Introduce a generic QFontEngine::canRender() implementation

...which uses the recently introduced glyphIndex() method;
get rid of re-implementations that did almost the same.

Change-Id: I6d32d2cee6a31f57de6aee05ed8d120d4a1f4e9c
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

6 files changed, 17 insertions, 56 deletions

diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index 61816c83fb..ed758f6f0f 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -385,6 +385,17 @@ bool QFontEngine::supportsScript(QChar::Script script) const
     return hbFace->supported_scripts[script_to_hbscript(script)];
 }
 
+bool QFontEngine::canRender(const QChar *str, int len) const
+{
+    QStringIterator it(str, str + len);
+    while (it.hasNext()) {
+        if (glyphIndex(it.next()) == 0)
+            return false;
+    }
+
+    return true;
+}
+
 glyph_metrics_t QFontEngine::boundingBox(glyph_t glyph, const QTransform &matrix)
 {
     glyph_metrics_t metrics = boundingBox(glyph);
@@ -1533,7 +1544,7 @@ const char *QFontEngineBox::name() const
     return "null";
 }
 
-bool QFontEngineBox::canRender(const QChar *, int)
+bool QFontEngineBox::canRender(const QChar *, int) const
 {
     return true;
 }
@@ -1951,7 +1962,7 @@ qreal QFontEngineMulti::minRightBearing() const
     return engine(0)->minRightBearing();
 }
 
-bool QFontEngineMulti::canRender(const QChar *string, int len)
+bool QFontEngineMulti::canRender(const QChar *string, int len) const
 {
     if (engine(0)->canRender(string, len))
         return true;
diff --git a/src/gui/text/qfontengine_ft.cpp b/src/gui/text/qfontengine_ft.cpp
index b50c8fd95a..04cf6bfdcb 100644
--- a/src/gui/text/qfontengine_ft.cpp
+++ b/src/gui/text/qfontengine_ft.cpp
@@ -1468,19 +1468,6 @@ static inline unsigned int getChar(const QChar *str, int &i, const int len)
     return ucs4;
 }
 
-bool QFontEngineFT::canRender(const QChar *string, int len)
-{
-    FT_Face face = freetype->face;
-    {
-        for ( int i = 0; i < len; i++ ) {
-            unsigned int uc = getChar(string, i, len);
-            if (!FT_Get_Char_Index(face, uc))
-                    return false;
-        }
-    }
-    return true;
-}
-
 void QFontEngineFT::addOutlineToPath(qreal x, qreal y, const QGlyphLayout &glyphs, QPainterPath *path, QTextItem::RenderFlags flags)
 {
     if (!glyphs.numGlyphs)
diff --git a/src/gui/text/qfontengine_ft_p.h b/src/gui/text/qfontengine_ft_p.h
index 7fc73c816d..fa6ef6f422 100644
--- a/src/gui/text/qfontengine_ft_p.h
+++ b/src/gui/text/qfontengine_ft_p.h
@@ -237,8 +237,6 @@ private:
 
     virtual bool supportsTransformation(const QTransform &transform) const;
 
-    virtual bool canRender(const QChar *string, int len);
-
     virtual void addGlyphsToPath(glyph_t *glyphs, QFixedPoint *positions, int nglyphs,
                          QPainterPath *path, QTextItem::RenderFlags flags);
     virtual void addOutlineToPath(qreal x, qreal y, const QGlyphLayout &glyphs,
diff --git a/src/gui/text/qfontengine_p.h b/src/gui/text/qfontengine_p.h
index f497085ce2..f5e4ae98fa 100644
--- a/src/gui/text/qfontengine_p.h
+++ b/src/gui/text/qfontengine_p.h
@@ -227,19 +227,8 @@ public:
 
     virtual const char *name() const = 0;
 
-    virtual bool canRender(const QChar *string, int len) = 0;
-    inline bool canRender(uint ucs4) {
-        QChar utf16[2];
-        int utf16len = 1;
-        if (QChar::requiresSurrogates(ucs4)) {
-            utf16[0] = QChar::highSurrogate(ucs4);
-            utf16[1] = QChar::lowSurrogate(ucs4);
-            ++utf16len;
-        } else {
-            utf16[0] = QChar(ucs4);
-        }
-        return canRender(utf16, utf16len);
-    }
+    inline bool canRender(uint ucs4) const { return glyphIndex(ucs4) != 0; }
+    virtual bool canRender(const QChar *str, int len) const;
 
     virtual bool supportsTransformation(const QTransform &transform) const;
 
@@ -374,7 +363,7 @@ public:
 
     virtual const char *name() const;
 
-    virtual bool canRender(const QChar *string, int len);
+    virtual bool canRender(const QChar *string, int len) const;
 
     virtual Type type() const;
     inline int size() const { return _size; }
@@ -421,7 +410,7 @@ public:
     virtual inline Type type() const
     { return QFontEngine::Multi; }
 
-    virtual bool canRender(const QChar *string, int len);
+    virtual bool canRender(const QChar *string, int len) const;
     inline virtual const char *name() const
     { return "Multi"; }
 
diff --git a/src/gui/text/qfontengine_qpa.cpp b/src/gui/text/qfontengine_qpa.cpp
index f48b44374e..b0bfd02448 100644
--- a/src/gui/text/qfontengine_qpa.cpp
+++ b/src/gui/text/qfontengine_qpa.cpp
@@ -515,29 +515,6 @@ QFontEngine::Type QFontEngineQPA::type() const
     return QFontEngine::QPF2;
 }
 
-bool QFontEngineQPA::canRender(const QChar *string, int len)
-{
-    const uchar *cmap = externalCMap ? externalCMap : (fontData + cmapOffset);
-
-    if (symbol) {
-        for (int i = 0; i < len; ++i) {
-            unsigned int uc = getChar(string, i, len);
-            glyph_t g = getTrueTypeGlyphIndex(cmap, uc);
-            if(!g && uc < 0x100)
-                g = getTrueTypeGlyphIndex(cmap, uc + 0xf000);
-            if (!g)
-                return false;
-        }
-    } else {
-        for (int i = 0; i < len; ++i) {
-            unsigned int uc = getChar(string, i, len);
-            if (!getTrueTypeGlyphIndex(cmap, uc))
-                return false;
-        }
-    }
-    return true;
-}
-
 bool QFontEngineQPA::isValid() const
 {
     return fontData && dataSize && (cmapOffset || externalCMap)
diff --git a/src/gui/text/qfontengine_qpa_p.h b/src/gui/text/qfontengine_qpa_p.h
index bcd48ca690..9d9140b842 100644
--- a/src/gui/text/qfontengine_qpa_p.h
+++ b/src/gui/text/qfontengine_qpa_p.h
@@ -184,7 +184,6 @@ public:
 
     Type type() const;
 
-    bool canRender(const QChar *string, int len);
     inline const char *name() const { return "QPF2"; }
 
     virtual int glyphCount() const { return glyphMapEntries; }