Optionally apply orientation on QImage read

Make it possible to read images with EXIF orientation automatically
applied. This was originally implemented without opt-out in Qt 5.4, but
reverted. Here it is implemented as opt-in for JPEG, and opt-out for TIFF
to keep behavioral consistency.

The EXIF support for JPEG was written by Rainer Keller.

[ChangeLog][QtGui][Image plugins] An option has been added to
QImageReader to enable automatic application of EXIF orientation.
This behavior was default in Qt 5.4.1, but reverted in Qt 5.4.2.

Task-number: QTBUG-37946
Task-number: QTBUG-43563
Task-number: QTBUG-45552
Task-number: QTBUG-45865
Change-Id: Iaafd2519b63ede66ecc1f8aa4c7118081312b8f5
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

1 files changed, 18 insertions, 1 deletions

diff --git a/src/gui/image/qimageiohandler.h b/src/gui/image/qimageiohandler.h
index b48226f619..80cd87c4c3 100644
--- a/src/gui/image/qimageiohandler.h
+++ b/src/gui/image/qimageiohandler.h
@@ -86,8 +86,25 @@ public:
         ImageFormat,
         SupportedSubTypes,
         OptimizedWrite,
-        ProgressiveScanWrite
+        ProgressiveScanWrite,
+        ImageTransformation
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+        , TransformedByDefault
+#endif
     };
+
+    enum Transformation {
+        TransformationNone = 0,
+        TransformationMirror = 1,
+        TransformationFlip = 2,
+        TransformationRotate180 = TransformationMirror | TransformationFlip,
+        TransformationRotate90 = 4,
+        TransformationMirrorAndRotate90 = TransformationMirror | TransformationRotate90,
+        TransformationFlipAndRotate90 = TransformationFlip | TransformationRotate90,
+        TransformationRotate270 = TransformationRotate180 | TransformationRotate90
+    };
+    Q_DECLARE_FLAGS(Transformations, Transformation)
+
     virtual QVariant option(ImageOption option) const;
     virtual void setOption(ImageOption option, const QVariant &value);
     virtual bool supportsOption(ImageOption option) const;