QMacStyle: fix tool buttons (in checked mode)

While switching to the 'momentary push in' button type, the old code that
shows button as pressed/checked was removed. Since 'square' buttons
were sharing this part with rounded push buttons, the change broke
checked square buttons. So we retain the old code for this particular
case.

Also, add a minimal baseline test for this scenario: square button,
triggering 'toolbutton' style with/out 'checked' state.

Fixes: QTBUG-100802
Pick-to: 6.3 6.2
Change-Id: Ib7b15b13ead834c7bb2cd36de76ccd5bedb07810
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

2 files changed, 33 insertions, 3 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index 757835f3ac..181122acb4 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -3722,9 +3722,14 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             // not show its state otherwise):
             [pb highlight:isPressed];
 
-            // For default/checked button this will give the required
-            // button accent color:
-            pb.keyEquivalent = isHighlighted ? @"\r" : @"";
+
+            if (cw.type == QMacStylePrivate::Button_SquareButton) {
+                pb.state = isHighlighted && !isPressed ? NSControlStateValueOn : NSControlStateValueOff;
+            } else {
+                // For default/checked button this will give the required
+                // button accent color:
+                pb.keyEquivalent = isHighlighted ? @"\r" : @"";
+            }
 
             d->drawNSViewInRect(pb, frameRect, p, ^(CGContextRef, const CGRect &r) {
                 [pb.cell drawBezelWithFrame:r inView:pb.superview];
diff --git a/tests/baseline/widgets/tst_baseline_widgets.cpp b/tests/baseline/widgets/tst_baseline_widgets.cpp
index b0a86ec8c3..34f9f74514 100644
--- a/tests/baseline/widgets/tst_baseline_widgets.cpp
+++ b/tests/baseline/widgets/tst_baseline_widgets.cpp
@@ -45,6 +45,8 @@ private slots:
     void tst_QPushButton_data();
     void tst_QPushButton();
 
+    void tst_QPushButtonSquare();
+
     void tst_QProgressBar_data();
     void tst_QProgressBar();
 
@@ -198,6 +200,29 @@ void tst_Widgets::tst_QPushButton()
     testButton->setDown(false);
 }
 
+void tst_Widgets::tst_QPushButtonSquare()
+{
+    QVBoxLayout layout;
+
+    QPushButton button(testWindow());
+    button.setText(QLatin1String("Square"));
+    const auto sizeHint = button.sizeHint().width();
+    // Depending on the current QStyle, this may result in
+    // a different button look - on macOS it will look as
+    // a toolbutton:
+    button.setFixedSize(sizeHint, sizeHint);
+
+    layout.addWidget(&button);
+    testWindow()->setLayout(&layout);
+
+    takeStandardSnapshots();
+
+    button.setCheckable(true);
+    QBASELINE_CHECK_DEFERRED(takeSnapshot(), "square_unchecked");
+    button.setChecked(true);
+    QBASELINE_CHECK_DEFERRED(takeSnapshot(), "square_checked");
+}
+
 void tst_Widgets::tst_QProgressBar_data()
 {
     QTest::addColumn<Qt::Orientation>("orientation");