call onGetUPEM to subclasses can optimize it, and place default behavior

(calling getAdvancedTypefaceMetrics) in base impl.

This allows us to remove SkFontHost::GetUnitsPerEm entirely
Review URL: https://codereview.chromium.org/12915003

git-svn-id: http://skia.googlecode.com/svn/trunk@8295 2bbb7eff-a529-9590-31e7-b0007b416f81

3 files changed, 19 insertions, 18 deletions

diff --git a/src/core/SkTypeface.cpp b/src/core/SkTypeface.cpp
index 54566c9242..9f72faa3de 100644
--- a/src/core/SkTypeface.cpp
+++ b/src/core/SkTypeface.cpp
@@ -132,32 +132,33 @@ SkStream* SkTypeface::openStream(int* ttcIndex) const {
 }
 
 int SkTypeface::getUnitsPerEm() const {
+    // should we try to cache this in the base-class?
+    return this->onGetUPEM();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkFontDescriptor.h"
+
+int SkTypeface::onGetUPEM() const {
     int upem = 0;
 
-#ifdef SK_BUILD_FOR_ANDROID
-    upem = SkFontHost::GetUnitsPerEm(fUniqueID);
-#else
     SkAdvancedTypefaceMetrics* metrics;
     metrics = this->getAdvancedTypefaceMetrics(
-                                 SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo,
-                                 NULL, 0);
+                             SkAdvancedTypefaceMetrics::kNo_PerGlyphInfo,
+                             NULL, 0);
     if (metrics) {
         upem = metrics->fEmSize;
         metrics->unref();
     }
-#endif
     return upem;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-///////////////////////////////////////////////////////////////////////////////
-
-#include "SkFontDescriptor.h"
-
-int SkTypeface::onGetUPEM() const { return 0; }
 int SkTypeface::onGetTableTags(SkFontTableTag tags[]) const { return 0; }
 size_t SkTypeface::onGetTableData(SkFontTableTag, size_t offset,
                                   size_t length, void* data) const { return 0; }
 void SkTypeface::onGetFontDescriptor(SkFontDescriptor* desc) const {
     desc->setStyle(this->style());
 }
+
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 6a36f4407a..4aaf31ba0c 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -698,8 +698,7 @@ void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
 #endif
 }
 
-#ifdef SK_BUILD_FOR_ANDROID
-uint32_t SkFontHost::GetUnitsPerEm(SkFontID fontID) {
+int SkTypeface_FreeType::onGetUPEM() const {
     SkAutoMutexAcquire ac(gFTMutex);
     FT_Library libInit = NULL;
     if (gFTCount == 0) {
@@ -708,17 +707,16 @@ uint32_t SkFontHost::GetUnitsPerEm(SkFontID fontID) {
         libInit = gFTLibrary;
     }
     SkAutoTCallIProc<struct FT_LibraryRec_, FT_Done_FreeType> ftLib(libInit);
-    SkFaceRec *rec = ref_ft_face(fontID);
-    uint16_t unitsPerEm = 0;
+    SkFaceRec *rec = ref_ft_face(this->uniqueID());
+    int unitsPerEm = 0;
 
     if (rec != NULL && rec->fFace != NULL) {
         unitsPerEm = rec->fFace->units_per_EM;
         unref_ft_face(rec->fFace);
     }
 
-    return (uint32_t)unitsPerEm;
+    return unitsPerEm;
 }
-#endif
 
 SkScalerContext_FreeType::SkScalerContext_FreeType(SkTypeface* typeface,
                                                    const SkDescriptor* desc)
diff --git a/src/ports/SkFontHost_FreeType_common.h b/src/ports/SkFontHost_FreeType_common.h
index a9b6be5f66..00b3bd6a7a 100644
--- a/src/ports/SkFontHost_FreeType_common.h
+++ b/src/ports/SkFontHost_FreeType_common.h
@@ -56,6 +56,8 @@ protected:
     virtual SkAdvancedTypefaceMetrics* onGetAdvancedTypefaceMetrics(
                                 SkAdvancedTypefaceMetrics::PerGlyphInfo,
                                 const uint32_t*, uint32_t) const SK_OVERRIDE;
+    virtual int onGetUPEM() const SK_OVERRIDE;
+
 private:
     typedef SkTypeface INHERITED;
 };