A remotable font management interface and DirectWrite implementation.

src/fonts/SkFontMgr_indirect.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkFontMgr_indirect.h"
+
+#include "SkDataTable.h"
+#include "SkFontStyle.h"
+#include "SkOnce.h"
+#include "SkStream.h"
+#include "SkTSearch.h"
+#include "SkTypeface.h"
+
+class SkData;
+class SkString;
+
+class SkStyleSet_Indirect : public SkFontStyleSet {
+public:
+    /** Takes ownership of the SkRemotableFontIdentitySet. */
+    SkStyleSet_Indirect(const SkFontMgr_Indirect* owner, int familyIndex,
+                        SkRemotableFontIdentitySet* data)
+        : fOwner(SkRef(owner)), fFamilyIndex(familyIndex), fData(data)
+    { }
+
+    virtual int count() SK_OVERRIDE { return fData->count(); }
+
+    virtual void getStyle(int index, SkFontStyle* fs, SkString* style) SK_OVERRIDE {
+        if (fs) {
+            *fs = fData->at(index).fFontStyle;
+        }
+        if (style) {
+            // TODO: is this useful? Current locale?
+            style->reset();
+        }
+    }
+
+    virtual SkTypeface* createTypeface(int index) SK_OVERRIDE {
+        return fOwner->createTypefaceFromFontId(fData->at(index));
+    }
+
+    virtual SkTypeface* matchStyle(const SkFontStyle& pattern) SK_OVERRIDE {
+        if (fFamilyIndex >= 0) {
+            SkFontIdentity id = fOwner->fProxy->matchIndexStyle(fFamilyIndex, pattern);
+            return fOwner->createTypefaceFromFontId(id);
+        }
+
+        // If this SkStyleSet was created via onMatchFamily we would need a call like
+        // fOwner->fProxy->matchNameStyle(fFamilyName, pattern);
+        // but would not activate fonts (only consider fonts which would come back from matchName).
+
+        // CSS policy sounds good.
+        struct Score {
+            int score;
+            int index;
+        };
+
+        // Width has the greatest priority.
+        // If the value of pattern.width is 5 (normal) or less,
+        //    narrower width values are checked first, then wider values.
+        // If the value of pattern.width is greater than 5 (normal),
+        //    wider values are checked first, followed by narrower values.
+
+        // Italic/Oblique has the next highest priority.
+        // If italic requested and there is some italic font, use it.
+        // If oblique requested and there is some oblique font, use it.
+        // If italic requested and there is some oblique font, use it.
+        // If oblique requested and there is some italic font, use it.
+
+        // Exact match.
+        // If pattern.weight < 400, weights below pattern.weight are checked
+        //   in descending order followed by weights above pattern.weight
+        //   in ascending order until a match is found.
+        // If pattern.weight > 500, weights above pattern.weight are checked
+        //   in ascending order followed by weights below pattern.weight
+        //   in descending order until a match is found.
+        // If pattern.weight is 400, 500 is checked first
+        //   and then the rule for pattern.weight < 400 is used.
+        // If pattern.weight is 500, 400 is checked first
+        //   and then the rule for pattern.weight < 400 is used
+
+        Score maxScore = { 0, 0 };
+        for (int i = 0; i < fData->count(); ++i) {
+            const SkFontStyle& current = fData->at(i).fFontStyle;
+            Score currentScore = { 0, i };
+
+            // CSS stretch. (This is the width.)
+            // This has the highest priority.
+            if (pattern.width() <= SkFontStyle::kNormal_Width) {
+                if (current.width() <= pattern.width()) {
+                    currentScore.score += 10 - pattern.width() + current.width();
+                } else {
+                    currentScore.score += 10 - current.width();
+                }
+            } else {
+                if (current.width() > pattern.width()) {
+                    currentScore.score += 10 + pattern.width() - current.width();
+                } else {
+                    currentScore.score += current.width();
+                }
+            }
+            currentScore.score *= 1002;
+
+            // CSS style (italic/oblique)
+            // Being italic trumps all valid weights which are not italic.
+            // Note that newer specs differentiate between italic and oblique.
+            if (pattern.isItalic() && current.isItalic()) {
+                currentScore.score += 1001;
+            }
+
+            // Synthetics (weight/style) [no stretch synthetic?]
+
+            // The 'closer' to the target weight, the higher the score.
+            // 1000 is the 'heaviest' recognized weight
+            if (pattern.weight() == current.weight()) {
+                currentScore.score += 1000;
+            } else if (pattern.weight() <= 500) {
+                if (pattern.weight() >= 400 && pattern.weight() < 450) {
+                    if (current.weight() >= 450 && current.weight() <= 500) {
+                        // Artificially boost the 500 weight.
+                        // TODO: determine correct number to use.
+                        currentScore.score += 500;
+                    }
+                }
+                if (current.weight() <= pattern.weight()) {
+                    currentScore.score += 1000 - pattern.weight() + current.weight();
+                } else {
+                    currentScore.score += 1000 - current.weight();
+                }
+            } else if (pattern.weight() > 500) {
+                if (current.weight() > pattern.weight()) {
+                    currentScore.score += 1000 + pattern.weight() - current.weight();
+                } else {
+                    currentScore.score += current.weight();
+                }
+            }
+
+            if (currentScore.score > maxScore.score) {
+                maxScore = currentScore;
+            }
+        }
+
+        return this->createTypeface(maxScore.index);
+    }
+private:
+    SkAutoTUnref<const SkFontMgr_Indirect> fOwner;
+    int fFamilyIndex;
+    SkAutoTUnref<SkRemotableFontIdentitySet> fData;
+};
+
+void SkFontMgr_Indirect::set_up_family_names(const SkFontMgr_Indirect* self) {
+    self->fFamilyNames.reset(self->fProxy->getFamilyNames());
+}
+
+int SkFontMgr_Indirect::onCountFamilies() const {
+    SkOnce(&fOnce, SkFontMgr_Indirect::set_up_family_names, this);
+    return fFamilyNames->count();
+}
+
+void SkFontMgr_Indirect::onGetFamilyName(int index, SkString* familyName) const {
+    SkOnce(&fOnce, SkFontMgr_Indirect::set_up_family_names, this);
+    if (index >= fFamilyNames->count()) {
+        familyName->reset();
+        return;
+    }
+    familyName->set(fFamilyNames->atStr(index));
+}
+
+SkFontStyleSet* SkFontMgr_Indirect::onCreateStyleSet(int index) const {
+    SkRemotableFontIdentitySet* set = fProxy->getIndex(index);
+    if (NULL == set) {
+        return NULL;
+    }
+    return SkNEW_ARGS(SkStyleSet_Indirect, (this, index, set));
+}
+
+SkFontStyleSet* SkFontMgr_Indirect::onMatchFamily(const char familyName[]) const {
+    return SkNEW_ARGS(SkStyleSet_Indirect, (this, -1, fProxy->matchName(familyName)));
+}
+
+SkTypeface* SkFontMgr_Indirect::createTypefaceFromFontId(const SkFontIdentity& id) const {
+    if (id.fDataId == SkFontIdentity::kInvalidDataId) {
+        return NULL;
+    }
+
+    SkAutoMutexAcquire ama(fDataCacheMutex);
+
+    SkAutoTUnref<SkTypeface> dataTypeface;
+    int dataTypefaceIndex = 0;
+    for (int i = 0; i < fDataCache.count(); ++i) {
+        const DataEntry& entry = fDataCache[i];
+        if (entry.fDataId == id.fDataId) {
+            if (entry.fTtcIndex == id.fTtcIndex &&
+                !entry.fTypeface->weak_expired() && entry.fTypeface->try_ref())
+            {
+                return entry.fTypeface;
+            }
+            if (dataTypeface.get() == NULL &&
+                !entry.fTypeface->weak_expired() && entry.fTypeface->try_ref())
+            {
+                dataTypeface.reset(entry.fTypeface);
+                dataTypefaceIndex = entry.fTtcIndex;
+            }
+        }
+
+        if (entry.fTypeface->weak_expired()) {
+            fDataCache.removeShuffle(i);
+            --i;
+        }
+    }
+
+    // No exact match, but did find a data match.
+    if (dataTypeface.get() != NULL) {
+        SkAutoTUnref<SkStream> stream(dataTypeface->openStream(NULL));
+        if (stream.get() != NULL) {
+            return fImpl->createFromStream(stream.get(), dataTypefaceIndex);
+        }
+    }
+
+    // No data match, request data and add entry.
+    SkAutoTUnref<SkStreamAsset> stream(fProxy->getData(id.fDataId));
+    if (stream.get() == NULL) {
+        return NULL;
+    }
+
+    SkAutoTUnref<SkTypeface> typeface(fImpl->createFromStream(stream, id.fTtcIndex));
+    if (typeface.get() == NULL) {
+        return NULL;
+    }
+
+    DataEntry& newEntry = fDataCache.push_back();
+    typeface->weak_ref();
+    newEntry.fDataId = id.fDataId;
+    newEntry.fTtcIndex = id.fTtcIndex;
+    newEntry.fTypeface = typeface.get();  // weak reference passed to new entry.
+
+    return typeface.detach();
+}
+
+SkTypeface* SkFontMgr_Indirect::onMatchFamilyStyle(const char familyName[],
+                                                   const SkFontStyle& fontStyle) const {
+    SkFontIdentity id = fProxy->matchNameStyle(familyName, fontStyle);
+    return this->createTypefaceFromFontId(id);
+}
+
+SkTypeface* SkFontMgr_Indirect::onMatchFamilyStyleCharacter(const char familyName[],
+                                                            const SkFontStyle& style,
+                                                            const char bpc47[],
+                                                            uint32_t character) const {
+    SkFontIdentity id = fProxy->matchNameStyleCharacter(familyName, style, bpc47, character);
+    return this->createTypefaceFromFontId(id);
+}
+
+SkTypeface* SkFontMgr_Indirect::onMatchFaceStyle(const SkTypeface* familyMember,
+                                                 const SkFontStyle& fontStyle) const {
+    SkString familyName;
+    familyMember->getFamilyName(&familyName);
+    return this->matchFamilyStyle(familyName.c_str(), fontStyle);
+}
+
+SkTypeface* SkFontMgr_Indirect::onCreateFromStream(SkStream* stream, int ttcIndex) const {
+    return fImpl->createFromStream(stream, ttcIndex);
+}
+
+SkTypeface* SkFontMgr_Indirect::onCreateFromFile(const char path[], int ttcIndex) const {
+    return fImpl->createFromFile(path, ttcIndex);
+}
+
+SkTypeface* SkFontMgr_Indirect::onCreateFromData(SkData* data, int ttcIndex) const {
+    return fImpl->createFromData(data, ttcIndex);
+}
+
+SkTypeface* SkFontMgr_Indirect::onLegacyCreateTypeface(const char familyName[],
+                                                       unsigned styleBits) const {
+    bool bold = SkToBool(styleBits & SkTypeface::kBold);
+    bool italic = SkToBool(styleBits & SkTypeface::kItalic);
+    SkFontStyle style = SkFontStyle(bold ? SkFontStyle::kBold_Weight
+                                         : SkFontStyle::kNormal_Weight,
+                                    SkFontStyle::kNormal_Width,
+                                    italic ? SkFontStyle::kItalic_Slant
+                                           : SkFontStyle::kUpright_Slant);
+
+    SkAutoTUnref<SkTypeface> face(this->matchFamilyStyle(familyName, style));
+
+    if (NULL == face.get()) {
+        face.reset(this->matchFamilyStyle(NULL, style));
+    }
+
+    if (NULL == face.get()) {
+        SkFontIdentity fontId = this->fProxy->matchIndexStyle(0, style);
+        face.reset(this->createTypefaceFromFontId(fontId));
+    }
+
+    return face.detach();
+}