qpixmap.cpp

奇趣公司比较新的qt/emd版本

    int d = data->d;
    // Create new pixmap
    QPixmap pm(QSize(w, h), d == 1 ? BitmapType : PixmapType);
#ifdef Q_WS_X11
    pm.x11SetScreen(data->xinfo.screen());
#endif // Q_WS_X11
    if (!data->uninit && !isNull()) {                // has existing pixmap
        // Copy old pixmap
        QPainter p(&pm);
        p.drawPixmap(0, 0, *this, 0, 0, qMin(width(), w), qMin(height(), h));
    }
#if defined(Q_WS_MAC)
#ifndef QT_MAC_NO_QUICKDRAW
    if(data->qd_alpha)
        data->macQDUpdateAlpha();
#endif
#elif defined(Q_WS_X11)
    if (data->x11_mask) {
        pm.data->x11_mask = (Qt::HANDLE)XCreatePixmap(X11->display, RootWindow(data->xinfo.display(), data->xinfo.screen()),
                                                      w, h, 1);
        GC gc = XCreateGC(X11->display, pm.data->x11_mask, 0, 0);
        XCopyArea(X11->display, data->x11_mask, pm.data->x11_mask, gc, 0, 0, qMin(width(), w), qMin(height(), h), 0, 0);
        XFreeGC(X11->display, gc);
    }
#else
    if (data->mask) {
        QBitmap m = *data->mask;
        m.resize(w, h);
        pm.setMask(m);
    }
#endif
    *this = pm;
}
#endif

/*!
    \fn void QPixmap::resize(int width, int height)
    \compat

    Use the QPixmap constructor that takes two \c{int}s (\a width and
    \a height) instead.

    \oldcode
        pixmap.resize(10, 20);
    \newcode
        pixmap = QPixmap(10, 20);
    \endcode
*/

/*!
    \fn bool QPixmap::selfMask() const
    \compat

    Returns whether the pixmap is its own mask or not.

    This function is no longer relevant since the concept of self
    masking doesn't exists anymore.
*/

#ifndef QT_NO_IMAGE_HEURISTIC_MASK
/*!
    Creates and returns a heuristic mask for this pixmap.

    The function works by selecting a color from one of the corners
    and then chipping away pixels of that color, starting at all the
    edges.  If \a clipTight is true (the default) the mask is just
    large enough to cover the pixels; otherwise, the mask is larger
    than the data pixels.

    The mask may not be perfect but it should be reasonable, so you
    can do things such as the following:

    \code
        QPixmap myPixmap;
        myPixmap->setMask(myPixmap->createHeuristicMask());
    \endcode

    This function is slow because it involves converting to/from a
    QImage, and non-trivial computations.

    \sa QImage::createHeuristicMask(), createMaskFromColor()
*/
QBitmap QPixmap::createHeuristicMask(bool clipTight) const
{
    QBitmap m = QBitmap::fromImage(toImage().createHeuristicMask(clipTight));
    return m;
}
#endif

/*!
    Creates and returns a mask for this pixmap based on the given \a
    maskColor. If the \a mode is Qt::MaskInColor, all pixels matching the
    maskColor will be opaque. If \a mode is Qt::MaskOutColor, all pixels
    matching the maskColor will be transparent.

    This function is slow because it involves converting to/from a
    QImage.

    \sa createHeuristicMask(), QImage::createMaskFromColor()
*/
QBitmap QPixmap::createMaskFromColor(const QColor &maskColor, Qt::MaskMode mode) const
{
    QImage image = toImage().convertToFormat(QImage::Format_ARGB32);
    return QBitmap::fromImage(image.createMaskFromColor(maskColor.rgba(), mode));
}

/*! \overload

    Creates and returns a mask for this pixmap based on the given \a
    maskColor. Same as calling createMaskFromColor(maskColor,
    Qt::MaskInColor)

    \sa createHeuristicMask(), QImage::createMaskFromColor()
*/
QBitmap QPixmap::createMaskFromColor(const QColor &maskColor) const
{
    return createMaskFromColor(maskColor, Qt::MaskInColor);
}

/*!
    Loads a pixmap from the file with the given \a fileName. Returns
    true if the pixmap was successfully loaded; otherwise returns
    false.

    The loader attempts to read the pixmap using the specified \a
    format. If the \a format is not specified (which is the default),
    the loader probes the file for a header to guess the file format.

    The file name can either refer to an actual file on disk or to one
    of the application's embedded resources. See the
    \l{resources.html}{Resource System} overview for details on how to
    embed pixmaps and other resource files in the application's
    executable.

    If the data needs to be modified to fit in a lower-resolution
    result (e.g. converting from 32-bit to 8-bit), use the \a flags to
    control the conversion.

    Note that QPixmaps are automatically added to the QPixmapCache
    when loaded from a file; the key used is internal and can not
    be acquired.

    \sa loadFromData(), {QPixmap#Reading and Writing Image
    Files}{Reading and Writing Image Files}
*/

bool QPixmap::load(const QString &fileName, const char *format, Qt::ImageConversionFlags flags)
{
    if (fileName.isEmpty())
        return false;

    QFileInfo info(fileName);
    QString key = QLatin1String("qt_pixmap_") + info.absoluteFilePath() + QLatin1Char('_') + info.lastModified().toString() + QLatin1Char('_') +
                  QString::number(info.size()) + QLatin1Char('_') + QString::number(data->type);

    if (QPixmapCache::find(key, *this))
        return true;
    QImage image = QImageReader(fileName, format).read();
    if (image.isNull())
        return false;
    QPixmap pm;
    if (data->type == BitmapType)
        pm = QBitmap::fromImage(image, flags);
    else
        pm = fromImage(image, flags);
    if (!pm.isNull()) {
        *this = pm;
        QPixmapCache::insert(key, *this);
        return true;
    }
    return false;
}

/*!
    \fn bool QPixmap::loadFromData(const uchar *data, uint len, const char *format, Qt::ImageConversionFlags flags)

    Loads a pixmap from the \a len first bytes of the given binary \a
    data.  Returns true if the pixmap was loaded successfully;
    otherwise returns false.

    The loader attempts to read the pixmap using the specified \a
    format. If the \a format is not specified (which is the default),
    the loader probes the file for a header to guess the file format.

    If the data needs to be modified to fit in a lower-resolution
    result (e.g. converting from 32-bit to 8-bit), use the \a flags to
    control the conversion.

    \sa load(), {QPixmap#Reading and Writing Image Files}{Reading and
    Writing Image Files}
*/

bool QPixmap::loadFromData(const uchar *buf, uint len, const char *format, Qt::ImageConversionFlags flags)
{
    QByteArray a = QByteArray::fromRawData(reinterpret_cast<const char *>(buf), len);
    QBuffer b(&a);
    b.open(QIODevice::ReadOnly);

    QImage image = QImageReader(&b, format).read();
    QPixmap pm;
    if (data->type == BitmapType)
        pm = QBitmap::fromImage(image, flags);
    else
        pm = fromImage(image, flags);
    if (!pm.isNull()) {
        *this = pm;
        return true;
    }
    return false;
}

/*!
    \fn bool QPixmap::loadFromData(const QByteArray &data, const char *format, Qt::ImageConversionFlags flags)

    \overload

    Loads a pixmap from the binary \a data using the specified \a
    format and conversion \a flags.
*/


/*!
    Saves the pixmap to the file with the given \a fileName using the
    specified image file \a format and \a quality factor. Returns true
    if successful; otherwise returns false.

    The \a quality factor must be in the range [0,100] or -1. Specify
    0 to obtain small compressed files, 100 for large uncompressed
    files, and -1 to use the default settings.

    If \a format is 0, an image format will be chosen from \a fileName's
    suffix.

    \sa {QPixmap#Reading and Writing Image Files}{Reading and Writing
    Image Files}
*/

bool QPixmap::save(const QString &fileName, const char *format, int quality) const
{
    if (isNull())
        return false;                                // nothing to save
    QImageWriter writer(fileName, format);
    return doImageIO(&writer, quality);
}

/*!
    \overload

    This function writes a QPixmap to the given \a device using the
    specified image file \a format and \a quality factor. This can be
    used, for example, to save a pixmap directly into a QByteArray:

    \quotefromfile snippets/image/image.cpp
    \skipto PIX SAVE
    \skipto QPixmap
    \printuntil save
*/

bool QPixmap::save(QIODevice* device, const char* format, int quality) const
{
    if (isNull())
        return false;                                // nothing to save
    QImageWriter writer(device, format);
    return doImageIO(&writer, quality);
}

/*! \internal
*/

bool QPixmap::doImageIO(QImageWriter *writer, int quality) const
{
    if (quality > 100  || quality < -1)
        qWarning("QPixmap::save: quality out of range [-1,100]");
    if (quality >= 0)
        writer->setQuality(qMin(quality,100));
    return writer->write(toImage());
}


// The implementation (and documentation) of
// QPixmap::fill(const QWidget *, const QPoint &)
// is in qwidget.cpp

/*!
    \fn void QPixmap::fill(const QWidget *widget, int x, int y)
    \overload

    Fills the pixmap with the \a widget's background color or pixmap.
    The given point, (\a x, \a y), defines an offset in widget
    coordinates to which the pixmap's top-left pixel will be mapped
    to.
*/

/*! \obsolete
    Returns a number that identifies the contents of this QPixmap
    object. Distinct QPixmap objects can only have the same serial
    number if they refer to the same contents (but they don't have
    to).

    Use cacheKey() instead.

    \warning The serial number doesn't necessarily change when
    the pixmap is altered. This means that it may be dangerous to use
    it as a cache key. For caching pixmaps, we recommend using the
    QPixmapCache class whenever possible.
*/
int QPixmap::serialNumber() const
{
    if (isNull())
        return 0;
    else
        return data->ser_no;
}

/*!
    Returns a number that identifies this QPixmap. Distinct QPixmap
    objects can only have the same cache key if they refer to the same
    contents.

    The cacheKey() will change when the pixmap is altered.
*/
qint64 QPixmap::cacheKey() const
{
    return (((qint64) data->ser_no) << 32) | ((qint64) (data->detach_no));
}

static void sendResizeEvents(QWidget *target)
{
    QResizeEvent e(target->size(), QSize());
    QApplication::sendEvent(target, &e);

    const QObjectList children = target->children();
    for (int i = 0; i < children.size(); ++i) {
        QWidget *child = static_cast<QWidget*>(children.at(i));
        if (child->isWidgetType() && !child->isWindow() && child->testAttribute(Qt::WA_PendingResizeEvent))
            sendResizeEvents(child);
    }
}

/*!
    \fn QPixmap QPixmap::grabWidget(QWidget * widget, const QRect &rectangle)

    Creates a pixmap and paints the given \a widget, restricted by the
    given \a rectangle, in it. If the \a widget has any children, then
    they are also painted in the appropriate positions.

    If no rectangle is specified (the default) the entire widget is
    painted.

    If \a widget is 0, the specified rectangle doesn't overlap the
    widget's rectangle, or an error occurs, the function will return a
    null QPixmap.  If the rectangle is a superset of the given \a
    widget, the areas outside the \a widget are covered with the
    widget's background.

    This function actually asks \a widget to paint itself (and its
    children to paint themselves) by calling paintEvent() with painter
    redirection turned on. But QPixmap also provides the grabWindow()
    function which is a bit faster grabbing pixels directly off the
    screen. In addition, if there are overlaying windows,
    grabWindow(), unlike grabWidget(), will see them.

    \warning Do not call this function from QWidget::paintEvent().

    \sa grabWindow()
*/

QPixmap QPixmap::grabWidget(QWidget * widget, const QRect &rect)
{
    if (!widget)
        return QPixmap();

    if (widget->testAttribute(Qt::WA_PendingResizeEvent) || !widget->testAttribute(Qt::WA_WState_Created))
        sendResizeEvents(widget);

    QRect r(rect);
    if (r.width() < 0)
        r.setWidth(widget->width() - rect.x());
    if (r.height() < 0)
        r.setHeight(widget->height() - rect.y());

    if (!r.intersects(widget->rect()))
        return QPixmap();

    QPixmap res(r.size());
    widget->render(&res, -r.topLeft(), r,
                   QWidget::DrawWindowBackground | QWidget::DrawChildren | QWidget::IgnoreMask);
    return res;
}

/*!
    \fn QPixmap QPixmap::grabWidget(QWidget *widget, int x, int y, int
    width, int height)

    \overload

    Creates a pixmap and paints the given \a widget, restricted by
    QRect(\a x, \a y, \a width, \a height), in it.

    \warning Do not call this function from QWidget::paintEvent().
*/


#if defined(Q_WS_X11) || defined(Q_WS_QWS)
/*!
    Returns the pixmap's handle to the device context.

    Note that, since QPixmap make use of \l {Implicit Data
    Sharing}{implicit data sharing}, the detach() function must be
    called explicitly to ensure that only \e this pixmap's data is
    modified if the pixmap data is shared.

    \warning This function is X11 specific; using it is non-portable.

    \sa detach()
*/

Qt::HANDLE QPixmap::handle() const
{
    return data->hd;
}
#endif


#ifdef QT3_SUPPORT
static Qt::ImageConversionFlags colorModeToFlags(QPixmap::ColorMode mode)
{
    Qt::ImageConversionFlags flags = Qt::AutoColor;
    switch (mode) {
      case QPixmap::Color:
        flags |= Qt::ColorOnly;
        break;
      case QPixmap::Mono:
        flags |= Qt::MonoOnly;
        break;
      default:
        break;// Nothing.
    }
    return flags;
}

/*!
    Use the constructor that takes a Qt::ImageConversionFlag instead.
*/

QPixmap::QPixmap(const QString& fileName, const char *format, ColorMode mode)
    : QPaintDevice()
{
    init(0, 0);
    load(fileName, format, colorModeToFlags(mode));
}

/*!
    Constructs a pixmap from the QImage \a image.

    Use the static fromImage() function instead.
*/

QPixmap::QPixmap(const QImage& image)
    : QPaintDevice()
{
    init(0, 0);
    if (data->type == BitmapType)
        *this = QBitmap::fromImage(image);
    else
        *this = fromImage(image);
}

/*!
    \overload

    Converts the given \a image to a pixmap that is assigned to this
    pixmap.

    Use the static fromImage() function instead.
*/

QPixmap &QPixmap::operator=(const QImage &image)