Scaling for high DPI mixes monitors

[Rémi D]

The scale factor of the primary screen only affects menus and titlebars (as expected, so far).
The scale factor of the secondary screen affects menus and titlebars, PLUS application fonts.

This behavior, in addition to not agree with the scale's label, is hard to handle.

PS : I didn't touched unity tweaks.

[Rémi D (bout-de-rim)]

We can correct the font scale factor in unity tweak tool.
But there is another bug here, I don't know if I should make a distinct report.

When we modify the font scale, the given scale is applied instantaneously, but in half a second, the scale is changed to a value that appears to be font_scale*menu_scale (with the menu's scale of my primary screen this time). The difficulty here is that "unity tweak manager" does not update its value, you have to reopen it to see the value has been changed externally.

To circumvent the problem, we have to enter the value of desired_font_scale/menu_scale.

[Stephen M. Webb (bregma)]

The windows content (for compliant applications) is scaled according to the "Scale all windows contents" setting in the Ubuntu Control Center. This is set by default to match the menu and title bars scale setting for the monitor with the smallest scale factor, but is selectable through the drop-down menu to choose another monitor or matching rule specifically.

The content scale factor is not dependent on a "primary" or "secndary" screen.

If the problem you are reporting is in the third-party "Unity tweak tool" you need to report it to the developers of that tool.

[Rémi D (bout-de-rim)]

OK, thank you.

I don't know why, before your explanation, the "Scale all windows content" setting was really unobvious. This much, I didn't thought it was related to the left scale.
May be it would benefit from a frame arround the two settings ? or anything else making it clear that the two are related.

Second thing, when the monitors have very different dpi, the choices are too extreme.
May be there could be a real scale from "screen with smallest controls" to "screen with biggest controls" ?