SkFontMgr.h is a core header.

Change-Id: Idad3c8b6961bb617afedb8e353060b9044edaee3
Reviewed-on: https://skia-review.googlesource.com/136066
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Auto-Submit: Hal Canary <halcanary@google.com>

1 files changed, 164 insertions, 0 deletions

diff --git a/include/core/SkFontMgr.h b/include/core/SkFontMgr.h
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+++ b/include/core/SkFontMgr.h
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+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkFontMgr_DEFINED
+#define SkFontMgr_DEFINED
+
+#include "SkFontArguments.h"
+#include "SkFontStyle.h"
+#include "SkRefCnt.h"
+#include "SkTypes.h"
+
+class SkData;
+class SkFontData;
+class SkStreamAsset;
+class SkString;
+class SkTypeface;
+
+class SK_API SkFontStyleSet : public SkRefCnt {
+public:
+    virtual int count() = 0;
+    virtual void getStyle(int index, SkFontStyle*, SkString* style) = 0;
+    virtual SkTypeface* createTypeface(int index) = 0;
+    virtual SkTypeface* matchStyle(const SkFontStyle& pattern) = 0;
+
+    static SkFontStyleSet* CreateEmpty();
+
+protected:
+    SkTypeface* matchStyleCSS3(const SkFontStyle& pattern);
+
+private:
+    typedef SkRefCnt INHERITED;
+};
+
+class SK_API SkFontMgr : public SkRefCnt {
+public:
+    int countFamilies() const;
+    void getFamilyName(int index, SkString* familyName) const;
+    SkFontStyleSet* createStyleSet(int index) const;
+
+    /**
+     *  The caller must call unref() on the returned object.
+     *  Never returns NULL; will return an empty set if the name is not found.
+     *
+     *  Passing nullptr as the parameter will return the default system family.
+     *  Note that most systems don't have a default system family, so passing nullptr will often
+     *  result in the empty set.
+     *
+     *  It is possible that this will return a style set not accessible from
+     *  createStyleSet(int) due to hidden or auto-activated fonts.
+     */
+    SkFontStyleSet* matchFamily(const char familyName[]) const;
+
+    /**
+     *  Find the closest matching typeface to the specified familyName and style
+     *  and return a ref to it. The caller must call unref() on the returned
+     *  object. Will never return NULL, as it will return the default font if
+     *  no matching font is found.
+     *
+     *  Passing |nullptr| as the parameter for |familyName| will return the
+     *  default system font.
+     *
+     *  It is possible that this will return a style set not accessible from
+     *  createStyleSet(int) or matchFamily(const char[]) due to hidden or
+     *  auto-activated fonts.
+     */
+    SkTypeface* matchFamilyStyle(const char familyName[], const SkFontStyle&) const;
+
+    /**
+     *  Use the system fallback to find a typeface for the given character.
+     *  Note that bcp47 is a combination of ISO 639, 15924, and 3166-1 codes,
+     *  so it is fine to just pass a ISO 639 here.
+     *
+     *  Will return NULL if no family can be found for the character
+     *  in the system fallback.
+     *
+     *  Passing |nullptr| as the parameter for |familyName| will return the
+     *  default system font.
+     *
+     *  bcp47[0] is the least significant fallback, bcp47[bcp47Count-1] is the
+     *  most significant. If no specified bcp47 codes match, any font with the
+     *  requested character will be matched.
+     */
+    SkTypeface* matchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
+                                          const char* bcp47[], int bcp47Count,
+                                          SkUnichar character) const;
+
+    SkTypeface* matchFaceStyle(const SkTypeface*, const SkFontStyle&) const;
+
+    /**
+     *  Create a typeface for the specified data and TTC index (pass 0 for none)
+     *  or NULL if the data is not recognized. The caller must call unref() on
+     *  the returned object if it is not null.
+     */
+    sk_sp<SkTypeface> makeFromData(sk_sp<SkData>, int ttcIndex = 0) const;
+
+    /**
+     *  Create a typeface for the specified stream and TTC index
+     *  (pass 0 for none) or NULL if the stream is not recognized. The caller
+     *  must call unref() on the returned object if it is not null.
+     */
+    sk_sp<SkTypeface> makeFromStream(std::unique_ptr<SkStreamAsset>, int ttcIndex = 0) const;
+
+    /* Experimental, API subject to change. */
+    sk_sp<SkTypeface> makeFromStream(std::unique_ptr<SkStreamAsset>, const SkFontArguments&) const;
+
+    /**
+     *  Create a typeface from the specified font data.
+     *  Will return NULL if the typeface could not be created.
+     *  The caller must call unref() on the returned object if it is not null.
+     */
+    sk_sp<SkTypeface> makeFromFontData(std::unique_ptr<SkFontData>) const;
+
+    /**
+     *  Create a typeface for the specified fileName and TTC index
+     *  (pass 0 for none) or NULL if the file is not found, or its contents are
+     *  not recognized. The caller must call unref() on the returned object
+     *  if it is not null.
+     */
+    sk_sp<SkTypeface> makeFromFile(const char path[], int ttcIndex = 0) const;
+
+    sk_sp<SkTypeface> legacyMakeTypeface(const char familyName[], SkFontStyle style) const;
+
+    /** Return the default fontmgr. */
+    static sk_sp<SkFontMgr> RefDefault();
+
+protected:
+    virtual int onCountFamilies() const = 0;
+    virtual void onGetFamilyName(int index, SkString* familyName) const = 0;
+    virtual SkFontStyleSet* onCreateStyleSet(int index)const  = 0;
+
+    /** May return NULL if the name is not found. */
+    virtual SkFontStyleSet* onMatchFamily(const char familyName[]) const = 0;
+
+    virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
+                                           const SkFontStyle&) const = 0;
+    virtual SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
+                                                    const char* bcp47[], int bcp47Count,
+                                                    SkUnichar character) const = 0;
+    virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
+                                         const SkFontStyle&) const = 0;
+
+    virtual sk_sp<SkTypeface> onMakeFromData(sk_sp<SkData>, int ttcIndex) const = 0;
+    virtual sk_sp<SkTypeface> onMakeFromStreamIndex(std::unique_ptr<SkStreamAsset>,
+                                                    int ttcIndex) const = 0;
+    virtual sk_sp<SkTypeface> onMakeFromStreamArgs(std::unique_ptr<SkStreamAsset>,
+                                                   const SkFontArguments&) const;
+    virtual sk_sp<SkTypeface> onMakeFromFontData(std::unique_ptr<SkFontData>) const;
+    virtual sk_sp<SkTypeface> onMakeFromFile(const char path[], int ttcIndex) const = 0;
+
+    virtual sk_sp<SkTypeface> onLegacyMakeTypeface(const char familyName[], SkFontStyle) const = 0;
+
+private:
+
+    /** Implemented by porting layer to return the default factory. */
+    static sk_sp<SkFontMgr> Factory();
+
+    typedef SkRefCnt INHERITED;
+};
+
+#endif