QMacStyle: use the 'momentary push in' type for push buttons

In the past, we were using different hacks to emulate the 'default' button
and a normal button (and them in a pressed/not pressed active/non-active
states). In macOS 12 old trick stopped working and UI looks a bit different:
non-default buttons never get accent color even if pressed. Instead of relying
on a combination of 'push on-push off' type's states and highlight, we can
use the 'momentary push in' (highlighted == YES gives an impression of a pressed
button) + setting a key equivalent (thanks to Tor Arne for the hint) gives
the desired 'default button' look.

Since we (re)use NSButton to render tab items, the 'momentary push in'
button type breaks the tab. Temporary restore the old 'push on/push off'
type if rendering a tab.

Fixes: QTBUG-99743
Change-Id: I54b11c1a35373292ecf0bcd5cf7b4ea4203cc031
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit cd446a7e250671c8994ee32395fe20a59d768466)

1 files changed, 29 insertions, 9 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index 58eb7735fe..86118b79cd 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -1680,8 +1680,8 @@ bool QMacStylePrivate::CocoaControl::getCocoaButtonTypeAndBezelStyle(NSButtonTyp
         *bezelStyle = NSShadowlessSquareBezelStyle;
         break;
     case Button_PushButton:
-        *buttonType = NSPushOnPushOffButton;
-        *bezelStyle = NSRoundedBezelStyle;
+        *buttonType = NSButtonTypeMomentaryPushIn;
+        *bezelStyle = NSBezelStyleRounded;
         break;
     default:
         return false;
@@ -3725,8 +3725,15 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             pb.frame = frameRect.toCGRect();
 
             pb.enabled = isEnabled;
+
+            // With the 'momentary push in' type this gives an impression of a
+            // button in a 'pressed' state (the 'momentary push in' does
+            // not show its state otherwise):
             [pb highlight:isPressed];
-            pb.state = isHighlighted && !isPressed ? NSOnState : NSOffState;
+            // 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];
             });
@@ -3768,16 +3775,22 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             const bool hasText = !btn.text.isEmpty();
             const bool isActive = btn.state & State_Active;
             const bool isPressed = btn.state & State_Sunken;
+            const bool isDefault = (btn.features & QStyleOptionButton::DefaultButton && !d->autoDefaultButton)
+                                                || d->autoDefaultButton == btn.styleObject;
 
             const auto ct = cocoaControlType(&btn, w);
 
             if (!hasMenu && ct != QMacStylePrivate::Button_SquareButton) {
-                if (isPressed
-                    || (isActive && isEnabled
-                        && ((btn.state & State_On)
-                            || ((btn.features & QStyleOptionButton::DefaultButton) && !d->autoDefaultButton)
-                            || d->autoDefaultButton == btn.styleObject)))
-                btn.palette.setColor(QPalette::ButtonText, Qt::white);
+                if (isPressed || (isActive && isEnabled && ((btn.state & State_On) || isDefault)))
+                    btn.palette.setColor(QPalette::ButtonText, Qt::white);
+            }
+
+            if (!isDarkMode() && QOperatingSystemVersion::current() > QOperatingSystemVersion::MacOSBigSur) {
+                if (!isDefault && !(btn.state & State_On)) {
+                    // On macOS 12 it's a gray button, white text color (if set in the
+                    // previous statement) would be almost invisible.
+                    btn.palette.setColor(QPalette::ButtonText, Qt::black);
+                }
             }
 
             if ((!hasIcon && !hasMenu) || (hasIcon && !hasText)) {
@@ -3955,6 +3968,13 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
             }
             pb.frame = frameRect.toCGRect();
 
+            if (!isPopupButton) {
+                // Note: these days we use 'momentary push in' for Button_PushButton,
+                // but tabs are also rendered using NSButton/ButtonPushButton, and
+                // here we need 'push on/off' to make it work (tab highlight colors).
+                pb.buttonType = NSButtonTypePushOnPushOff;
+            }
+
             pb.enabled = isEnabled;
             [pb highlight:isPressed];
             // Set off state when inactive. See needsInactiveHack for when it's selected