Preserve QImage metadata in image transforms

Some QImage methods were not preserving image metadata, or only
preserving some of it. This adds the missing parts and adds a test for
metadata.

Change-Id: Ib5892a23e49dfde5ea26074d3deaa887fa930c6b
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/tests/auto/gui/image/qimage/tst_qimage.cpp b/tests/auto/gui/image/qimage/tst_qimage.cpp
index 5691a654d7..51e4c6233e 100644
--- a/tests/auto/gui/image/qimage/tst_qimage.cpp
+++ b/tests/auto/gui/image/qimage/tst_qimage.cpp
@@ -184,6 +184,8 @@ private slots:
 
     void devicePixelRatio();
 
+    void metadataPassthrough();
+
 private:
     const QString m_prefix;
 };
@@ -2827,5 +2829,39 @@ void tst_QImage::devicePixelRatio()
     QCOMPARE(b.devicePixelRatio(), qreal(1.0));
 }
 
+void tst_QImage::metadataPassthrough()
+{
+    QImage a(64, 64, QImage::Format_ARGB32);
+    a.fill(Qt::white);
+    a.setText(QStringLiteral("Test"), QStringLiteral("Text"));
+    a.setDotsPerMeterX(100);
+    a.setDotsPerMeterY(80);
+    a.setDevicePixelRatio(2.0);
+
+    QImage scaled = a.scaled(QSize(32, 32), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+    QCOMPARE(scaled.text(QStringLiteral("Test")), a.text(QStringLiteral("Test")));
+    QCOMPARE(scaled.dotsPerMeterX(), a.dotsPerMeterX());
+    QCOMPARE(scaled.dotsPerMeterY(), a.dotsPerMeterY());
+    QCOMPARE(scaled.devicePixelRatio(), a.devicePixelRatio());
+
+    scaled = a.scaled(QSize(128, 128), Qt::IgnoreAspectRatio, Qt::FastTransformation);
+    QCOMPARE(scaled.text(QStringLiteral("Test")), a.text(QStringLiteral("Test")));
+    QCOMPARE(scaled.dotsPerMeterX(), a.dotsPerMeterX());
+    QCOMPARE(scaled.dotsPerMeterY(), a.dotsPerMeterY());
+    QCOMPARE(scaled.devicePixelRatio(), a.devicePixelRatio());
+
+    QImage mirrored = a.mirrored();
+    QCOMPARE(mirrored.text(QStringLiteral("Test")), a.text(QStringLiteral("Test")));
+    QCOMPARE(mirrored.dotsPerMeterX(), a.dotsPerMeterX());
+    QCOMPARE(mirrored.dotsPerMeterY(), a.dotsPerMeterY());
+    QCOMPARE(mirrored.devicePixelRatio(), a.devicePixelRatio());
+
+    QImage swapped = a.rgbSwapped();
+    QCOMPARE(swapped.text(QStringLiteral("Test")), a.text(QStringLiteral("Test")));
+    QCOMPARE(swapped.dotsPerMeterX(), a.dotsPerMeterX());
+    QCOMPARE(swapped.dotsPerMeterY(), a.dotsPerMeterY());
+    QCOMPARE(swapped.devicePixelRatio(), a.devicePixelRatio());
+}
+
 QTEST_GUILESS_MAIN(tst_QImage)
 #include "tst_qimage.moc"