Amend f441590c

[lyx.git] / src / frontends / qt4 / GuiFontMetrics.cpp

diff --git a/src/frontends/qt4/GuiFontMetrics.cpp b/src/frontends/qt4/GuiFontMetrics.cpp
index 804813a5629b6294ba132bc29df6893bfd3a3566..c58be2aee3c60c83475f199040288010bce52e99 100644 (file)
--- a/src/frontends/qt4/GuiFontMetrics.cpp
+++ b/src/frontends/qt4/GuiFontMetrics.cpp
@@ -23,8 +23,6 @@
 
 #include "support/lassert.h"
 
-#include <QTextLayout>
-
 using namespace std;
 using namespace lyx::support;
 
@@ -53,7 +51,11 @@ inline QChar const ucs4_to_qchar(char_type const ucs4)
 } // anon namespace
 
 
-GuiFontMetrics::GuiFontMetrics(QFont const & font) : font_(font), metrics_(font, 0)
+// Limit strwidth_cache_ size to 512kB of string data
+GuiFontMetrics::GuiFontMetrics(QFont const & font)
+       : font_(font), metrics_(font, 0),
+         strwidth_cache_(1 << 19),
+         tl_cache_rtl_(false), tl_cache_wordspacing_(-1.0)
 {
 }
 
@@ -78,10 +80,28 @@ int GuiFontMetrics::em() const
 }
 
 
+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;
@@ -120,14 +140,14 @@ int GuiFontMetrics::rbearing(char_type c) const
 
 int GuiFontMetrics::width(docstring const & s) const
 {
-       int w = 0;
-       map<docstring, int>::const_iterator it = strwidth_cache_.find(s);
-       if (it != strwidth_cache_.end()) {
-               w = it->second;
-       } else {
-               w = metrics_.width(toqstr(s));
-               strwidth_cache_[s] = w;
-       }
+       QByteArray qba =
+               QByteArray(reinterpret_cast<char const *>(s.data()),
+                          s.size() * sizeof(docstring::value_type));
+       int * pw = strwidth_cache_[qba];
+       if (pw)
+               return *pw;
+       int w = metrics_.width(toqstr(s));
+       strwidth_cache_.insert(qba, new int(w), qba.size());
        return w;
 }
 
@@ -149,33 +169,44 @@ int GuiFontMetrics::signedWidth(docstring const & s) const
                return width(s);
 }
 
-namespace {
-void setTextLayout(QTextLayout & tl, docstring const & s, QFont const & font,
-                            bool const rtl)
+
+QTextLayout const &
+GuiFontMetrics::getTextLayout(docstring const & s, QFont font,
+                              bool const rtl, double const wordspacing) const
 {
-       tl.setText(toqstr(s));
-       tl.setFont(font);
-       // Note that both setFlags and the enums are undocumented
-       tl.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
-       tl.beginLayout();
-       tl.createLine();
-       tl.endLayout();
-}
+       if (s != tl_cache_s_ || font != tl_cache_font_ || rtl != tl_cache_rtl_
+           || wordspacing != tl_cache_wordspacing_) {
+               tl_cache_.setText(toqstr(s));
+               font.setWordSpacing(wordspacing);
+               tl_cache_.setFont(font);
+               // Note that both setFlags and the enums are undocumented
+               tl_cache_.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight);
+               tl_cache_.beginLayout();
+               tl_cache_.createLine();
+               tl_cache_.endLayout();
+               tl_cache_s_ = s;
+               tl_cache_font_ = font;
+               tl_cache_rtl_ = rtl;
+               tl_cache_wordspacing_ = wordspacing;
+       }
+       return tl_cache_;
 }
 
 
-int GuiFontMetrics::pos2x(docstring const & s, int const pos, bool const rtl) const
+int GuiFontMetrics::pos2x(docstring const & s, int const pos, bool const rtl,
+                          double const wordspacing) const
 {
-       QTextLayout tl;
-       setTextLayout(tl, s, font_, rtl);
+       QFont copy = font_;
+       copy.setWordSpacing(wordspacing);
+       QTextLayout const & tl = getTextLayout(s, font_, rtl, wordspacing);
        return static_cast<int>(tl.lineForTextPosition(pos).cursorToX(pos));
 }
 
 
-int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl) const
+int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl,
+                          double const wordspacing) const
 {
-       QTextLayout tl;
-       setTextLayout(tl, s, font_, rtl);
+       QTextLayout const & tl = getTextLayout(s, font_, rtl, wordspacing);
        int pos = tl.lineForTextPosition(0).xToCursor(x);
        // correct x value to the actual cursor position.
        x = static_cast<int>(tl.lineForTextPosition(0).cursorToX(pos));