Make a string translatable

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

diff --git a/src/frontends/qt4/GuiFontMetrics.cpp b/src/frontends/qt4/GuiFontMetrics.cpp
index 31c45481ae6af56eac56b86e7b46ce1d89eb1d15..8381dd1ee38396353cdb8f07290f38db4b3289ba 100644 (file)
--- a/src/frontends/qt4/GuiFontMetrics.cpp
+++ b/src/frontends/qt4/GuiFontMetrics.cpp
@@ -51,10 +51,18 @@ 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)
+// but it does not seem to work well on MacOS X.
+#if (QT_VERSION < 0x050000) || defined(Q_OS_MAC)
 int cache_metrics_qtextlayout_size = 500;
 #else
 int cache_metrics_qtextlayout_size = 0;
@@ -83,12 +91,6 @@ inline QChar const ucs4_to_qchar(char_type const ucs4)
 } // anon namespace
 
 
-/*
- * 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.
- */
 GuiFontMetrics::GuiFontMetrics(QFont const & font)
        : font_(font), metrics_(font, 0),
          strwidth_cache_(cache_metrics_width_size),
@@ -271,9 +273,34 @@ int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl,
                           double const wordspacing) const
 {
        shared_ptr<QTextLayout const> tl = getTextLayout(s, rtl, wordspacing);
-       int const qpos = tl->lineForTextPosition(0).xToCursor(x);
+       QTextLine const & tline = tl->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).
+       // To work around this, let's have a look at adjacent positions to
+       // see whether we find closer matches.
+       if (rtl && newx < x) {
+               while (qpos > 0) {
+                       int const xm = static_cast<int>(tline.cursorToX(qpos - 1));
+                       if (abs(xm - x) < abs(newx - x)) {
+                               --qpos;
+                               newx = xm;
+                       } else
+                               break;
+               }
+       } else if (rtl && newx > x) {
+               while (qpos < tline.textLength()) {
+                       int const xp = static_cast<int>(tline.cursorToX(qpos + 1));
+                       if (abs(xp - x) < abs(newx - x)) {
+                               ++qpos;
+                               newx = xp;
+                       } else
+                               break;
+               }
+       }
        // correct x value to the actual cursor position.
-       x = static_cast<int>(tl->lineForTextPosition(0).cursorToX(qpos));
+       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).