Merge branch '4.7' of scm.dev.nokia.troll.no:qt/qt into 4.7

1 files changed, 69 insertions, 0 deletions

diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 806779a..9271f34 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -2697,6 +2697,75 @@ QFixed QTextEngine::leadingSpaceWidth(const QScriptLine &line)
     return width(line.from + pos, line.length - pos);
 }
 
+// Scan in logClusters[from..to-1] for glyph_pos
+int QTextEngine::getClusterLength(unsigned short *logClusters,
+                                  const HB_CharAttributes *attributes,
+                                  int from, int to, int glyph_pos, int *start)
+{
+    int clusterLength = 0;
+    for (int i = from; i < to; i++) {
+        if (logClusters[i] == glyph_pos && attributes[i].charStop) {
+            if (*start < 0)
+                *start = i;
+            clusterLength++;
+        }
+        else if (clusterLength)
+            break;
+    }
+    return clusterLength;
+}
+
+int QTextEngine::positionInLigature(const QScriptItem *si, int end,
+                                    QFixed x, QFixed edge, int glyph_pos,
+                                    bool cursorOnCharacter)
+{
+    unsigned short *logClusters = this->logClusters(si);
+    int clusterStart = -1;
+    int clusterLength = 0;
+
+    if (si->analysis.script != QUnicodeTables::Common &&
+        si->analysis.script != QUnicodeTables::Greek) {
+        if (glyph_pos == -1)
+            return si->position + end;
+        else {
+            int i;
+            for (i = 0; i < end; i++)
+                if (logClusters[i] == glyph_pos)
+                    break;
+            return si->position + i;
+        }
+    }
+
+    if (glyph_pos == -1 && end > 0)
+        glyph_pos = logClusters[end - 1];
+    else {
+        if (x <= edge)
+            glyph_pos--;
+    }
+
+    const HB_CharAttributes *attrs = attributes();
+    clusterLength = getClusterLength(logClusters, attrs, 0, end, glyph_pos, &clusterStart);
+
+    if (clusterLength) {
+        const QGlyphLayout &glyphs = shapedGlyphs(si);
+        QFixed glyphWidth = glyphs.effectiveAdvance(glyph_pos);
+        // the approximate width of each individual element of the ligature
+        QFixed perItemWidth = glyphWidth / clusterLength;
+        QFixed left = x > edge ? edge : edge - glyphWidth;
+        int n = ((x - left) / perItemWidth).floor().toInt();
+        QFixed dist = x - left - n * perItemWidth;
+        int closestItem = dist > (perItemWidth / 2) ? n + 1 : n;
+        if (cursorOnCharacter && closestItem > 0)
+            closestItem--;
+        int pos = si->position + clusterStart + closestItem;
+        // Jump to the next charStop
+        while (!attrs[pos].charStop && pos < end)
+            pos++;
+        return pos;
+    }
+    return si->position + end;
+}
+
 QStackTextEngine::QStackTextEngine(const QString &string, const QFont &f)
     : QTextEngine(string, f),
       _layoutData(string, _memory, MemSize)