Generalize image file name @2x suffix handling to higher scale factors

@3x is in use on iOS already, so extend the handling in QImageReader
to all single-digit factors, like QIcon does.

Fixes: QTBUG-76273
Change-Id: Ic9442731c0549dbe8f797e1ddb1a09d8447e8441
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
 

1 files changed, 6 insertions, 4 deletions

diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index 0fb1d808e5..0c75196612 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -1319,10 +1319,12 @@ bool QImageReader::read(QImage *image)
         }
     }
 
-    // successful read; check for "@2x" file name suffix and set device pixel ratio.
-    static bool disable2xImageLoading = !qEnvironmentVariableIsEmpty("QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING");
-    if (!disable2xImageLoading && QFileInfo(fileName()).baseName().endsWith(QLatin1String("@2x"))) {
-           image->setDevicePixelRatio(2.0);
+    // successful read; check for "@Nx" file name suffix and set device pixel ratio.
+    static bool disableNxImageLoading = !qEnvironmentVariableIsEmpty("QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING");
+    if (!disableNxImageLoading) {
+        const QByteArray suffix = QFileInfo(fileName()).baseName().right(3).toLatin1();
+        if (suffix.length() == 3 && suffix[0] == '@' && suffix[1] >= '2' && suffix[1] <= '9' && suffix[2] == 'x')
+            image->setDevicePixelRatio(suffix[1] - '0');
     }
     if (autoTransform())
         qt_imageTransform(*image, transformation());