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>

1 files changed, 17 insertions, 1 deletions

diff --git a/src/quick/items/qquickborderimage.cpp b/src/quick/items/qquickborderimage.cpp
index c53a39ca09..430fa1b094 100644
--- a/src/quick/items/qquickborderimage.cpp
+++ b/src/quick/items/qquickborderimage.cpp
@@ -343,7 +343,7 @@ void QQuickBorderImage::load()
 
             QUrl loadUrl = d->url;
             resolve2xLocalFile(d->url, targetDevicePixelRatio, &loadUrl, &d->devicePixelRatio);
-            d->pix.load(qmlEngine(this), loadUrl, d->sourcesize * d->devicePixelRatio, options);
+            d->pix.load(qmlEngine(this), loadUrl, d->sourcesize * d->devicePixelRatio, options, QQuickImageProviderOptions(), d->currentFrame, d->frameCount);
 
             if (d->pix.isLoading()) {
                 if (d->progress != 0.0) {
@@ -534,6 +534,10 @@ void QQuickBorderImage::requestFinished()
         d->oldSourceSize = sourceSize();
         emit sourceSizeChanged();
     }
+    if (d->frameCount != d->pix.frameCount()) {
+        d->frameCount = d->pix.frameCount();
+        emit frameCountChanged();
+    }
 
     pixmapChange();
 }
@@ -693,6 +697,18 @@ void QQuickBorderImage::pixmapChange()
     update();
 }
 
+/*!
+    \qmlproperty int QtQuick::BorderImage::currentFrame
+    \qmlproperty int QtQuick::BorderImage::frameCount
+    \since 5.14
+
+    currentFrame is the frame that is currently visible. The default is \c 0.
+    You can set it to a number between \c 0 and \c {frameCount - 1} to display a
+    different frame, if the image contains multiple frames.
+
+    frameCount is the number of frames in the image. Most images have only one frame.
+*/
+
 QT_END_NAMESPACE
 
 #include "moc_qquickborderimage_p.cpp"