Deprecate implicit QPixmap conversion to QBitmap

It is lossy, so should be requested explicitly, using a dedicated
fromPixmap factory function.

Deprecate the constructor and assignment operator, and make the
constructor explicit.

[ChangeLog][QtGui][QBitmap] Implicitly constructing and assigning
to a QBitmap from a QPixmap has been deprecated, and the respective
constructor has been made explicit. Use the fromPixmap factory
function instead.

Change-Id: I68ce85b26c901415137b664a1db687021d48bae0
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/gui/image/qbitmap.h b/src/gui/image/qbitmap.h
index a114db17e0..9052e62db6 100644
--- a/src/gui/image/qbitmap.h
+++ b/src/gui/image/qbitmap.h
@@ -52,12 +52,16 @@ class Q_GUI_EXPORT QBitmap : public QPixmap
 {
 public:
     QBitmap();
-    QBitmap(const QPixmap &);
+#if QT_DEPRECATED_SINCE(6, 0)
+    QT_DEPRECATED_VERSION_X_6_0("Use fromPixmap instead.") explicit QBitmap(const QPixmap &);
+#endif
     QBitmap(int w, int h);
     explicit QBitmap(const QSize &);
     explicit QBitmap(const QString &fileName, const char *format = nullptr);
 
-    QBitmap &operator=(const QPixmap &);
+#if QT_DEPRECATED_SINCE(6, 0)
+    QT_DEPRECATED_VERSION_X_6_0("Use fromPixmap instead.") QBitmap &operator=(const QPixmap &);
+#endif
     inline void swap(QBitmap &other) { QPixmap::swap(other); } // prevent QBitmap<->QPixmap swaps
     operator QVariant() const;
 
@@ -67,6 +71,7 @@ public:
     static QBitmap fromImage(QImage &&image, Qt::ImageConversionFlags flags = Qt::AutoColor);
     static QBitmap fromData(const QSize &size, const uchar *bits,
                             QImage::Format monoFormat = QImage::Format_MonoLSB);
+    static QBitmap fromPixmap(const QPixmap &pixmap);
 
     QBitmap transformed(const QTransform &matrix) const;