Decouple QSGDistanceFieldGlyphNode from it's cache manager.

To implement a custom distance field glyph node currently it's
necessary to also provide a duplicate implementation of
QSGContext::createDistanceFieldGlyphCache() as the default implemention
references the cache manager created by createGlyphNode().  By isolating
references to the cache manager to just createDistanceFieldGlyph() cache
it becomes possible to just overwrite createGlyphNode() and still use
the default cache.

Change-Id: I7261bdbf247966b55512d2671e2ee85239bcca05
Reviewed-by: Yoann Lopes <yoann.lopes@nokia.com>

9 files changed, 99 insertions, 83 deletions

diff --git a/src/quick/scenegraph/qsgadaptationlayer.cpp b/src/quick/scenegraph/qsgadaptationlayer.cpp
index ed0c2f8197..c78e243dcd 100644
--- a/src/quick/scenegraph/qsgadaptationlayer.cpp
+++ b/src/quick/scenegraph/qsgadaptationlayer.cpp
@@ -222,7 +222,7 @@ void QSGDistanceFieldGlyphCache::setGlyphsPosition(const QList<GlyphPosition> &g
     }
 
     if (!invalidatedGlyphs.isEmpty()) {
-        QLinkedList<QSGDistanceFieldGlyphNode *>::iterator it = m_registeredNodes.begin();
+        QLinkedList<QSGDistanceFieldGlyphConsumer *>::iterator it = m_registeredNodes.begin();
         while (it != m_registeredNodes.end()) {
             (*it)->invalidateGlyphs(invalidatedGlyphs);
             ++it;
@@ -268,7 +268,7 @@ void QSGDistanceFieldGlyphCache::setGlyphsTexture(const QVector<glyph_t> &glyphs
     }
 
     if (!invalidatedGlyphs.isEmpty()) {
-        QLinkedList<QSGDistanceFieldGlyphNode *>::iterator it = m_registeredNodes.begin();
+        QLinkedList<QSGDistanceFieldGlyphConsumer*>::iterator it = m_registeredNodes.begin();
         while (it != m_registeredNodes.end()) {
             (*it)->invalidateGlyphs(invalidatedGlyphs);
             ++it;
@@ -296,5 +296,4 @@ void QSGDistanceFieldGlyphCache::updateTexture(GLuint oldTex, GLuint newTex, con
     }
 }
 
-
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgadaptationlayer_p.h b/src/quick/scenegraph/qsgadaptationlayer_p.h
index e1cd79d4e4..77cd814ce8 100644
--- a/src/quick/scenegraph/qsgadaptationlayer_p.h
+++ b/src/quick/scenegraph/qsgadaptationlayer_p.h
@@ -134,6 +134,14 @@ protected:
     QQuickItem *m_ownerElement;
 };
 
+class Q_QUICK_EXPORT QSGDistanceFieldGlyphConsumer
+{
+public:
+    virtual ~QSGDistanceFieldGlyphConsumer() {}
+
+    virtual void invalidateGlyphs(const QVector<quint32> &glyphs) = 0;
+};
+
 class Q_QUICK_EXPORT QSGDistanceFieldGlyphCache
 {
 public:
@@ -195,8 +203,8 @@ public:
 
     void update();
 
-    void registerGlyphNode(QSGDistanceFieldGlyphNode *node) { m_registeredNodes.append(node); }
-    void unregisterGlyphNode(QSGDistanceFieldGlyphNode *node) { m_registeredNodes.removeOne(node); }
+    void registerGlyphNode(QSGDistanceFieldGlyphConsumer *node) { m_registeredNodes.append(node); }
+    void unregisterGlyphNode(QSGDistanceFieldGlyphConsumer *node) { m_registeredNodes.removeOne(node); }
 
     virtual void registerOwnerElement(QQuickItem *ownerElement);
     virtual void unregisterOwnerElement(QQuickItem *ownerElement);
@@ -247,7 +255,7 @@ private:
     QList<Texture> m_textures;
     QHash<glyph_t, GlyphData> m_glyphsData;
     QDataBuffer<glyph_t> m_pendingGlyphs;
-    QLinkedList<QSGDistanceFieldGlyphNode*> m_registeredNodes;
+    QLinkedList<QSGDistanceFieldGlyphConsumer*> m_registeredNodes;
 
     static Texture s_emptyTexture;
 };
diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index 6eae5c3abd..37a49f9ed8 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -97,6 +97,11 @@ public:
     QSGContextPrivate()
         : gl(0)
         , distanceFieldCacheManager(0)
+    #ifndef QT_OPENGL_ES
+        , distanceFieldAntialiasing(QSGGlyphNode::HighQualitySubPixelAntialiasing)
+    #else
+        , distanceFieldAntialiasing(QSGGlyphNode::GrayAntialiasing)
+    #endif
         , flashMode(qmlFlashMode())
         , distanceFieldDisabled(qmlDisableDistanceField())
     {
@@ -115,6 +120,8 @@ public:
 
     QSGDistanceFieldGlyphCacheManager *distanceFieldCacheManager;
 
+    QSGDistanceFieldGlyphNode::AntialiasingMode distanceFieldAntialiasing;
+
     bool flashMode;
     float renderAlpha;
     bool distanceFieldDisabled;
@@ -142,6 +149,17 @@ public:
 QSGContext::QSGContext(QObject *parent) :
     QObject(*(new QSGContextPrivate), parent)
 {
+    Q_D(QSGContext);
+    // ### Do something with these before final release...
+    static bool doSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing"));
+    static bool doLowQualSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing-lowq"));
+    static bool doGray = qApp->arguments().contains(QLatin1String("--text-gray-antialiasing"));
+    if (doSubpixel)
+        d->distanceFieldAntialiasing = QSGGlyphNode::HighQualitySubPixelAntialiasing;
+    else if (doLowQualSubpixel)
+        d->distanceFieldAntialiasing = QSGGlyphNode::LowQualitySubPixelAntialiasing;
+    else if (doGray)
+       d->distanceFieldAntialiasing = QSGGlyphNode::GrayAntialiasing;
 }
 
 
@@ -271,39 +289,47 @@ QSGImageNode *QSGContext::createImageNode()
 /*!
     Factory function for scene graph backends of the distance-field glyph cache.
  */
-QSGDistanceFieldGlyphCache *QSGContext::createDistanceFieldGlyphCache(const QRawFont &font)
+QSGDistanceFieldGlyphCache *QSGContext::distanceFieldGlyphCache(const QRawFont &font)
 {
     Q_D(QSGContext);
 
-    QPlatformIntegration *platformIntegration = QGuiApplicationPrivate::platformIntegration();
-    if (platformIntegration != 0
-        && platformIntegration->hasCapability(QPlatformIntegration::SharedGraphicsCache)) {
-        QFontEngine *fe = QRawFontPrivate::get(font)->fontEngine;
-        if (!fe->faceId().filename.isEmpty()) {
-            QByteArray keyName = fe->faceId().filename;
-            if (font.style() != QFont::StyleNormal)
-                keyName += QByteArray(" I");
-            if (font.weight() != QFont::Normal)
-                keyName += " " + QByteArray::number(font.weight());
-            keyName += QByteArray(" DF");
-            QPlatformSharedGraphicsCache *sharedGraphicsCache =
-                    platformIntegration->createPlatformSharedGraphicsCache(keyName);
-
-            if (sharedGraphicsCache != 0) {
-                sharedGraphicsCache->ensureCacheInitialized(keyName,
-                                                            QPlatformSharedGraphicsCache::OpenGLTexture,
-                                                            QPlatformSharedGraphicsCache::Alpha8);
-
-                return new QSGSharedDistanceFieldGlyphCache(keyName,
-                                                            sharedGraphicsCache,
-                                                            d->distanceFieldCacheManager,
-                                                            glContext(),
-                                                            font);
+    if (!d->distanceFieldCacheManager)
+        d->distanceFieldCacheManager = new QSGDistanceFieldGlyphCacheManager;
+
+    QSGDistanceFieldGlyphCache *cache = d->distanceFieldCacheManager->cache(font);
+    if (!cache) {
+        QPlatformIntegration *platformIntegration = QGuiApplicationPrivate::platformIntegration();
+        if (platformIntegration != 0
+            && platformIntegration->hasCapability(QPlatformIntegration::SharedGraphicsCache)) {
+            QFontEngine *fe = QRawFontPrivate::get(font)->fontEngine;
+            if (!fe->faceId().filename.isEmpty()) {
+                QByteArray keyName = fe->faceId().filename;
+                if (font.style() != QFont::StyleNormal)
+                    keyName += QByteArray(" I");
+                if (font.weight() != QFont::Normal)
+                    keyName += " " + QByteArray::number(font.weight());
+                keyName += QByteArray(" DF");
+                QPlatformSharedGraphicsCache *sharedGraphicsCache =
+                        platformIntegration->createPlatformSharedGraphicsCache(keyName);
+
+                if (sharedGraphicsCache != 0) {
+                    sharedGraphicsCache->ensureCacheInitialized(keyName,
+                                                                QPlatformSharedGraphicsCache::OpenGLTexture,
+                                                                QPlatformSharedGraphicsCache::Alpha8);
+
+                    cache = new QSGSharedDistanceFieldGlyphCache(keyName,
+                                                                sharedGraphicsCache,
+                                                                d->distanceFieldCacheManager,
+                                                                glContext(),
+                                                                font);
+                }
             }
         }
+        if (!cache)
+            cache = new QSGDefaultDistanceFieldGlyphCache(d->distanceFieldCacheManager, glContext(), font);
+        d->distanceFieldCacheManager->insertCache(font, cache);
     }
-
-    return new QSGDefaultDistanceFieldGlyphCache(d->distanceFieldCacheManager, glContext(), font);
+    return cache;
 }
 
 /*!
@@ -313,25 +339,11 @@ QSGGlyphNode *QSGContext::createGlyphNode()
 {
     Q_D(QSGContext);
 
-    // ### Do something with these before final release...
-    static bool doSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing"));
-    static bool doLowQualSubpixel = qApp->arguments().contains(QLatin1String("--text-subpixel-antialiasing-lowq"));
-    static bool doGray = qApp->arguments().contains(QLatin1String("--text-gray-antialiasing"));
-
     if (d->distanceFieldDisabled) {
         return new QSGDefaultGlyphNode;
     } else {
-        if (!d->distanceFieldCacheManager) {
-            d->distanceFieldCacheManager = new QSGDistanceFieldGlyphCacheManager(this);
-            if (doSubpixel)
-                d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::HighQualitySubPixelAntialiasing);
-            else if (doLowQualSubpixel)
-                d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::LowQualitySubPixelAntialiasing);
-            else if (doGray)
-               d->distanceFieldCacheManager->setDefaultAntialiasingMode(QSGGlyphNode::GrayAntialiasing);
-        }
-
-        QSGGlyphNode *node = new QSGDistanceFieldGlyphNode(d->distanceFieldCacheManager);
+        QSGDistanceFieldGlyphNode *node = new QSGDistanceFieldGlyphNode(this);
+        node->setPreferredAntialiasingMode(d->distanceFieldAntialiasing);
         return node;
     }
 }
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index dfb960f420..7ca3406417 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -95,7 +95,7 @@ public:
 
     virtual void renderNextFrame(QSGRenderer *renderer, GLuint fboId);
 
-    virtual QSGDistanceFieldGlyphCache *createDistanceFieldGlyphCache(const QRawFont &font);
+    virtual QSGDistanceFieldGlyphCache *distanceFieldGlyphCache(const QRawFont &font);
 
     virtual QSGRectangleNode *createRectangleNode();
     virtual QSGImageNode *createImageNode();
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp b/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
index 56c79b1975..16a8ce2d79 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode.cpp
@@ -46,9 +46,9 @@
 
 QT_BEGIN_NAMESPACE
 
-QSGDistanceFieldGlyphNode::QSGDistanceFieldGlyphNode(QSGDistanceFieldGlyphCacheManager *cacheManager)
-    : m_material(0)
-    , m_glyph_cacheManager(cacheManager)
+QSGDistanceFieldGlyphNode::QSGDistanceFieldGlyphNode(QSGContext *context)
+    : m_context(context)
+    , m_material(0)
     , m_glyph_cache(0)
     , m_geometry(QSGGeometry::defaultAttributes_TexturedPoint2D(), 0)
     , m_style(QQuickText::Normal)
@@ -59,7 +59,6 @@ QSGDistanceFieldGlyphNode::QSGDistanceFieldGlyphNode(QSGDistanceFieldGlyphCacheM
 {
     m_geometry.setDrawingMode(GL_TRIANGLES);
     setGeometry(&m_geometry);
-    setPreferredAntialiasingMode(cacheManager->defaultAntialiasingMode());
     setFlag(UsePreprocess);
 #ifdef QML_RUNTIME_TESTING
     description = QLatin1String("glyphs");
@@ -108,7 +107,7 @@ void QSGDistanceFieldGlyphNode::setGlyphs(const QPointF &position, const QGlyphR
     m_glyphs = glyphs;
 
     QSGDistanceFieldGlyphCache *oldCache = m_glyph_cache;
-    m_glyph_cache = m_glyph_cacheManager->cache(m_glyphs.rawFont());
+    m_glyph_cache = m_context->distanceFieldGlyphCache(m_glyphs.rawFont());
     if (m_glyph_cache != oldCache) {
         Q_ASSERT(ownerElement() != 0);
         if (oldCache) {
@@ -290,7 +289,7 @@ void QSGDistanceFieldGlyphNode::updateGeometry()
     while (ite != glyphsInOtherTextures.constEnd()) {
         QHash<const QSGDistanceFieldGlyphCache::Texture *, QSGDistanceFieldGlyphNode *>::iterator subIt = m_subNodes.find(ite.key());
         if (subIt == m_subNodes.end()) {
-            QSGDistanceFieldGlyphNode *subNode = new QSGDistanceFieldGlyphNode(m_glyph_cacheManager);
+            QSGDistanceFieldGlyphNode *subNode = new QSGDistanceFieldGlyphNode(m_context);
             subNode->setOwnerElement(m_ownerElement);
             subNode->setColor(m_color);
             subNode->setStyle(m_style);
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
index 9406ee1bc8..f8c8267e4f 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode_p.h
@@ -51,12 +51,13 @@ QT_BEGIN_HEADER
 
 QT_BEGIN_NAMESPACE
 
+class QSGContext;
 class QSGDistanceFieldGlyphCacheManager;
 class QSGDistanceFieldTextMaterial;
-class QSGDistanceFieldGlyphNode: public QSGGlyphNode
+class QSGDistanceFieldGlyphNode: public QSGGlyphNode, public QSGDistanceFieldGlyphConsumer
 {
 public:
-    QSGDistanceFieldGlyphNode(QSGDistanceFieldGlyphCacheManager *cacheManager);
+    QSGDistanceFieldGlyphNode(QSGContext *context);
     ~QSGDistanceFieldGlyphNode();
 
     virtual QPointF baseLine() const { return m_baseLine; }
@@ -80,11 +81,11 @@ private:
 
     QColor m_color;
     QPointF m_baseLine;
+    QSGContext *m_context;
     QSGDistanceFieldTextMaterial *m_material;
     QPointF m_originalPosition;
     QPointF m_position;
     QGlyphRun m_glyphs;
-    QSGDistanceFieldGlyphCacheManager *m_glyph_cacheManager;
     QSGDistanceFieldGlyphCache *m_glyph_cache;
     QSGGeometry m_geometry;
     QQuickText::TextStyle m_style;
diff --git a/src/quick/scenegraph/qsgdistancefieldglyphnode_p_p.h b/src/quick/scenegraph/qsgdistancefieldglyphnode_p_p.h
index 5dc461f30d..8b2654e078 100644
--- a/src/quick/scenegraph/qsgdistancefieldglyphnode_p_p.h
+++ b/src/quick/scenegraph/qsgdistancefieldglyphnode_p_p.h
@@ -48,7 +48,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QSGDistanceFieldTextMaterial: public QSGMaterial
+class Q_QUICK_EXPORT QSGDistanceFieldTextMaterial: public QSGMaterial
 {
 public:
     QSGDistanceFieldTextMaterial();
@@ -82,7 +82,7 @@ protected:
     qreal m_fontScale;
 };
 
-class QSGDistanceFieldStyledTextMaterial : public QSGDistanceFieldTextMaterial
+class Q_QUICK_EXPORT QSGDistanceFieldStyledTextMaterial : public QSGDistanceFieldTextMaterial
 {
 public:
     QSGDistanceFieldStyledTextMaterial();
@@ -99,7 +99,7 @@ protected:
     QColor m_styleColor;
 };
 
-class QSGDistanceFieldOutlineTextMaterial : public QSGDistanceFieldStyledTextMaterial
+class Q_QUICK_EXPORT QSGDistanceFieldOutlineTextMaterial : public QSGDistanceFieldStyledTextMaterial
 {
 public:
     QSGDistanceFieldOutlineTextMaterial();
@@ -109,7 +109,7 @@ public:
     virtual QSGMaterialShader *createShader() const;
 };
 
-class QSGDistanceFieldShiftedStyleTextMaterial : public QSGDistanceFieldStyledTextMaterial
+class Q_QUICK_EXPORT QSGDistanceFieldShiftedStyleTextMaterial : public QSGDistanceFieldStyledTextMaterial
 {
 public:
     QSGDistanceFieldShiftedStyleTextMaterial();
@@ -125,14 +125,14 @@ protected:
     QPointF m_shift;
 };
 
-class QSGHiQSubPixelDistanceFieldTextMaterial : public QSGDistanceFieldTextMaterial
+class Q_QUICK_EXPORT QSGHiQSubPixelDistanceFieldTextMaterial : public QSGDistanceFieldTextMaterial
 {
 public:
     virtual QSGMaterialType *type() const;
     virtual QSGMaterialShader *createShader() const;
 };
 
-class QSGLoQSubPixelDistanceFieldTextMaterial : public QSGDistanceFieldTextMaterial
+class Q_QUICK_EXPORT QSGLoQSubPixelDistanceFieldTextMaterial : public QSGDistanceFieldTextMaterial
 {
 public:
     virtual QSGMaterialType *type() const;
diff --git a/src/quick/scenegraph/util/qsgdistancefieldutil.cpp b/src/quick/scenegraph/util/qsgdistancefieldutil.cpp
index ba19d51911..ecfdf9b03c 100644
--- a/src/quick/scenegraph/util/qsgdistancefieldutil.cpp
+++ b/src/quick/scenegraph/util/qsgdistancefieldutil.cpp
@@ -62,16 +62,10 @@ static float defaultAntialiasingSpreadFunc(float glyphScale)
     return range / glyphScale;
 }
 
-QSGDistanceFieldGlyphCacheManager::QSGDistanceFieldGlyphCacheManager(QSGContext *c)
-    : sgCtx(c)
-    , m_threshold_func(defaultThresholdFunc)
+QSGDistanceFieldGlyphCacheManager::QSGDistanceFieldGlyphCacheManager()
+    : m_threshold_func(defaultThresholdFunc)
     , m_antialiasingSpread_func(defaultAntialiasingSpreadFunc)
 {
-#ifndef QT_OPENGL_ES
-    m_defaultAntialiasingMode = QSGGlyphNode::HighQualitySubPixelAntialiasing;
-#else
-    m_defaultAntialiasingMode = QSGGlyphNode::GrayAntialiasing;
-#endif
 }
 
 QSGDistanceFieldGlyphCacheManager::~QSGDistanceFieldGlyphCacheManager()
@@ -86,10 +80,17 @@ QSGDistanceFieldGlyphCache *QSGDistanceFieldGlyphCacheManager::cache(const QRawF
                   .arg(font.styleName())
                   .arg(font.weight())
                   .arg(font.style());
-    QHash<QString , QSGDistanceFieldGlyphCache *>::iterator cache = m_caches.find(key);
-    if (cache == m_caches.end())
-        cache = m_caches.insert(key, sgCtx->createDistanceFieldGlyphCache(font));
-    return cache.value();
+    return m_caches.value(key, 0);
+}
+
+void QSGDistanceFieldGlyphCacheManager::insertCache(const QRawFont &font, QSGDistanceFieldGlyphCache *cache)
+{
+    QString key = QString::fromLatin1("%1_%2_%3_%4")
+                  .arg(font.familyName())
+                  .arg(font.styleName())
+                  .arg(font.weight())
+                  .arg(font.style());
+    m_caches.insert(key, cache);
 }
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/util/qsgdistancefieldutil_p.h b/src/quick/scenegraph/util/qsgdistancefieldutil_p.h
index b04b70e06f..4ed4c28657 100644
--- a/src/quick/scenegraph/util/qsgdistancefieldutil_p.h
+++ b/src/quick/scenegraph/util/qsgdistancefieldutil_p.h
@@ -58,13 +58,11 @@ class QSGContext;
 class Q_QUICK_EXPORT QSGDistanceFieldGlyphCacheManager
 {
 public:
-    QSGDistanceFieldGlyphCacheManager(QSGContext *c);
+    QSGDistanceFieldGlyphCacheManager();
     ~QSGDistanceFieldGlyphCacheManager();
 
     QSGDistanceFieldGlyphCache *cache(const QRawFont &font);
-
-    QSGGlyphNode::AntialiasingMode defaultAntialiasingMode() const { return m_defaultAntialiasingMode; }
-    void setDefaultAntialiasingMode(QSGGlyphNode::AntialiasingMode mode) { m_defaultAntialiasingMode = mode; }
+    void insertCache(const QRawFont &font, QSGDistanceFieldGlyphCache *cache);
 
     ThresholdFunc thresholdFunc() const { return m_threshold_func; }
     void setThresholdFunc(ThresholdFunc func) { m_threshold_func = func; }
@@ -75,8 +73,6 @@ public:
 private:
     QHash<QString, QSGDistanceFieldGlyphCache *> m_caches;
 
-    QSGContext *sgCtx;
-
     QSGGlyphNode::AntialiasingMode m_defaultAntialiasingMode;
     ThresholdFunc m_threshold_func;
     AntialiasingSpreadFunc m_antialiasingSpread_func;