qxpmhandler.cpp

奇趣公司比较新的qt/emd版本

{
    QByteArray buf(200, 0);

    if (!read_xpm_string(buf, device, source, index, state))
        return false;

#if defined(_MSC_VER) && _MSC_VER >= 1400
	if (sscanf_s(buf, "%d %d %d %d", w, h, ncols, cpp) < 4)
#else
    if (sscanf(buf, "%d %d %d %d", w, h, ncols, cpp) < 4)
#endif
        return false;                                        // < 4 numbers parsed

    return true;
}

// Reads XPM body (color information & pixels).

static bool read_xpm_body(
    QIODevice *device, const char * const * source, int& index, QByteArray& state,
    int cpp, int ncols, int w, int h, QImage& image)
{
    QByteArray buf(200, 0);
    int i;

    if (cpp > 15)
        return false;

    // For > 256 colors, we delay creation of the image until
    // after we have read the color specifications, so that we can
    // create it in correct format (Format_RGB32 vs Format_ARGB32,
    // depending on absence or presence of "c none", respectively)
    if (ncols <= 256) {
        if (image.size() != QSize(w, h) || image.format() != QImage::Format_Indexed8) {
            image = QImage(w, h, QImage::Format_Indexed8);
            if (image.isNull())
                return false;
        }
        image.setNumColors(ncols);
    }

    QMap<quint64, int> colorMap;
    int currentColor;
    bool hasTransparency = false;

    for(currentColor=0; currentColor < ncols; ++currentColor) {
        if (!read_xpm_string(buf, device, source, index, state)) {
            qWarning("QImage: XPM color specification missing");
            return false;
        }
        QByteArray index;
        index = buf.left(cpp);
        buf = buf.mid(cpp).simplified().trimmed().toLower();
        QList<QByteArray> tokens = buf.split(' ');
        i = tokens.indexOf("c");
        if (i < 0)
            i = tokens.indexOf("g");
        if (i < 0)
            i = tokens.indexOf("g4");
        if (i < 0)
            i = tokens.indexOf("m");
        if (i < 0) {
            qWarning("QImage: XPM color specification is missing: %s", buf.constData());
            return false;        // no c/g/g4/m specification at all
        }
        QByteArray color;
        while ((++i < tokens.size()) && !is_xpm_color_spec_prefix(tokens.at(i))) {
            color.append(tokens.at(i));
        }
        if (color.isEmpty()) {
            qWarning("QImage: XPM color value is missing from specification: %s", buf.constData());
            return false;        // no color value
        }
        buf = color;
        if (buf == "none") {
            hasTransparency = true;
            int transparentColor = currentColor;
            if (ncols <= 256) {
                image.setColor(transparentColor, 0);
                colorMap.insert(xpmHash(QLatin1String(index.constData())), transparentColor);
            } else {
                colorMap.insert(xpmHash(QLatin1String(index.constData())), 0);
            }
        } else {
            QRgb c_rgb;
            if (((buf.length()-1) % 3) && (buf[0] == '#')) {
                buf.truncate(((buf.length()-1) / 4 * 3) + 1); // remove alpha channel left by imagemagick
            }
            if (buf[0] == '#') {
                qt_get_hex_rgb(buf, &c_rgb);
            } else {
                qt_get_named_xpm_rgb(buf, &c_rgb);
            }
            if (ncols <= 256) {
                image.setColor(currentColor, 0xff000000 | c_rgb);
                colorMap.insert(xpmHash(QLatin1String(index.constData())), currentColor);
            } else {
                colorMap.insert(xpmHash(QLatin1String(index.constData())), 0xff000000 | c_rgb);
            }
        }
    }

    if (ncols > 256) {
        // Now we can create 32-bit image of appropriate format
        QImage::Format format = hasTransparency ?
                                QImage::Format_ARGB32 : QImage::Format_RGB32;
        if (image.size() != QSize(w, h) || image.format() != format) {
            image = QImage(w, h, format);
            if (image.isNull())
                return false;
        }
    }

    // Read pixels
    for(int y=0; y<h; y++) {
        if (!read_xpm_string(buf, device, source, index, state)) {
            qWarning("QImage: XPM pixels missing on image line %d", y);
            return false;
        }
        if (image.depth() == 8) {
            uchar *p = image.scanLine(y);
            uchar *d = (uchar *)buf.data();
            uchar *end = d + buf.length();
            int x;
            if (cpp == 1) {
                char b[2];
                b[1] = '\0';
                for (x=0; x<w && d<end; x++) {
                    b[0] = *d++;
                    *p++ = (uchar)colorMap[xpmHash(b)];
                }
            } else {
                char b[16];
                b[cpp] = '\0';
                for (x=0; x<w && d<end; x++) {
                    memcpy(b, (char *)d, cpp);
                    *p++ = (uchar)colorMap[xpmHash(b)];
                    d += cpp;
                }
            }
        } else {
            QRgb *p = (QRgb*)image.scanLine(y);
            uchar *d = (uchar *)buf.data();
            uchar *end = d + buf.length();
            int x;
            char b[16];
            b[cpp] = '\0';
            for (x=0; x<w && d<end; x++) {
                memcpy(b, (char *)d, cpp);
                *p++ = (QRgb)colorMap[xpmHash(b)];
                d += cpp;
            }
        }
    }

    if (device) {
        // Rewind unused characters, and skip to the end of the XPM struct.
        for (int i = state.size() - 1; i >= 0; --i)
            device->ungetChar(state[i]);
        char c;
        while (device->getChar(&c) && c != ';');
        while (device->getChar(&c) && c != '\n');
    }
    return true;
}

//
// INTERNAL
//
// Reads an .xpm from either the QImageIO or from the QString *.
// One of the two HAS to be 0, the other one is used.
//

bool qt_read_xpm_image_or_array(QIODevice *device, const char * const * source, QImage &image)
{
    if (!source)
        return true;
    
    QByteArray buf(200, 0);
    QByteArray state;

    int cpp, ncols, w, h, index = 0;

    if (device) {
        // "/* XPM */"
        int readBytes;
        if ((readBytes = device->readLine(buf.data(), buf.size())) < 0)
            return false;

        if (buf.indexOf("/* XPM") != 0) {
            while (readBytes > 0) {
                device->ungetChar(buf.at(readBytes - 1));
                --readBytes;
            }
            return false;
        }// bad magic
    }

    if (!read_xpm_header(device, source, index, state, &cpp, &ncols, &w, &h))
        return false;

    return read_xpm_body(device, source, index, state, cpp, ncols, w, h, image);
}

static const char* xpm_color_name(int cpp, int index)
{
    static char returnable[5];
    static const char code[] = ".#abcdefghijklmnopqrstuvwxyzABCD"
                               "EFGHIJKLMNOPQRSTUVWXYZ0123456789";
    // cpp is limited to 4 and index is limited to 64^cpp
    if (cpp > 1) {
        if (cpp > 2) {
            if (cpp > 3) {
                returnable[3] = code[index % 64];
                index /= 64;
            } else
                returnable[3] = '\0';
            returnable[2] = code[index % 64];
            index /= 64;
        } else
            returnable[2] = '\0';
        // the following 4 lines are a joke!
        if (index == 0)
            index = 64*44+21;
        else if (index == 64*44+21)
            index = 0;
        returnable[1] = code[index % 64];
        index /= 64;
    } else
        returnable[1] = '\0';
    returnable[0] = code[index];

    return returnable;
}


// write XPM image data
static bool write_xpm_image(const QImage &sourceImage, QIODevice *device, const QString &fileName)
{
    if (!device->isWritable())
        return false;

    QImage image;
    if (sourceImage.depth() != 32)
        image = sourceImage.convertToFormat(QImage::Format_RGB32);
    else
        image = sourceImage;

    QMap<QRgb, int> colorMap;

    int w = image.width(), h = image.height(), ncolors = 0;
    int x, y;

    // build color table
    for(y=0; y<h; y++) {
        QRgb * yp = (QRgb *)image.scanLine(y);
        for(x=0; x<w; x++) {
            QRgb color = *(yp + x);
            if (!colorMap.contains(color))
                colorMap.insert(color, ncolors++);
        }
    }

    // number of 64-bit characters per pixel needed to encode all colors
    int cpp = 1;
    for (int k = 64; ncolors > k; k *= 64) {
        ++cpp;
        // limit to 4 characters per pixel
        // 64^4 colors is enough for a 4096x4096 image
         if (cpp > 4)
            break;
    }

    QString line;

    // write header
    QTextStream s(device);
    s << "/* XPM */" << endl
      << "static char *" << fbname(fileName) << "[]={" << endl
      << "\"" << w << " " << h << " " << ncolors << " " << cpp << "\"";

    // write palette
    QMap<QRgb, int>::Iterator c = colorMap.begin();
    while (c != colorMap.end()) {
        QRgb color = c.key();
        if (image.format() != QImage::Format_RGB32 && !qAlpha(color))
            line.sprintf("\"%s c None\"",
                          xpm_color_name(cpp, *c));
        else
            line.sprintf("\"%s c #%02x%02x%02x\"",
                          xpm_color_name(cpp, *c),
                          qRed(color),
                          qGreen(color),
                          qBlue(color));
        ++c;
        s << "," << endl << line;
    }

    // write pixels, limit to 4 characters per pixel
    line.truncate(cpp*w);
    for(y=0; y<h; y++) {
        QRgb * yp = (QRgb *) image.scanLine(y);
        int cc = 0;
        for(x=0; x<w; x++) {
            int color = (int)(*(yp + x));
            QByteArray chars(xpm_color_name(cpp, colorMap[color]));
            line[cc++] = QLatin1Char(chars[0]);
            if (cpp > 1) {
                line[cc++] = QLatin1Char(chars[1]);
                if (cpp > 2) {
                    line[cc++] = QLatin1Char(chars[2]);
                    if (cpp > 3) {
                        line[cc++] = QLatin1Char(chars[3]);
                    }
                }
            }
        }
        s << "," << endl << "\"" << line << "\"";
    }
    s << "};" << endl;
    return (s.status() == QTextStream::Ok);
}

QXpmHandler::QXpmHandler()
    : state(Ready), index(0)
{
}

bool QXpmHandler::readHeader()
{
    state = Error;
    if (!read_xpm_header(device(), 0, index, buffer, &cpp, &ncols, &width, &height))
        return false;
    state = ReadHeader;
    return true;
}

bool QXpmHandler::readImage(QImage *image)
{
    if (state == Error)
        return false;
    
    if (state == Ready && !readHeader()) {
        state = Error;
        return false;
    }

    if (!read_xpm_body(device(), 0, index, buffer, cpp, ncols, width, height, *image)) {
        state = Error;
        return false;
    }

    state = Ready;
    return true;
}

bool QXpmHandler::canRead() const
{
    if (state == Ready && canRead(device())) {
        setFormat("xpm");
        return true;
    }
    return state != Error;
}

bool QXpmHandler::canRead(QIODevice *device)
{
    if (!device) {
        qWarning("QXpmHandler::canRead() called with no device");
        return false;
    }

    char head[6];
    if (device->peek(head, sizeof(head)) != sizeof(head))
        return false;

    return qstrncmp(head, "/* XPM", 6) == 0;
}

bool QXpmHandler::read(QImage *image)
{
    if (!canRead())
        return false;
    return readImage(image);
}

bool QXpmHandler::write(const QImage &image)
{
    return write_xpm_image(image, device(), fileName);
}

bool QXpmHandler::supportsOption(ImageOption option) const
{
    return option == Name
        || option == Size;
}

QVariant QXpmHandler::option(ImageOption option) const
{
    if (option == Name) {
        return fileName;
    } else if (option == Size) {
        if (state == Error)
            return QVariant();
        if (state == Ready && !const_cast<QXpmHandler*>(this)->readHeader())
            return QVariant();
        return QSize(width, height);
    }
    return QVariant();
}

void QXpmHandler::setOption(ImageOption option, const QVariant &value)
{
    if (option == Name)
        fileName = value.toString();
}

QByteArray QXpmHandler::name() const
{
    return "xpm";
}

#endif // QT_NO_IMAGEFORMAT_XPM