Clarify docs of hscroll in RTL text

* doc/lispref/windows.texi (Horizontal Scrolling): Clarify the
meaning of a window's horizontal scroll amount for RTL paragraphs.
This commit is contained in:
Eli Zaretskii 2015-12-30 19:13:44 +02:00
parent 4c8f8db24e
commit 7c83d84619

View file

@ -3706,6 +3706,11 @@ The return value is the total amount of leftward horizontal scrolling in
effect after the change---just like the value returned by effect after the change---just like the value returned by
@code{window-hscroll} (below). @code{window-hscroll} (below).
Note that text in paragraphs whose base direction is right-to-left
(@pxref{Bidirectional Display}) moves in the opposite direction: e.g.,
it moves to the right when @code{scroll-left} is invoked with a
positive value of @var{count}.
Once you scroll a window as far right as it can go, back to its normal Once you scroll a window as far right as it can go, back to its normal
position where the total leftward scrolling is zero, attempts to scroll position where the total leftward scrolling is zero, attempts to scroll
any farther right have no effect. any farther right have no effect.
@ -3727,8 +3732,9 @@ of scrolling, this works just like @code{scroll-left}.
@defun window-hscroll &optional window @defun window-hscroll &optional window
This function returns the total leftward horizontal scrolling of This function returns the total leftward horizontal scrolling of
@var{window}---the number of columns by which the text in @var{window} @var{window}---the number of columns by which the text in @var{window}
is scrolled left past the left margin. The default for is scrolled left past the left margin. (In right-to-left paragraphs,
@var{window} is the selected window. the value is the total amount of the rightward scrolling instead.)
The default for @var{window} is the selected window.
The return value is never negative. It is zero when no horizontal The return value is never negative. It is zero when no horizontal
scrolling has been done in @var{window} (which is usually the case). scrolling has been done in @var{window} (which is usually the case).
@ -3753,9 +3759,10 @@ scrolling has been done in @var{window} (which is usually the case).
@defun set-window-hscroll window columns @defun set-window-hscroll window columns
This function sets horizontal scrolling of @var{window}. The value of This function sets horizontal scrolling of @var{window}. The value of
@var{columns} specifies the amount of scrolling, in terms of columns @var{columns} specifies the amount of scrolling, in terms of columns
from the left margin. The argument @var{columns} should be zero or from the left margin (right margin in right-to-left paragraphs). The
positive; if not, it is taken as zero. Fractional values of argument @var{columns} should be zero or positive; if not, it is taken
@var{columns} are not supported at present. as zero. Fractional values of @var{columns} are not supported at
present.
Note that @code{set-window-hscroll} may appear not to work if you test Note that @code{set-window-hscroll} may appear not to work if you test
it by evaluating a call with @kbd{M-:} in a simple way. What happens it by evaluating a call with @kbd{M-:} in a simple way. What happens