diff options
| -rw-r--r-- | src/gui/graphicsview/qgraphicsproxywidget.cpp | 8 | ||||
| -rw-r--r-- | src/gui/image/qimage.cpp | 12 | ||||
| -rw-r--r-- | src/gui/image/qpixmap.cpp | 18 | ||||
| -rw-r--r-- | src/gui/painting/qpainter.cpp | 10 |
4 files changed, 43 insertions, 5 deletions
diff --git a/src/gui/graphicsview/qgraphicsproxywidget.cpp b/src/gui/graphicsview/qgraphicsproxywidget.cpp index 1d2721b..e660879 100644 --- a/src/gui/graphicsview/qgraphicsproxywidget.cpp +++ b/src/gui/graphicsview/qgraphicsproxywidget.cpp @@ -177,6 +177,10 @@ QT_BEGIN_NAMESPACE while the widget is embedded. In this state, the widget may differ slightly in behavior from when it is not embedded. + \warning This class is provided for convenience when bridging + QWidgets and QGraphicsItems, it should not be used for + high-performance scenarios. + \sa QGraphicsScene::addWidget(), QGraphicsWidget */ @@ -1033,7 +1037,7 @@ void QGraphicsProxyWidget::dragMoveEvent(QGraphicsSceneDragDropEvent *event) if (receiver != d->dragDropWidget) { // Try to enter before we leave QDragEnterEvent dragEnter(receiverPos, event->possibleActions(), event->mimeData(), event->buttons(), event->modifiers()); - dragEnter.setDropAction(event->proposedAction()); + dragEnter.setDropAction(event->proposedAction()); QApplication::sendEvent(receiver, &dragEnter); event->setAccepted(dragEnter.isAccepted()); event->setDropAction(dragEnter.dropAction()); @@ -1431,7 +1435,7 @@ int QGraphicsProxyWidget::type() const Creates a proxy widget for the given \a child of the widget contained in this proxy. - + This function makes it possible to aquire proxies for non top-level widgets. For instance, you can embed a dialog, and then transform only one of its widgets. diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp index dc236e4..6945ef8 100644 --- a/src/gui/image/qimage.cpp +++ b/src/gui/image/qimage.cpp @@ -114,7 +114,7 @@ Q_GUI_EXPORT _qt_image_cleanup_hook qt_image_cleanup_hook = 0; typedef void (*_qt_image_cleanup_hook_64)(qint64); Q_GUI_EXPORT _qt_image_cleanup_hook_64 qt_image_cleanup_hook_64 = 0; -static QImage rotated90(const QImage &src); +static QImage rotated90(const QImage &src);= static QImage rotated180(const QImage &src); static QImage rotated270(const QImage &src); @@ -3607,6 +3607,9 @@ int QImage::pixelIndex(int x, int y) const If the \a position is not valid, the results are undefined. + \warning This function is expensive when used for massive pixel + manipulations. + \sa setPixel(), valid(), {QImage#Pixel Manipulation}{Pixel Manipulation} */ @@ -5581,6 +5584,8 @@ bool QImage::isDetached() const Use one of the composition mods in QPainter::CompositionMode instead. + \warning This function is expensive. + \sa alphaChannel(), {QImage#Image Transformations}{Image Transformations}, {QImage#Image Formats}{Image Formats} */ @@ -5663,6 +5668,11 @@ void QImage::setAlphaChannel(const QImage &alphaChannel) \l{QPixmap::}{alphaChannel()}, which works in the same way as this function on QPixmaps. + Most usecases for this function can be replaced with QPainter and + using composition modes. + + \warning This is an expensive function. + \sa setAlphaChannel(), hasAlphaChannel(), {QPixmap#Pixmap Information}{Pixmap}, {QImage#Image Transformations}{Image Transformations} diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp index 8684a1b..efb8260 100644 --- a/src/gui/image/qpixmap.cpp +++ b/src/gui/image/qpixmap.cpp @@ -674,7 +674,7 @@ void QPixmap::resize_helper(const QSize &s) pixels black. The effect of this function is undefined when the pixmap is being painted on. - This is potentially an expensive operation. + \warning This is potentially an expensive operation. \sa mask(), {QPixmap#Pixmap Transformations}{Pixmap Transformations}, QBitmap @@ -1380,6 +1380,12 @@ void QPixmap::deref() 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} @@ -1751,6 +1757,10 @@ int QPixmap::metric(PaintDeviceMetric metric) const The effect of this function is undefined when the pixmap is being painted on. + \warning This is potentially an expensive operation. Most usecases + for this function are covered by QPainter and compositionModes + which will normally execute faster. + \sa alphaChannel(), {QPixmap#Pixmap Transformations}{Pixmap Transformations} */ @@ -1793,6 +1803,9 @@ void QPixmap::setAlphaChannel(const QPixmap &alphaChannel) \image alphachannelimage.png The pixmap and channelImage QPixmaps + \warning This is an expensive operation. The alpha channel of the + pixmap is extracted dynamically from the pixeldata. + \sa setAlphaChannel(), {QPixmap#Pixmap Information}{Pixmap Information} */ @@ -1814,7 +1827,8 @@ QPaintEngine *QPixmap::paintEngine() const Extracts a bitmap mask from the pixmap's alphachannel. - This is potentially an expensive operation. + \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} */ diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp index b2f0ac4..2beb8c2 100644 --- a/src/gui/painting/qpainter.cpp +++ b/src/gui/painting/qpainter.cpp @@ -2371,6 +2371,11 @@ void QPainter::setClipping(bool enable) Returns the currently set clip region. Note that the clip region is given in logical coordinates. + \warning QPainter does not store the combined clip explicitly as + this is handled by the underlying QPaintEngine, so the path is + recreated on demand and transformed to the current logical + coordinate system. This is potentially an expensive operation. + \sa setClipRegion(), clipPath(), setClipping() */ @@ -2486,6 +2491,11 @@ extern QPainterPath qt_regionToPath(const QRegion ®ion); Returns the currently clip as a path. Note that the clip path is given in logical coordinates. + \warning QPainter does not store the combined clip explicitly as + this is handled by the underlying QPaintEngine, so the path is + recreated on demand and transformed to the current logical + coordinate system. This is potentially an expensive operation. + \sa setClipPath(), clipRegion(), setClipping() */ QPainterPath QPainter::clipPath() const |