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| author | Tor Arne Vestbø <tor.arne.vestbo@qt.io> | 2021-11-17 13:37:08 +0100 |
|---|---|---|
| committer | Tor Arne Vestbø <tor.arne.vestbo@qt.io> | 2021-11-18 23:41:02 +0100 |
| commit | 3cc1a32f97d2d3fe4a4c4eb83b46bdeb79cd64c3 (patch) | |
| tree | fc2c4a91f66a1591040663acfd77adca011a21f5 /src/gui/painting | |
| parent | 71f75bf6c5140920227f6019716c05fe7bfb0b20 (diff) | |
Clarify validity of image returned from QPlatformBackingStore::toImage()
The backingstore may reconfigure the internal data, so clients should
not assume that the image is valid beyond any new operations on the
backingstore.
Pick-to: 6.2
Change-Id: I137ad4f2adb45ec8bb78a989fbb5bac1e72965ce
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Diffstat (limited to 'src/gui/painting')
| -rw-r--r-- | src/gui/painting/qplatformbackingstore.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/gui/painting/qplatformbackingstore.cpp b/src/gui/painting/qplatformbackingstore.cpp index bf7dc55644..3bd9746441 100644 --- a/src/gui/painting/qplatformbackingstore.cpp +++ b/src/gui/painting/qplatformbackingstore.cpp @@ -217,12 +217,17 @@ void QPlatformBackingStore::composeAndFlush(QWindow *window, const QRegion ®i If QPlatformIntegration::RasterGLSurface is supported, either this function or toTexture() must be implemented. + The returned image is only valid until the next operation (resize, paint, scroll, + or flush) on the backingstore. The caller must not store the return value between + calls, but instead call this function before each use, or make an explicit copy. + \sa toTexture() */ QImage QPlatformBackingStore::toImage() const { return QImage(); } + #ifndef QT_NO_OPENGL /*! May be reimplemented in subclasses to return the content of the |