diff options
| -rw-r--r-- | src/gui/image/qpixmap.cpp | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp index d1e5c40..1df7946 100644 --- a/src/gui/image/qpixmap.cpp +++ b/src/gui/image/qpixmap.cpp @@ -1670,10 +1670,9 @@ QPixmap QPixmap::transformed(const QMatrix &matrix, Qt::TransformationMode mode) \o The hasAlphaChannel() returns true if the pixmap has a format that - respects the alpha channel, otherwise returns false, while the - hasAlpha() function returns true if the pixmap has an alpha - channel \e or a mask (otherwise false). The mask() function returns - the mask as a QBitmap object, which can be set using setMask(). + 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 @@ -1760,6 +1759,8 @@ QPixmap QPixmap::transformed(const QMatrix &matrix, Qt::TransformationMode mode) Returns true if this pixmap has an alpha channel, \e or has a mask, otherwise returns false. + \warning This is potentially an expensive operation. + \sa hasAlphaChannel(), mask() */ bool QPixmap::hasAlpha() const |