qpixmap.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

                                                          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);
        }
#elif !defined(Q_WS_MAC)
    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 transformation to a
    QImage, non-trivial computations and a transformation back to a
    QBitmap.

    \sa QImage::createHeuristicMask(), {QPixmap#Pixmap
    Transformations}{Pixmap Transformations}
*/
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.

    This function is slow because it involves transformation to a
    QImage and a transformation back to a QBitmap.

    \sa createHeuristicMask(), {QPixmap#Pixmap Transformations}{Pixmap
    Transformations}
*/
QBitmap QPixmap::createMaskFromColor(const QColor &maskColor) const
{
    QImage maskImage(size(), QImage::Format_MonoLSB);
    QImage image = toImage();
    QRgb mColor = maskColor.rgba();
    for (int w = 0; w < width(); w++) {
        for (int h = 0; h < height(); h++) {
            if (image.pixel(w, h) == mColor)
                maskImage.setPixel(w, h, Qt::color1);
            else
                maskImage.setPixel(w, h, Qt::color0);
        }
    }
    QBitmap m = QBitmap::fromImage(maskImage);
    return m;
}

/*!
    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.

    \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()
                  + 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.

    \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.
*/

/*!
    \fn int QPixmap::serialNumber() const

    Returns a number that uniquely identifies the contents of this
    QPixmap object.

    This means that multiple QPixmap objects only can have the same
    serial number as long as they refer to the same contents. A null
    pixmap has always a serial number of 0.

    An example of where this is useful is for caching QPixmaps.

    \sa {QPixmap#Pixmap Information}{Pixmap Information}
*/
int QPixmap::serialNumber() const
{
    if (isNull())
        return 0;
    else
        return data->ser_no;
}

/*
  Fills \a buf with \a r in \a widget. Then blits \a buf on \a res at
  position \a offset
 */
#ifdef Q_WS_MAC
static void grabWidget_helper(QWidget *widget, QPixmap &res, QPixmap &buf,
                              const QRect &r, const QPoint &offset)
{
    buf.fill(widget, r.topLeft());
    QPainter::setRedirected(widget, &buf, r.topLeft());
    QPaintEvent e(r & widget->rect());
    QApplication::sendEvent(widget, &e);
    QPainter::restoreRedirected(widget);
    {
        QPainter pt(&res);
        pt.drawPixmap(offset.x(), offset.y(), buf, 0, 0, r.width(), r.height());
    }

    const QObjectList children = widget->children();
    for (int i = 0; i < children.size(); ++i) {
        QWidget *child = static_cast<QWidget*>(children.at(i));
        if (!child->isWidgetType() || child->isWindow()
            || child->isHidden() || !child->geometry().intersects(r))
            continue;
        QRect cr = r & child->geometry();
        cr.translate(-child->pos());
        grabWidget_helper(child, res, buf, cr, offset + child->pos());
    }
}
#endif
/*!
    \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();

    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());

#ifndef Q_WS_MAC
    widget->d_func()->drawWidget(&res, r, -r.topLeft(),
                                 QWidgetPrivate::DrawRecursive | QWidgetPrivate::DrawAsRoot
                                 | QWidgetPrivate::DrawPaintOnScreen | QWidgetPrivate::DrawInvisible);
#else
    QPixmap buf(r.size());
    if(res.isNull() || buf.isNull())
        return res;

    grabWidget_helper(widget, res, buf, r, QPoint());
#endif
    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.