QQuickImage: take DPI into account for implicit and painted sizes

As an example, an @2x image will report an implicit size that is twice
as large as it should be when its fillMode is set to PreserveAspectFit.

This commit adds code that was likely missed in 63fb30eb.

Change-Id: I38cfdf3a429726639209c88dfb38eebb0b9ff162
Reviewed-by: Robin Burchell <robin.burchell@crimson.no>
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

2 files changed, 79 insertions, 14 deletions

diff --git a/src/quick/items/qquickimage.cpp b/src/quick/items/qquickimage.cpp
index f71a2fbdbd..f3d7dc4b56 100644
--- a/src/quick/items/qquickimage.cpp
+++ b/src/quick/items/qquickimage.cpp
@@ -514,37 +514,41 @@ void QQuickImage::updatePaintedGeometry()
             setImplicitSize(0, 0);
             return;
         }
-        qreal w = widthValid() ? width() : d->pix.width();
-        qreal widthScale = w / qreal(d->pix.width());
-        qreal h = heightValid() ? height() : d->pix.height();
-        qreal heightScale = h / qreal(d->pix.height());
+        const qreal pixWidth = d->pix.width() / d->devicePixelRatio;
+        const qreal pixHeight = d->pix.height() / d->devicePixelRatio;
+        const qreal w = widthValid() ? width() : pixWidth;
+        const qreal widthScale = w / pixWidth;
+        const qreal h = heightValid() ? height() : pixHeight;
+        const qreal heightScale = h / pixHeight;
         if (widthScale <= heightScale) {
             d->paintedWidth = w;
-            d->paintedHeight = widthScale * qreal(d->pix.height());
+            d->paintedHeight = widthScale * pixHeight;
         } else if (heightScale < widthScale) {
-            d->paintedWidth = heightScale * qreal(d->pix.width());
+            d->paintedWidth = heightScale * pixWidth;
             d->paintedHeight = h;
         }
-        qreal iHeight = (widthValid() && !heightValid()) ? d->paintedHeight : d->pix.height();
-        qreal iWidth = (heightValid() && !widthValid()) ? d->paintedWidth : d->pix.width();
+        const qreal iHeight = (widthValid() && !heightValid()) ? d->paintedHeight : pixHeight;
+        const qreal iWidth = (heightValid() && !widthValid()) ? d->paintedWidth : pixWidth;
         setImplicitSize(iWidth, iHeight);
 
     } else if (d->fillMode == PreserveAspectCrop) {
         if (!d->pix.width() || !d->pix.height())
             return;
-        qreal widthScale = width() / qreal(d->pix.width());
-        qreal heightScale = height() / qreal(d->pix.height());
+        const qreal pixWidth = d->pix.width() / d->devicePixelRatio;
+        const qreal pixHeight = d->pix.height() / d->devicePixelRatio;
+        qreal widthScale = width() / pixWidth;
+        qreal heightScale = height() / pixHeight;
         if (widthScale < heightScale) {
             widthScale = heightScale;
         } else if (heightScale < widthScale) {
             heightScale = widthScale;
         }
 
-        d->paintedHeight = heightScale * qreal(d->pix.height());
-        d->paintedWidth = widthScale * qreal(d->pix.width());
+        d->paintedHeight = heightScale * pixHeight;
+        d->paintedWidth = widthScale * pixWidth;
     } else if (d->fillMode == Pad) {
-        d->paintedWidth = d->pix.width();
-        d->paintedHeight = d->pix.height();
+        d->paintedWidth = d->pix.width() / d->devicePixelRatio;
+        d->paintedHeight = d->pix.height() / d->devicePixelRatio;
     } else {
         d->paintedWidth = width();
         d->paintedHeight = height();
diff --git a/tests/auto/quick/qquickimage/tst_qquickimage.cpp b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
index 4699f947a1..2681f1a966 100644
--- a/tests/auto/quick/qquickimage/tst_qquickimage.cpp
+++ b/tests/auto/quick/qquickimage/tst_qquickimage.cpp
@@ -91,6 +91,8 @@ private slots:
     void sourceSizeChanges();
     void correctStatus();
     void highdpi();
+    void highDpiFillModesAndSizes_data();
+    void highDpiFillModesAndSizes();
     void hugeImages();
 
 private:
@@ -971,6 +973,65 @@ void tst_qquickimage::highdpi()
     delete obj;
 }
 
+void tst_qquickimage::highDpiFillModesAndSizes_data()
+{
+    QTest::addColumn<QQuickImage::FillMode>("fillMode");
+    QTest::addColumn<qreal>("expectedHeightAfterSettingWidthTo100");
+    QTest::addColumn<qreal>("expectedImplicitHeightAfterSettingWidthTo100");
+    QTest::addColumn<qreal>("expectedPaintedWidthAfterSettingWidthTo100");
+    QTest::addColumn<qreal>("expectedPaintedHeightAfterSettingWidthTo100");
+
+    QTest::addRow("Stretch") << QQuickImage::Stretch << 150.0 << 150.0 << 100.0 << 150.0;
+    QTest::addRow("PreserveAspectFit") << QQuickImage::PreserveAspectFit << 100.0 << 100.0 << 100.0 << 100.0;
+    QTest::addRow("PreserveAspectCrop") << QQuickImage::PreserveAspectCrop << 150.0 << 150.0 << 150.0 << 150.0;
+    QTest::addRow("Tile") << QQuickImage::Tile << 150.0 << 150.0 << 100.0 << 150.0;
+    QTest::addRow("TileVertically") << QQuickImage::TileVertically << 150.0 << 150.0 << 100.0 << 150.0;
+    QTest::addRow("TileHorizontally") << QQuickImage::TileHorizontally << 150.0 << 150.0 << 100.0 << 150.0;
+    QTest::addRow("Pad") << QQuickImage::Pad << 150.0 << 150.0 << 150.0 << 150.0;
+}
+
+void tst_qquickimage::highDpiFillModesAndSizes()
+{
+    QFETCH(QQuickImage::FillMode, fillMode);
+    QFETCH(qreal, expectedHeightAfterSettingWidthTo100);
+    QFETCH(qreal, expectedImplicitHeightAfterSettingWidthTo100);
+    QFETCH(qreal, expectedPaintedWidthAfterSettingWidthTo100);
+    QFETCH(qreal, expectedPaintedHeightAfterSettingWidthTo100);
+
+    QString componentStr = "import QtQuick 2.0\nImage { source: srcImage; }";
+    QQmlComponent component(&engine);
+    component.setData(componentStr.toLatin1(), QUrl::fromLocalFile(""));
+
+    engine.rootContext()->setContextProperty("srcImage", testFileUrl("heart-highdpi@2x.png"));
+
+    QScopedPointer<QQuickImage> image(qobject_cast<QQuickImage*>(component.create()));
+    QVERIFY(image);
+    QCOMPARE(image->width(), 150.0);
+    QCOMPARE(image->height(), 150.0);
+    QCOMPARE(image->paintedWidth(), 150.0);
+    QCOMPARE(image->paintedHeight(), 150.0);
+    QCOMPARE(image->implicitWidth(), 150.0);
+    QCOMPARE(image->implicitHeight(), 150.0);
+    QCOMPARE(image->paintedWidth(), 150.0);
+    QCOMPARE(image->paintedHeight(), 150.0);
+
+    // The implicit size should not change when setting any fillMode here.
+    image->setFillMode(fillMode);
+    QCOMPARE(image->fillMode(), fillMode);
+    QCOMPARE(image->implicitWidth(), 150.0);
+    QCOMPARE(image->implicitHeight(), 150.0);
+    QCOMPARE(image->paintedWidth(), 150.0);
+    QCOMPARE(image->paintedHeight(), 150.0);
+
+    image->setWidth(100.0);
+    QCOMPARE(image->width(), 100.0);
+    QCOMPARE(image->height(), expectedHeightAfterSettingWidthTo100);
+    QCOMPARE(image->implicitWidth(), 150.0);
+    QCOMPARE(image->implicitHeight(), expectedImplicitHeightAfterSettingWidthTo100);
+    QCOMPARE(image->paintedWidth(), expectedPaintedWidthAfterSettingWidthTo100);
+    QCOMPARE(image->paintedHeight(), expectedPaintedHeightAfterSettingWidthTo100);
+}
+
 void tst_qquickimage::hugeImages()
 {
     QQuickView view;