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katie/src/gui/image/qpixmap.cpp
Ivailo Monev 99e98bf3ed qpixmap_mac_p.h is no more 
Signed-off-by: Ivailo Monev <xakepa10@laimg.moc>
2016-08-06 03:44:42 +00:00

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/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <qglobal.h>
#include "qpixmap.h"
#include "qpixmapdata_p.h"
#include "qimagepixmapcleanuphooks_p.h"
#include "qbitmap.h"
#include "qcolormap.h"
#include "qimage.h"
#include "qwidget.h"
#include "qpainter.h"
#include "qdatastream.h"
#include "qbuffer.h"
#include "qapplication.h"
#include <qapplication_p.h>
#include <qgraphicssystem_p.h>
#include <qwidget_p.h>
#include "qevent.h"
#include "qfile.h"
#include "qfileinfo.h"
#include "qpixmapcache.h"
#include "qdatetime.h"
#include "qimagereader.h"
#include "qimagewriter.h"
#include "qpaintengine.h"
#include "qthread.h"
#ifdef Q_WS_MAC
# include "qt_mac_p.h"
#endif
#if defined(Q_WS_X11)
# include "qx11info_x11.h"
# include <qt_x11_p.h>
# include <qpixmap_x11_p.h>
#endif
#include "qpixmap_raster_p.h"
#include "qstylehelper_p.h"
QT_BEGIN_NAMESPACE
static bool qt_pixmap_thread_test()
{
if (!qApp) {
qFatal("QPixmap: Must construct a QApplication before a QPaintDevice");
return false;
}
if (qApp->thread() != QThread::currentThread()) {
bool fail = false;
#if defined (Q_WS_X11)
if (!QApplication::testAttribute(Qt::AA_X11InitThreads))
fail = true;
#else
if (QApplicationPrivate::graphics_system_name != QLatin1String("raster"))
fail = true;
#endif
if (fail) {
qWarning("QPixmap: It is not safe to use pixmaps outside the GUI thread");
return false;
}
}
return true;
}
extern QApplication::Type qt_appType;
void QPixmap::init(int w, int h, int type)
{
if (qt_appType == QApplication::Tty) {
qWarning("QPixmap: Cannot create a QPixmap when no GUI is being used");
data = 0;
return;
}
if ((w > 0 && h > 0) || type == QPixmapData::BitmapType)
data = QPixmapData::create(w, h, (QPixmapData::PixelType) type);
else
data = 0;
}
/*!
\enum QPixmap::ColorMode
\compat
This enum type defines the color modes that exist for converting
QImage objects to QPixmap. It is provided here for compatibility
with earlier versions of Qt.
Use Qt::ImageConversionFlags instead.
\value Auto Select \c Color or \c Mono on a case-by-case basis.
\value Color Always create colored pixmaps.
\value Mono Always create bitmaps.
*/
/*!
Constructs a null pixmap.
\sa isNull()
*/
QPixmap::QPixmap()
: QPaintDevice()
{
(void) qt_pixmap_thread_test();
init(0, 0, QPixmapData::PixmapType);
}
/*!
\fn QPixmap::QPixmap(int width, int height)
Constructs a pixmap with the given \a width and \a height. If
either \a width or \a height is zero, a null pixmap is
constructed.
\warning This will create a QPixmap with uninitialized data. Call
fill() to fill the pixmap with an appropriate color before drawing
onto it with QPainter.
\sa isNull()
*/
QPixmap::QPixmap(int w, int h)
: QPaintDevice()
{
if (!qt_pixmap_thread_test())
init(0, 0, QPixmapData::PixmapType);
else
init(w, h, QPixmapData::PixmapType);
}
/*!
\overload
Constructs a pixmap of the given \a size.
\warning This will create a QPixmap with uninitialized data. Call
fill() to fill the pixmap with an appropriate color before drawing
onto it with QPainter.
*/
QPixmap::QPixmap(const QSize &size)
: QPaintDevice()
{
if (!qt_pixmap_thread_test())
init(0, 0, QPixmapData::PixmapType);
else
init(size.width(), size.height(), QPixmapData::PixmapType);
}
/*!
\internal
*/
QPixmap::QPixmap(const QSize &s, int type)
{
if (!qt_pixmap_thread_test())
init(0, 0, static_cast<QPixmapData::PixelType>(type));
else
init(s.width(), s.height(), static_cast<QPixmapData::PixelType>(type));
}
/*!
\internal
*/
QPixmap::QPixmap(QPixmapData *d)
: QPaintDevice(), data(d)
{
}
/*!
Constructs a pixmap from the file with the given \a fileName. If the
file does not exist or is of an unknown format, the pixmap becomes a
null pixmap.
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 images and other resource files in the application's
executable.
If the image 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.
The \a fileName, \a format and \a flags parameters are
passed on to load(). This means that the data in \a fileName is
not compiled into the binary. If \a fileName contains a relative
path (e.g. the filename only) the relevant file must be found
relative to the runtime working directory.
\sa {QPixmap#Reading and Writing Image Files}{Reading and Writing
Image Files}
*/
QPixmap::QPixmap(const QString& fileName, const char *format, Qt::ImageConversionFlags flags)
: QPaintDevice()
{
init(0, 0, QPixmapData::PixmapType);
if (!qt_pixmap_thread_test())
return;
load(fileName, format, flags);
}
/*!
Constructs a pixmap that is a copy of the given \a pixmap.
\sa copy()
*/
QPixmap::QPixmap(const QPixmap &pixmap)
: QPaintDevice()
{
if (!qt_pixmap_thread_test()) {
init(0, 0, QPixmapData::PixmapType);
return;
}
if (pixmap.paintingActive()) { // make a deep copy
operator=(pixmap.copy());
} else {
data = pixmap.data;
}
}
/*!
Constructs a pixmap from the given \a xpm data, which must be a
valid XPM image.
Errors are silently ignored.
Note that it's possible to squeeze the XPM variable a little bit
by using an unusual declaration:
\snippet doc/src/snippets/code/src_gui_image_qpixmap.cpp 0
The extra \c const makes the entire definition read-only, which is
slightly more efficient (for example, when the code is in a shared
library) and ROMable when the application is to be stored in ROM.
*/
#ifndef QT_NO_IMAGEFORMAT_XPM
QPixmap::QPixmap(const char * const xpm[])
: QPaintDevice()
{
init(0, 0, QPixmapData::PixmapType);
if (!xpm)
return;
QImage image(xpm);
if (!image.isNull()) {
if (data && data->pixelType() == QPixmapData::BitmapType)
*this = QBitmap::fromImage(image);
else
*this = fromImage(image);
}
}
#endif
/*!
Destroys the pixmap.
*/
QPixmap::~QPixmap()
{
Q_ASSERT(!data || data->ref >= 1); // Catch if ref-counting changes again
}
/*!
\internal
*/
int QPixmap::devType() const
{
return QInternal::Pixmap;
}
/*!
\fn QPixmap QPixmap::copy(int x, int y, int width, int height) const
\overload
Returns a deep copy of the subset of the pixmap that is specified
by the rectangle QRect( \a x, \a y, \a width, \a height).
*/
/*!
\fn QPixmap QPixmap::copy(const QRect &rectangle) const
Returns a deep copy of the subset of the pixmap that is specified
by the given \a rectangle. For more information on deep copies,
see the \l {Implicit Data Sharing} documentation.
If the given \a rectangle is empty, the whole image is copied.
\sa operator=(), QPixmap(), {QPixmap#Pixmap
Transformations}{Pixmap Transformations}
*/
QPixmap QPixmap::copy(const QRect &rect) const
{
if (isNull())
return QPixmap();
QRect r(0, 0, width(), height());
if (!rect.isEmpty())
r = r.intersected(rect);
QPixmapData *d = data->createCompatiblePixmapData();
d->copy(data.data(), r);
return QPixmap(d);
}
/*!
\fn QPixmap::scroll(int dx, int dy, int x, int y, int width, int height, QRegion *exposed)
\since 4.6
This convenience function is equivalent to calling QPixmap::scroll(\a dx,
\a dy, QRect(\a x, \a y, \a width, \a height), \a exposed).
\sa QWidget::scroll(), QGraphicsItem::scroll()
*/
/*!
\since 4.6
Scrolls the area \a rect of this pixmap by (\a dx, \a dy). The exposed
region is left unchanged. You can optionally pass a pointer to an empty
QRegion to get the region that is \a exposed by the scroll operation.
\snippet doc/src/snippets/code/src_gui_image_qpixmap.cpp 2
You cannot scroll while there is an active painter on the pixmap.
\sa QWidget::scroll(), QGraphicsItem::scroll()
*/
void QPixmap::scroll(int dx, int dy, const QRect &rect, QRegion *exposed)
{
if (isNull() || (dx == 0 && dy == 0))
return;
QRect dest = rect & this->rect();
QRect src = dest.translated(-dx, -dy) & dest;
if (src.isEmpty()) {
if (exposed)
*exposed += dest;
return;
}
detach();
if (!data->scroll(dx, dy, src)) {
// Fallback
QPixmap pix = *this;
QPainter painter(&pix);
painter.setCompositionMode(QPainter::CompositionMode_Source);
painter.drawPixmap(src.translated(dx, dy), *this, src);
painter.end();
*this = pix;
}
if (exposed) {
*exposed += dest;
*exposed -= src.translated(dx, dy);
}
}
/*!
Assigns the given \a pixmap to this pixmap and returns a reference
to this pixmap.
\sa copy(), QPixmap()
*/
QPixmap &QPixmap::operator=(const QPixmap &pixmap)
{
if (paintingActive()) {
qWarning("QPixmap::operator=: Cannot assign to pixmap during painting");
return *this;
}
if (pixmap.paintingActive()) { // make a deep copy
*this = pixmap.copy();
} else {
data = pixmap.data;
}
return *this;
}
/*!
\fn void QPixmap::swap(QPixmap &other)
\since 4.8
Swaps pixmap \a other with this pixmap. This operation is very
fast and never fails.
*/
/*!
Returns the pixmap as a QVariant.
*/
QPixmap::operator QVariant() const
{
return QVariant(QVariant::Pixmap, this);
}
/*!
\fn bool QPixmap::operator!() const
Returns true if this is a null pixmap; otherwise returns false.
\sa isNull()
*/
/*!
\fn QPixmap::operator QImage() const
Returns the pixmap as a QImage.
Use the toImage() function instead.
*/
/*!
Converts the pixmap to a QImage. Returns a null image if the
conversion fails.
If the pixmap has 1-bit depth, the returned image will also be 1
bit deep. Images with more bits will be returned in a format
closely represents the underlying system. Usually this will be
QImage::Format_ARGB32_Premultiplied for pixmaps with an alpha and
QImage::Format_RGB32 or QImage::Format_RGB16 for pixmaps without
alpha.
Note that for the moment, alpha masks on monochrome images are
ignored.
\sa fromImage(), {QImage#Image Formats}{Image Formats}
*/
QImage QPixmap::toImage() const
{
if (isNull())
return QImage();
return data->toImage();
}
/*!
\fn QMatrix QPixmap::trueMatrix(const QTransform &matrix, int width, int height)
Returns the actual matrix used for transforming a pixmap with the
given \a width, \a height and \a matrix.
When transforming a pixmap using the transformed() function, the
transformation matrix is internally adjusted to compensate for
unwanted translation, i.e. transformed() returns the smallest
pixmap containing all transformed points of the original
pixmap. This function returns the modified matrix, which maps
points correctly from the original pixmap into the new pixmap.
\sa transformed(), {QPixmap#Pixmap Transformations}{Pixmap
Transformations}
*/
QTransform QPixmap::trueMatrix(const QTransform &m, int w, int h)
{
return QImage::trueMatrix(m, w, h);
}
/*!
\overload
This convenience function loads the matrix \a m into a
QTransform and calls the overloaded function with the
QTransform and the width \a w and the height \a h.
*/
QMatrix QPixmap::trueMatrix(const QMatrix &m, int w, int h)
{
return trueMatrix(QTransform(m), w, h).toAffine();
}
/*!
\fn bool QPixmap::isQBitmap() const
Returns true if this is a QBitmap; otherwise returns false.
*/
bool QPixmap::isQBitmap() const
{
return data->type == QPixmapData::BitmapType;
}
/*!
\fn bool QPixmap::isNull() const
Returns true if this is a null pixmap; otherwise returns false.
A null pixmap has zero width, zero height and no contents. You
cannot draw in a null pixmap.
*/
bool QPixmap::isNull() const
{
return !data || data->isNull();
}
/*!
\fn int QPixmap::width() const
Returns the width of the pixmap.
\sa size(), {QPixmap#Pixmap Information}{Pixmap Information}
*/
int QPixmap::width() const
{
return data ? data->width() : 0;
}
/*!
\fn int QPixmap::height() const
Returns the height of the pixmap.
\sa size(), {QPixmap#Pixmap Information}{Pixmap Information}
*/
int QPixmap::height() const
{
return data ? data->height() : 0;
}
/*!
\fn QSize QPixmap::size() const
Returns the size of the pixmap.
\sa width(), height(), {QPixmap#Pixmap Information}{Pixmap
Information}
*/
QSize QPixmap::size() const
{
return data ? QSize(data->width(), data->height()) : QSize(0, 0);
}
/*!
\fn QRect QPixmap::rect() const
Returns the pixmap's enclosing rectangle.
\sa {QPixmap#Pixmap Information}{Pixmap Information}
*/
QRect QPixmap::rect() const
{
return data ? QRect(0, 0, data->width(), data->height()) : QRect();
}
/*!
\fn int QPixmap::depth() const
Returns the depth of the pixmap.
The pixmap depth is also called bits per pixel (bpp) or bit planes
of a pixmap. A null pixmap has depth 0.
\sa defaultDepth(), {QPixmap#Pixmap Information}{Pixmap
Information}
*/
int QPixmap::depth() const
{
return data ? data->depth() : 0;
}
/*!
\fn void QPixmap::resize(const QSize &size)
\overload
\compat
Use QPixmap::copy() instead to get the pixmap with the new size.
\oldcode
pixmap.resize(size);
\newcode
pixmap = pixmap.copy(QRect(QPoint(0, 0), size));
\endcode
*/
/*!
\fn void QPixmap::resize(int width, int height)
\compat
Use QPixmap::copy() instead to get the pixmap with the new size.
\oldcode
pixmap.resize(10, 20);
\newcode
pixmap = pixmap.copy(0, 0, 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.
*/
/*!
Sets a mask bitmap.
This function merges the \a mask with the pixmap's alpha channel. A pixel
value of 1 on the mask means the pixmap's pixel is unchanged; a value of 0
means the pixel is transparent. The mask must have the same size as this
pixmap.
Setting a null mask resets the mask, leaving the previously transparent
pixels black. The effect of this function is undefined when the pixmap is
being painted on.
\warning This is potentially an expensive operation.
\sa mask(), {QPixmap#Pixmap Transformations}{Pixmap Transformations},
QBitmap
*/
void QPixmap::setMask(const QBitmap &mask)
{
if (paintingActive()) {
qWarning("QPixmap::setMask: Cannot set mask while pixmap is being painted on");
return;
}
if (!mask.isNull() && mask.size() != size()) {
qWarning("QPixmap::setMask() mask size differs from pixmap size");
return;
}
if (isNull())
return;
if (static_cast<const QPixmap &>(mask).data == data) // trying to selfmask
return;
detach();
data->setMask(mask);
}
#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:
\snippet doc/src/snippets/code/src_gui_image_qpixmap.cpp 1
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 transparent. If \a mode is Qt::MaskOutColor, all pixels
matching the maskColor will be opaque.
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));
}
/*!
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 = QLatin1Literal("qt_pixmap")
% info.absoluteFilePath()
% HexString<uint>(info.lastModified().toTime_t())
% HexString<quint64>(info.size())
% HexString<uint>(data ? data->pixelType() : QPixmapData::PixmapType);
// Note: If no extension is provided, we try to match the
// file against known plugin extensions
if (!info.completeSuffix().isEmpty() && !info.exists())
return false;
if (QPixmapCache::find(key, *this))
return true;
QScopedPointer<QPixmapData> tmp(QPixmapData::create(0, 0, data ? data->type : QPixmapData::PixmapType));
if (tmp->fromFile(fileName, format, flags)) {
data = tmp.take();
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)
{
if (len == 0 || buf == 0)
return false;
if (!data)
data = QPixmapData::create(0, 0, QPixmapData::PixmapType);
return data->fromData(buf, len, format, flags);
}
/*!
\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:
\snippet doc/src/snippets/image/image.cpp 1
*/
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.
*/
/*!
Fills the pixmap with the given \a color.
The effect of this function is undefined when the pixmap is
being painted on.
\sa {QPixmap#Pixmap Transformations}{Pixmap Transformations}
*/
void QPixmap::fill(const QColor &color)
{
if (isNull())
return;
// Some people are probably already calling fill while a painter is active, so to not break
// their programs, only print a warning and return when the fill operation could cause a crash.
if (paintingActive() && (color.alpha() != 255) && !hasAlphaChannel()) {
qWarning("QPixmap::fill: Cannot fill while pixmap is being painted on");
return;
}
if (data->ref == 1) {
// detach() will also remove this pixmap from caches, so
// it has to be called even when ref == 1.
detach();
} else {
// Don't bother to make a copy of the data object, since
// it will be filled with new pixel data anyway.
QPixmapData *d = data->createCompatiblePixmapData();
d->resize(data->width(), data->height());
data = d;
}
data->fill(color);
}
/*!
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
{
if (isNull())
return 0;
Q_ASSERT(data);
return data->cacheKey();
}
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 by grabbing pixels directly off the
screen. In addition, if there are overlaying windows,
grabWindow(), unlike grabWidget(), will see them.
\warning Do not grab a widget from its QWidget::paintEvent().
However, it is safe to grab a widget from another widget's
\l {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);
widget->d_func()->prepareToRender(QRegion(),
QWidget::DrawWindowBackground | QWidget::DrawChildren | QWidget::IgnoreMask);
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());
if (!qt_widget_private(widget)->isOpaque)
res.fill(Qt::transparent);
widget->d_func()->render(&res, QPoint(), r, QWidget::DrawWindowBackground
| QWidget::DrawChildren | QWidget::IgnoreMask, true);
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 grab a widget from its QWidget::paintEvent().
However, it is safe to grab a widget from another widget's
\l {QWidget::}{paintEvent()}.
*/
/*!
\since 4.5
\enum QPixmap::ShareMode
This enum type defines the share modes that are available when
creating a QPixmap object from a raw X11 Pixmap handle.
\value ImplicitlyShared This mode will cause the QPixmap object to
create a copy of the internal data before it is modified, thus
keeping the original X11 pixmap intact.
\value ExplicitlyShared In this mode, the pixmap data will \e not be
copied before it is modified, which in effect will change the
original X11 pixmap.
\warning This enum is only used for X11 specific functions; using
it is non-portable.
\sa QPixmap::fromX11Pixmap()
*/
/*!
\since 4.5
\fn QPixmap QPixmap::fromX11Pixmap(Qt::HANDLE pixmap, QPixmap::ShareMode mode)
Creates a QPixmap from the native X11 Pixmap handle \a pixmap,
using \a mode as the share mode. The default share mode is
QPixmap::ImplicitlyShared, which means that a copy of the pixmap is
made if someone tries to modify it by e.g. drawing onto it.
QPixmap does \e not take ownership of the \a pixmap handle, and
have to be deleted by the user.
\warning This function is X11 specific; using it is non-portable.
\sa QPixmap::ShareMode
*/
#if defined(Q_WS_X11)
/*!
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.
\warning Since 4.8, pixmaps do not have an X11 handle unless
created with \l {QPixmap::}{fromX11Pixmap()}, or if the native
graphics system is explicitly enabled.
\sa detach()
\sa QApplication::setGraphicsSystem()
*/
Qt::HANDLE QPixmap::handle() const
{
#if defined(Q_WS_X11)
const QPixmapData *pd = pixmapData();
if (pd && pd->classId() == QPixmapData::X11Class)
return static_cast<const QX11PixmapData*>(pd)->handle();
#endif
return 0;
}
#endif
/*****************************************************************************
QPixmap stream functions
*****************************************************************************/
#if !defined(QT_NO_DATASTREAM)
/*!
\relates QPixmap
Writes the given \a pixmap to the given \a stream as a PNG
image. Note that writing the stream to a file will not produce a
valid image file.
\sa QPixmap::save(), {Serializing Qt Data Types}
*/
QDataStream &operator<<(QDataStream &stream, const QPixmap &pixmap)
{
return stream << pixmap.toImage();
}
/*!
\relates QPixmap
Reads an image from the given \a stream into the given \a pixmap.
\sa QPixmap::load(), {Serializing Qt Data Types}
*/
QDataStream &operator>>(QDataStream &stream, QPixmap &pixmap)
{
QImage image;
stream >> image;
if (image.isNull()) {
pixmap = QPixmap();
} else if (image.depth() == 1) {
pixmap = QBitmap::fromImage(image);
} else {
pixmap = QPixmap::fromImage(image);
}
return stream;
}
#endif // QT_NO_DATASTREAM
/*!
\internal
*/
bool QPixmap::isDetached() const
{
return data && data->ref == 1;
}
/*!
\fn QImage QPixmap::convertToImage() const
Use the toImage() function instead.
*/
/*!
Replaces this pixmap's data with the given \a image using the
specified \a flags to control the conversion. The \a flags
argument is a bitwise-OR of the \l{Qt::ImageConversionFlags}.
Passing 0 for \a flags sets all the default options. Returns true
if the result is that this pixmap is not null.
Note: this function was part of Qt 3 support in Qt 4.6 and earlier.
It has been promoted to official API status in 4.7 to support updating
the pixmap's image without creating a new QPixmap as fromImage() would.
\sa fromImage()
\since 4.7
*/
bool QPixmap::convertFromImage(const QImage &image, Qt::ImageConversionFlags flags)
{
if (image.isNull() || !data)
*this = QPixmap::fromImage(image, flags);
else
data->fromImage(image, flags);
return !isNull();
}
/*!
\fn QPixmap QPixmap::xForm(const QMatrix &matrix) const
Use transformed() instead.
*/
/*!
\fn QPixmap QPixmap::scaled(int width, int height,
Qt::AspectRatioMode aspectRatioMode, Qt::TransformationMode
transformMode) const
\overload
Returns a copy of the pixmap scaled to a rectangle with the given
\a width and \a height according to the given \a aspectRatioMode and
\a transformMode.
If either the \a width or the \a height is zero or negative, this
function returns a null pixmap.
*/
/*!
\fn QPixmap QPixmap::scaled(const QSize &size, Qt::AspectRatioMode
aspectRatioMode, Qt::TransformationMode transformMode) const
Scales the pixmap to the given \a size, using the aspect ratio and
transformation modes specified by \a aspectRatioMode and \a
transformMode.
\image qimage-scaling.png
\list
\i If \a aspectRatioMode is Qt::IgnoreAspectRatio, the pixmap
is scaled to \a size.
\i If \a aspectRatioMode is Qt::KeepAspectRatio, the pixmap is
scaled to a rectangle as large as possible inside \a size, preserving the aspect ratio.
\i If \a aspectRatioMode is Qt::KeepAspectRatioByExpanding,
the pixmap is scaled to a rectangle as small as possible
outside \a size, preserving the aspect ratio.
\endlist
If the given \a size is empty, this function returns a null
pixmap.
In some cases it can be more beneficial to draw the pixmap to a
painter with a scale set rather than scaling the pixmap. This is
the case when the painter is for instance based on OpenGL or when
the scale factor changes rapidly.
\sa isNull(), {QPixmap#Pixmap Transformations}{Pixmap
Transformations}
*/
QPixmap QPixmap::scaled(const QSize& s, Qt::AspectRatioMode aspectMode, Qt::TransformationMode mode) const
{
if (isNull()) {
qWarning("QPixmap::scaled: Pixmap is a null pixmap");
return QPixmap();
}
if (s.isEmpty())
return QPixmap();
QSize newSize = size();
newSize.scale(s, aspectMode);
newSize.rwidth() = qMax(newSize.width(), 1);
newSize.rheight() = qMax(newSize.height(), 1);
if (newSize == size())
return *this;
QTransform wm = QTransform::fromScale((qreal)newSize.width() / width(),
(qreal)newSize.height() / height());
QPixmap pix = transformed(wm, mode);
return pix;
}
/*!
\fn QPixmap QPixmap::scaledToWidth(int width, Qt::TransformationMode
mode) const
Returns a scaled copy of the image. The returned image is scaled
to the given \a width using the specified transformation \a mode.
The height of the pixmap is automatically calculated so that the
aspect ratio of the pixmap is preserved.
If \a width is 0 or negative, a null pixmap is returned.
\sa isNull(), {QPixmap#Pixmap Transformations}{Pixmap
Transformations}
*/
QPixmap QPixmap::scaledToWidth(int w, Qt::TransformationMode mode) const
{
if (isNull()) {
qWarning("QPixmap::scaleWidth: Pixmap is a null pixmap");
return copy();
}
if (w <= 0)
return QPixmap();
qreal factor = (qreal) w / width();
QTransform wm = QTransform::fromScale(factor, factor);
return transformed(wm, mode);
}
/*!
\fn QPixmap QPixmap::scaledToHeight(int height,
Qt::TransformationMode mode) const
Returns a scaled copy of the image. The returned image is scaled
to the given \a height using the specified transformation \a mode.
The width of the pixmap is automatically calculated so that the
aspect ratio of the pixmap is preserved.
If \a height is 0 or negative, a null pixmap is returned.
\sa isNull(), {QPixmap#Pixmap Transformations}{Pixmap
Transformations}
*/
QPixmap QPixmap::scaledToHeight(int h, Qt::TransformationMode mode) const
{
if (isNull()) {
qWarning("QPixmap::scaleHeight: Pixmap is a null pixmap");
return copy();
}
if (h <= 0)
return QPixmap();
qreal factor = (qreal) h / height();
QTransform wm = QTransform::fromScale(factor, factor);
return transformed(wm, mode);
}
/*!
Returns a copy of the pixmap that is transformed using the given
transformation \a transform and transformation \a mode. The original
pixmap is not changed.
The transformation \a transform is internally adjusted to compensate
for unwanted translation; i.e. the pixmap produced is the smallest
pixmap that contains all the transformed points of the original
pixmap. Use the trueMatrix() function to retrieve the actual
matrix used for transforming the pixmap.
This function is slow because it involves transformation to a
QImage, non-trivial computations and a transformation back to a
QPixmap.
\sa trueMatrix(), {QPixmap#Pixmap Transformations}{Pixmap
Transformations}
*/
QPixmap QPixmap::transformed(const QTransform &transform,
Qt::TransformationMode mode) const
{
if (isNull() || transform.type() <= QTransform::TxTranslate)
return *this;
return data->transformed(transform, mode);
}
/*!
\overload
This convenience function loads the \a matrix into a
QTransform and calls the overloaded function.
*/
QPixmap QPixmap::transformed(const QMatrix &matrix, Qt::TransformationMode mode) const
{
return transformed(QTransform(matrix), mode);
}
/*!
\class QPixmap
\brief The QPixmap class is an off-screen image representation
that can be used as a paint device.
\ingroup painting
\ingroup shared
Qt provides four classes for handling image data: QImage, QPixmap,
QBitmap and QPicture. QImage is designed and optimized for I/O,
and for direct pixel access and manipulation, while QPixmap is
designed and optimized for showing images on screen. QBitmap is
only a convenience class that inherits QPixmap, ensuring a depth
of 1. The isQBitmap() function returns true if a QPixmap object is
really a bitmap, otherwise returns false. Finally, the QPicture class
is a paint device that records and replays QPainter commands.
A QPixmap can easily be displayed on the screen using QLabel or
one of QAbstractButton's subclasses (such as QPushButton and
QToolButton). QLabel has a pixmap property, whereas
QAbstractButton has an icon property.
In addition to the ordinary constructors, a QPixmap can be
constructed using the static grabWidget() and grabWindow()
functions which creates a QPixmap and paints the given widget, or
window, into it.
QPixmap objects can be passed around by value since the QPixmap
class uses implicit data sharing. For more information, see the \l
{Implicit Data Sharing} documentation. QPixmap objects can also be
streamed.
Note that the pixel data in a pixmap is internal and is managed by
the underlying window system. Because QPixmap is a QPaintDevice
subclass, QPainter can be used to draw directly onto pixmaps.
Pixels can only be accessed through QPainter functions or by
converting the QPixmap to a QImage. However, the fill() function
is available for initializing the entire pixmap with a given color.
There are functions to convert between QImage and
QPixmap. Typically, the QImage class is used to load an image
file, optionally manipulating the image data, before the QImage
object is converted into a QPixmap to be shown on
screen. Alternatively, if no manipulation is desired, the image
file can be loaded directly into a QPixmap. On Windows, the
QPixmap class also supports conversion between \c HBITMAP and
QPixmap. On Symbian, the QPixmap class also supports conversion
between CFbsBitmap and QPixmap.
QPixmap provides a collection of functions that can be used to
obtain a variety of information about the pixmap. In addition,
there are several functions that enables transformation of the
pixmap.
\tableofcontents
\section1 Reading and Writing Image Files
QPixmap provides several ways of reading an image file: The file
can be loaded when constructing the QPixmap object, or by using
the load() or loadFromData() functions later on. When loading an
image, the file name can either refer to an actual file on disk or
to one of the application's embedded resources. See \l{The Qt
Resource System} overview for details on how to embed images and
other resource files in the application's executable.
Simply call the save() function to save a QPixmap object.
The complete list of supported file formats are available through
the QImageReader::supportedImageFormats() and
QImageWriter::supportedImageFormats() functions. New file formats
can be added as plugins. By default, Qt supports the following
formats:
\table
\header \o Format \o Description \o Qt's support
\row \o BMP \o Windows Bitmap \o Read/write
\row \o GIF \o Graphic Interchange Format (optional) \o Read
\row \o JPG \o Joint Photographic Experts Group \o Read/write
\row \o JPEG \o Joint Photographic Experts Group \o Read/write
\row \o PNG \o Portable Network Graphics \o Read/write
\row \o PBM \o Portable Bitmap \o Read
\row \o PGM \o Portable Graymap \o Read
\row \o PPM \o Portable Pixmap \o Read/write
\row \o XBM \o X11 Bitmap \o Read/write
\row \o XPM \o X11 Pixmap \o Read/write
\endtable
\section1 Pixmap Information
QPixmap provides a collection of functions that can be used to
obtain a variety of information about the pixmap:
\table
\header
\o \o Available Functions
\row
\o Geometry
\o
The size(), width() and height() functions provide information
about the pixmap's size. The rect() function returns the image's
enclosing rectangle.
\row
\o Alpha component
\o
The hasAlphaChannel() returns true if the pixmap has a format that
respects the alpha channel, otherwise returns false. The hasAlpha(),
setMask() and mask() functions are legacy and should not be used.
They are potentially very slow.
The createHeuristicMask() function creates and returns a 1-bpp
heuristic mask (i.e. a QBitmap) for this pixmap. It works by
selecting a color from one of the corners and then chipping away
pixels of that color, starting at all the edges. The
createMaskFromColor() function creates and returns a mask (i.e. a
QBitmap) for the pixmap based on a given color.
\row
\o Low-level information
\o
The depth() function returns the depth of the pixmap. The
defaultDepth() function returns the default depth, i.e. the depth
used by the application on the given screen.
The cacheKey() function returns a number that uniquely
identifies the contents of the QPixmap object.
The x11Info() function returns information about the configuration
of the X display used by the screen to which the pixmap currently
belongs. The x11PictureHandle() function returns the X11 Picture
handle of the pixmap for XRender support. Note that the two latter
functions are only available on x11.
\endtable
\section1 Pixmap Conversion
A QPixmap object can be converted into a QImage using the
toImage() function. Likewise, a QImage can be converted into a
QPixmap using the fromImage(). If this is too expensive an
operation, you can use QBitmap::fromImage() instead.
In addition, on Windows, the QPixmap class supports conversion to
and from HBITMAP: the toWinHBITMAP() function creates a HBITMAP
equivalent to the QPixmap, based on the given HBitmapFormat, and
returns the HBITMAP handle. The fromWinHBITMAP() function returns
a QPixmap that is equivalent to the given bitmap which has the
specified format. The QPixmap class also supports conversion to
and from HICON: the toWinHICON() function creates a HICON equivalent
to the QPixmap, and returns the HICON handle. The fromWinHICON()
function returns a QPixmap that is equivalent to the given icon.
In addition, on Symbian, the QPixmap class supports conversion to
and from CFbsBitmap: the toSymbianCFbsBitmap() function creates
CFbsBitmap equivalent to the QPixmap, based on given mode and returns
a CFbsBitmap object. The fromSymbianCFbsBitmap() function returns a
QPixmap that is equivalent to the given bitmap and given mode.
\section1 Pixmap Transformations
QPixmap supports a number of functions for creating a new pixmap
that is a transformed version of the original:
The scaled(), scaledToWidth() and scaledToHeight() functions
return scaled copies of the pixmap, while the copy() function
creates a QPixmap that is a plain copy of the original one.
The transformed() function returns a copy of the pixmap that is
transformed with the given transformation matrix and
transformation mode: Internally, the transformation matrix is
adjusted to compensate for unwanted translation,
i.e. transformed() returns the smallest pixmap containing all
transformed points of the original pixmap. The static trueMatrix()
function returns the actual matrix used for transforming the
pixmap.
\note When using the native X11 graphics system, the pixmap
becomes invalid when the QApplication instance is destroyed.
\sa QBitmap, QImage, QImageReader, QImageWriter
*/
/*!
\typedef QPixmap::DataPtr
\internal
*/
/*!
\fn DataPtr &QPixmap::data_ptr()
\internal
*/
/*!
Returns true if this pixmap has an alpha channel, \e or has a
mask, otherwise returns false.
\sa hasAlphaChannel(), mask()
*/
bool QPixmap::hasAlpha() const
{
#if defined(Q_WS_X11)
if (data && data->hasAlphaChannel())
return true;
QPixmapData *pd = pixmapData();
if (pd && pd->classId() == QPixmapData::X11Class) {
QX11PixmapData *x11Data = static_cast<QX11PixmapData*>(pd);
#ifndef QT_NO_XRENDER
if (x11Data->picture && x11Data->d == 32)
return true;
#endif
if (x11Data->d == 1 || x11Data->x11_mask)
return true;
}
return false;
#else
return data && data->hasAlphaChannel();
#endif
}
/*!
Returns true if the pixmap has a format that respects the alpha
channel, otherwise returns false.
\sa hasAlpha()
*/
bool QPixmap::hasAlphaChannel() const
{
return data && data->hasAlphaChannel();
}
/*!
\internal
*/
int QPixmap::metric(PaintDeviceMetric metric) const
{
return data ? data->metric(metric) : 0;
}
/*!
\internal
*/
QPaintEngine *QPixmap::paintEngine() const
{
return data ? data->paintEngine() : 0;
}
/*!
\fn QBitmap QPixmap::mask() const
Extracts a bitmap mask from the pixmap's alpha channel.
\warning This is potentially an expensive operation. The mask of
the pixmap is extracted dynamically from the pixeldata.
\sa setMask(), {QPixmap#Pixmap Information}{Pixmap Information}
*/
QBitmap QPixmap::mask() const
{
return data ? data->mask() : QBitmap();
}
/*!
Returns the default pixmap depth used by the application.
On Windows and Mac, the default depth is always 32. On X11 and
embedded, the depth of the screen will be returned by this
function.
\sa depth(), QColormap::depth(), {QPixmap#Pixmap Information}{Pixmap Information}
*/
int QPixmap::defaultDepth()
{
#if defined(Q_WS_X11)
return QX11Info::appDepth();
#elif defined(Q_WS_WINCE)
return QColormap::instance().depth();
#elif defined(Q_WS_WIN)
return 32; // XXX
#elif defined(Q_WS_MAC)
return 32;
#endif
}
/*!
Detaches the pixmap from shared pixmap data.
A pixmap is automatically detached by Qt whenever its contents are
about to change. This is done in almost all QPixmap member
functions that modify the pixmap (fill(), fromImage(),
load(), etc.), and in QPainter::begin() on a pixmap.
There are two exceptions in which detach() must be called
explicitly, that is when calling the handle() or the
x11PictureHandle() function (only available on X11). Otherwise,
any modifications done using system calls, will be performed on
the shared data.
The detach() function returns immediately if there is just a
single reference or if the pixmap has not been initialized yet.
*/
void QPixmap::detach()
{
if (!data)
return;
// QPixmap.data member may be QRuntimePixmapData so use pixmapData() function to get
// the actual underlaying runtime pixmap data.
QPixmapData *pd = pixmapData();
QPixmapData::ClassId id = pd->classId();
if (id == QPixmapData::RasterClass) {
QRasterPixmapData *rasterData = static_cast<QRasterPixmapData*>(pd);
rasterData->image.detach();
}
if (data->is_cached && data->ref == 1)
QImagePixmapCleanupHooks::executePixmapDataModificationHooks(data.data());
if (data->ref != 1) {
*this = copy();
}
++data->detach_no;
#if defined(Q_WS_X11)
if (pd->classId() == QPixmapData::X11Class) {
QX11PixmapData *d = static_cast<QX11PixmapData*>(pd);
d->flags &= ~QX11PixmapData::Uninitialized;
// reset the cache data
if (d->hd2) {
XFreePixmap(X11->display, d->hd2);
d->hd2 = 0;
}
}
#endif
}
/*!
\fn QPixmap QPixmap::fromImage(const QImage &image, Qt::ImageConversionFlags flags)
Converts the given \a image to a pixmap using the specified \a
flags to control the conversion. The \a flags argument is a
bitwise-OR of the \l{Qt::ImageConversionFlags}. Passing 0 for \a
flags sets all the default options.
In case of monochrome and 8-bit images, the image is first
converted to a 32-bit pixmap and then filled with the colors in
the color table. If this is too expensive an operation, you can
use QBitmap::fromImage() instead.
\sa fromImageReader(), toImage(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
QPixmap QPixmap::fromImage(const QImage &image, Qt::ImageConversionFlags flags)
{
if (image.isNull())
return QPixmap();
QGraphicsSystem* gs = QApplicationPrivate::graphics_system;
QScopedPointer<QPixmapData> data(gs ? gs->createPixmapData(QPixmapData::PixmapType)
: QGraphicsSystem::createDefaultPixmapData(QPixmapData::PixmapType));
data->fromImage(image, flags);
return QPixmap(data.take());
}
/*!
\fn QPixmap QPixmap::fromImageReader(QImageReader *imageReader, Qt::ImageConversionFlags flags)
Create a QPixmap from an image read directly from an \a imageReader.
The \a flags argument is a bitwise-OR of the \l{Qt::ImageConversionFlags}.
Passing 0 for \a flags sets all the default options.
On some systems, reading an image directly to QPixmap can use less memory than
reading a QImage to convert it to QPixmap.
\sa fromImage(), toImage(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
QPixmap QPixmap::fromImageReader(QImageReader *imageReader, Qt::ImageConversionFlags flags)
{
QGraphicsSystem *gs = QApplicationPrivate::graphics_system;
QScopedPointer<QPixmapData> data(gs ? gs->createPixmapData(QPixmapData::PixmapType)
: QGraphicsSystem::createDefaultPixmapData(QPixmapData::PixmapType));
data->fromImageReader(imageReader, flags);
return QPixmap(data.take());
}
/*!
\fn QPixmap QPixmap::grabWindow(WId window, int x, int y, int
width, int height)
Creates and returns a pixmap constructed by grabbing the contents
of the given \a window restricted by QRect(\a x, \a y, \a width,
\a height).
The arguments (\a{x}, \a{y}) specify the offset in the window,
whereas (\a{width}, \a{height}) specify the area to be copied. If
\a width is negative, the function copies everything to the right
border of the window. If \a height is negative, the function
copies everything to the bottom of the window.
The window system identifier (\c WId) can be retrieved using the
QWidget::winId() function. The rationale for using a window
identifier and not a QWidget, is to enable grabbing of windows
that are not part of the application, window system frames, and so
on.
The grabWindow() function grabs pixels from the screen, not from
the window, i.e. if there is another window partially or entirely
over the one you grab, you get pixels from the overlying window,
too. The mouse cursor is generally not grabbed.
Note on X11 that if the given \a window doesn't have the same depth
as the root window, and another window partially or entirely
obscures the one you grab, you will \e not get pixels from the
overlying window. The contents of the obscured areas in the
pixmap will be undefined and uninitialized.
On Windows Vista and above grabbing a layered window, which is
created by setting the Qt::WA_TranslucentBackground attribute, will
not work. Instead grabbing the desktop widget should work.
\warning In general, grabbing an area outside the screen is not
safe. This depends on the underlying window system.
\sa grabWidget(), {Screenshot Example}
*/
/*!
\internal
*/
QPixmapData* QPixmap::pixmapData() const
{
if (data) {
QPixmapData* pm = data.data();
return pm->runtimeData() ? pm->runtimeData() : pm;
}
return 0;
}
/*!
\enum QPixmap::HBitmapFormat
\bold{Win32 only:} This enum defines how the conversion between \c
HBITMAP and QPixmap is performed.
\warning This enum is only available on Windows.
\value NoAlpha The alpha channel is ignored and always treated as
being set to fully opaque. This is preferred if the \c HBITMAP is
used with standard GDI calls, such as \c BitBlt().
\value PremultipliedAlpha The \c HBITMAP is treated as having an
alpha channel and premultiplied colors. This is preferred if the
\c HBITMAP is accessed through the \c AlphaBlend() GDI function.
\value Alpha The \c HBITMAP is treated as having a plain alpha
channel. This is the preferred format if the \c HBITMAP is going
to be used as an application icon or systray icon.
\sa fromWinHBITMAP(), toWinHBITMAP()
*/
/*! \fn HBITMAP QPixmap::toWinHBITMAP(HBitmapFormat format) const
\bold{Win32 only:} Creates a \c HBITMAP equivalent to the QPixmap,
based on the given \a format. Returns the \c HBITMAP handle.
It is the caller's responsibility to free the \c HBITMAP data
after use.
\warning This function is only available on Windows.
\sa fromWinHBITMAP(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
/*! \fn QPixmap QPixmap::fromWinHBITMAP(HBITMAP bitmap, HBitmapFormat format)
\bold{Win32 only:} Returns a QPixmap that is equivalent to the
given \a bitmap. The conversion is based on the specified \a
format.
\warning This function is only available on Windows.
\sa toWinHBITMAP(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
/*! \fn HICON QPixmap::toWinHICON() const
\since 4.6
\bold{Win32 only:} Creates a \c HICON equivalent to the QPixmap.
Returns the \c HICON handle.
It is the caller's responsibility to free the \c HICON data after use.
\warning This function is only available on Windows.
\sa fromWinHICON(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
/*! \fn QPixmap QPixmap::fromWinHICON(HICON icon)
\since 4.6
\bold{Win32 only:} Returns a QPixmap that is equivalent to the given
\a icon.
\warning This function is only available on Windows.
\sa toWinHICON(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}
*/
/*! \fn const QX11Info &QPixmap::x11Info() const
\bold{X11 only:} Returns information about the configuration of
the X display used by the screen to which the pixmap currently belongs.
\warning This function is only available on X11.
\sa {QPixmap#Pixmap Information}{Pixmap Information}
*/
/*! \fn Qt::HANDLE QPixmap::x11PictureHandle() const
\bold{X11 only:} Returns the X11 Picture handle of the pixmap for
XRender support.
This function will return 0 if XRender support is not compiled
into Qt, if the XRender extension is not supported on the X11
display, or if the handle could not be created. Use of this
function is not portable.
\warning This function is only available on X11.
\sa {QPixmap#Pixmap Information}{Pixmap Information}
*/
/*! \fn int QPixmap::x11SetDefaultScreen(int screen)
\internal
*/
/*! \fn void QPixmap::x11SetScreen(int screen)
\internal
*/
/*! \fn QRgb* QPixmap::clut() const
\internal
*/
/*! \fn int QPixmap::colorCount() const
\since 4.6
\internal
*/
QT_END_NAMESPACE
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