window-body-height vs window-text-height

window-body-height vs window-text-height

[martin rudalics]

Can someone tell me the difference between `window-body-height' and
`window-text-height'?  It seems a bit confusing having two function do
more or less the same thing - but maybe the partial-height lines make
the difference.

Thanks, martin.

Re: window-body-height vs window-text-height

[Miles Bader]

martin rudalics <rudalics@gmx.at> writes:
> Can someone tell me the difference between `window-body-height' and
> `window-text-height'?  It seems a bit confusing having two function do
> more or less the same thing - but maybe the partial-height lines make
> the difference.

If there is a partial line at the bottom of the window,
window-text-height rounds down, and window-body-height rounds up.
If there are no fractional lines, both return the same value.

[In both cases, the number of lines assumes the default face -- neither
measures what's actually displayed.]

-Miles

-- 
"I distrust a research person who is always obviously busy on a task."
   --Robert Frosch, VP, GM Research

Re: window-body-height vs window-text-height

[martin rudalics]

 > If there is a partial line at the bottom of the window,
 > window-text-height rounds down, and window-body-height rounds up.
 > If there are no fractional lines, both return the same value.
 >
 > [In both cases, the number of lines assumes the default face -- neither
 > measures what's actually displayed.]

Aha.  Thanks for this information.

martin

RE: window-body-height vs window-text-height

[Drew Adams]

>  > If there is a partial line at the bottom of the window,
>  > window-text-height rounds down, and window-body-height rounds up.
>  > If there are no fractional lines, both return the same value.
>  >
>  > [In both cases, the number of lines assumes the default 
>  > face -- neither measures what's actually displayed.]
> 
> Aha.  Thanks for this information.

Just wondering: Why not just one function, with an additional arg to indicate
the difference?

Re: window-body-height vs window-text-height

[Stefan Monnier]

>> Can someone tell me the difference between `window-body-height' and
>> `window-text-height'?  It seems a bit confusing having two function do
>> more or less the same thing - but maybe the partial-height lines make
>> the difference.

> If there is a partial line at the bottom of the window,
> window-text-height rounds down, and window-body-height rounds up.
> If there are no fractional lines, both return the same value.

> [In both cases, the number of lines assumes the default face -- neither
> measures what's actually displayed.]

Now I'm confused.  IIUC window sizes can only be multiples of the
default face size, so the number of lines (assuming the default face)
can only be a whole number and can never include partial lines, no?


        Stefan

Re: window-body-height vs window-text-height

[Miles Bader]

Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> If there is a partial line at the bottom of the window,
>> window-text-height rounds down, and window-body-height rounds up.
>> If there are no fractional lines, both return the same value.
>
>> [In both cases, the number of lines assumes the default face -- neither
>> measures what's actually displayed.]
>
> Now I'm confused.  IIUC window sizes can only be multiples of the
> default face size, so the number of lines (assuming the default face)
> can only be a whole number and can never include partial lines, no?

But the numbers returned by those functions don't include the
mode-line/header-line -- and AFAIK, it's only true that the _total_
window height (including the mode-line/header-line) must be a multiple
of the default face height.  If you use e.g. a mode-line which is taller
than a normal text line, you'll get a fractional last line in the text
display area.

-Miles

-- 
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