Add high-resolution pixmaps for macOS dock widget title icons

The macOS style falls back to the QCommonStyle for those, and that
style loads the macstyle pixmaps. Weird, but cleaning that up is
for another commit.

Fixes: QTBUG-38776
Pick-to: 6.1 6.2 5.15
Change-Id: Ie1fe721387e64cb91ee5fc528667a63e6ddd6eed
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/widgets/CMakeLists.txt

@@ -246,10 +246,30 @@ qt_internal_add_resource(Widgets "qstyle"
         ${qstyle_resource_files}
 )
 set(qstyle1_resource_files
+    "styles/images/closedock-down-macstyle-10.png"
     "styles/images/closedock-down-macstyle-16.png"
+    "styles/images/closedock-down-macstyle-20.png"
+    "styles/images/closedock-down-macstyle-32.png"
+    "styles/images/closedock-down-macstyle-48.png"
+    "styles/images/closedock-down-macstyle-64.png"
+    "styles/images/closedock-macstyle-10.png"
     "styles/images/closedock-macstyle-16.png"
+    "styles/images/closedock-macstyle-20.png"
+    "styles/images/closedock-macstyle-32.png"
+    "styles/images/closedock-macstyle-48.png"
+    "styles/images/closedock-macstyle-64.png"
+    "styles/images/dockdock-down-macstyle-10.png"
     "styles/images/dockdock-down-macstyle-16.png"
+    "styles/images/dockdock-down-macstyle-20.png"
+    "styles/images/dockdock-down-macstyle-32.png"
+    "styles/images/dockdock-down-macstyle-48.png"
+    "styles/images/dockdock-down-macstyle-64.png"
+    "styles/images/dockdock-macstyle-10.png"
     "styles/images/dockdock-macstyle-16.png"
+    "styles/images/dockdock-macstyle-20.png"
+    "styles/images/dockdock-macstyle-32.png"
+    "styles/images/dockdock-macstyle-48.png"
+    "styles/images/dockdock-macstyle-64.png"
     "styles/images/toolbar-ext-macstyle.png"
     "styles/images/toolbar-ext-macstyle@2x.png"
 )

src/widgets/styles/qcommonstyle.cpp

@@ -6094,14 +6094,14 @@ QIcon QCommonStyle::standardIcon(StandardPixmap standardIcon, const QStyleOption
         case SP_TitleBarNormalButton:
         case SP_TitleBarCloseButton: {
             QIcon titleBarIcon;
-            if (standardIcon == SP_TitleBarCloseButton) {
-                titleBarIcon.addFile(QStringLiteral(":/qt-project.org/styles/macstyle/images/closedock-macstyle-16.png"));
-                titleBarIcon.addFile(QStringLiteral(":/qt-project.org/styles/macstyle/images/closedock-down-macstyle-16.png"),
-                                     QSize(16, 16), QIcon::Normal, QIcon::On);
-            } else {
-                titleBarIcon.addFile(QStringLiteral(":/qt-project.org/styles/macstyle/images/dockdock-macstyle-16.png"));
-                titleBarIcon.addFile(QStringLiteral(":/qt-project.org/styles/macstyle/images/dockdock-down-macstyle-16.png"),
-                                     QSize(16, 16), QIcon::Normal, QIcon::On);
+            QString prefix = standardIcon == SP_TitleBarCloseButton
+                            ? QStringLiteral(":/qt-project.org/styles/macstyle/images/closedock-")
+                            : QStringLiteral(":/qt-project.org/styles/macstyle/images/dockdock-");
+            for (const auto size : dockTitleIconSizes) {
+                titleBarIcon.addFile(prefix + QStringLiteral("macstyle-") + QString::number(size) + iconPngSuffix(),
+                                     QSize(size, size), QIcon::Normal, QIcon::Off);
+                titleBarIcon.addFile(prefix + QStringLiteral("down-macstyle-") + QString::number(size) + iconPngSuffix(),
+                                     QSize(size, size), QIcon::Normal, QIcon::On);
             }
             return titleBarIcon;
         }