#include "insets/Inset.h"
+#include "support/convert.h"
#include "support/lassert.h"
-#include <QTextLayout>
+#define DISABLE_PMPROF
+#include "support/pmprof.h"
+
+#include <QByteArray>
using namespace std;
using namespace lyx::support;
+namespace std {
+
+/*
+ * Argument-dependent lookup implies that this function shall be
+ * declared in the namespace of its argument. But this is std
+ * namespace, since lyx::docstring is just std::basic_string<wchar_t>.
+ */
+uint qHash(lyx::docstring const & s)
+{
+ return qHash(QByteArray(reinterpret_cast<char const *>(s.data()),
+ s.size() * sizeof(lyx::docstring::value_type)));
+}
+
+}
+
namespace lyx {
namespace frontend {
+
+/*
+ * Limit (strwidth|breakat)_cache_ size to 512kB of string data.
+ * Limit qtextlayout_cache_ size to 500 elements (we do not know the
+ * size of the QTextLayout objects anyway).
+ * Note that all these numbers are arbitrary.
+ * Also, setting size to 0 is tantamount to disabling the cache.
+ */
+int cache_metrics_width_size = 1 << 19;
+int cache_metrics_breakat_size = 1 << 19;
+// Qt 5.x already has its own caching of QTextLayout objects
+#if (QT_VERSION < 0x050000)
+int cache_metrics_qtextlayout_size = 500;
+#else
+int cache_metrics_qtextlayout_size = 0;
+#endif
+
+
namespace {
/**
* Convert a UCS4 character into a QChar.
} // anon namespace
-GuiFontMetrics::GuiFontMetrics(QFont const & font) : font_(font), metrics_(font, 0)
+GuiFontMetrics::GuiFontMetrics(QFont const & font)
+ : font_(font), metrics_(font, 0),
+ strwidth_cache_(cache_metrics_width_size),
+ breakat_cache_(cache_metrics_breakat_size),
+ qtextlayout_cache_(cache_metrics_qtextlayout_size)
{
}
}
+int GuiFontMetrics::lineWidth() const
+{
+ return metrics_.lineWidth();
+}
+
+
+int GuiFontMetrics::underlinePos() const
+{
+ return metrics_.underlinePos();
+}
+
+
+int GuiFontMetrics::strikeoutPos() const
+{
+ return metrics_.strikeOutPos();
+}
+
+
int GuiFontMetrics::lbearing(char_type c) const
{
if (!is_utf16(c))
- // FIXME: QFontMetrics::leftBearingdoes not support the
+ // FIXME: QFontMetrics::leftBearing does not support the
// full unicode range. Once it does, we could use:
//return metrics_.leftBearing(toqstr(docstring(1, c)));
return 0;
int GuiFontMetrics::width(docstring const & s) const
{
+ PROFILE_THIS_BLOCK(width);
+ if (strwidth_cache_.contains(s))
+ return strwidth_cache_[s];
+ PROFILE_CACHE_MISS(width);
+ /* For some reason QMetrics::width returns a wrong value with Qt5
+ * with some arabic text. OTOH, QTextLayout is broken for single
+ * characters with null width (like \not in mathed). Also, as a
+ * safety measure, always use QMetrics::width with our math fonts.
+ */
int w = 0;
- map<docstring, int>::const_iterator it = strwidth_cache_.find(s);
- if (it != strwidth_cache_.end()) {
- w = it->second;
- } else {
+ if (s.length() == 1
+#if QT_VERSION >= 0x040800
+ || font_.styleName() == "LyX"
+#endif
+ )
w = metrics_.width(toqstr(s));
- strwidth_cache_[s] = w;
+ else {
+ QTextLayout tl;
+ tl.setText(toqstr(s));
+ tl.setFont(font_);
+ tl.beginLayout();
+ QTextLine line = tl.createLine();
+ tl.endLayout();
+ w = int(line.naturalTextWidth());
}
+ strwidth_cache_.insert(s, w, s.size() * sizeof(char_type));
return w;
}
return width(s);
}
-namespace {
-void setTextLayout(QTextLayout & tl, docstring const & s, QFont font,
- bool const rtl, double const wordspacing)
+
+shared_ptr<QTextLayout const>
+GuiFontMetrics::getTextLayout(docstring const & s, bool const rtl,
+ double const wordspacing) const
{
- tl.setText(toqstr(s));
- font.setWordSpacing(wordspacing);
- tl.setFont(font);
+ PROFILE_THIS_BLOCK(getTextLayout);
+ docstring const s_cache =
+ s + (rtl ? "r" : "l") + convert<docstring>(wordspacing);
+ if (auto ptl = qtextlayout_cache_[s_cache])
+ return ptl;
+ PROFILE_CACHE_MISS(getTextLayout);
+ auto const ptl = make_shared<QTextLayout>();
+ ptl->setCacheEnabled(true);
+ ptl->setText(toqstr(s));
+ QFont copy = font_;
+ copy.setWordSpacing(wordspacing);
+ ptl->setFont(copy);
// Note that both setFlags and the enums are undocumented
- tl.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
- tl.beginLayout();
- tl.createLine();
- tl.endLayout();
-}
+ ptl->setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
+ ptl->beginLayout();
+ ptl->createLine();
+ ptl->endLayout();
+ qtextlayout_cache_.insert(s_cache, ptl);
+ return ptl;
}
-int GuiFontMetrics::pos2x(docstring const & s, int const pos, bool const rtl,
+int GuiFontMetrics::pos2x(docstring const & s, int pos, bool const rtl,
double const wordspacing) const
{
- QTextLayout tl;
- QFont copy = font_;
- copy.setWordSpacing(wordspacing);
- setTextLayout(tl, s, font_, rtl, wordspacing);
- return static_cast<int>(tl.lineForTextPosition(pos).cursorToX(pos));
+ 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).
+ */
+ int const qpos = toqstr(s.substr(0, pos)).length();
+ return static_cast<int>(tl->lineForTextPosition(qpos).cursorToX(qpos));
}
int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl,
double const wordspacing) const
{
- QTextLayout tl;
- setTextLayout(tl, s, font_, rtl, wordspacing);
- int pos = tl.lineForTextPosition(0).xToCursor(x);
+ shared_ptr<QTextLayout const> tl = getTextLayout(s, rtl, wordspacing);
+ int const qpos = tl->lineForTextPosition(0).xToCursor(x);
// correct x value to the actual cursor position.
- x = static_cast<int>(tl.lineForTextPosition(0).cursorToX(pos));
+ x = static_cast<int>(tl->lineForTextPosition(0).cursorToX(qpos));
+ /* 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
+ return qstring_to_ucs4(tl->text().left(qpos)).length();
+#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 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
}
-bool GuiFontMetrics::breakAt(docstring & s, int & x, bool const rtl, bool const force) const
+int GuiFontMetrics::countExpanders(docstring const & str) const
+{
+ // Numbers of characters that are expanded by inter-word spacing. These
+ // characters are spaces, except for characters 09-0D which are treated
+ // specially. (From a combination of testing with the notepad found in qt's
+ // examples, and reading the source code.) In addition, consecutive spaces
+ // only count as one expander.
+ bool wasspace = false;
+ int nexp = 0;
+ for (char_type c : str)
+ if (c > 0x0d && QChar(c).isSpace()) {
+ if (!wasspace) {
+ ++nexp;
+ wasspace = true;
+ }
+ } else
+ wasspace = false;
+ return nexp;
+}
+
+
+pair<int, int>
+GuiFontMetrics::breakAt_helper(docstring const & s, int const x,
+ bool const rtl, bool const force) const
{
- if (s.empty())
- return false;
QTextLayout tl;
- tl.setText(toqstr(s));
- tl.setFont(font_);
+ /* 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;
+#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
+ qs = QChar(0x202E) + qs;
+ else
+ // Left-to-right override: forces to draw text left-to-right
+ qs = QChar(0x202D) + qs;
+ int const offset = 2;
+#else
+ // Alternative version that breaks with Qt5 and arabic text (#10436)
// Note that both setFlags and the enums are undocumented
tl.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
+ int const offset = 1;
+#endif
+
+ tl.setText(qs);
+ tl.setFont(font_);
QTextOption to;
- to.setWrapMode(force ? QTextOption::WrapAnywhere : QTextOption::WordWrap);
+ to.setWrapMode(force ? QTextOption::WrapAtWordBoundaryOrAnywhere
+ : QTextOption::WordWrap);
tl.setTextOption(to);
tl.beginLayout();
QTextLine line = tl.createLine();
line.setLineWidth(x);
tl.createLine();
tl.endLayout();
- if (int(line.naturalTextWidth()) > x)
+ if ((force && line.textLength() == offset) || int(line.naturalTextWidth()) > x)
+ return {-1, -1};
+ /* 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 `offset' 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 = line.textLength() - offset - (line.textLength() == qs.length());
+#if QT_VERSION < 0x040801 || QT_VERSION >= 0x050100
+ int len = qstring_to_ucs4(qs.mid(offset, qlen)).length();
+#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>(s.length()));
+ while (len >= 0 && toqstr(s.substr(0, len)).length() != qlen)
+ --len;
+ LASSERT(len > 0 || qlen == 0, /**/);
+#endif
+ // The -1 is here to account for the leading zerow_nbsp.
+ return {len, int(line.naturalTextWidth())};
+}
+
+
+bool GuiFontMetrics::breakAt(docstring & s, int & x, bool const rtl, bool const force) const
+{
+ PROFILE_THIS_BLOCK(breakAt);
+ if (s.empty())
return false;
- x = int(line.naturalTextWidth());
- s = s.substr(0, line.textLength());
+
+ docstring const s_cache =
+ s + convert<docstring>(x) + (rtl ? "r" : "l") + (force ? "f" : "w");
+ pair<int, int> pp;
+
+ if (breakat_cache_.contains(s_cache))
+ pp = breakat_cache_[s_cache];
+ else {
+ PROFILE_CACHE_MISS(breakAt);
+ pp = breakAt_helper(s, x, rtl, force);
+ breakat_cache_.insert(s_cache, pp, s_cache.size() * sizeof(char_type));
+ }
+ if (pp.first == -1)
+ return false;
+ s = s.substr(0, pp.first);
+ x = pp.second;
return true;
}
}
-
void GuiFontMetrics::buttonText(docstring const & str,
int & w, int & ascent, int & descent) const
{
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