We have noted that we need to reboot for the policy and screen config changes to apply. Sometimes it has required multiple reboots etc.
We are not 100% sure how frequently Chrome devices check for policy updates, however, as noted 1 or 2 reboots will normally force the device to resync the policy. If the display settings are changed in Signagelive, the device will automatically reboot within 5 seconds and the changes will be applied automatically on the next startup.
Will the Signagelive app read the admin console policy and attempt to setup the config without using the app on device setup?
The setup screen loads the initial settings based on those configured for the device after the initial policy sync so in effect if no changes are made locally Signagelive will use the configuration from the Google Admin policy.
In SignageLive CMS – on the player/system page for a device, what function does the edit resolution have?
For Chrome, this will not have any effect as it is not currently possible to update the resolution for Chrome players remotely. This feature is used by other player types.
Is the Signagelive app writing screen config to the ChromeOS using the API's (chrome.system.display) to set the rotation etc?
Yes. The way that Signagelive currently works is that when the Signagelive Setup screen is loaded it queries the chrome.system.display API for:
Information about all connected displays (chrome.system.display.getInfo)
The layout of the displays including whether or not unified desktop is enabled (chrome.system.display.getDisplayLayout)
In the UI you can configure whether or not:
Signagelive is set to span all connected displays (this is essentially whether or not unified desktop is enabled). Note for this to work Unified Desktop must be Allowed/Enabled via the Kiosk App settings in the Google Admin setup.
The rotation/orientation of each connected display. This will default to the orientation set in the Google Admin policy set against the kiosk app.
The layout and positioning of the displays relative to one another. As noted the default layout may not always be correct.
When you save any changes made via the Signagelive Setup screen, the changes are not immediately applied. Instead the device is rebooted and the settings are applied on the next start. These settings are also re-applied after each subsequent reboot (if necessary).
Could it be possible that would cause conflicts? Which would take precedence?
We have not observed any conflicts. If you override the orientation locally, the local Signagelive settings will take precedence.
What value is used in the amended display name? It does not match the device’s serial number.
The Display Name column has been updated to include the following:
The index of the display in the list of returned displays, for example: (1). This is what will display on each connected display when you click "Identify Displays".
The display name of the display (the user-friendly name), for example: CHROME SIGNAGE
The Chrome unique Id for the display, for example - 27763255353
As a result the full entry will look like: (1) - CHROME SIGNAGE - 27763255353
The Chrome docs do not provide any further information aside from to say "The unique identifier of the display" so we do not know exactly how this Id is derived. We know it is not the serial number of the display. What we can say is that this Id is unique for each display and always remains the same even if you disconnect and reconnect the displays.
Chrome OS does not expose the serial number from the EDID.
Note on display layout changes
One thing you likely notice is that if you change the position of the displays relative to one another, the next time you open the setup screen the order and configuration of the connected displays is reported differently in the UI to how it was previously even though the end result is still the same. This can be a bit confusing so it is worth pointing out.
This is just how the chrome.system.display API works and returns the connected display information to us. It works this way because when the display layout is updated, internally Chrome sets the top-left display as the primary/parent display and then updates the position of other displays relative to the primary display.