Best way to determine user's screensize?

[Grant Edwards]

On 2020-10-31, Random832 <random832 at fastmail.com> wrote:
> On Fri, Oct 30, 2020, at 20:18, Igor Korot wrote:
>> Hi,
>> 
>> On Fri, Oct 30, 2020 at 6:59 PM Peter J. Holzer <hjp-python at hjp.at> wrote:
>> > So, assuming the user is invoking the application for the first time,
>> > how should an application determine how much of the screen it should
>> > use? It has to make some choice, and any hard-coded value is almost
>> > certainly wrong. So why should an application not use the screen size as
>> > one factor?
>> 
>> It is not up to application.
>> It is up to the underlying layout system to decide.
>
> What is a "layout system"?

In a GUI toolkit, it's a set of constructs that lets you specify the
relative positions of widgets, which widgets are flexible and which
aren't, and so on. The layout system then determines the sizes of
widgets and windows.

> I don't think such a thing exists, in
> general, for positioning top-level windows on major platforms.

On Linux/Unix, there certainly is. It's called a window manager. There
are many to chose from, and they have various user-configurable
settings that allow the user to control the sizes and positions of
top-level windows.

> Each application has to write its own,

Nonsense.

> and it is reasonable for the layout system itself [which, as I've
> pointed out, is part of the application - there is no such thing as
> a system service] to need access to this information.

There are two levels of layout system services: the GUI
toolkit/framework and the window manager.