gistfile1.cpp

/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
class UnicodeIterator {
public:
    UnicodeIterator(const SkPaint& paint, const void* txt, size_t len)
        : fBegin((const char*)txt)
        , fEnd((const char*)txt + len)
        , fEncoding(encoding) {}
    class ConstIter {
    public:
        void operator++() {
            if (fPtr == fEnd) {
                return;
            }
            switch (fPaint.getTextEncoding()) {
                case SkPaint::kUTF8_TextEncoding:
                    fUnichar = SkUTF8_NextUnichar(&fPtr);
                    break;
                case SkPaint::kUTF16_TextEncoding:
                    fUnichar = SkUTF16_NextUnichar((const uint16_t**)&ptr);
                    break;
                case SkPaint::kUTF32_TextEncoding:
                    fUnichar = *(const SkUnichar*)fPtr;
                    fPtr += 4;
                    break;
                case SkPaint::kGlyphID_TextEncoding:
                    fPaint.glyphsToUnichars((const uint16_t*)fPtr, 2, &fUnichar);
                    fPtr += 2;
                    break;
                default:
                    SkASSERT(false);
            }
            if (fPtr > fEnd) {
                fPtr = fEnd;
            }
        }
        SkUnichar operator*() const { return fUnichar; }
        bool operator!=(const ConstIter& rhs) const { return fPtr != rhs.fPtr; }
        ConstIter(const char* p, const char* e, const SkPaint& p) : 
            fPtr(p), fEnd(e), fPaint(p), fUnichar(0) { ++*this; }
    private:
        const char* fPtr;
        const char* const fEnd;
        SkUnichar  fUnichar;
        const SkPaint& fPaint;
        
    };
    ConstIter begin() const { return ConstIter(fBegin, fEnd, fPaint); }
    ConstIter end() const { return ConstIter(fEnd, fEnd, fPaint); }
private:
    const char* const fBegin;
    const char* const fEnd;
    const SkPaint& fPaint;
};