macOS: Use dark gradients for title and status bar in dark mode

These were hardcoded to light colors, which made the
QMainWindow status bar look out of place and made the
(light) text hard to read.

Hardcode to dark colors for DarkAqua which more or less
match the native look. Keep the optimization where the
Gradients are stored in static variabless.

Change-Id: I3e75b42c41d3e2d18e4bc0f17d950a702ccad662
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Gabriel de Dietrich (DO NOT ADD TO REVIEWS) <gabriel.dedietrich@gmail.com>

1 files changed, 38 insertions, 18 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac.mm b/src/plugins/styles/mac/qmacstyle_mac.mm
index c70d1729c0..2a21673054 100644
--- a/src/plugins/styles/mac/qmacstyle_mac.mm
+++ b/src/plugins/styles/mac/qmacstyle_mac.mm
@@ -253,33 +253,50 @@ QVector<QPointer<QObject> > QMacStylePrivate::scrollBars;
 
 static QLinearGradient titlebarGradientActive()
 {
-    static QLinearGradient gradient;
-    if (gradient == QLinearGradient()) {
+    static QLinearGradient darkGradient = [](){
+        QLinearGradient gradient;
+        // FIXME: colors are chosen somewhat arbitrarily and could be fine-tuned,
+        // or ideally determined by calling a native API.
+        gradient.setColorAt(0, QColor(47, 47, 47));
+        return gradient;
+    }();
+    static QLinearGradient lightGradient = [](){
+        QLinearGradient gradient;
         gradient.setColorAt(0, QColor(235, 235, 235));
         gradient.setColorAt(0.5, QColor(210, 210, 210));
         gradient.setColorAt(0.75, QColor(195, 195, 195));
         gradient.setColorAt(1, QColor(180, 180, 180));
-    }
-    return gradient;
+        return gradient;
+    }();
+    return qt_mac_applicationIsInDarkMode() ? darkGradient : lightGradient;
 }
 
 static QLinearGradient titlebarGradientInactive()
 {
-    static QLinearGradient gradient;
-    if (gradient == QLinearGradient()) {
+    static QLinearGradient darkGradient = [](){
+        QLinearGradient gradient;
+        gradient.setColorAt(1, QColor(42, 42, 42));
+        return gradient;
+    }();
+    static QLinearGradient lightGradient = [](){
+        QLinearGradient gradient;
         gradient.setColorAt(0, QColor(250, 250, 250));
         gradient.setColorAt(1, QColor(225, 225, 225));
-    }
-    return gradient;
+        return gradient;
+    }();
+    return qt_mac_applicationIsInDarkMode() ? darkGradient : lightGradient;
 }
 
 static const QColor titlebarSeparatorLineActive(111, 111, 111);
 static const QColor titlebarSeparatorLineInactive(131, 131, 131);
+static const QColor darkModeSeparatorLine(88, 88, 88);
 
 // Gradient colors used for the dock widget title bar and
 // non-unifed tool bar bacground.
-static const QColor mainWindowGradientBegin(240, 240, 240);
-static const QColor mainWindowGradientEnd(200, 200, 200);
+static const QColor lightMainWindowGradientBegin(240, 240, 240);
+static const QColor lightMainWindowGradientEnd(200, 200, 200);
+static const QColor darkMainWindowGradientBegin(47, 47, 47);
+static const QColor darkMainWindowGradientEnd(47, 47, 47);
 
 static const int DisclosureOffset = 4;
 
@@ -4233,12 +4250,13 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
 #ifndef QT_NO_TOOLBAR
     case CE_ToolBar: {
         const QStyleOptionToolBar *toolBar = qstyleoption_cast<const QStyleOptionToolBar *>(opt);
+        const bool isDarkMode = qt_mac_applicationIsInDarkMode();
 
         // Unified title and toolbar drawing. In this mode the cocoa platform plugin will
         // fill the top toolbar area part with a background gradient that "unifies" with
         // the title bar. The following code fills the toolBar area with transparent pixels
         // to make that gradient visible.
-        if (w)  {
+        if (w) {
 #if QT_CONFIG(mainwindow)
             if (QMainWindow * mainWindow = qobject_cast<QMainWindow *>(w->window())) {
                 if (toolBar && toolBar->toolBarArea == Qt::TopToolBarArea && mainWindow->unifiedTitleAndToolBarOnMac()) {
@@ -4248,7 +4266,7 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
                     p->fillRect(opt->rect, Qt::transparent);
                     p->restore();
 
-                    // Drow a horizontal separator line at the toolBar bottom if the "unified" area ends here.
+                    // Draw a horizontal separator line at the toolBar bottom if the "unified" area ends here.
                     // There might be additional toolbars or other widgets such as tab bars in document
                     // mode below. Determine this by making a unified toolbar area test for the row below
                     // this toolbar.
@@ -4257,7 +4275,7 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
                     if (isEndOfUnifiedArea) {
                         const int margin = qt_mac_aqua_get_metric(SeparatorSize);
                         const auto separatorRect = QRect(opt->rect.left(), opt->rect.bottom(), opt->rect.width(), margin);
-                        p->fillRect(separatorRect, opt->palette.dark().color());
+                        p->fillRect(separatorRect, isDarkMode ? darkModeSeparatorLine : opt->palette.dark().color());
                     }
                     break;
                 }
@@ -4272,21 +4290,23 @@ void QMacStyle::drawControl(ControlElement ce, const QStyleOption *opt, QPainter
         else
             linearGrad = QLinearGradient(opt->rect.left(), 0,  opt->rect.right(), 0);
 
+        QColor mainWindowGradientBegin = isDarkMode ? darkMainWindowGradientBegin : lightMainWindowGradientBegin;
+        QColor mainWindowGradientEnd = isDarkMode ? darkMainWindowGradientEnd : lightMainWindowGradientEnd;
+
         linearGrad.setColorAt(0, mainWindowGradientBegin);
         linearGrad.setColorAt(1, mainWindowGradientEnd);
         p->fillRect(opt->rect, linearGrad);
 
         p->save();
         if (opt->state & State_Horizontal) {
-            p->setPen(mainWindowGradientBegin.lighter(114));
+            p->setPen(isDarkMode ? darkModeSeparatorLine : mainWindowGradientBegin.lighter(114));
             p->drawLine(opt->rect.topLeft(), opt->rect.topRight());
-            p->setPen(mainWindowGradientEnd.darker(114));
+            p->setPen(isDarkMode ? darkModeSeparatorLine :mainWindowGradientEnd.darker(114));
             p->drawLine(opt->rect.bottomLeft(), opt->rect.bottomRight());
-
         } else {
-            p->setPen(mainWindowGradientBegin.lighter(114));
+            p->setPen(isDarkMode ? darkModeSeparatorLine : mainWindowGradientBegin.lighter(114));
             p->drawLine(opt->rect.topLeft(), opt->rect.bottomLeft());
-            p->setPen(mainWindowGradientEnd.darker(114));
+            p->setPen(isDarkMode ? darkModeSeparatorLine : mainWindowGradientEnd.darker(114));
             p->drawLine(opt->rect.topRight(), opt->rect.bottomRight());
         }
         p->restore();