diff --git a/src/frontends/qt4/GuiFontMetrics.cpp b/src/frontends/qt4/GuiFontMetrics.cpp index 484a41bfa1..3911fd1b47 100644 --- a/src/frontends/qt4/GuiFontMetrics.cpp +++ b/src/frontends/qt4/GuiFontMetrics.cpp @@ -256,13 +256,27 @@ GuiFontMetrics::getTextLayout(docstring const & s, bool const rtl, PROFILE_CACHE_MISS(getTextLayout); auto const ptl = make_shared(); ptl->setCacheEnabled(true); - ptl->setText(toqstr(s)); QFont copy = font_; copy.setWordSpacing(wordspacing); ptl->setFont(copy); - // FIXME: This might not work in all cases. See breakAt_helper. +#if 1 + /* 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 + ptl->setText(QChar(0x202E) + toqstr(s)); + else + // Left-to-right override: forces to draw text left-to-right + ptl->setText(QChar(0x202D) + toqstr(s)); +#define TEXTLAYOUT_OFFSET 1 +#else + // FIXME: This does not work with Qt 5.11 (ticket #11284). // Note that both setFlags and the enums are undocumented ptl->setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight); + ptl->setText(toqstr(s)); +#define TEXTLAYOUT_OFFSET 0 +#endif ptl->beginLayout(); ptl->createLine(); ptl->endLayout(); @@ -281,7 +295,9 @@ int GuiFontMetrics::pos2x(docstring const & s, int pos, bool const rtl, * not be the same when there are high-plan unicode characters * (bug #10443). */ - int const qpos = toqstr(s.substr(0, pos)).length(); + // TEXTLAYOUT_OFFSET accounts for a possible direction override + // character in front of the string. + int const qpos = toqstr(s.substr(0, pos)).length() + TEXTLAYOUT_OFFSET; return static_cast(tl->lineForTextPosition(qpos).cursorToX(qpos)); } @@ -323,7 +339,9 @@ int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl, * (bug #10443). */ #if QT_VERSION < 0x040801 || QT_VERSION >= 0x050100 - return qstring_to_ucs4(tl->text().left(qpos)).length(); + 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 - TEXTLAYOUT_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 @@ -333,6 +351,8 @@ int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl, * 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 - TEXTLAYOUT_OFFSET, 0); int pos = min(qpos, static_cast(s.length())); while (pos >= 0 && toqstr(s.substr(0, pos)).length() != qpos) --pos;