Add a SkTypeface::CreateForChars() function.

This allows us to do font fallback for strange scripts.
Added empty stubs to the implementations on all platforms.

Patch-by: Evan Martin
Signed-off-by: Adam Langley

http://codereview.appspot.com/950041

git-svn-id: http://skia.googlecode.com/svn/trunk@557 2bbb7eff-a529-9590-31e7-b0007b416f81

11 files changed, 44 insertions, 15 deletions

diff --git a/include/core/SkFontHost.h b/include/core/SkFontHost.h
index ec345839ad..ca538d16c1 100644
--- a/include/core/SkFontHost.h
+++ b/include/core/SkFontHost.h
@@ -59,14 +59,16 @@ typedef uint32_t SkFontTableTag;
 class SkFontHost {
 public:
     /** Return a new, closest matching typeface given either an existing family
-        (specified by a typeface in that family) or by a familyName, and a
-        requested style.
-        1) If familyFace is null, use famillyName.
-        2) If famillyName is null, use familyFace.
-        3) If both are null, return the default font that best matches style
+        (specified by a typeface in that family) or by a familyName and a
+        requested style, or by a set of Unicode codepoitns to cover in a given
+        style.
+        1) If familyFace is null, use familyName.
+        2) If familyName is null, use data (UTF-16 to cover).
+        3) If all are null, return the default font that best matches style
      */
     static SkTypeface* CreateTypeface(const SkTypeface* familyFace,
-                                      const char famillyName[],
+                                      const char familyName[],
+                                      const void* data, size_t bytelength,
                                       SkTypeface::Style style);
 
     /** Return a new typeface given the data buffer. If the data does not
diff --git a/include/core/SkTypeface.h b/include/core/SkTypeface.h
index bf783a3ff7..d4af700b34 100644
--- a/include/core/SkTypeface.h
+++ b/include/core/SkTypeface.h
@@ -83,6 +83,18 @@ public:
     */
     static SkTypeface* CreateFromName(const char familyName[], Style style);
 
+    /** Return a new reference to the typeface that covers a set of Unicode
+        code points with the specified Style. Use this call if you want to
+        pick any font that covers a given string of text.
+
+        @param data        UTF-16 characters
+        @param bytelength  length of data, in bytes
+        @return reference to the closest-matching typeface. Call must call
+                unref() when they are done.
+    */
+    static SkTypeface* CreateForChars(const void* data, size_t bytelength,
+                                      Style s);
+
     /** Return a new reference to the typeface that most closely matches the
         requested typeface and specified Style. Use this call if you want to
         pick a new style from the same family of the existing typeface.
diff --git a/src/core/SkTypeface.cpp b/src/core/SkTypeface.cpp
index 65052c1cec..44337610c8 100644
--- a/src/core/SkTypeface.cpp
+++ b/src/core/SkTypeface.cpp
@@ -12,8 +12,9 @@ uint32_t SkTypeface::UniqueID(const SkTypeface* face) {
     static uint32_t gDefaultFontID;
     
     if (0 == gDefaultFontID) {
-        SkTypeface* defaultFace = SkFontHost::CreateTypeface(NULL, NULL,
-                                                    SkTypeface::kNormal);
+        SkTypeface* defaultFace =
+                SkFontHost::CreateTypeface(NULL, NULL, NULL, 0,
+                                           SkTypeface::kNormal);
         SkASSERT(defaultFace);
         gDefaultFontID = defaultFace->uniqueID();
         defaultFace->unref();
@@ -28,11 +29,16 @@ bool SkTypeface::Equal(const SkTypeface* facea, const SkTypeface* faceb) {
 ///////////////////////////////////////////////////////////////////////////////
 
 SkTypeface* SkTypeface::CreateFromName(const char name[], Style style) {
-    return SkFontHost::CreateTypeface(NULL, name, style);
+    return SkFontHost::CreateTypeface(NULL, name, NULL, 0, style);
+}
+
+SkTypeface* SkTypeface::CreateForChars(const void* data, size_t bytelength,
+                                       Style s) {
+    return SkFontHost::CreateTypeface(NULL, NULL, data, bytelength, s);
 }
 
 SkTypeface* SkTypeface::CreateFromTypeface(const SkTypeface* family, Style s) {
-    return SkFontHost::CreateTypeface(family, NULL, s);
+    return SkFontHost::CreateTypeface(family, NULL, NULL, NULL, s);
 }
 
 SkTypeface* SkTypeface::CreateFromStream(SkStream* stream) {
diff --git a/src/ports/SkFontHost_FONTPATH.cpp b/src/ports/SkFontHost_FONTPATH.cpp
index 211ed90f66..308adf8070 100644
--- a/src/ports/SkFontHost_FONTPATH.cpp
+++ b/src/ports/SkFontHost_FONTPATH.cpp
@@ -241,6 +241,7 @@ static uint32_t ptr2uint32(const void* p)
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                        const char familyName[],
+                                       const void* data, size_t bytelength,
                                        SkTypeface::Style style)
 {
     const FontFamilyRec* family;
diff --git a/src/ports/SkFontHost_android.cpp b/src/ports/SkFontHost_android.cpp
index f50e35952c..3eb755d468 100644
--- a/src/ports/SkFontHost_android.cpp
+++ b/src/ports/SkFontHost_android.cpp
@@ -542,7 +542,7 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
                 for (int j = i; j >= 0; --j) {
                     if (rec[j].fNames != NULL) {
                         return SkFontHost::CreateTypeface(NULL,
-                                    rec[j].fNames[0], (SkTypeface::Style)style);
+                                    rec[j].fNames[0], NULL, 0, (SkTypeface::Style)style);
                     }
                 }
             }
@@ -555,6 +555,7 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                        const char familyName[],
+                                       const void* data, size_t bytelength,
                                        SkTypeface::Style style) {
     load_system_fonts();
 
diff --git a/src/ports/SkFontHost_fontconfig.cpp b/src/ports/SkFontHost_fontconfig.cpp
index 83a75ce74d..d1da8d1589 100644
--- a/src/ports/SkFontHost_fontconfig.cpp
+++ b/src/ports/SkFontHost_fontconfig.cpp
@@ -219,6 +219,7 @@ static unsigned FileIdFromFilename(const char* filename)
 // static
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                        const char familyName[],
+                                       const void* data, size_t bytelength,
                                        SkTypeface::Style style)
 {
     const char* resolved_family_name = NULL;
diff --git a/src/ports/SkFontHost_linux.cpp b/src/ports/SkFontHost_linux.cpp
index c838d8ca85..ebebd08bda 100644
--- a/src/ports/SkFontHost_linux.cpp
+++ b/src/ports/SkFontHost_linux.cpp
@@ -509,14 +509,14 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
                 // backup until we hit the fNames
                 for (int j = i; j >= 0; --j) {
                     if (rec[j].fNames != NULL) {
-                        return SkFontHost::CreateTypeface(NULL, rec[j].fNames[0],
+                        return SkFontHost::CreateTypeface(NULL, rec[j].fNames[0], NULL, 0,
                                                           (SkTypeface::Style)style);
                     }
                 }
             }
         }
     }
-    return SkFontHost::CreateTypeface(NULL, NULL, (SkTypeface::Style)style);
+    return SkFontHost::CreateTypeface(NULL, NULL, NULL, 0, (SkTypeface::Style)style);
 #endif
     sk_throw();
     return NULL;
@@ -526,6 +526,7 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                        const char familyName[],
+                                       const void* data, size_t bytelength,
                                        SkTypeface::Style style) {
     load_system_fonts();
     
diff --git a/src/ports/SkFontHost_mac.cpp b/src/ports/SkFontHost_mac.cpp
index a652d9d3d1..a0239e224c 100755
--- a/src/ports/SkFontHost_mac.cpp
+++ b/src/ports/SkFontHost_mac.cpp
@@ -492,7 +492,9 @@ uint32_t SkFontHost::NextLogicalFont(uint32_t fontID) {
 }
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
-                            const char familyName[], SkTypeface::Style style) {
+                            const char familyName[],
+                            const void* data, size_t bytelength,
+                            SkTypeface::Style style) {
     // todo: we don't know how to respect style bits
     if (NULL == familyName && NULL != familyFace) {
         familyFace->ref();
diff --git a/src/ports/SkFontHost_none.cpp b/src/ports/SkFontHost_none.cpp
index 9132c74e61..ae56ae4e14 100644
--- a/src/ports/SkFontHost_none.cpp
+++ b/src/ports/SkFontHost_none.cpp
@@ -17,6 +17,7 @@
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                      const char famillyName[],
+                                     const void* data, size_t bytelength,
                                      SkTypeface::Style style) {
     SkASSERT(!"SkFontHost::FindTypeface unimplemented");
     return NULL;
diff --git a/src/ports/SkFontHost_simple.cpp b/src/ports/SkFontHost_simple.cpp
index deda04d090..9e126bccf8 100644
--- a/src/ports/SkFontHost_simple.cpp
+++ b/src/ports/SkFontHost_simple.cpp
@@ -507,7 +507,7 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
                 for (int j = i; j >= 0; --j) {
                     if (rec[j].fNames != NULL) {
                         return SkFontHost::CreateTypeface(NULL,
-                                    rec[j].fNames[0], (SkTypeface::Style)style);
+                                    rec[j].fNames[0], NULL, 0, (SkTypeface::Style)style);
                     }
                 }
             }
@@ -520,6 +520,7 @@ SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
 
 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                        const char familyName[],
+                                       const void* data, size_t bytelength,
                                        SkTypeface::Style style) {
     load_system_fonts();
 
diff --git a/src/ports/SkFontHost_win.cpp b/src/ports/SkFontHost_win.cpp
index 4533d3c0e4..f9ed7ad67c 100644
--- a/src/ports/SkFontHost_win.cpp
+++ b/src/ports/SkFontHost_win.cpp
@@ -540,6 +540,7 @@ SkScalerContext* SkFontHost::CreateScalerContext(const SkDescriptor* desc) {
 

 SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,

                                        const char familyName[],

+                                       const void* data, size_t bytelength,

                                        SkTypeface::Style style) {

 

     SkAutoMutexAcquire  ac(gFTMutex);