QMacStyle - fix PE_InticatorTabClose handling

for the case a custom style sheet is in use and QStyleSheetStyle
replaces the widget (close button) with its parent (QTabBar).
We still need this button though to compare against tabButton
on a hovered tab. This allows us to have, indeed, native-looking
tabs as documented (aka similar to Safari or the "Terminal" application).

Change-Id: I53ff78699e705db6d7c7b84774b8e188a1277535
Fixes: QTBUG-61092
Fixes: QTBUG-74689
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

2 files changed, 12 insertions, 3 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index fd006b1ca3..0745e917a2 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -3411,18 +3411,20 @@ void QMacStyle::drawPrimitive(PrimitiveElement pe, const QStyleOption *opt, QPai
     case PE_IndicatorTabClose: {
         // Make close button visible only on the hovered tab.
         QTabBar *tabBar = qobject_cast<QTabBar*>(w->parentWidget());
+        const QWidget *closeBtn = w;
         if (!tabBar) {
             // QStyleSheetStyle instead of CloseButton (which has
             // a QTabBar as a parent widget) uses the QTabBar itself:
             tabBar = qobject_cast<QTabBar *>(const_cast<QWidget*>(w));
+            closeBtn = decltype(closeBtn)(property("_q_styleSheetRealCloseButton").value<void *>());
         }
         if (tabBar) {
             const bool documentMode = tabBar->documentMode();
             const QTabBarPrivate *tabBarPrivate = static_cast<QTabBarPrivate *>(QObjectPrivate::get(tabBar));
             const int hoveredTabIndex = tabBarPrivate->hoveredTabIndex();
             if (!documentMode ||
-                (hoveredTabIndex != -1 && ((w == tabBar->tabButton(hoveredTabIndex, QTabBar::LeftSide)) ||
-                                           (w == tabBar->tabButton(hoveredTabIndex, QTabBar::RightSide))))) {
+                (hoveredTabIndex != -1 && ((closeBtn == tabBar->tabButton(hoveredTabIndex, QTabBar::LeftSide)) ||
+                                           (closeBtn == tabBar->tabButton(hoveredTabIndex, QTabBar::RightSide))))) {
                 const bool hover = (opt->state & State_MouseOver);
                 const bool selected = (opt->state & State_Selected);
                 const bool pressed = (opt->state & State_Sunken);
diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index 79fa20851f..73b147e622 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -4590,8 +4590,12 @@ void QStyleSheetStyle::drawPrimitive(PrimitiveElement pe, const QStyleOption *op
         break;
 #if QT_CONFIG(tabbar)
     case PE_IndicatorTabClose:
-        if (w)
+        if (w) {
+            // QMacStyle needs a real widget, not its parent - to implement
+            // 'document mode' properly, drawing nothing if a tab is not hovered.
+            baseStyle()->setProperty("_q_styleSheetRealCloseButton", QVariant::fromValue((void *)w));
             w = w->parentWidget(); //match on the QTabBar instead of the CloseButton
+        }
         pseudoElement = PseudoElement_TabBarTabCloseButton;
 #endif
 
@@ -4609,6 +4613,9 @@ void QStyleSheetStyle::drawPrimitive(PrimitiveElement pe, const QStyleOption *op
     } else {
         baseStyle()->drawPrimitive(pe, opt, p, w);
     }
+
+    if (baseStyle()->property("_q_styleSheetRealCloseButton").toBool())
+        baseStyle()->setProperty("_q_styleSheetRealCloseButton", QVariant(QVariant::Invalid));
 }
 
 QPixmap QStyleSheetStyle::generatedIconPixmap(QIcon::Mode iconMode, const QPixmap& pixmap,