Subject: Re: bug#34516: Multi-monitor frame sets

From: Andy Moreton <[email-masked]>
Date: Mon, 04 Mar 2019 13:56:42 +0000

On Mon 04 Mar 2019, Robert Pluim wrote:

> Alan Third <[email-masked]> writes:
>
>> On Sat, Mar 02, 2019 at 11:57:35PM +0000, Andy Moreton wrote:
>>> On Sat 02 Mar 2019, Alan Third wrote:
>>> 
>>> > On Sun, Feb 24, 2019 at 01:56:31PM +0100, Robert Pluim wrote:
>>> >> Juri Linkov <[email-masked]> writes:
>>> >> 
>>> >> > on macOS it could return something like that or generate fake names
>>> >> > from geometry like "1920x1080+0+0", "2560x1440+1920+16".
>>> 
>>> It would be more usefulr to use the underlying device name, like on other
>>> platforms.
>>
>> It doesn’t look like macOS gives displays any sort of human readable
>> name. The closest I can find is the monitor’s make and model, which
>> appears to be lifted directly from the device driver. I expect if you
>> have two identical monitors then it will be the same for both.
>>
>
> At least in 'system preferences/display', when you have two identical monitors
> attached, they're called something like 'DELL 1234X' and 'DELL 1234X
> (2)' (I canʼt test that right now). If you can show me code on how to
> get those names in 10.14, I can confirm. That would be better than
> making up names.

There are usually two different names involved: the name of the
file/device that represents the monitor, and a human-readable name for
the UI.

In Windows, the GUI settings/display describes the monitors as 1 and
2. In emacs, display-monitor-attributes-list reports the device
names \\.\DISPLAY1 and \\.\DISPLAY2 (you can see these device names
with the WinObj tool from SysInternals). Note that the device names do
not mention the make/model of the hardware.

For OSX, ioreg or the IoRegistryExplorer app show similar information
from the IO registry (a non-persistent database of IO device
information). I don't use a mac any more, so I don't know if these tools
are still available).

    AndyM