[Question] getprop in a confined app?

[pparent]

Hi,

In order to adapt properly the scaling of my app I would need to do

/usr/bin/getprop ro.sf.lcd_density

The problem is that if I do that inside a confined app I get

aa-exec[6536]: ./launcher.sh: 12: /usr/bin/getprop: Permission denied

But if I copy the binary /usr/bin/getprop inside my app install repo in /opt/click.ubuntu.com/ and call it then it works well. The thing is I want to make something clean, and not dumping a binary from the phone inside my app, not even knowing if it will work for every phone.

Is there a way to do without copying the getprop binary in my app install dir? Otherwise is there a way to download the getprop binary from official ubports build sources? Where does this binary come from?

Thank's a lot in advance!

[pparent]

said in [Question] getprop in a confined app?:

libhybris-utils

Ok I've found

apt download libhybris-utils:arm64

Inside the clickable containre allows to download the deb package, then you can extract from it the getprop binary.

[lduboeuf]

@pparent
I doubt a confined app can access Android properties.
For the "where does it came from" :
https://gitlab.com/ubports/development/core/packaging/libhybris/-/blob/ubports/latest/debian/control?ref_type=heads#L153

[pparent]

@lduboeuf said in [Question] getprop in a confined app?:

I doubt a confined app can access Android properties.

I can garanty you that if it embeeds a local copy of /usr/bin/getprop then it can.

[pparent]

@lduboeuf said in [Question] getprop in a confined app?:

For the "where does it came from" :
https://gitlab.com/ubports/development/core/packaging/libhybris/-/blob/ubports/latest/debian/control?ref_type=heads#L153

Thank's but it there a way to download the compiled version in a similar fashion that it would be doable with lauanchpad in official Canonical Ubuntu ?

[pparent]

This is outdated:

https://launchpad.net/ubuntu/xenial/+package/libhybris-utils

[pparent]

said in [Question] getprop in a confined app?:

libhybris-utils

Ok I've found

apt download libhybris-utils:arm64

Inside the clickable containre allows to download the deb package, then you can extract from it the getprop binary.

[kugiigi]

Can't you get the density somewhere else? For example in QML, you use Screen.

[pparent]

@kugiigi

Well I've tried with density from qt, but it does not seem to give coherent results across devices.

[gpatel-fr]

@pparent said in [Question] getprop in a confined app?:

coherent results !

well, concerning Fairphone specs, not sure if coherence is an appropriate word. For example, on the Fairphone site and so everywhere on the web, you can read that FP5 screen is 6.46 inches; that is, about 16.4 cm unless they have special dutch inches.
I have a Fairphone 5 and it is no more than 16 cm in total, including the somewhat 10mm of margins in the height direction, so real meaningful screen height is more about 15cm, that is, what you could imply from the mentioned density on third party sites, so 5.88 inches (2700 / 459 = 5.88). BTW getprop returns 480 dpi on my FP5.
It's difficult to square up all these numbers and I wonder if the FP4 is any better.

[pparent]

@gpatel-fr

Here are the datas I have for vollaphone 22 and vollaphone x23

                          Official PPI    Qt sensity      getprop density
    Vollaphone  22        410	            252	            480
    Vollaphone X23        282	            216	            320

Getprop seems always official value rounded up to the closest possible value for android (that seem to be only a handfull of values), but seem quite coherent in proportion, contrary to qt density.