Fix bold text rendering of Thai and Vietnamese on Symbian

The Symbian Qt font database made the wrong assumption that a font face
name maps one to one to a font. That led to a mismaptch between actual
font face variants (bold) versus the retrieved font tables.

S60, usually comes with two 'Series 60 Sans' font files where one is
semi bold. The rasterizer plugin merges both fonts to one and returns
the semi bold font if a bold font is requested, otherwise it returns
the normal font. Both font files have slight differences in the cmap.

Qt's font implementation always retrieved the font tables for the
normal font even if it drew the bold font. That led to wrong glyphs
in some languages (Thai, Vietnamese), thanks to the cmap differences.

This fix makes sure that when retrieving the font tables, bold and
italic are considered. It avoids innecessary double allocations of
MOpenFontTrueTypeExtension instances. Also the ChunkHeap size of
m_heap does now depend on the number of loaded font files.

Task-number: QTBUG-6812
Reviewed-by: Aleksandar Sasha Babic

1 files changed, 40 insertions, 17 deletions

diff --git a/src/gui/text/qfontdatabase_s60.cpp b/src/gui/text/qfontdatabase_s60.cpp
index 376ad43..4171e40 100644
--- a/src/gui/text/qfontdatabase_s60.cpp
+++ b/src/gui/text/qfontdatabase_s60.cpp
@@ -98,18 +98,26 @@ public:
     QSymbianFontDatabaseExtrasImplementation();
     ~QSymbianFontDatabaseExtrasImplementation();
 
-    const QSymbianTypeFaceExtras *extras(const QString &typeface) const;
+    const QSymbianTypeFaceExtras *extras(const QString &typeface, bool bold, bool italic) const;
 
 private:
     RHeap* m_heap;
     CFontStore *m_store;
     COpenFontRasterizer *m_rasterizer;
-    mutable QHash<QString, const QSymbianTypeFaceExtras *> m_extras;
+    mutable QList<const QSymbianTypeFaceExtras *> m_extras;
+    mutable QHash<QString, const QSymbianTypeFaceExtras *> m_extrasHash;
 };
 
 QSymbianFontDatabaseExtrasImplementation::QSymbianFontDatabaseExtrasImplementation()
 {
-    m_heap = User::ChunkHeap(NULL, 0x1000, 0x100000);
+    QStringList filters;
+    filters.append(QLatin1String("*.ttf"));
+    filters.append(QLatin1String("*.ccc"));
+    const QFileInfoList fontFiles = alternativeFilePaths(QLatin1String("resource\\Fonts"), filters);
+
+    const TInt heapMinLength = 0x1000;
+    const TInt heapMaxLength = qMax(0x20000 * fontFiles.count(), heapMinLength);
+    m_heap = User::ChunkHeap(NULL, heapMinLength, heapMaxLength);
     QT_TRAP_THROWING(
         m_store = CFontStore::NewL(m_heap);
         m_rasterizer = COpenFontRasterizer::NewL(TUid::Uid(0x101F7F5E));
@@ -117,19 +125,16 @@ QSymbianFontDatabaseExtrasImplementation::QSymbianFontDatabaseExtrasImplementati
         m_store->InstallRasterizerL(m_rasterizer);
         CleanupStack::Pop(m_rasterizer););
 
-    QStringList filters;
-    filters.append(QString::fromLatin1("*.ttf"));
-    filters.append(QString::fromLatin1("*.ccc"));
-    const QFileInfoList fontFiles = alternativeFilePaths(QString::fromLatin1("resource\\Fonts"), filters);
     foreach (const QFileInfo &fontFileInfo, fontFiles) {
         const QString fontFile = QDir::toNativeSeparators(fontFileInfo.absoluteFilePath());
         TPtrC fontFilePtr(qt_QString2TPtrC(fontFile));
         QT_TRAP_THROWING(m_store->AddFileL(fontFilePtr));
     }
 }
+
 QSymbianFontDatabaseExtrasImplementation::~QSymbianFontDatabaseExtrasImplementation()
 {
-    typedef QHash<QString, const QSymbianTypeFaceExtras *>::iterator iterator;
+    typedef QList<const QSymbianTypeFaceExtras *>::iterator iterator;
     for (iterator p = m_extras.begin(); p != m_extras.end(); ++p) {
         m_store->ReleaseFont((*p)->fontOwner());
         delete *p;
@@ -156,13 +161,18 @@ COpenFont* OpenFontFromBitmapFont(const CBitmapFont* aBitmapFont)
 }
 #endif // FNTSTORE_H_INLINES_SUPPORT_FMM
 
-const QSymbianTypeFaceExtras *QSymbianFontDatabaseExtrasImplementation::extras(const QString &typeface) const
+const QSymbianTypeFaceExtras *QSymbianFontDatabaseExtrasImplementation::extras(const QString &typeface,
+                                                                               bool bold, bool italic) const
 {
-    if (!m_extras.contains(typeface)) {
+    const QString searchKey = typeface + QString::number(int(bold)) + QString::number(int(italic));
+    if (!m_extrasHash.contains(searchKey)) {
         CFont* font = NULL;
-        TFontSpec spec(qt_QString2TPtrC(typeface), 1);
-        spec.iHeight = 1;
-        const TInt err = m_store->GetNearestFontToDesignHeightInPixels(font, spec);
+        TFontSpec searchSpec(qt_QString2TPtrC(typeface), 1);
+        if (bold)
+            searchSpec.iFontStyle.SetStrokeWeight(EStrokeWeightBold);
+        if (italic)
+            searchSpec.iFontStyle.SetPosture(EPostureItalic);
+        const TInt err = m_store->GetNearestFontToDesignHeightInPixels(font, searchSpec);
         Q_ASSERT(err == KErrNone && font);
         const CBitmapFont *bitmapFont = static_cast<CBitmapFont*>(font);
         COpenFont *openFont =
@@ -171,9 +181,20 @@ const QSymbianTypeFaceExtras *QSymbianFontDatabaseExtrasImplementation::extras(c
 #else
             OpenFontFromBitmapFont(bitmapFont);
 #endif // FNTSTORE_H_INLINES_SUPPORT_FMM
-        m_extras.insert(typeface, new QSymbianTypeFaceExtras(font, openFont));
+        const TOpenFontFaceAttrib* const attrib = openFont->FaceAttrib();
+        const QString foundKey =
+                QString((const QChar*)attrib->FullName().Ptr(), attrib->FullName().Length());
+        if (!m_extrasHash.contains(foundKey)) {
+            QSymbianTypeFaceExtras *extras = new QSymbianTypeFaceExtras(font, openFont);
+            m_extras.append(extras);
+            m_extrasHash.insert(searchKey, extras);
+            m_extrasHash.insert(foundKey, extras);
+        } else {
+            m_store->ReleaseFont(font);
+            m_extrasHash.insert(searchKey, m_extrasHash.value(foundKey));
+        }
     }
-    return m_extras.value(typeface);
+    return m_extrasHash.value(searchKey);
 }
 #else
 class QFontEngineFTS60 : public QFontEngineFT
@@ -273,7 +294,8 @@ static void initializeDb()
             style->smoothScalable = typefaceSupport.iIsScalable;
             style->pixelSize(0, true);
 
-            const QSymbianTypeFaceExtras *typeFaceExtras = dbExtras->extras(familyName);
+            const QSymbianTypeFaceExtras *typeFaceExtras =
+                    dbExtras->extras(familyName, faceAttrib.IsBold(), faceAttrib.IsItalic());
             const QByteArray os2Table = typeFaceExtras->getSfntTable(MAKE_TAG('O', 'S', '/', '2'));
             const unsigned char* data = reinterpret_cast<const unsigned char*>(os2Table.constData());
             const unsigned char* ulUnicodeRange = data + 42;
@@ -396,7 +418,8 @@ QFontEngine *QFontDatabase::findFont(int script, const QFontPrivate *, const QFo
 #if defined(QT_NO_FREETYPE)
         const QSymbianFontDatabaseExtrasImplementation *dbExtras =
                 static_cast<const QSymbianFontDatabaseExtrasImplementation*>(db->symbianExtras);
-        const QSymbianTypeFaceExtras *typeFaceExtras = dbExtras->extras(fontFamily);
+        const QSymbianTypeFaceExtras *typeFaceExtras =
+                dbExtras->extras(fontFamily, request.weight > QFont::Normal, request.style != QFont::StyleNormal);
         fe = new QFontEngineS60(request, typeFaceExtras);
 #else
         QFontEngine::FaceId faceId;