Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2:
  Check engine existence before increasing reference count
  Keep reference count for cached font engines in QTextEngine
  Optimize text layout.
  Fix crash when app font is added

3 files changed, 117 insertions, 44 deletions

diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 9271f34..648f5c0 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -1385,6 +1385,15 @@ void QTextEngine::shape(int item) const
     }
 }
 
+static inline void releaseCachedFontEngine(QFontEngine *fontEngine)
+{
+    if (fontEngine) {
+        fontEngine->ref.deref();
+        if (fontEngine->cache_count == 0 && fontEngine->ref == 0)
+            delete fontEngine;
+    }
+}
+
 void QTextEngine::invalidate()
 {
     freeMemory();
@@ -1392,6 +1401,10 @@ void QTextEngine::invalidate()
     maxWidth = 0;
     if (specialData)
         specialData->resolvedFormatIndices.clear();
+
+    releaseCachedFontEngine(feCache.prevFontEngine);
+    releaseCachedFontEngine(feCache.prevScaledFontEngine);
+    feCache.reset();
 }
 
 void QTextEngine::clearLineData()
@@ -1783,6 +1796,13 @@ QFont QTextEngine::font(const QScriptItem &si) const
     return font;
 }
 
+QTextEngine::FontEngineCache::FontEngineCache()
+{
+    reset();
+}
+
+//we cache the previous results of this function, as calling it numerous times with the same effective
+//input is common (and hard to cache at a higher level)
 QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFixed *descent, QFixed *leading) const
 {
     QFontEngine *engine = 0;
@@ -1791,28 +1811,53 @@ QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFix
 
     QFont font = fnt;
     if (hasFormats()) {
-        QTextCharFormat f = format(&si);
-        font = f.font();
-
-        if (block.docHandle() && block.docHandle()->layout()) {
-            // Make sure we get the right dpi on printers
-            QPaintDevice *pdev = block.docHandle()->layout()->paintDevice();
-            if (pdev)
-                font = QFont(font, pdev);
+        if (feCache.prevFontEngine && feCache.prevPosition == si.position && feCache.prevLength == length(&si) && feCache.prevScript == script) {
+            engine = feCache.prevFontEngine;
+            scaledEngine = feCache.prevScaledFontEngine;
         } else {
-            font = font.resolve(fnt);
-        }
-        engine = font.d->engineForScript(script);
-        QTextCharFormat::VerticalAlignment valign = f.verticalAlignment();
-        if (valign == QTextCharFormat::AlignSuperScript || valign == QTextCharFormat::AlignSubScript) {
-            if (font.pointSize() != -1)
-                font.setPointSize((font.pointSize() * 2) / 3);
-            else
-                font.setPixelSize((font.pixelSize() * 2) / 3);
-            scaledEngine = font.d->engineForScript(script);
+            QTextCharFormat f = format(&si);
+            font = f.font();
+
+            if (block.docHandle() && block.docHandle()->layout()) {
+                // Make sure we get the right dpi on printers
+                QPaintDevice *pdev = block.docHandle()->layout()->paintDevice();
+                if (pdev)
+                    font = QFont(font, pdev);
+            } else {
+                font = font.resolve(fnt);
+            }
+            engine = font.d->engineForScript(script);
+            QTextCharFormat::VerticalAlignment valign = f.verticalAlignment();
+            if (valign == QTextCharFormat::AlignSuperScript || valign == QTextCharFormat::AlignSubScript) {
+                if (font.pointSize() != -1)
+                    font.setPointSize((font.pointSize() * 2) / 3);
+                else
+                    font.setPixelSize((font.pixelSize() * 2) / 3);
+                scaledEngine = font.d->engineForScript(script);
+            }
+            feCache.prevFontEngine = engine;
+            if (engine)
+                engine->ref.ref();
+            feCache.prevScaledFontEngine = scaledEngine;
+            if (scaledEngine)
+                scaledEngine->ref.ref();
+            feCache.prevScript = script;
+            feCache.prevPosition = si.position;
+            feCache.prevLength = length(&si);
         }
     } else {
-        engine = font.d->engineForScript(script);
+        if (feCache.prevFontEngine && feCache.prevScript == script && feCache.prevPosition == -1)
+            engine = feCache.prevFontEngine;
+        else {
+            engine = font.d->engineForScript(script);
+            feCache.prevFontEngine = engine;
+            if (engine)
+                engine->ref.ref();
+            feCache.prevScript = script;
+            feCache.prevPosition = -1;
+            feCache.prevLength = -1;
+            feCache.prevScaledFontEngine = 0;
+        }
     }
 
     if (si.analysis.flags == QScriptAnalysis::SmallCaps) {
@@ -2778,6 +2823,22 @@ QTextItemInt::QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFo
     : justified(false), underlineStyle(QTextCharFormat::NoUnderline), charFormat(format),
       num_chars(0), chars(0), logClusters(0), f(0), fontEngine(0)
 {
+    f = font;
+    fontEngine = f->d->engineForScript(si.analysis.script);
+    Q_ASSERT(fontEngine);
+
+    initWithScriptItem(si);
+}
+
+QTextItemInt::QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars_, int numChars, QFontEngine *fe, const QTextCharFormat &format)
+    : flags(0), justified(false), underlineStyle(QTextCharFormat::NoUnderline), charFormat(format),
+      num_chars(numChars), chars(chars_), logClusters(0), f(font),  glyphs(g), fontEngine(fe)
+{
+}
+
+// Fix up flags and underlineStyle with given info
+void QTextItemInt::initWithScriptItem(const QScriptItem &si)
+{
     // explicitly initialize flags so that initFontAttributes can be called
     // multiple times on the same TextItem
     flags = 0;
@@ -2785,13 +2846,10 @@ QTextItemInt::QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFo
         flags |= QTextItem::RightToLeft;
     ascent = si.ascent;
     descent = si.descent;
-    f = font;
-    fontEngine = f->d->engineForScript(si.analysis.script);
-    Q_ASSERT(fontEngine);
 
-    if (format.hasProperty(QTextFormat::TextUnderlineStyle)) {
-        underlineStyle = format.underlineStyle();
-    } else if (format.boolProperty(QTextFormat::FontUnderline)
+    if (charFormat.hasProperty(QTextFormat::TextUnderlineStyle)) {
+        underlineStyle = charFormat.underlineStyle();
+    } else if (charFormat.boolProperty(QTextFormat::FontUnderline)
                || f->d->underline) {
         underlineStyle = QTextCharFormat::SingleUnderline;
     }
@@ -2800,18 +2858,12 @@ QTextItemInt::QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFo
     if (underlineStyle == QTextCharFormat::SingleUnderline)
         flags |= QTextItem::Underline;
 
-    if (f->d->overline || format.fontOverline())
+    if (f->d->overline || charFormat.fontOverline())
         flags |= QTextItem::Overline;
-    if (f->d->strikeOut || format.fontStrikeOut())
+    if (f->d->strikeOut || charFormat.fontStrikeOut())
         flags |= QTextItem::StrikeOut;
 }
 
-QTextItemInt::QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars_, int numChars, QFontEngine *fe)
-    : flags(0), justified(false), underlineStyle(QTextCharFormat::NoUnderline),
-      num_chars(numChars), chars(chars_), logClusters(0), f(font),  glyphs(g), fontEngine(fe)
-{
-}
-
 QTextItemInt QTextItemInt::midItem(QFontEngine *fontEngine, int firstGlyphIndex, int numGlyphs) const
 {
     QTextItemInt ti = *this;
diff --git a/src/gui/text/qtextengine_p.h b/src/gui/text/qtextengine_p.h
index 09610ff..c920c7b 100644
--- a/src/gui/text/qtextengine_p.h
+++ b/src/gui/text/qtextengine_p.h
@@ -311,11 +311,13 @@ public:
           logClusters(0), f(0), fontEngine(0)
     {}
     QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFormat &format = QTextCharFormat());
-    QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars, int numChars, QFontEngine *fe);
+    QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars, int numChars, QFontEngine *fe,
+                 const QTextCharFormat &format = QTextCharFormat());
 
     /// copy the structure items, adjusting the glyphs arrays to the right subarrays.
     /// the width of the returned QTextItemInt is not adjusted, for speed reasons
     QTextItemInt midItem(QFontEngine *fontEngine, int firstGlyphIndex, int numGlyphs) const;
+    void initWithScriptItem(const QScriptItem &si);
 
     QFixed descent;
     QFixed ascent;
@@ -556,6 +558,23 @@ public:
 
     mutable QScriptLineArray lines;
 
+    struct FontEngineCache {
+        FontEngineCache();
+        mutable QFontEngine *prevFontEngine;
+        mutable QFontEngine *prevScaledFontEngine;
+        mutable int prevScript;
+        mutable int prevPosition;
+        mutable int prevLength;
+        inline void reset() {
+            prevFontEngine = 0;
+            prevScaledFontEngine = 0;
+            prevScript = -1;
+            prevPosition = -1;
+            prevLength = -1;
+        }
+    };
+    mutable FontEngineCache feCache;
+
     QString text;
     QFont fnt;
     QTextBlock block;
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 0fbf838..183bcea 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -386,6 +386,7 @@ QTextLayout::~QTextLayout()
 void QTextLayout::setFont(const QFont &font)
 {
     d->fnt = font;
+    d->feCache.reset();
 }
 
 /*!
@@ -518,6 +519,7 @@ void QTextLayout::setAdditionalFormats(const QList<FormatRange> &formatList)
     }
     if (d->block.docHandle())
         d->block.docHandle()->documentChange(d->block.position(), d->block.length());
+    d->feCache.reset();
 }
 
 /*!
@@ -1867,14 +1869,14 @@ void QTextLine::layout_helper(int maxGlyphs)
             lbh.currentPosition = qMax(line.from, current.position);
             end = current.position + eng->length(item);
             lbh.glyphs = eng->shapedGlyphs(&current);
+            QFontEngine *fontEngine = eng->fontEngine(current);
+            if (lbh.fontEngine != fontEngine) {
+                lbh.fontEngine = fontEngine;
+                lbh.minimumRightBearing = qMin(QFixed(),
+                                               QFixed::fromReal(fontEngine->minRightBearing()));
+            }
         }
         const QScriptItem &current = eng->layoutData->items[item];
-        QFontEngine *fontEngine = eng->fontEngine(current);
-        if (lbh.fontEngine != fontEngine) {
-            lbh.fontEngine = fontEngine;
-            lbh.minimumRightBearing = qMin(QFixed(),
-                                           QFixed::fromReal(fontEngine->minRightBearing()));
-        }
 
         lbh.tmpData.leading = qMax(lbh.tmpData.leading + lbh.tmpData.ascent,
                                    current.leading + current.ascent) - qMax(lbh.tmpData.ascent,
@@ -2319,13 +2321,13 @@ void QTextLine::draw(QPainter *p, const QPointF &pos, const QTextLayout::FormatR
         unsigned short *logClusters = eng->logClusters(&si);
         QGlyphLayout glyphs = eng->shapedGlyphs(&si);
 
-        QTextItemInt gf(si, &f, format);
-        gf.glyphs = glyphs.mid(iterator.glyphsStart, iterator.glyphsEnd - iterator.glyphsStart);
-        gf.chars = eng->layoutData->string.unicode() + iterator.itemStart;
+        QTextItemInt gf(glyphs.mid(iterator.glyphsStart, iterator.glyphsEnd - iterator.glyphsStart),
+                        &f, eng->layoutData->string.unicode() + iterator.itemStart,
+                        iterator.itemEnd - iterator.itemStart, eng->fontEngine(si), format);
         gf.logClusters = logClusters + iterator.itemStart - si.position;
-        gf.num_chars = iterator.itemEnd - iterator.itemStart;
         gf.width = iterator.itemWidth;
         gf.justified = line.justified;
+        gf.initWithScriptItem(si);
 
         Q_ASSERT(gf.fontEngine);