Access private properties via sandbox-safe API on Apple OSes

We detect whether or not we're running inside a sandbox and bail out if
so. We use runtime lookup of the property, so that static analysis of the
application will not mistakenly think we're using the API in sandboxed
situations.

Change-Id: I5f5c42f5a4a44b62de061d945b62ac63167ece09
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@qt.io>

1 files changed, 8 insertions, 23 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index 5999163c91..2d212bfe3b 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -248,24 +248,6 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QVerticalSplitView);
 }
 @end
 
-#if !QT_CONFIG(appstore_compliant)
-
-// This API was requested to Apple in rdar #36197888.
-// We know it's safe to use up to macOS 10.13.3.
-// See drawComplexControl(CC_ComboBox) for its usage.
-
-@interface NSComboBoxCell (QtButtonCell)
-@property (readonly) NSButtonCell *qt_buttonCell;
-@end
-
-@implementation NSComboBoxCell (QtButtonCell)
-- (NSButtonCell *)qt_buttonCell {
-    return self->_buttonCell;
-}
-@end
-
-#endif
-
 QT_BEGIN_NAMESPACE
 
 // The following constants are used for adjusting the size
@@ -5215,11 +5197,14 @@ void QMacStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex
                 auto *cb = static_cast<NSComboBox *>(cc);
                 const auto frameRect = cw.adjustedControlFrame(combo->rect);
                 cb.frame = frameRect.toCGRect();
-#if !QT_CONFIG(appstore_compliant)
-                static_cast<NSComboBoxCell *>(cc.cell).qt_buttonCell.highlighted = isPressed;
-#else
-                // TODO Render to pixmap and darken the button manually
-#endif
+
+                // This API was requested to Apple in rdar #36197888. We know it's safe to use up to macOS 10.13.3
+                if (NSButtonCell *cell = static_cast<NSButtonCell *>([cc.cell qt_valueForPrivateKey:@"_buttonCell"])) {
+                    cell.highlighted = isPressed;
+                } else {
+                    // TODO Render to pixmap and darken the button manually
+                }
+
                 d->drawNSViewInRect(cb, frameRect, p, ^(CGContextRef __unused ctx, const CGRect &r) {
                     // FIXME This is usually drawn in the control's superview, but we wouldn't get inactive look in this case
                     [cb.cell drawWithFrame:r inView:cb];