RFR: 8209937: Enhance java.io.Console - provide methods to query console width and height

[Alan Bateman]

On 24/08/2018 14:18, Langer, Christoph wrote:
> Hi Rémi, Hi Peter,
>
> thanks for your quick answers.
>
> What you've suggested, Rémi, is perfectly right. I've updated my webrev. The methods were copied from our old implementation (of a different class) where they were provided as static.
>
> I will also think of using an optional. I'm furthermore wondering if we should provide a method "dimensions()" returning an (optional) java.io.Console.Dimension object that contains both height and width...
>
> Here is a new webrev: http://cr.openjdk.java.net/~clanger/webrevs/8209937.1/
I'm in two minds as to whether this API is the right thing to do. Can 
you expand a bit on how you are using them? There have been several 
requests for additions to the Console API over the years, mostly to 
support formatting or exposing the console encoding, but I don't recall 
anyone looking for the dimensions. Roger is right that it's a bit of a 
slippery slope. As I recall, java.io.Console was deliberately minimized 
for Java SE 6 to focus on password input and avoid introducing an 
extensive API.  In the mean-time, the additional of jshell has exposed 
some of the shorting comings and maybe we should look at exposing just 
enough to support that type of use-case (editing and line history mostly).

As regards the proposal then I think the API docs will need fleshing out 
to define what height and width as the current javadoc isn't clear if it 
means bytes, characters, pixels in whatever font is used for the 
console, or something else. In addition, the javadoc would need to be 
clear that it's just a snaphot of the dimension as it can change at any 
time.

-Alan