Move currentFrame and frameCount properties up to QQuickImageBase

AnimatedImage already had these properties, but some typically non-animated
image formats such as PDF, TIFF and ICO can also support multiple pages.
In either case, the currentFrame property can be used to select a specific
frame or page.  However an AnimatedImage uses a QMovie to do that, whereas
a plain Image uses QQuickPixmap.  So the accessors need to be virtual in
order to have these different implementations.

[ChangeLog][QtQuick][Image] Image and BorderImage now have currentFrame
and frameCount properties which can be used to step through the frames of
multi-page image formats such as TIFF, WEBP and ICO.

Task-number: QTBUG-77506
Change-Id: Id4d95a99a26a862957e44b1bd8ffe06d7eababef
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

4 files changed, 63 insertions, 0 deletions

diff --git a/tests/auto/quick/qquickimage/data/multi.ico b/tests/auto/quick/qquickimage/data/multi.ico
new file mode 100644
index 0000000000..b748ceaa29
--- /dev/null
+++ b/tests/auto/quick/qquickimage/data/multi.ico
diff --git a/tests/auto/quick/qquickimage/data/multiframe.qml b/tests/auto/quick/qquickimage/data/multiframe.qml
new file mode 100644
index 0000000000..df70bc784c
--- /dev/null
+++ b/tests/auto/quick/qquickimage/data/multiframe.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.14
+
+Image {
+    source: "multi.ico"
+}
diff --git a/tests/auto/quick/qquickimage/data/multiframeAsync.qml b/tests/auto/quick/qquickimage/data/multiframeAsync.qml
new file mode 100644
index 0000000000..167b4a3e57
--- /dev/null
+++ b/tests/auto/quick/qquickimage/data/multiframeAsync.qml
@@ -0,0 +1,6 @@
+import QtQuick 2.14
+
+Image {
+    source: "multi.ico"
+    asynchronous: true
+}
diff --git a/tests/auto/quick/qquickimage/tst_qquickimage.cpp b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
index 34c18aa64b..23635590e4 100644
--- a/tests/auto/quick/qquickimage/tst_qquickimage.cpp
+++ b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
@@ -97,6 +97,8 @@ private slots:
     void highDpiFillModesAndSizes();
     void hugeImages();
     void urlInterceptor();
+    void multiFrame_data();
+    void multiFrame();
 
 private:
     QQmlEngine engine;
@@ -1132,6 +1134,56 @@ void tst_qquickimage::urlInterceptor()
     QTRY_COMPARE(object->progress(), 1.0);
 }
 
+void tst_qquickimage::multiFrame_data()
+{
+    QTest::addColumn<QString>("qmlfile");
+    QTest::addColumn<bool>("asynchronous");
+
+    QTest::addRow("default") << "multiframe.qml" << false;
+    QTest::addRow("async") << "multiframeAsync.qml" << true;
+}
+
+void tst_qquickimage::multiFrame()
+{
+    QFETCH(QString, qmlfile);
+    QFETCH(bool, asynchronous);
+    Q_UNUSED(asynchronous)
+
+    QQuickView view(testFileUrl(qmlfile));
+    QQuickImage *image = qobject_cast<QQuickImage*>(view.rootObject());
+    QVERIFY(image);
+    QSignalSpy countSpy(image, SIGNAL(frameCountChanged()));
+    QSignalSpy currentSpy(image, SIGNAL(currentFrameChanged()));
+    if (asynchronous) {
+        QCOMPARE(image->frameCount(), 0);
+        QTRY_COMPARE(image->frameCount(), 4);
+        QCOMPARE(countSpy.count(), 1);
+    } else {
+        QCOMPARE(image->frameCount(), 4);
+    }
+    QCOMPARE(image->currentFrame(), 0);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+
+    QImage contents = view.grabWindow();
+    // The first frame is a blue ball, approximately qRgba(0x33, 0x6d, 0xcc, 0xff)
+    QRgb color = contents.pixel(16, 16);
+    QVERIFY(qRed(color) < 0xc0);
+    QVERIFY(qGreen(color) < 0xc0);
+    QVERIFY(qBlue(color) > 0xc0);
+
+    image->setCurrentFrame(1);
+    QTRY_COMPARE(image->status(), QQuickImageBase::Ready);
+    QCOMPARE(currentSpy.count(), 1);
+    QCOMPARE(image->currentFrame(), 1);
+    contents = view.grabWindow();
+    // The second frame is a green ball, approximately qRgba(0x27, 0xc8, 0x22, 0xff)
+    color = contents.pixel(16, 16);
+    QVERIFY(qRed(color) < 0xc0);
+    QVERIFY(qGreen(color) > 0xc0);
+    QVERIFY(qBlue(color) < 0xc0);
+}
+
 QTEST_MAIN(tst_qquickimage)
 
 #include "tst_qquickimage.moc"