Commit e342a24d authored by Eli Zaretskii's avatar Eli Zaretskii

Retrospective commit from 2009-09-27.

Support character mirroring.
Support iteration that starts in the middle of a line.
Misc cleanups.

 xdisp.c (next_element_from_buffer): If called not at line
 beginning, start bidi iteration from line beginning.
 bidi.c (bidi_paragraph_init): Use
 bidi_overriding_paragraph_direction instead of a literal zero.
 (bidi_initialize): Fix some character types, per Unicode 5.x.
 (bidi_get_type): Abort if called with invalid character code.
 dispextern.h: Add prototype of bidi_mirror_char.
 xdisp.c (get_next_display_element): Mirror characters whose
 resolved type is STRONG_R.
parent 9c82e145
2009-09-27 Eli Zaretskii <eliz@gnu.org>
* xdisp.c (next_element_from_buffer): If called not at line
beginning, start bidi iteration from line beginning.
* bidi.c (bidi_paragraph_init): Use
bidi_overriding_paragraph_direction instead of a literal zero.
(bidi_initialize): Fix some character types, per Unicode 5.x.
(bidi_get_type): Abort if called with invalid character code.
* dispextern.h: Add prototype of bidi_mirror_char.
* xdisp.c (get_next_display_element): Mirror characters whose
resolved type is STRONG_R.
2009-09-26 Eli Zaretskii <eliz@gnu.org>
* bidi.c (bidi_paragraph_init): Don't set bidi_it->ch_len. Abort
......
......@@ -99,14 +99,6 @@ int bidi_ignore_explicit_marks_for_paragraph_level = 1;
/* FIXME: Should be user-definable. */
bidi_dir_t bidi_overriding_paragraph_direction = L2R;
/* FIXME: Unused? */
#define ASCII_BIDI_TYPE_SET(STR, TYPE) \
do { \
unsigned char *p; \
for (p = (STR); *p; p++) \
CHAR_TABLE_SET (bidi_type_table, *p, (TYPE)); \
} while (0)
static void
bidi_initialize ()
{
......@@ -128,11 +120,10 @@ bidi_initialize ()
{ 0x0021, 0x0022, NEUTRAL_ON },
{ 0x0023, 0x0025, WEAK_ET },
{ 0x0026, 0x002A, NEUTRAL_ON },
{ 0x002B, 0x0000, WEAK_ET },
{ 0x002B, 0x0000, WEAK_ES },
{ 0x002C, 0x0000, WEAK_CS },
{ 0x002D, 0x0000, WEAK_ET },
{ 0x002E, 0x0000, WEAK_CS },
{ 0x002F, 0x0000, WEAK_ES },
{ 0x002D, 0x0000, WEAK_ES },
{ 0x002E, 0x002F, WEAK_CS },
{ 0x0030, 0x0039, WEAK_EN },
{ 0x003A, 0x0000, WEAK_CS },
{ 0x003B, 0x0040, NEUTRAL_ON },
......@@ -145,7 +136,9 @@ bidi_initialize ()
{ 0x00A1, 0x0000, NEUTRAL_ON },
{ 0x00A2, 0x00A5, WEAK_ET },
{ 0x00A6, 0x00A9, NEUTRAL_ON },
{ 0x00AB, 0x00AF, NEUTRAL_ON },
{ 0x00AB, 0x00AC, NEUTRAL_ON },
{ 0x00AD, 0x0000, WEAK_BN },
{ 0x00AE, 0x00Af, NEUTRAL_ON },
{ 0x00B0, 0x00B1, WEAK_ET },
{ 0x00B2, 0x00B3, WEAK_EN },
{ 0x00B4, 0x0000, NEUTRAL_ON },
......@@ -171,7 +164,9 @@ bidi_initialize ()
{ 0x05C0, 0x0000, STRONG_R },
{ 0x05C1, 0x05C2, WEAK_NSM },
{ 0x05C3, 0x0000, STRONG_R },
{ 0x05C4, 0x0000, WEAK_NSM },
{ 0x05C4, 0x05C5, WEAK_NSM },
{ 0x05C6, 0x0000, STRONG_R },
{ 0x05C7, 0x0000, WEAK_NSM },
{ 0x05D0, 0x05F4, STRONG_R },
{ 0x060C, 0x0000, WEAK_CS },
{ 0x061B, 0x064A, STRONG_AL },
......@@ -400,18 +395,14 @@ bidi_initialize ()
bidi_initialized = 1;
}
static int
bidi_is_arabic_number (int ch)
{
return 0; /* FIXME! */
}
/* Return the bidi type of a character CH. */
bidi_type_t
bidi_get_type (int ch)
{
if (ch == BIDI_EOB)
return NEUTRAL_B;
if (ch < 0 || ch > MAX_CHAR)
abort ();
return (bidi_type_t) XINT (CHAR_TABLE_REF (bidi_type_table, ch));
}
......@@ -457,6 +448,10 @@ bidi_get_category (bidi_type_t type)
}
}
/* Return the mirrored character of C, if any.
Note: The conditions in UAX#9 clause L4 must be tested by the
caller. */
/* FIXME: exceedingly temporary! Should consult the Unicode database
of character properties. */
int
......@@ -722,7 +717,7 @@ bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
that we find on the two sides of the level boundary (see UAX#9,
clause X10), and so we don't need to know the final embedding
level to which we descend after processing all the PDFs. */
if (level_before < level_after || !bidi_it->prev_was_pdf)
if (!bidi_it->prev_was_pdf || level_before < level_after)
/* FIXME: should the default sor direction be user selectable? */
bidi_it->sor = (higher_level & 1) != 0 ? R2L : L2R;
if (level_before > level_after)
......@@ -742,8 +737,7 @@ bidi_set_sor_type (struct bidi_it *bidi_it, int level_before, int level_after)
void
bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it)
{
int pos = bidi_it->charpos, bytepos = bidi_it->bytepos;
int ch, ch_len;
int bytepos = bidi_it->bytepos;
/* We should never be called at EOB or before BEGV. */
if (bytepos >= ZV_BYTE || bytepos < BEGV_BYTE)
......@@ -756,20 +750,16 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it)
|| FETCH_CHAR (bytepos - 1) == '\n'))
abort ();
ch = FETCH_CHAR (bytepos);
ch_len = CHAR_BYTES (ch);
bidi_it->level_stack[0].level = 0; /* default for L2R */
if (dir == R2L)
bidi_it->level_stack[0].level = 1;
else if (dir == NEUTRAL_DIR) /* P2 */
{
bidi_type_t type;
/* FIXME: should actually go to where the paragraph begins and
start the loop below from there, since UAX#9 says to find the
first strong directional character in the paragraph. */
int ch = FETCH_CHAR (bytepos), ch_len = CHAR_BYTES (ch);
int pos = bidi_it->charpos;
bidi_type_t type = bidi_get_type (ch);
for (type = bidi_get_type (ch), pos++, bytepos += ch_len;
for (pos++, bytepos += ch_len;
/* NOTE: UAX#9 says to search only for L, AL, or R types of
characters, and ignore RLE, RLO, LRE, and LRO. However,
I'm not sure it makes sense to omit those 4; should try
......@@ -795,7 +785,8 @@ bidi_paragraph_init (bidi_dir_t dir, struct bidi_it *bidi_it)
bidi_it->new_paragraph = 0;
bidi_it->next_en_pos = -1;
bidi_it->next_for_ws.type = UNKNOWN_BT;
bidi_set_sor_type (bidi_it, bidi_it->level_stack[0].level, 0); /* X10 */
bidi_set_sor_type (bidi_it, bidi_overriding_paragraph_direction,
bidi_it->level_stack[0].level); /* X10 */
bidi_cache_reset ();
}
......
......@@ -2801,6 +2801,7 @@ extern EMACS_INT tool_bar_button_relief;
extern void bidi_init_it P_ ((int, int, struct bidi_it *));
extern void bidi_get_next_char_visually P_ ((struct bidi_it *));
extern void bidi_paragraph_init P_ ((bidi_dir_t, struct bidi_it *));
extern int bidi_mirror_char P_ ((int));
/* Defined in xdisp.c */
......
......@@ -5682,6 +5682,13 @@ get_next_display_element (it)
if (it->what == IT_CHARACTER)
{
/* UAX#9, L4: "A character is depicted by a mirrored glyph if
and only if (a) the resolved directionality of that character
is R..." */
/* FIXME: Do we need an exception for characters from display
tables? */
if (it->bidi_p && it->bidi_it.type == STRONG_R)
it->c = bidi_mirror_char (it->c);
/* Map via display table or translate control characters.
IT->c, IT->len etc. have been set to the next character by
the function call above. If we have a display table, and it
......@@ -6505,17 +6512,46 @@ next_element_from_buffer (it)
the character at IT_CHARPOS. */
if (it->bidi_p && it->bidi_it.first_elt)
{
/* FIXME: L2R below is just for easyness of testing, as we
currently support only left-to-right paragraphs. The value
should be user-definable and/or come from some ``higher
protocol''. In the absence of any other guidance, the default
for this initialization should be NEUTRAL_DIR. */
it->bidi_it.charpos = IT_CHARPOS (*it);
it->bidi_it.bytepos = IT_BYTEPOS (*it);
bidi_paragraph_init (L2R, &it->bidi_it);
bidi_get_next_char_visually (&it->bidi_it);
it->bidi_it.first_elt = 0;
/* Adjust IT's position information to where we moved. */
/* If we are at the beginning of a line, we can produce the next
element right away. */
if (it->bidi_it.bytepos == BEGV_BYTE
/* FIXME: Should support all Unicode line separators. */
|| FETCH_CHAR (it->bidi_it.bytepos - 1) == '\n'
|| FETCH_CHAR (it->bidi_it.bytepos) == '\n')
{
/* FIXME: L2R below is just for easyness of testing, as we
currently support only left-to-right paragraphs. The
value should be user-definable and/or come from some
``higher protocol''. In the absence of any other
guidance, the default for this initialization should be
NEUTRAL_DIR. */
bidi_paragraph_init (L2R, &it->bidi_it);
bidi_get_next_char_visually (&it->bidi_it);
}
else
{
int orig_bytepos = IT_BYTEPOS (*it);
/* We need to prime the bidi iterator starting at the line's
beginning, before we will be able to produce the next
element. */
IT_CHARPOS (*it) = find_next_newline_no_quit (IT_CHARPOS (*it), -1);
IT_BYTEPOS (*it) = CHAR_TO_BYTE (IT_CHARPOS (*it));
it->bidi_it.charpos = IT_CHARPOS (*it);
it->bidi_it.bytepos = IT_BYTEPOS (*it);
bidi_paragraph_init (L2R, &it->bidi_it);
do {
/* Now return to buffer position where we were asked to
get the next display element, and produce that. */
bidi_get_next_char_visually (&it->bidi_it);
} while (it->bidi_it.bytepos != orig_bytepos
&& it->bidi_it.bytepos < ZV_BYTE);
}
it->bidi_it.first_elt = 0; /* paranoia: bidi.c does this */
/* Adjust IT's position information to where we ended up. */
IT_CHARPOS (*it) = it->bidi_it.charpos;
IT_BYTEPOS (*it) = it->bidi_it.bytepos;
SET_TEXT_POS (it->position, IT_CHARPOS (*it), IT_BYTEPOS (*it));
......
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