#include "support/convert.h"
#include "support/debug.h"
#include "support/lassert.h"
-#include "support/lstrings.h" // for breakString_helper with qt4
#include "support/lyxlib.h"
+#include "support/textutils.h"
#define DISABLE_PMPROF
#include "support/pmprof.h"
using namespace std;
using namespace lyx::support;
-/* Define what mechanism is used to enforce text direction. Different
- * methods work with different Qt versions. Here we try to use both
- * methods together.
+/* Define what mechanisms are used to enforce text direction. There
+ * are two methods that work with different Qt versions. Here we try
+ * to use both methods together.
*/
// Define to use unicode override characters to force direction
#define BIDI_USE_OVERRIDE
-// Define to use flag to force direction
+// Define to use QTextLayout flag to force direction
#define BIDI_USE_FLAG
-#ifdef BIDI_USE_OVERRIDE
-# define BIDI_OFFSET 1
-#else
-# define BIDI_OFFSET 0
-#endif
-
#if !defined(BIDI_USE_OVERRIDE) && !defined(BIDI_USE_FLAG)
# error "Define at least one of BIDI_USE_OVERRIDE or BIDI_USE_FLAG"
#endif
slope_ = defaultSlope;
LYXERR(Debug::FONT, "Italic slope: " << slope_);
}
+ // If those characters have a non-zero width, we need to avoid them.
+ // This happens with Qt4 with monospace fonts
+ needs_naked_ = width(QString() + QChar(0x2060) + QChar(0x202d) + QChar(0x202e)) > 0;
+ // if (needs_naked_)
+ // LYXERR0("Font " << font.family() << " needs naked text layouts!");
}
return std::qHash(key.s) ^ ::qHash(params);
}
-shared_ptr<QTextLayout const>
-GuiFontMetrics::getTextLayout(docstring const & s, bool const rtl,
- double const wordspacing) const
+
+// This holds a translation table between the original string and the
+// QString that we can use with QTextLayout.
+struct TextLayoutHelper
{
- PROFILE_THIS_BLOCK(getTextLayout);
- TextLayoutKey key{s, rtl, wordspacing};
- if (auto ptl = qtextlayout_cache_[key])
- return ptl;
- PROFILE_CACHE_MISS(getTextLayout);
- auto const ptl = make_shared<QTextLayout>();
- ptl->setCacheEnabled(true);
- QFont copy = font_;
- copy.setWordSpacing(wordspacing);
- ptl->setFont(copy);
+ /// Create the helper
+ /// \c s is the original string
+ /// \c isrtl is true if the string is right-to-left
+ /// \c naked is true to disable the insertion of zero width annotations
+ /// FIXME: remove \c naked argument when Qt4 support goes away.
+ TextLayoutHelper(docstring const & s, bool isrtl, bool naked = false);
-#ifdef BIDI_USE_FLAG
- /* Use undocumented flag to enforce drawing direction
- * FIXME: This does not work with Qt 5.11 (ticket #11284).
+ /// translate QString index to docstring index
+ docstring::size_type qpos2pos(int qpos) const
+ {
+ return lower_bound(pos2qpos_.begin(), pos2qpos_.end(), qpos) - pos2qpos_.begin();
+ }
+
+ /// Translate docstring index to QString index
+ int pos2qpos(docstring::size_type pos) const { return pos2qpos_[pos]; }
+
+ // The original string
+ docstring docstr;
+ // The mirror string
+ QString qstr;
+ // is string right-to-left?
+ bool rtl;
+
+private:
+ // This vector contains the QString pos for each string position
+ vector<int> pos2qpos_;
+};
+
+
+TextLayoutHelper::TextLayoutHelper(docstring const & s, bool isrtl, bool naked)
+ : docstr(s), rtl(isrtl)
+{
+ // Reserve memory for performance purpose
+ pos2qpos_.reserve(s.size());
+ qstr.reserve(2 * s.size());
+
+ /* Qt will not break at a leading or trailing space, and we need
+ * that sometimes, see http://www.lyx.org/trac/ticket/9921.
+ *
+ * To work around the problem, we enclose the string between
+ * word joiner characters so that the QTextLayout algorithm will
+ * agree to break the text at these extremal spaces.
*/
- ptl->setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
-#endif
+ // Unicode character WORD JOINER
+ QChar const word_joiner(0x2060);
+ if (!naked)
+ qstr += word_joiner;
#ifdef BIDI_USE_OVERRIDE
- /* Use unicode override characters to enforce drawing direction
+ /* Unicode override characters enforce drawing direction
* Source: http://www.iamcal.com/understanding-bidirectional-text/
+ * Left-to-right override is 0x202d and right-to-left override is 0x202e.
*/
- if (rtl)
- // Right-to-left override: forces to draw text right-to-left
- ptl->setText(QChar(0x202E) + toqstr(s));
- else
- // Left-to-right override: forces to draw text left-to-right
- ptl->setText(QChar(0x202D) + toqstr(s));
-#else
- ptl->setText(toqstr(s));
+ if (!naked)
+ qstr += QChar(rtl ? 0x202e : 0x202d);
#endif
+ // Now translate the string character-by-character.
+ bool was_space = false;
+ for (char_type const c : s) {
+ // insert a word joiner character between consecutive spaces
+ bool const is_space = isSpace(c);
+ if (!naked && is_space && was_space)
+ qstr += word_joiner;
+ was_space = is_space;
+ // Remember the QString index at this point
+ pos2qpos_.push_back(qstr.size());
+ // Performance: UTF-16 characters are easier
+ if (is_utf16(c))
+ qstr += ucs4_to_qchar(c);
+ else
+ qstr += toqstr(c);
+ }
+
+ // Final word joiner (see above)
+ if (!naked)
+ qstr += word_joiner;
+
+ // Add virtual position at the end of the string
+ pos2qpos_.push_back(qstr.size());
+
+ //QString dump = qstr;
+ //LYXERR0("TLH: " << dump.replace(word_joiner, "|").toStdString());
+}
+
+
+namespace {
+
+shared_ptr<QTextLayout>
+getTextLayout_helper(TextLayoutHelper const & tlh, double const wordspacing,
+ QFont font)
+{
+ auto const ptl = make_shared<QTextLayout>();
+ ptl->setCacheEnabled(true);
+ font.setWordSpacing(wordspacing);
+ ptl->setFont(font);
+#ifdef BIDI_USE_FLAG
+ /* Use undocumented flag to enforce drawing direction
+ * FIXME: This does not work with Qt 5.11 (ticket #11284).
+ */
+ ptl->setFlags(tlh.rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
+#endif
+ ptl->setText(tlh.qstr);
+
ptl->beginLayout();
ptl->createLine();
ptl->endLayout();
+
+ return ptl;
+}
+
+}
+
+shared_ptr<QTextLayout const>
+GuiFontMetrics::getTextLayout(TextLayoutHelper const & tlh,
+ double const wordspacing) const
+{
+ PROFILE_THIS_BLOCK(getTextLayout_TLH);
+ TextLayoutKey key{tlh.docstr, tlh.rtl, wordspacing};
+ if (auto ptl = qtextlayout_cache_[key])
+ return ptl;
+ PROFILE_CACHE_MISS(getTextLayout_TLH);
+ auto const ptl = getTextLayout_helper(tlh, wordspacing, font_);
+ qtextlayout_cache_.insert(key, ptl);
+ return ptl;
+}
+
+
+shared_ptr<QTextLayout const>
+GuiFontMetrics::getTextLayout(docstring const & s, bool const rtl,
+ double const wordspacing) const
+{
+ PROFILE_THIS_BLOCK(getTextLayout);
+ TextLayoutKey key{s, rtl, wordspacing};
+ if (auto ptl = qtextlayout_cache_[key])
+ return ptl;
+ PROFILE_CACHE_MISS(getTextLayout);
+ TextLayoutHelper tlh(s, rtl, needs_naked_);
+ auto const ptl = getTextLayout_helper(tlh, wordspacing, font_);
qtextlayout_cache_.insert(key, ptl);
return ptl;
}
int GuiFontMetrics::pos2x(docstring const & s, int pos, bool const rtl,
double const wordspacing) const
{
- if (pos <= 0)
- pos = 0;
- shared_ptr<QTextLayout const> tl = getTextLayout(s, rtl, wordspacing);
- /* Since QString is UTF-16 and docstring is UCS-4, the offsets may
- * not be the same when there are high-plan unicode characters
- * (bug #10443).
- */
- // BIDI_OFFSET accounts for a possible direction override
- // character in front of the string.
- int const qpos = toqstr(s.substr(0, pos)).length() + BIDI_OFFSET;
- return static_cast<int>(tl->lineForTextPosition(qpos).cursorToX(qpos));
+ TextLayoutHelper tlh(s, rtl, needs_naked_);
+ auto ptl = getTextLayout(tlh, wordspacing);
+ // pos can be negative, see #10506.
+ int const qpos = tlh.pos2qpos(max(pos, 0));
+ return static_cast<int>(ptl->lineForTextPosition(qpos).cursorToX(qpos));
}
int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl,
double const wordspacing) const
{
- shared_ptr<QTextLayout const> tl = getTextLayout(s, rtl, wordspacing);
- QTextLine const & tline = tl->lineForTextPosition(0);
+ TextLayoutHelper tlh(s, rtl, needs_naked_);
+ auto ptl = getTextLayout(tlh, wordspacing);
+ QTextLine const & tline = ptl->lineForTextPosition(0);
int qpos = tline.xToCursor(x);
int newx = static_cast<int>(tline.cursorToX(qpos));
// The value of qpos may be wrong in rtl text (see ticket #10569).
// correct x value to the actual cursor position.
x = newx;
- /* Since QString is UTF-16 and docstring is UCS-4, the offsets may
- * not be the same when there are high-plan unicode characters
- * (bug #10443).
- */
-#if QT_VERSION < 0x040801 || QT_VERSION >= 0x050100
- int pos = qstring_to_ucs4(tl->text().left(qpos)).length();
- // there may be a direction override character in front of the string.
- return max(pos - BIDI_OFFSET, 0);
-#else
- /* Due to QTBUG-25536 in 4.8.1 <= Qt < 5.1.0, the string returned
- * by QString::toUcs4 (used by qstring_to_ucs4) may have wrong
- * length. We work around the problem by trying all docstring
- * positions until the right one is found. This is slow only if
- * there are many high-plane Unicode characters. It might be
- * worthwhile to implement a dichotomy search if this shows up
- * under a profiler.
- */
- // there may be a direction override character in front of the string.
- qpos = max(qpos - BIDI_OFFSET, 0);
- int pos = min(qpos, static_cast<int>(s.length()));
- while (pos >= 0 && toqstr(s.substr(0, pos)).length() != qpos)
- --pos;
- LASSERT(pos > 0 || qpos == 0, /**/);
- return pos;
-#endif
+ return tlh.qpos2pos(qpos);
}
-namespace {
-
-const int brkStrOffset = 1 + BIDI_OFFSET;
-
-
-QString createBreakableString(docstring const & s, bool rtl, QTextLayout & tl)
+FontMetrics::Breaks
+GuiFontMetrics::breakString_helper(docstring const & s, int first_wid, int wid,
+ bool rtl, bool force) const
{
- /* Qt will not break at a leading or trailing space, and we need
- * that sometimes, see http://www.lyx.org/trac/ticket/9921.
- *
- * To work around the problem, we enclose the string between
- * zero-width characters so that the QTextLayout algorithm will
- * agree to break the text at these extremal spaces.
- */
- // Unicode character ZERO WIDTH NO-BREAK SPACE
- QChar const zerow_nbsp(0xfeff);
- QString qs = zerow_nbsp + toqstr(s) + zerow_nbsp;
+ TextLayoutHelper const tlh(s, rtl, needs_naked_);
+
+ QTextLayout tl;
#ifdef BIDI_USE_FLAG
/* Use undocumented flag to enforce drawing direction
* FIXME: This does not work with Qt 5.11 (ticket #11284).
*/
tl.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
#endif
-
-#ifdef BIDI_USE_OVERRIDE
- /* Use unicode override characters to enforce drawing direction
- * Source: http://www.iamcal.com/understanding-bidirectional-text/
- */
- if (rtl)
- // Right-to-left override: forces to draw text right-to-left
- qs = QChar(0x202E) + qs;
- else
- // Left-to-right override: forces to draw text left-to-right
- qs = QChar(0x202D) + qs;
-#endif
- return qs;
-}
-
-
-docstring::size_type brkstr2str_pos(QString brkstr, docstring const & str, int pos)
-{
- /* Since QString is UTF-16 and docstring is UCS-4, the offsets may
- * not be the same when there are high-plan unicode characters
- * (bug #10443).
- */
- // The variable `brkStrOffset' is here to account for the extra leading characters.
- // The ending character zerow_nbsp has to be ignored if the line is complete.
- int const qlen = max(pos - brkStrOffset - (pos == brkstr.length()), 0);
-#if QT_VERSION < 0x040801 || QT_VERSION >= 0x050100
- auto const len = qstring_to_ucs4(brkstr.mid(brkStrOffset, qlen)).length();
- // Avoid warning
- (void)str;
-#else
- /* Due to QTBUG-25536 in 4.8.1 <= Qt < 5.1.0, the string returned
- * by QString::toUcs4 (used by qstring_to_ucs4) may have wrong
- * length. We work around the problem by trying all docstring
- * positions until the right one is found. This is slow only if
- * there are many high-plane Unicode characters. It might be
- * worthwhile to implement a dichotomy search if this shows up
- * under a profiler.
- */
- int len = min(qlen, static_cast<int>(str.length()));
- while (len >= 0 && toqstr(str.substr(0, len)).length() != qlen)
- --len;
- LASSERT(len > 0 || qlen == 0, /**/);
-#endif
- return len;
-}
-
-}
-
-FontMetrics::Breaks
-GuiFontMetrics::breakString_helper(docstring const & s, int first_wid, int wid,
- bool rtl, bool force) const
-{
- QTextLayout tl;
- QString qs = createBreakableString(s, rtl, tl);
- tl.setText(qs);
+ tl.setText(tlh.qstr);
tl.setFont(font_);
QTextOption to;
/*
for (int i = 0 ; i < tl.lineCount() ; ++i) {
QTextLine const & line = tl.lineAt(i);
int const line_epos = line.textStart() + line.textLength();
- int const epos = brkstr2str_pos(qs, s, line_epos);
-#if QT_VERSION >= 0x050000
+ int const epos = tlh.qpos2pos(line_epos);
// This does not take trailing spaces into account, except for the last line.
int const wid = iround(line.naturalTextWidth());
// If the line is not the last one, trailing space is always omitted.
int nspc_wid = wid;
// For the last line, compute the width without trailing space
- if (i + 1 == tl.lineCount()) {
- // trim_pos points to the last character that is not a space
- auto trim_pos = s.find_last_not_of(from_ascii(" "));
- if (trim_pos == docstring::npos)
- nspc_wid = 0;
- else if (trim_pos + 1 < s.length()) {
- int const num_spaces = s.length() - trim_pos - 1;
- // find the position on the line before trailing
- // spaces. Remove 1 to account for the ending
- // non-breaking space of qs.
- nspc_wid = iround(line.cursorToX(line_epos - num_spaces - 1));
- }
- }
-#else
- // With some monospace fonts, the value of horizontalAdvance()
- // can be wrong with Qt4. One hypothesis is that the invisible
- // characters that we use are given a non-null width.
- // FIXME: this is slower than it could be but we'll get rid of Qt4 anyway
- docstring const ss = s.substr(pos, epos - pos);
- int const wid = width(ss);
- int const nspc_wid = i + 1 < tl.lineCount() ? width(rtrim(ss)) : wid;
-#endif
+ if (i + 1 == tl.lineCount() && !s.empty() && isSpace(s.back())
+ && line.textStart() <= tlh.pos2qpos(s.size() - 1))
+ nspc_wid = iround(line.cursorToX(tlh.pos2qpos(s.size() - 1)));
breaks.emplace_back(epos - pos, wid, nspc_wid);
pos = epos;
-#if 0
- // FIXME: should it be kept in some form?
- if ((force && line.textLength() == brkStrOffset) || line_wid > x)
- return {-1, line_wid};
-#endif
}
return breaks;
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