* qt_helpers.h:

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

diff --git a/src/frontends/qt4/GuiFontMetrics.h b/src/frontends/qt4/GuiFontMetrics.h
index 924c0e0cd61de3851a1fb5f4c0297a521de64581..e2e168a9ff9464deea2cde79841c4d4c38ab354a 100644 (file)
--- a/src/frontends/qt4/GuiFontMetrics.h
+++ b/src/frontends/qt4/GuiFontMetrics.h
@@ -17,12 +17,12 @@
 #include "support/docstring.h"
 
 #include <QFontMetrics>
+#include <QHash>
 
 // Starting with version 3.1.0, Qt/X11 does its own caching of
 // character width, so it is not necessary to provide ours.
 #if defined(Q_WS_MACX) || defined(Q_WS_WIN32)
 #define USE_LYX_FONTCACHE
-#include <map>
 #endif
 
 namespace lyx {
@@ -39,17 +39,24 @@ public:
 
        virtual int maxAscent() const;
        virtual int maxDescent() const;
-       virtual int ascent(lyx::char_type c) const;
-       int descent(lyx::char_type c) const;
-       virtual int lbearing(lyx::char_type c) const;
-       virtual int rbearing(lyx::char_type c) const;
-       virtual int width(lyx::char_type const * s, size_t n) const;
-       virtual int signedWidth(lyx::docstring const & s) const;
-       virtual void rectText(lyx::docstring const & str,
+#ifndef USE_LYX_FONTCACHE
+       virtual int width(char_type c) const {
+               return metrics_.width(QChar(static_cast<short int>(c)));
+       }
+#else
+       virtual int width(char_type c) const;
+#endif
+       virtual int ascent(char_type c) const;
+       virtual int descent(char_type c) const;
+       virtual int lbearing(char_type c) const;
+       virtual int rbearing(char_type c) const;
+       virtual int width(char_type const * s, size_t n) const;
+       virtual int signedWidth(docstring const & s) const;
+       virtual void rectText(docstring const & str,
                int & width,
                int & ascent,
                int & descent) const;
-       virtual void buttonText(lyx::docstring const & str,
+       virtual void buttonText(docstring const & str,
                int & width,
                int & ascent,
                int & descent) const;
@@ -65,16 +72,24 @@ private:
 
        bool smallcaps_shape_;
 
-#ifndef USE_LYX_FONTCACHE
-       /// Return pixel width for the given unicode char
-       int width(unsigned short val) const { return metrics_.width(QChar(val)); }
-
-#else
-       /// Return pixel width for the given unicode char
-       int width(unsigned short val) const;
+#ifdef USE_LYX_FONTCACHE
 
        /// Cache of char widths
-       mutable int widthcache_[65536];
+       /** This cache adds 20Mo of memory to the LyX executable when
+       * loading UserGuide.lyx which contains a good number of fonts. If
+       * this turns out to be too much, we can switch to a \c QHash based
+       * solution.
+       **/
+       mutable QHash<char_type, int> width_cache_;
+
+       struct AscendDescend {
+               short int ascent;
+               short int descent;
+       };
+       mutable QHash<char_type, AscendDescend> metrics_cache_;
+       /// fill in \c metrics_cache_ at specified value.
+       void fillMetricsCache(char_type) const;
+
 #endif // USE_LYX_FONTCACHE
 };