Refactor SkFontHost_linux into SkFontMgr_custom.

Review URL: https://codereview.chromium.org/1184923002

1 files changed, 514 insertions, 0 deletions

diff --git a/src/ports/SkFontMgr_custom.cpp b/src/ports/SkFontMgr_custom.cpp
new file mode 100644
index 0000000000..49744a1f63
--- /dev/null
+++ b/src/ports/SkFontMgr_custom.cpp
@@ -0,0 +1,514 @@
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkFontHost_FreeType_common.h"
+#include "SkFontDescriptor.h"
+#include "SkFontMgr.h"
+#include "SkFontMgr_custom.h"
+#include "SkDescriptor.h"
+#include "SkOSFile.h"
+#include "SkPaint.h"
+#include "SkRTConf.h"
+#include "SkString.h"
+#include "SkStream.h"
+#include "SkThread.h"
+#include "SkTSearch.h"
+#include "SkTypefaceCache.h"
+#include "SkTArray.h"
+
+#include <limits>
+
+/** The base SkTypeface implementation for the custom font manager. */
+class SkTypeface_Custom : public SkTypeface_FreeType {
+public:
+    SkTypeface_Custom(const SkFontStyle& style, bool isFixedPitch,
+                      bool sysFont, const SkString familyName, int index)
+        : INHERITED(style, SkTypefaceCache::NewFontID(), isFixedPitch)
+        , fIsSysFont(sysFont), fFamilyName(familyName), fIndex(index)
+    { }
+
+    bool isSysFont() const { return fIsSysFont; }
+
+protected:
+    void onGetFamilyName(SkString* familyName) const override {
+        *familyName = fFamilyName;
+    }
+
+    void onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const override {
+        desc->setFamilyName(fFamilyName.c_str());
+        *isLocal = !this->isSysFont();
+    }
+
+    int getIndex() const { return fIndex; }
+
+private:
+    const bool fIsSysFont;
+    const SkString fFamilyName;
+    const int fIndex;
+
+    typedef SkTypeface_FreeType INHERITED;
+};
+
+/** The empty SkTypeface implementation for the custom font manager.
+ *  Used as the last resort fallback typeface.
+ */
+class SkTypeface_Empty : public SkTypeface_Custom {
+public:
+    SkTypeface_Empty() : INHERITED(SkFontStyle(), false, true, SkString(), 0) {}
+
+protected:
+    SkStreamAsset* onOpenStream(int*) const override { return NULL; }
+
+private:
+    typedef SkTypeface_Custom INHERITED;
+};
+
+/** The stream SkTypeface implementation for the custom font manager. */
+class SkTypeface_Stream : public SkTypeface_Custom {
+public:
+    SkTypeface_Stream(const SkFontStyle& style, bool isFixedPitch, bool sysFont,
+                      const SkString familyName, SkStreamAsset* stream, int index)
+        : INHERITED(style, isFixedPitch, sysFont, familyName, index)
+        , fStream(stream)
+    { }
+
+protected:
+    SkStreamAsset* onOpenStream(int* ttcIndex) const override {
+        *ttcIndex = this->getIndex();
+        return fStream->duplicate();
+    }
+
+private:
+    const SkAutoTDelete<const SkStreamAsset> fStream;
+
+    typedef SkTypeface_Custom INHERITED;
+};
+
+/** The file SkTypeface implementation for the custom font manager. */
+class SkTypeface_File : public SkTypeface_Custom {
+public:
+    SkTypeface_File(const SkFontStyle& style, bool isFixedPitch, bool sysFont,
+                    const SkString familyName, const char path[], int index)
+        : INHERITED(style, isFixedPitch, sysFont, familyName, index)
+        , fPath(path)
+    { }
+
+protected:
+    SkStreamAsset* onOpenStream(int* ttcIndex) const override {
+        *ttcIndex = this->getIndex();
+        return SkStream::NewFromFile(fPath.c_str());
+    }
+
+private:
+    SkString fPath;
+
+    typedef SkTypeface_Custom INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ *  SkFontStyleSet_Custom
+ *
+ *  This class is used by SkFontMgr_Custom to hold SkTypeface_Custom families.
+ */
+class SkFontStyleSet_Custom : public SkFontStyleSet {
+public:
+    explicit SkFontStyleSet_Custom(const SkString familyName) : fFamilyName(familyName) { }
+
+    /** Should only be called during the inital build phase. */
+    void appendTypeface(SkTypeface_Custom* typeface) {
+        fStyles.push_back().reset(typeface);
+    }
+
+    int count() override {
+        return fStyles.count();
+    }
+
+    void getStyle(int index, SkFontStyle* style, SkString* name) override {
+        SkASSERT(index < fStyles.count());
+        bool bold = fStyles[index]->isBold();
+        bool italic = fStyles[index]->isItalic();
+        *style = SkFontStyle(bold ? SkFontStyle::kBold_Weight : SkFontStyle::kNormal_Weight,
+                             SkFontStyle::kNormal_Width,
+                             italic ? SkFontStyle::kItalic_Slant : SkFontStyle::kUpright_Slant);
+        name->reset();
+    }
+
+    SkTypeface* createTypeface(int index) override {
+        SkASSERT(index < fStyles.count());
+        return SkRef(fStyles[index].get());
+    }
+
+    static int match_score(const SkFontStyle& pattern, const SkFontStyle& candidate) {
+        int score = 0;
+        score += (pattern.width() - candidate.width()) * 100;
+        score += (pattern.isItalic() == candidate.isItalic()) ? 0 : 1000;
+        score += pattern.weight() - candidate.weight();
+        return score;
+    }
+
+    SkTypeface* matchStyle(const SkFontStyle& pattern) override {
+        if (0 == fStyles.count()) {
+            return NULL;
+        }
+
+        SkTypeface_Custom* closest = fStyles[0];
+        int minScore = std::numeric_limits<int>::max();
+        for (int i = 0; i < fStyles.count(); ++i) {
+            bool bold = fStyles[i]->isBold();
+            bool italic = fStyles[i]->isItalic();
+            SkFontStyle style = SkFontStyle(bold ? SkFontStyle::kBold_Weight
+                                                 : SkFontStyle::kNormal_Weight,
+                                            SkFontStyle::kNormal_Width,
+                                            italic ? SkFontStyle::kItalic_Slant
+                                                   : SkFontStyle::kUpright_Slant);
+
+            int score = match_score(pattern, style);
+            if (score < minScore) {
+                closest = fStyles[i];
+                minScore = score;
+            }
+        }
+        return SkRef(closest);
+    }
+
+    SkString getFamilyName() { return fFamilyName; }
+
+private:
+    SkTArray<SkAutoTUnref<SkTypeface_Custom>, true> fStyles;
+    SkString fFamilyName;
+
+    friend class SkFontMgr_Custom;
+};
+
+/**
+ *  SkFontMgr_Custom
+ *
+ *  This class is essentially a collection of SkFontStyleSet_Custom,
+ *  one SkFontStyleSet_Custom for each family. This class may be modified
+ *  to load fonts from any source by changing the initialization.
+ */
+class SkFontMgr_Custom : public SkFontMgr {
+public:
+    typedef SkTArray<SkAutoTUnref<SkFontStyleSet_Custom>, true> Families;
+    class SystemFontLoader {
+    public:
+        virtual ~SystemFontLoader() { }
+        virtual void loadSystemFonts(const SkTypeface_FreeType::Scanner&, Families*) const = 0;
+    };
+    explicit SkFontMgr_Custom(const SystemFontLoader& loader) : fDefaultFamily(NULL) {
+        loader.loadSystemFonts(fScanner, &fFamilies);
+
+        // Try to pick a default font.
+        static const char* defaultNames[] = {
+            "Arial", "Verdana", "Times New Roman", "Droid Sans", NULL
+        };
+        for (size_t i = 0; i < SK_ARRAY_COUNT(defaultNames); ++i) {
+            SkFontStyleSet_Custom* set = this->onMatchFamily(defaultNames[i]);
+            if (NULL == set) {
+                continue;
+            }
+
+            SkTypeface* tf = set->matchStyle(SkFontStyle(SkFontStyle::kNormal_Weight,
+                                                         SkFontStyle::kNormal_Width,
+                                                         SkFontStyle::kUpright_Slant));
+            if (NULL == tf) {
+                continue;
+            }
+
+            fDefaultFamily = set;
+            break;
+        }
+        if (NULL == fDefaultFamily) {
+            fDefaultFamily = fFamilies[0];
+        }
+    }
+
+protected:
+    int onCountFamilies() const override {
+        return fFamilies.count();
+    }
+
+    void onGetFamilyName(int index, SkString* familyName) const override {
+        SkASSERT(index < fFamilies.count());
+        familyName->set(fFamilies[index]->getFamilyName());
+    }
+
+    SkFontStyleSet_Custom* onCreateStyleSet(int index) const override {
+        SkASSERT(index < fFamilies.count());
+        return SkRef(fFamilies[index].get());
+    }
+
+    SkFontStyleSet_Custom* onMatchFamily(const char familyName[]) const override {
+        for (int i = 0; i < fFamilies.count(); ++i) {
+            if (fFamilies[i]->getFamilyName().equals(familyName)) {
+                return SkRef(fFamilies[i].get());
+            }
+        }
+        return NULL;
+    }
+
+    SkTypeface* onMatchFamilyStyle(const char familyName[],
+                                   const SkFontStyle& fontStyle) const override
+    {
+        SkAutoTUnref<SkFontStyleSet> sset(this->matchFamily(familyName));
+        return sset->matchStyle(fontStyle);
+    }
+
+    SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
+                                            const char* bcp47[], int bcp47Count,
+                                            SkUnichar character) const override
+    {
+        return NULL;
+    }
+
+    SkTypeface* onMatchFaceStyle(const SkTypeface* familyMember,
+                                 const SkFontStyle& fontStyle) const override
+    {
+        for (int i = 0; i < fFamilies.count(); ++i) {
+            for (int j = 0; j < fFamilies[i]->fStyles.count(); ++j) {
+                if (fFamilies[i]->fStyles[j] == familyMember) {
+                    return fFamilies[i]->matchStyle(fontStyle);
+                }
+            }
+        }
+        return NULL;
+    }
+
+    SkTypeface* onCreateFromData(SkData* data, int ttcIndex) const override {
+        return this->createFromStream(new SkMemoryStream(data), ttcIndex);
+    }
+
+    SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
+        SkAutoTDelete<SkStreamAsset> stream(bareStream);
+        if (NULL == stream || stream->getLength() <= 0) {
+            return NULL;
+        }
+
+        bool isFixedPitch;
+        SkFontStyle style;
+        SkString name;
+        if (fScanner.scanFont(stream, ttcIndex, &name, &style, &isFixedPitch, NULL)) {
+            return SkNEW_ARGS(SkTypeface_Stream, (style, isFixedPitch, false, name,
+                                                  stream.detach(), ttcIndex));
+        } else {
+            return NULL;
+        }
+    }
+
+    SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
+        SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
+        return stream.get() ? this->createFromStream(stream.detach(), ttcIndex) : NULL;
+    }
+
+    SkTypeface* onLegacyCreateTypeface(const char familyName[], unsigned styleBits) const override {
+        SkTypeface::Style oldStyle = (SkTypeface::Style)styleBits;
+        SkFontStyle style = SkFontStyle(oldStyle & SkTypeface::kBold
+                                                 ? SkFontStyle::kBold_Weight
+                                                 : SkFontStyle::kNormal_Weight,
+                                        SkFontStyle::kNormal_Width,
+                                        oldStyle & SkTypeface::kItalic
+                                                 ? SkFontStyle::kItalic_Slant
+                                                 : SkFontStyle::kUpright_Slant);
+        SkTypeface* tf = NULL;
+
+        if (familyName) {
+            tf = this->onMatchFamilyStyle(familyName, style);
+        }
+
+        if (NULL == tf) {
+            tf = fDefaultFamily->matchStyle(style);
+        }
+
+        return SkSafeRef(tf);
+    }
+
+private:
+    Families fFamilies;
+    SkFontStyleSet_Custom* fDefaultFamily;
+    SkTypeface_FreeType::Scanner fScanner;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class DirectorySystemFontLoader : public SkFontMgr_Custom::SystemFontLoader {
+public:
+    DirectorySystemFontLoader(const char* dir) : fBaseDirectory(dir) { }
+
+    void loadSystemFonts(const SkTypeface_FreeType::Scanner& scanner,
+                         SkFontMgr_Custom::Families* families) const override
+    {
+        load_directory_fonts(scanner, fBaseDirectory, ".ttf", families);
+        load_directory_fonts(scanner, fBaseDirectory, ".ttc", families);
+        load_directory_fonts(scanner, fBaseDirectory, ".otf", families);
+        load_directory_fonts(scanner, fBaseDirectory, ".pfb", families);
+
+        if (families->empty()) {
+            SkFontStyleSet_Custom* family = new SkFontStyleSet_Custom(SkString());
+            families->push_back().reset(family);
+            family->appendTypeface(SkNEW(SkTypeface_Empty));
+        }
+    }
+
+private:
+    static SkFontStyleSet_Custom* find_family(SkFontMgr_Custom::Families& families,
+                                              const char familyName[])
+    {
+       for (int i = 0; i < families.count(); ++i) {
+            if (families[i]->getFamilyName().equals(familyName)) {
+                return families[i].get();
+            }
+        }
+        return NULL;
+    }
+
+    static void load_directory_fonts(const SkTypeface_FreeType::Scanner& scanner,
+                                     const SkString& directory, const char* suffix,
+                                     SkFontMgr_Custom::Families* families)
+    {
+        SkOSFile::Iter iter(directory.c_str(), suffix);
+        SkString name;
+
+        while (iter.next(&name, false)) {
+            SkString filename(SkOSPath::Join(directory.c_str(), name.c_str()));
+            SkAutoTDelete<SkStream> stream(SkStream::NewFromFile(filename.c_str()));
+            if (!stream.get()) {
+                SkDebugf("---- failed to open <%s>\n", filename.c_str());
+                continue;
+            }
+
+            int numFaces;
+            if (!scanner.recognizedFont(stream, &numFaces)) {
+                SkDebugf("---- failed to open <%s> as a font\n", filename.c_str());
+                continue;
+            }
+
+            for (int faceIndex = 0; faceIndex < numFaces; ++faceIndex) {
+                bool isFixedPitch;
+                SkString realname;
+                SkFontStyle style = SkFontStyle(); // avoid uninitialized warning
+                if (!scanner.scanFont(stream, faceIndex, &realname, &style, &isFixedPitch, NULL)) {
+                    SkDebugf("---- failed to open <%s> <%d> as a font\n",
+                             filename.c_str(), faceIndex);
+                    continue;
+                }
+
+                SkTypeface_Custom* tf = SkNEW_ARGS(SkTypeface_File, (
+                                                    style,
+                                                    isFixedPitch,
+                                                    true,  // system-font (cannot delete)
+                                                    realname,
+                                                    filename.c_str(),
+                                                    faceIndex));
+
+                SkFontStyleSet_Custom* addTo = find_family(*families, realname.c_str());
+                if (NULL == addTo) {
+                    addTo = new SkFontStyleSet_Custom(realname);
+                    families->push_back().reset(addTo);
+                }
+                addTo->appendTypeface(tf);
+            }
+        }
+
+        SkOSFile::Iter dirIter(directory.c_str());
+        while (dirIter.next(&name, true)) {
+            if (name.startsWith(".")) {
+                continue;
+            }
+            SkString dirname(SkOSPath::Join(directory.c_str(), name.c_str()));
+            load_directory_fonts(scanner, dirname, suffix, families);
+        }
+    }
+
+    SkString fBaseDirectory;
+};
+
+SK_API SkFontMgr* SkFontMgr_New_Custom_Directory(const char* dir) {
+    return new SkFontMgr_Custom(DirectorySystemFontLoader(dir));
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct SkEmbeddedResource { const uint8_t* data; size_t size; };
+struct SkEmbeddedResourceHeader { const SkEmbeddedResource* entries; int count; };
+
+class EmbeddedSystemFontLoader : public SkFontMgr_Custom::SystemFontLoader {
+public:
+    EmbeddedSystemFontLoader(const SkEmbeddedResourceHeader* header) : fHeader(header) { }
+
+    void loadSystemFonts(const SkTypeface_FreeType::Scanner& scanner,
+                         SkFontMgr_Custom::Families* families) const override
+    {
+        for (int i = 0; i < fHeader->count; ++i) {
+            const SkEmbeddedResource& fontEntry = fHeader->entries[i];
+            load_embedded_font(scanner, fontEntry.data, fontEntry.size, i, families);
+        }
+
+        if (families->empty()) {
+            SkFontStyleSet_Custom* family = new SkFontStyleSet_Custom(SkString());
+            families->push_back().reset(family);
+            family->appendTypeface(SkNEW(SkTypeface_Empty));
+        }
+    }
+
+private:
+    static SkFontStyleSet_Custom* find_family(SkFontMgr_Custom::Families& families,
+                                              const char familyName[])
+    {
+       for (int i = 0; i < families.count(); ++i) {
+            if (families[i]->getFamilyName().equals(familyName)) {
+                return families[i].get();
+            }
+        }
+        return NULL;
+    }
+
+    static void load_embedded_font(const SkTypeface_FreeType::Scanner& scanner,
+                                   const uint8_t* data, size_t size, int index,
+                                   SkFontMgr_Custom::Families* families)
+    {
+        SkAutoTDelete<SkMemoryStream> stream(new SkMemoryStream(data, size, false));
+
+        int numFaces;
+        if (!scanner.recognizedFont(stream, &numFaces)) {
+            SkDebugf("---- failed to open <%d> as a font\n", index);
+            return;
+        }
+
+        for (int faceIndex = 0; faceIndex < numFaces; ++faceIndex) {
+            bool isFixedPitch;
+            SkString realname;
+            SkFontStyle style = SkFontStyle(); // avoid uninitialized warning
+            if (!scanner.scanFont(stream, faceIndex, &realname, &style, &isFixedPitch, NULL)) {
+                SkDebugf("---- failed to open <%d> <%d> as a font\n", index, faceIndex);
+                return;
+            }
+
+            SkTypeface_Custom* tf = SkNEW_ARGS(SkTypeface_Stream, (
+                                                style,
+                                                isFixedPitch,
+                                                true,  // system-font (cannot delete)
+                                                realname,
+                                                stream.detach(),
+                                                faceIndex));
+
+            SkFontStyleSet_Custom* addTo = find_family(*families, realname.c_str());
+            if (NULL == addTo) {
+                addTo = new SkFontStyleSet_Custom(realname);
+                families->push_back().reset(addTo);
+            }
+            addTo->appendTypeface(tf);
+        }
+    }
+
+    const SkEmbeddedResourceHeader* fHeader;
+};
+
+SkFontMgr* SkFontMgr_New_Custom_Embedded(const SkEmbeddedResourceHeader* header) {
+    return new SkFontMgr_Custom(EmbeddedSystemFontLoader(header));
+}