needs written permission: support@datumhue.com.

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This Font Software is licensed under the SIL Open Font License, Version 1.1.
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