add separate impl file for SkFontMgr_fontconfig, so we don't polute

SkFontHost_fontconfig, which should be sharable w/ android. Eventaully
we will remove that FontHost file completely, and just use the SkFontMgr.

R=djsollen@google.com

Review URL: https://codereview.chromium.org/15077008

git-svn-id: http://skia.googlecode.com/svn/trunk@9114 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 276 insertions, 0 deletions

diff --git a/src/fonts/SkFontMgr_fontconfig.cpp b/src/fonts/SkFontMgr_fontconfig.cpp
new file mode 100644
index 0000000000..e93e9f8e93
--- /dev/null
+++ b/src/fonts/SkFontMgr_fontconfig.cpp
@@ -0,0 +1,276 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkFontMgr.h"
+#include "SkFontStyle.h"
+#include "SkFontConfigInterface.h"
+#include "SkMath.h"
+#include "SkString.h"
+#include "SkTDArray.h"
+
+// for now we pull these in directly. eventually we will solely rely on the
+// SkFontConfigInterface instance.
+#include <fontconfig/fontconfig.h>
+#include <unistd.h>
+
+// borrow this global from SkFontHost_fontconfig. eventually that file should
+// go away, and be replaced with this one.
+extern SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
+static SkFontConfigInterface* RefFCI() {
+    return SkFontHost_fontconfig_ref_global();
+}
+
+// look for the last substring after a '/' and return that, or return null.
+static const char* find_just_name(const char* str) {
+    const char* last = strrchr(str, '/');
+    return last ? last + 1 : NULL;
+}
+
+static bool is_lower(char c) {
+    return c >= 'a' && c <= 'z';
+}
+
+static int get_int(FcPattern* pattern, const char field[]) {
+    int value;
+    if (FcPatternGetInteger(pattern, field, 0, &value) != FcResultMatch) {
+        value = SK_MinS32;
+    }
+    return value;
+}
+
+static const char* get_name(FcPattern* pattern, const char field[]) {
+    const char* name;
+    if (FcPatternGetString(pattern, field, 0, (FcChar8**)&name) != FcResultMatch) {
+        name = "";
+    }
+    return name;
+}
+
+static bool valid_pattern(FcPattern* pattern) {
+    FcBool is_scalable;
+    if (FcPatternGetBool(pattern, FC_SCALABLE, 0, &is_scalable) != FcResultMatch || !is_scalable) {
+        return false;
+    }
+
+    // fontconfig can also return fonts which are unreadable
+    const char* c_filename = get_name(pattern, FC_FILE);
+    if (0 == *c_filename) {
+        return false;
+    }
+    if (access(c_filename, R_OK) != 0) {
+        return false;
+    }
+    return true;
+}
+
+static bool match_name(FcPattern* pattern, const char family_name[]) {
+    return !strcasecmp(family_name, get_name(pattern, FC_FAMILY));
+}
+
+static FcPattern** MatchFont(FcFontSet* font_set,
+                             const char post_config_family[],
+                             int* count) {
+  // Older versions of fontconfig have a bug where they cannot select
+  // only scalable fonts so we have to manually filter the results.
+
+    FcPattern** iter = font_set->fonts;
+    FcPattern** stop = iter + font_set->nfont;
+    // find the first good match
+    for (; iter < stop; ++iter) {
+        if (valid_pattern(*iter)) {
+            break;
+        }
+    }
+
+    if (iter == stop || !match_name(*iter, post_config_family)) {
+        return NULL;
+    }
+
+    FcPattern** firstIter = iter++;
+    for (; iter < stop; ++iter) {
+        if (!valid_pattern(*iter) || !match_name(*iter, post_config_family)) {
+            break;
+        }
+    }
+
+    *count = iter - firstIter;
+    return firstIter;
+}
+
+class SkFontStyleSet_FC : public SkFontStyleSet {
+public:
+    SkFontStyleSet_FC(FcPattern** matches, int count);
+    virtual ~SkFontStyleSet_FC();
+
+    virtual int count() SK_OVERRIDE { return fRecCount; }
+    virtual void getStyle(int index, SkFontStyle*, SkString* style) SK_OVERRIDE;
+    virtual SkTypeface* createTypeface(int index) SK_OVERRIDE;
+    virtual SkTypeface* matchStyle(const SkFontStyle& pattern) SK_OVERRIDE;
+
+private:
+    struct Rec {
+        SkString    fStyleName;
+        SkString    fFileName;
+        SkFontStyle fStyle;
+    };
+    Rec* fRecs;
+    int  fRecCount;
+};
+
+static int map_range(int value,
+                     int old_min, int old_max, int new_min, int new_max) {
+    SkASSERT(old_min < old_max);
+    SkASSERT(new_min < new_max);
+    return new_min + SkMulDiv(value - old_min,
+                              new_max - new_min, old_max - old_min);
+}
+
+static SkFontStyle make_fontconfig_style(FcPattern* match) {
+    int weight = get_int(match, FC_WEIGHT);
+    int width = get_int(match, FC_WIDTH);
+    int slant = get_int(match, FC_SLANT);
+//    SkDebugf("old weight %d new weight %d\n", weight, map_range(weight, 0, 80, 0, 400));
+
+    // fontconfig weight seems to be 0..200 or so, so we remap it here
+    weight = map_range(weight, 0, 80, 0, 400);
+    width = map_range(width, 0, 200, 0, 9);
+    return SkFontStyle(weight, width, slant > 0 ? SkFontStyle::kItalic_Slant
+                                                : SkFontStyle::kUpright_Slant);
+}
+
+SkFontStyleSet_FC::SkFontStyleSet_FC(FcPattern** matches, int count) {
+    fRecCount = count;
+    fRecs = SkNEW_ARRAY(Rec, count);
+    for (int i = 0; i < count; ++i) {
+        fRecs[i].fStyleName.set(get_name(matches[i], FC_STYLE));
+        fRecs[i].fFileName.set(get_name(matches[i], FC_FILE));
+        fRecs[i].fStyle = make_fontconfig_style(matches[i]);
+    }
+}
+
+SkFontStyleSet_FC::~SkFontStyleSet_FC() {
+    SkDELETE_ARRAY(fRecs);
+}
+
+void SkFontStyleSet_FC::getStyle(int index, SkFontStyle* style,
+                                 SkString* styleName) {
+    SkASSERT((unsigned)index < (unsigned)fRecCount);
+    if (style) {
+        *style = fRecs[index].fStyle;
+    }
+    if (styleName) {
+        *styleName = fRecs[index].fStyleName;
+    }
+}
+
+SkTypeface* SkFontStyleSet_FC::createTypeface(int index) {
+    return NULL;
+}
+
+SkTypeface* SkFontStyleSet_FC::matchStyle(const SkFontStyle& pattern) {
+    return NULL;
+}
+
+class SkFontMgr_fontconfig : public SkFontMgr {
+    SkAutoTUnref<SkFontConfigInterface> fFCI;
+    SkDataTable* fFamilyNames;
+
+    void init() {
+        if (!fFamilyNames) {
+            fFamilyNames = fFCI->getFamilyNames();
+        }
+    }
+
+public:
+    SkFontMgr_fontconfig(SkFontConfigInterface* fci)
+        : fFCI(fci)
+        , fFamilyNames(NULL) {}
+
+    virtual ~SkFontMgr_fontconfig() {
+        SkSafeUnref(fFamilyNames);
+    }
+
+protected:
+    virtual int onCountFamilies() {
+        this->init();
+        return fFamilyNames->count();
+    }
+
+    virtual void onGetFamilyName(int index, SkString* familyName) {
+        this->init();
+        familyName->set(fFamilyNames->atStr(index));
+    }
+
+    virtual SkFontStyleSet* onCreateStyleSet(int index) {
+        this->init();
+        return this->onMatchFamily(fFamilyNames->atStr(index));
+    }
+
+    virtual SkFontStyleSet* onMatchFamily(const char familyName[]) {
+        this->init();
+
+        FcPattern* pattern = FcPatternCreate();
+
+        FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
+#if 0
+        FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
+#endif
+        FcConfigSubstitute(NULL, pattern, FcMatchPattern);
+        FcDefaultSubstitute(pattern);
+
+        const char* post_config_family = get_name(pattern, FC_FAMILY);
+
+        FcResult result;
+        FcFontSet* font_set = FcFontSort(0, pattern, 0, 0, &result);
+        if (!font_set) {
+            FcPatternDestroy(pattern);
+            return NULL;
+        }
+
+        int count;
+        FcPattern** match = MatchFont(font_set, post_config_family, &count);
+        if (!match) {
+            FcPatternDestroy(pattern);
+            FcFontSetDestroy(font_set);
+            return NULL;
+        }
+
+        FcPatternDestroy(pattern);
+
+        SkTDArray<FcPattern*> trimmedMatches;
+        for (int i = 0; i < count; ++i) {
+            const char* justName = find_just_name(get_name(match[i], FC_FILE));
+            if (!is_lower(*justName)) {
+                *trimmedMatches.append() = match[i];
+            }
+        }
+
+        SkFontStyleSet_FC* sset = SkNEW_ARGS(SkFontStyleSet_FC,
+                                             (trimmedMatches.begin(),
+                                              trimmedMatches.count()));
+        return sset;
+    }
+
+    virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
+                                           const SkFontStyle&) { return NULL; }
+    virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
+                                         const SkFontStyle&) { return NULL; }
+
+    virtual SkTypeface* onCreateFromData(SkData*, int ttcIndex) { return NULL; }
+    virtual SkTypeface* onCreateFromStream(SkStream*, int ttcIndex) {
+        return NULL;
+    }
+    virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) {
+        return NULL;
+    }
+};
+
+SkFontMgr* SkFontMgr::Factory() {
+    SkFontConfigInterface* fci = RefFCI();
+    return fci ? SkNEW_ARGS(SkFontMgr_fontconfig, (fci)) : NULL;
+}
+