Add support for multipage TIFF images to QTiffHandlerv5.9.0-alpha1

Allows multipage TIFF images to be read via QImageReader::jumpToImage
and QImageReader::jumpNextToImage.

[ChangeLog][QtGui][QImageReader] Support multipage TIFF images through
QImageReader

Change-Id: Id6ac68b75500148e51be11eff3d296c929d2d95c
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

3 files changed, 45 insertions, 0 deletions

diff --git a/tests/auto/tiff/tst_qtiff.cpp b/tests/auto/tiff/tst_qtiff.cpp
index 8e3d0c9..65cc56c 100644
--- a/tests/auto/tiff/tst_qtiff.cpp
+++ b/tests/auto/tiff/tst_qtiff.cpp
@@ -78,6 +78,9 @@ private slots:
     void resolution_data();
     void resolution();
 
+    void multipage_data();
+    void multipage();
+
 private:
     QString prefix;
 };
@@ -513,5 +516,46 @@ void tst_qtiff::resolution()
     QCOMPARE(expectedDotsPerMeterY, generatedImage.dotsPerMeterY());
 }
 
+void tst_qtiff::multipage_data()
+{
+    QTest::addColumn<QString>("filename");
+    QTest::addColumn<int>("expectedNumPages");
+    QTest::addColumn<QVector<QSize>>("expectedSizes");
+
+    QVector<QSize> sizes = QVector<QSize>() << QSize(640, 480) << QSize(800, 600) << QSize(320, 240);
+    QTest::newRow("3 page TIFF") << ("multipage.tiff") << 3 << sizes;
+}
+
+void tst_qtiff::multipage()
+{
+    QFETCH(QString, filename);
+    QFETCH(int, expectedNumPages);
+    QFETCH(QVector<QSize>, expectedSizes);
+
+    QImageReader reader(prefix + filename);
+    QCOMPARE(reader.imageCount(), expectedNumPages);
+
+    // Test jumpToImage, currentImageNumber and whether the actual image is correct
+    QCOMPARE(reader.jumpToImage(-1), false);
+    for (int i = 0; i < expectedNumPages; ++i) {
+        reader.jumpToImage(i);
+        QCOMPARE(reader.currentImageNumber(), i);
+        QSize size = reader.size();
+        QCOMPARE(size.width(), expectedSizes[i].width());
+        QCOMPARE(size.height(), expectedSizes[i].height());
+        QImage image = reader.read();
+        QVERIFY2(!image.isNull(), qPrintable(reader.errorString()));
+    }
+    QCOMPARE(reader.jumpToImage(expectedNumPages), false);
+
+    // Test jumpToNextImage
+    reader.jumpToImage(0);
+    QCOMPARE(reader.currentImageNumber(), 0);
+    for (int i = 0; i < expectedNumPages - 1; ++i) {
+        QCOMPARE(reader.jumpToNextImage(), true);
+    }
+    QCOMPARE(reader.jumpToNextImage(), false);
+}
+
 QTEST_MAIN(tst_qtiff)
 #include "tst_qtiff.moc"
diff --git a/tests/shared/images/tiff.qrc b/tests/shared/images/tiff.qrc
index 8fcab8b..c98a72c 100644
--- a/tests/shared/images/tiff.qrc
+++ b/tests/shared/images/tiff.qrc
@@ -21,6 +21,7 @@
         <file>tiff/mono_orientation_6.tiff</file>
         <file>tiff/mono_orientation_7.tiff</file>
         <file>tiff/mono_orientation_8.tiff</file>
+        <file>tiff/multipage.tiff</file>
         <file>tiff/original_indexed.tiff</file>
         <file>tiff/original_mono.tiff</file>
         <file>tiff/original_rgb.tiff</file>
diff --git a/tests/shared/images/tiff/multipage.tiff b/tests/shared/images/tiff/multipage.tiff
new file mode 100644
index 0000000..0c2f266
--- /dev/null
+++ b/tests/shared/images/tiff/multipage.tiff