Commit 1cbbecee authored by Eli Zaretskii's avatar Eli Zaretskii

Fix automatic hscrolling of only the current line

* src/xdisp.c (display_line): When hscrolling only the current
line, increment iterator's first_visible_x and last_visible_x
values to account for the hscroll.  This propagates the hscroll
effect on the iterator geometry all the way down to the
subroutines called by display_line, and avoids scrolling bugs
under large hscroll values.  (Bug#26994)
parent 7d00410a
......@@ -20671,8 +20671,11 @@ display_line (struct it *it, int cursor_vpos)
ptrdiff_t min_pos = ZV + 1, max_pos = 0;
ptrdiff_t min_bpos UNINIT, max_bpos UNINIT;
bool pending_handle_line_prefix = false;
bool hscroll_this_line = (cursor_vpos >= 0 && it->vpos == cursor_vpos
&& hscrolling_current_line_p (it->w));
int first_visible_x = it->first_visible_x;
int last_visible_x = it->last_visible_x;
int x_incr = 0;
/* We always start displaying at hpos zero even if hscrolled. */
eassert (it->hpos == 0 && it->current_x == 0);
......@@ -20704,25 +20707,23 @@ display_line (struct it *it, int cursor_vpos)
/* If we are going to display the cursor's line, account for the
hscroll of that line. */
if (cursor_vpos >= 0 && it->vpos == cursor_vpos
&& hscrolling_current_line_p (it->w))
{
int x_incr =
window_hscroll_limited (it->w, it->f) * FRAME_COLUMN_WIDTH (it->f);
first_visible_x += x_incr;
last_visible_x += x_incr;
}
if (hscroll_this_line)
x_incr = window_hscroll_limited (it->w, it->f) * FRAME_COLUMN_WIDTH (it->f);
/* Move over display elements that are not visible because we are
hscrolled. This may stop at an x-position < first_visible_x
if the first glyph is partially visible or if we hit a line end. */
if (it->current_x < first_visible_x)
if (it->current_x < it->first_visible_x + x_incr)
{
enum move_it_result move_result;
this_line_min_pos = row->start.pos;
move_result = move_it_in_display_line_to (it, ZV, first_visible_x,
if (hscroll_this_line)
{
it->first_visible_x += x_incr;
it->last_visible_x += x_incr;
}
move_result = move_it_in_display_line_to (it, ZV, it->first_visible_x,
MOVE_TO_POS | MOVE_TO_X);
/* If we are under a large hscroll, move_it_in_display_line_to
could hit the end of the line without reaching
......@@ -20730,10 +20731,10 @@ display_line (struct it *it, int cursor_vpos)
especially important on a TTY, where we will call
extend_face_to_end_of_line, which needs to know how many
blank glyphs to produce. */
if (it->current_x < first_visible_x
if (it->current_x < it->first_visible_x
&& (move_result == MOVE_NEWLINE_OR_CR
|| move_result == MOVE_POS_MATCH_OR_ZV))
it->current_x = first_visible_x;
it->current_x = it->first_visible_x;
/* Record the smallest positions seen while we moved over
display elements that are not visible. This is needed by
......@@ -20927,7 +20928,7 @@ display_line (struct it *it, int cursor_vpos)
if (/* Not a newline. */
nglyphs > 0
/* Glyphs produced fit entirely in the line. */
&& it->current_x < last_visible_x)
&& it->current_x < it->last_visible_x)
{
it->hpos += nglyphs;
row->ascent = max (row->ascent, it->max_ascent);
......@@ -20937,13 +20938,13 @@ display_line (struct it *it, int cursor_vpos)
it->max_phys_ascent + it->max_phys_descent);
row->extra_line_spacing = max (row->extra_line_spacing,
it->max_extra_line_spacing);
if (it->current_x - it->pixel_width < first_visible_x
if (it->current_x - it->pixel_width < it->first_visible_x
/* In R2L rows, we arrange in extend_face_to_end_of_line
to add a right offset to the line, by a suitable
change to the stretch glyph that is the leftmost
glyph of the line. */
&& !row->reversed_p)
row->x = x - first_visible_x;
row->x = x - it->first_visible_x;
/* Record the maximum and minimum buffer positions seen so
far in glyphs that will be displayed by this row. */
if (it->bidi_p)
......@@ -20968,9 +20969,9 @@ display_line (struct it *it, int cursor_vpos)
if (/* Lines are continued. */
it->line_wrap != TRUNCATE
&& (/* Glyph doesn't fit on the line. */
new_x > last_visible_x
new_x > it->last_visible_x
/* Or it fits exactly on a window system frame. */
|| (new_x == last_visible_x
|| (new_x == it->last_visible_x
&& FRAME_WINDOW_P (it->f)
&& (row->reversed_p
? WINDOW_LEFT_FRINGE_WIDTH (it->w)
......@@ -20979,7 +20980,7 @@ display_line (struct it *it, int cursor_vpos)
/* End of a continued line. */
if (it->hpos == 0
|| (new_x == last_visible_x
|| (new_x == it->last_visible_x
&& FRAME_WINDOW_P (it->f)
&& (row->reversed_p
? WINDOW_LEFT_FRINGE_WIDTH (it->w)
......@@ -21122,10 +21123,10 @@ display_line (struct it *it, int cursor_vpos)
? WINDOW_LEFT_FRINGE_WIDTH (it->w)
: WINDOW_RIGHT_FRINGE_WIDTH (it->w)) == 0)
produce_special_glyphs (it, IT_CONTINUATION);
it->continuation_lines_width += last_visible_x;
it->continuation_lines_width += it->last_visible_x;
row->ends_in_middle_of_char_p = true;
row->continued_p = true;
glyph->pixel_width = last_visible_x - x;
glyph->pixel_width = it->last_visible_x - x;
it->starts_in_middle_of_char_p = true;
if (WINDOW_LEFT_MARGIN_WIDTH (it->w) > 0
|| WINDOW_RIGHT_MARGIN_WIDTH (it->w) > 0)
......@@ -21169,7 +21170,7 @@ display_line (struct it *it, int cursor_vpos)
break;
}
else if (new_x > first_visible_x)
else if (new_x > it->first_visible_x)
{
/* Increment number of glyphs actually displayed. */
++it->hpos;
......@@ -21180,14 +21181,14 @@ display_line (struct it *it, int cursor_vpos)
if (it->bidi_p)
RECORD_MAX_MIN_POS (it);
if (x < first_visible_x && !row->reversed_p)
if (x < it->first_visible_x && !row->reversed_p)
/* Glyph is partially visible, i.e. row starts at
negative X position. Don't do that in R2L
rows, where we arrange to add a right offset to
the line in extend_face_to_end_of_line, by a
suitable change to the stretch glyph that is
the leftmost glyph of the line. */
row->x = x - first_visible_x;
row->x = x - it->first_visible_x;
/* When the last glyph of an R2L row only fits
partially on the line, we need to set row->x to a
negative offset, so that the leftmost glyph is
......@@ -21195,12 +21196,12 @@ display_line (struct it *it, int cursor_vpos)
going to produce the truncation glyph, this will
be taken care of in produce_special_glyphs. */
if (row->reversed_p
&& new_x > last_visible_x
&& new_x > it->last_visible_x
&& !(it->line_wrap == TRUNCATE
&& WINDOW_LEFT_FRINGE_WIDTH (it->w) == 0))
{
eassert (FRAME_WINDOW_P (it->f));
row->x = last_visible_x - new_x;
row->x = it->last_visible_x - new_x;
}
}
else
......@@ -21210,7 +21211,7 @@ display_line (struct it *it, int cursor_vpos)
move_it_in_display_line at the start of this
function, unless the text display area of the
window is empty. */
eassert (first_visible_x <= last_visible_x);
eassert (it->first_visible_x <= it->last_visible_x);
}
}
/* Even if this display element produced no glyphs at all,
......@@ -21279,8 +21280,8 @@ display_line (struct it *it, int cursor_vpos)
? WINDOW_LEFT_FRINGE_WIDTH (it->w)
: WINDOW_RIGHT_FRINGE_WIDTH (it->w))
|| it->what == IT_IMAGE))
? (it->current_x >= last_visible_x)
: (it->current_x > last_visible_x)))
? (it->current_x >= it->last_visible_x)
: (it->current_x > it->last_visible_x)))
{
/* Maybe add truncation glyphs. */
if (!FRAME_WINDOW_P (it->f)
......@@ -21314,7 +21315,7 @@ display_line (struct it *it, int cursor_vpos)
/* produce_special_glyphs overwrites the last glyph, so
we don't want that if we want to keep that last
glyph, which means it's an image. */
if (it->current_x > last_visible_x)
if (it->current_x > it->last_visible_x)
{
it->current_x = x_before;
if (!FRAME_WINDOW_P (it->f))
......@@ -21375,7 +21376,7 @@ display_line (struct it *it, int cursor_vpos)
/* If line is not empty and hscrolled, maybe insert truncation glyphs
at the left window margin. */
if (first_visible_x
if (it->first_visible_x
&& IT_CHARPOS (*it) != CHARPOS (row->start.pos))
{
if (!FRAME_WINDOW_P (it->f)
......@@ -21503,6 +21504,13 @@ display_line (struct it *it, int cursor_vpos)
row to be used. */
it->current_x = it->hpos = 0;
it->current_y += row->height;
/* Restore the first and last visible X if we adjusted them for
current-line hscrolling. */
if (hscroll_this_line)
{
it->first_visible_x = first_visible_x;
it->last_visible_x = last_visible_x;
}
SET_TEXT_POS (it->eol_pos, 0, 0);
++it->vpos;
++it->glyph_row;
......
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