grab from latest android



git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/ports/SkFontHost_linux.cpp b/src/ports/SkFontHost_linux.cpp
new file mode 100644
index 0000000..f75718d
--- /dev/null
+++ b/src/ports/SkFontHost_linux.cpp
@@ -0,0 +1,604 @@
+/* libs/graphics/ports/SkFontHost_android.cpp
+ **
+ ** Copyright 2006, The Android Open Source Project
+ **
+ ** Licensed under the Apache License, Version 2.0 (the "License"); 
+ ** you may not use this file except in compliance with the License. 
+ ** You may obtain a copy of the License at 
+ **
+ **     http://www.apache.org/licenses/LICENSE-2.0 
+ **
+ ** Unless required by applicable law or agreed to in writing, software 
+ ** distributed under the License is distributed on an "AS IS" BASIS, 
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+ ** See the License for the specific language governing permissions and 
+ ** limitations under the License.
+ */
+
+#include "SkFontHost.h"
+#include "SkDescriptor.h"
+#include "SkMMapStream.h"
+#include "SkOSFile.h"
+#include "SkPaint.h"
+#include "SkString.h"
+#include "SkStream.h"
+#include "SkThread.h"
+#include "SkTSearch.h"
+#include <stdio.h>
+
+#define FONT_CACHE_MEMORY_BUDGET    (1 * 1024 * 1024)
+
+#ifndef SK_FONT_FILE_PREFIX
+    #define SK_FONT_FILE_PREFIX      "/usr/share/fonts/truetype/msttcorefonts/"
+#endif
+
+SkTypeface::Style find_name_and_style(SkStream* stream, SkString* name);
+
+static void GetFullPathForSysFonts(SkString* full, const char name[])
+{
+    full->append(SK_FONT_FILE_PREFIX);
+    full->append(name);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+struct FamilyRec;
+
+/*  This guy holds a mapping of a name -> family, used for looking up fonts.
+ Since it is stored in a stretchy array that doesn't preserve object
+ semantics, we don't use constructor/destructors, but just have explicit
+ helpers to manage our internal bookkeeping.
+ */
+struct NameFamilyPair {
+    const char* fName;      // we own this
+    FamilyRec*  fFamily;    // we don't own this, we just reference it
+    
+    void construct(const char name[], FamilyRec* family)
+    {
+        fName = strdup(name);
+        fFamily = family;   // we don't own this, so just record the referene
+    }
+    void destruct()
+    {
+        free((char*)fName);
+        // we don't own family, so just ignore our reference
+    }
+};
+
+// we use atomic_inc to grow this for each typeface we create
+static int32_t gUniqueFontID;
+
+// this is the mutex that protects these globals
+static SkMutex gFamilyMutex;
+static FamilyRec* gFamilyHead;
+static SkTDArray<NameFamilyPair> gNameList;
+
+struct FamilyRec {
+    FamilyRec*  fNext;
+    SkTypeface* fFaces[4];
+    
+    FamilyRec()
+    {
+        fNext = gFamilyHead;
+        memset(fFaces, 0, sizeof(fFaces));
+        gFamilyHead = this;
+    }
+};
+
+static SkTypeface* find_best_face(const FamilyRec* family,
+                                  SkTypeface::Style style)
+{
+    SkTypeface* const* faces = family->fFaces;
+    
+    if (faces[style] != NULL) { // exact match
+        return faces[style];
+    }
+    // look for a matching bold
+    style = (SkTypeface::Style)(style ^ SkTypeface::kItalic);
+    if (faces[style] != NULL) {
+        return faces[style];
+    }
+    // look for the plain
+    if (faces[SkTypeface::kNormal] != NULL) {
+        return faces[SkTypeface::kNormal];
+    }
+    // look for anything
+    for (int i = 0; i < 4; i++) {
+        if (faces[i] != NULL) {
+            return faces[i];
+        }
+    }
+    // should never get here, since the faces list should not be empty
+    SkASSERT(!"faces list is empty");
+    return NULL;
+}
+
+static FamilyRec* find_family(const SkTypeface* member)
+{
+    FamilyRec* curr = gFamilyHead;
+    while (curr != NULL) {
+        for (int i = 0; i < 4; i++) {
+            if (curr->fFaces[i] == member) {
+                return curr;
+            }
+        }
+        curr = curr->fNext;
+    }
+    return NULL;
+}
+
+static SkTypeface* resolve_uniqueID(uint32_t uniqueID)
+{
+    FamilyRec* curr = gFamilyHead;
+    while (curr != NULL) {
+        for (int i = 0; i < 4; i++) {
+            SkTypeface* face = curr->fFaces[i];
+            if (face != NULL && face->uniqueID() == uniqueID) {
+                return face;
+            }
+        }
+        curr = curr->fNext;
+    }
+    return NULL;
+}
+
+/*  Remove reference to this face from its family. If the resulting family
+ is empty (has no faces), return that family, otherwise return NULL
+ */
+static FamilyRec* remove_from_family(const SkTypeface* face)
+{
+    FamilyRec* family = find_family(face);
+    SkASSERT(family->fFaces[face->style()] == face);
+    family->fFaces[face->style()] = NULL;
+    
+    for (int i = 0; i < 4; i++) {
+        if (family->fFaces[i] != NULL) {    // family is non-empty
+            return NULL;
+        }
+    }
+    return family;  // return the empty family
+}
+
+// maybe we should make FamilyRec be doubly-linked
+static void detach_and_delete_family(FamilyRec* family)
+{
+    FamilyRec* curr = gFamilyHead;
+    FamilyRec* prev = NULL;
+    
+    while (curr != NULL) {
+        FamilyRec* next = curr->fNext;
+        if (curr == family) {
+            if (prev == NULL) {
+                gFamilyHead = next;
+            } else {
+                prev->fNext = next;
+            }
+            SkDELETE(family);
+            return;
+        }
+        prev = curr;
+        curr = next;
+    }
+    SkASSERT(!"Yikes, couldn't find family in our list to remove/delete");
+}
+
+static FamilyRec* find_familyrec(const char name[]) {
+    const NameFamilyPair* list = gNameList.begin();    
+    int index = SkStrLCSearch(&list[0].fName, gNameList.count(), name,
+                              sizeof(list[0]));
+    return index >= 0 ? list[index].fFamily : NULL;
+}
+
+static SkTypeface* find_typeface(const char name[], SkTypeface::Style style) {
+    FamilyRec* rec = find_familyrec(name);
+    return rec ? find_best_face(rec, style) : NULL;
+}
+
+static SkTypeface* find_typeface(const SkTypeface* familyMember,
+                                 SkTypeface::Style style)
+{
+    const FamilyRec* family = find_family(familyMember);
+    return family ? find_best_face(family, style) : NULL;
+}
+
+static void add_name(const char name[], FamilyRec* family)
+{
+    SkAutoAsciiToLC tolc(name);
+    name = tolc.lc();
+    
+    NameFamilyPair* list = gNameList.begin();
+    int             count = gNameList.count();
+    
+    int index = SkStrLCSearch(&list[0].fName, count, name, sizeof(list[0]));
+    
+    if (index < 0) {
+        list = gNameList.insert(~index);
+        list->construct(name, family);
+    }
+}
+
+static void remove_from_names(FamilyRec* emptyFamily)
+{
+#ifdef SK_DEBUG
+    for (int i = 0; i < 4; i++) {
+        SkASSERT(emptyFamily->fFaces[i] == NULL);
+    }
+#endif
+    
+    SkTDArray<NameFamilyPair>& list = gNameList;
+    
+    // must go backwards when removing
+    for (int i = list.count() - 1; i >= 0; --i) {
+        NameFamilyPair* pair = &list[i];
+        if (pair->fFamily == emptyFamily) {
+            pair->destruct();
+            list.remove(i);
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+class FamilyTypeface : public SkTypeface {
+public:
+    FamilyTypeface(Style style, bool sysFont, FamilyRec* family)
+    : SkTypeface(style, sk_atomic_inc(&gUniqueFontID) + 1)
+    {
+        fIsSysFont = sysFont;
+        
+        SkAutoMutexAcquire  ac(gFamilyMutex);
+        
+        if (NULL == family) {
+            family = SkNEW(FamilyRec);
+        }
+        family->fFaces[style] = this;
+        fFamilyRec = family;    // just record it so we can return it if asked
+    }
+    
+    virtual ~FamilyTypeface()
+    {
+        SkAutoMutexAcquire  ac(gFamilyMutex);
+        
+        // remove us from our family. If the family is now empty, we return
+        // that and then remove that family from the name list
+        FamilyRec* family = remove_from_family(this);
+        if (NULL != family) {
+            remove_from_names(family);
+            detach_and_delete_family(family);
+        }
+    }
+    
+    bool isSysFont() const { return fIsSysFont; }
+    FamilyRec* getFamily() const { return fFamilyRec; }
+    
+    virtual SkStream* openStream() = 0;
+    virtual void closeStream(SkStream*) = 0;
+    virtual const char* getUniqueString() const = 0;
+    
+private:
+    FamilyRec*  fFamilyRec; // we don't own this, just point to it
+    bool        fIsSysFont;
+    
+    typedef SkTypeface INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class StreamTypeface : public FamilyTypeface {
+public:
+    StreamTypeface(Style style, bool sysFont, FamilyRec* family,
+                   SkStream* stream)
+    : INHERITED(style, sysFont, family)
+    {
+        fStream = stream;
+    }
+    virtual ~StreamTypeface()
+    {
+        SkDELETE(fStream);
+    }
+    
+    // overrides
+    virtual SkStream* openStream() { return fStream; }
+    virtual void closeStream(SkStream*) {}
+    virtual const char* getUniqueString() const { return NULL; }
+    
+private:
+    SkStream* fStream;
+    
+    typedef FamilyTypeface INHERITED;
+};
+
+class FileTypeface : public FamilyTypeface {
+public:
+    FileTypeface(Style style, bool sysFont, FamilyRec* family,
+                 const char path[])
+        : INHERITED(style, sysFont, family) {
+        fPath.set(path);
+    }
+    
+    // overrides
+    virtual SkStream* openStream()
+    {
+        SkStream* stream = SkNEW_ARGS(SkMMAPStream, (fPath.c_str()));
+        
+        // check for failure
+        if (stream->getLength() <= 0) {
+            SkDELETE(stream);
+            // maybe MMAP isn't supported. try FILE
+            stream = SkNEW_ARGS(SkFILEStream, (fPath.c_str()));
+            if (stream->getLength() <= 0) {
+                SkDELETE(stream);
+                stream = NULL;
+            }
+        }
+        return stream;
+    }
+    virtual void closeStream(SkStream* stream)
+    {
+        SkDELETE(stream);
+    }
+    virtual const char* getUniqueString() const {
+        const char* str = strrchr(fPath.c_str(), '/');
+        if (str) {
+            str += 1;   // skip the '/'
+        }
+        return str;
+    }
+    
+private:
+    SkString fPath;
+    
+    typedef FamilyTypeface INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+///////////////////////////////////////////////////////////////////////////////
+
+static bool get_name_and_style(const char path[], SkString* name,
+                               SkTypeface::Style* style)
+{    
+    SkMMAPStream stream(path);
+    if (stream.getLength() > 0) {
+        *style = find_name_and_style(&stream, name);
+        return true;
+    }
+    else {
+        SkFILEStream stream(path);
+        if (stream.getLength() > 0) {
+            *style = find_name_and_style(&stream, name);
+            return true;
+        }
+    }
+    
+    SkDebugf("---- failed to open <%s> as a font\n", path);
+    return false;
+}
+
+// these globals are assigned (once) by load_system_fonts()
+static SkTypeface* gFallBackTypeface;
+static FamilyRec* gDefaultFamily;
+static SkTypeface* gDefaultNormal;
+
+static void load_system_fonts()
+{
+    // check if we've already be called
+    if (NULL != gDefaultNormal) {
+        return;
+    }
+    
+    SkOSFile::Iter    iter(SK_FONT_FILE_PREFIX, ".ttf");
+    SkString          name;
+
+    while (iter.next(&name, false)) {
+        SkString filename;
+        GetFullPathForSysFonts(&filename, name.c_str());
+//    while (filename.size() == 0) { filename.set("/usr/share/fonts/truetype/msttcorefonts/Arial.ttf");
+
+        SkString realname;
+        SkTypeface::Style style;
+        
+        if (!get_name_and_style(filename.c_str(), &realname, &style)) {
+            SkDebugf("------ can't load <%s> as a font\n", filename.c_str());
+            continue;
+        }
+        
+//        SkDebugf("font: <%s> %d <%s>\n", realname.c_str(), style, filename.c_str());
+        
+        FamilyRec* family = find_familyrec(realname.c_str());
+        // this constructor puts us into the global gFamilyHead llist
+        FamilyTypeface* tf = SkNEW_ARGS(FileTypeface,
+                                        (style,
+                                         true,  // system-font (cannot delete)
+                                         family, // what family to join
+                                         filename.c_str()) // filename
+                                        );
+
+        if (NULL == family) {
+            add_name(realname.c_str(), tf->getFamily());
+        }
+    }
+    
+    // do this after all fonts are loaded. This is our default font, and it
+    // acts as a sentinel so we only execute load_system_fonts() once
+    static const char* gDefaultNames[] = {
+        "Arial", "Verdana", "Times New Roman", NULL
+    };
+    const char** names = gDefaultNames;
+    while (*names) {
+        SkTypeface* tf = find_typeface(*names++, SkTypeface::kNormal);
+        if (tf) {
+            gDefaultNormal = tf;
+            break;
+        }
+    }
+    // check if we found *something*
+    if (NULL == gDefaultNormal) {
+        if (NULL == gFamilyHead) {
+            sk_throw();
+        }
+        for (int i = 0; i < 4; i++) {
+            if ((gDefaultNormal = gFamilyHead->fFaces[i]) != NULL) {
+                break;
+            }
+        }
+    }
+    if (NULL == gDefaultNormal) {
+        sk_throw();
+    }
+    gFallBackTypeface = gDefaultNormal;    
+    gDefaultFamily = find_family(gDefaultNormal);
+
+//    SkDebugf("---- default %p head %p family %p\n", gDefaultNormal, gFamilyHead, gDefaultFamily);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+void SkFontHost::Serialize(const SkTypeface* face, SkWStream* stream) {
+#if 0
+    const char* name = ((FamilyTypeface*)face)->getUniqueString();
+    
+    stream->write8((uint8_t)face->getStyle());
+    
+    if (NULL == name || 0 == *name) {
+        stream->writePackedUInt(0);
+        //        SkDebugf("--- fonthost serialize null\n");
+    } else {
+        uint32_t len = strlen(name);
+        stream->writePackedUInt(len);
+        stream->write(name, len);
+        //      SkDebugf("--- fonthost serialize <%s> %d\n", name, face->getStyle());
+    }
+#endif
+    sk_throw();
+}
+
+SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
+#if 0
+    load_system_fonts();
+    
+    int style = stream->readU8();
+    
+    int len = stream->readPackedUInt();
+    if (len > 0) {
+        SkString str;
+        str.resize(len);
+        stream->read(str.writable_str(), len);
+        
+        const FontInitRec* rec = gSystemFonts;
+        for (size_t i = 0; i < SK_ARRAY_COUNT(gSystemFonts); i++) {
+            if (strcmp(rec[i].fFileName, str.c_str()) == 0) {
+                // backup until we hit the fNames
+                for (int j = i; j >= 0; --j) {
+                    if (rec[j].fNames != NULL) {
+                        return SkFontHost::FindTypeface(NULL, rec[j].fNames[0],
+                                                        (SkTypeface::Style)style);
+                    }
+                }
+            }
+        }
+    }
+    return SkFontHost::FindTypeface(NULL, NULL, (SkTypeface::Style)style);
+#endif
+    sk_throw();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkTypeface* SkFontHost::FindTypeface(const SkTypeface* familyFace,
+                                     const char familyName[],
+                                     SkTypeface::Style style)
+{
+    load_system_fonts();
+    
+    SkAutoMutexAcquire  ac(gFamilyMutex);
+    
+    // clip to legal style bits
+    style = (SkTypeface::Style)(style & SkTypeface::kBoldItalic);
+    
+    SkTypeface* tf = NULL;
+    
+    if (NULL != familyFace) {
+        tf = find_typeface(familyFace, style);
+    } else if (NULL != familyName) {
+        //        SkDebugf("======= familyName <%s>\n", familyName);
+        tf = find_typeface(familyName, style);
+    }
+    
+    if (NULL == tf) {
+        tf = find_best_face(gDefaultFamily, style);
+    }
+    
+    return tf;
+}
+
+SkTypeface* SkFontHost::ResolveTypeface(uint32_t fontID)
+{
+    SkAutoMutexAcquire  ac(gFamilyMutex);
+    
+    return resolve_uniqueID(fontID);
+}
+
+SkStream* SkFontHost::OpenStream(uint32_t fontID)
+{
+    
+    FamilyTypeface* tf = (FamilyTypeface*)SkFontHost::ResolveTypeface(fontID);
+    SkStream* stream = tf ? tf->openStream() : NULL;
+    
+    if (NULL == stream || stream->getLength() == 0) {
+        delete stream;
+        stream = NULL;
+    }
+    return stream;
+}
+
+void SkFontHost::CloseStream(uint32_t fontID, SkStream* stream)
+{
+    FamilyTypeface* tf = (FamilyTypeface*)SkFontHost::ResolveTypeface(fontID);
+    if (NULL != tf) {
+        tf->closeStream(stream);
+    }
+}
+
+SkScalerContext* SkFontHost::CreateFallbackScalerContext(
+                                                         const SkScalerContext::Rec& rec)
+{
+    load_system_fonts();
+    
+    SkAutoDescriptor    ad(sizeof(rec) + SkDescriptor::ComputeOverhead(1));
+    SkDescriptor*       desc = ad.getDesc();
+    
+    desc->init();
+    SkScalerContext::Rec* newRec =
+    (SkScalerContext::Rec*)desc->addEntry(kRec_SkDescriptorTag,
+                                          sizeof(rec), &rec);
+    newRec->fFontID = gFallBackTypeface->uniqueID();
+    desc->computeChecksum();
+    
+    return SkFontHost::CreateScalerContext(desc);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkTypeface* SkFontHost::CreateTypeface(SkStream* stream)
+{
+    if (NULL == stream || stream->getLength() <= 0) {
+        SkDELETE(stream);
+        return NULL;
+    }
+    
+    SkString name;
+    SkTypeface::Style style = find_name_and_style(stream, &name);
+    
+    return SkNEW_ARGS(StreamTypeface, (style, false, NULL, stream));
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar)
+{
+    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
+        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
+    else
+        return 0;   // nothing to do
+}
+