sync: from linuxdeepin/dtkwidget

Synchronize source files from linuxdeepin/dtkwidget.

Source-pull-request: linuxdeepin/dtkwidget#567

src/widgets/dstyle.cpp

@@ -716,7 +716,19 @@ void drawTitleBarIcon(QPainter *pa, const QRectF &rect, const QString &iconName)
 
 void drawTitleBarMenuButton(QPainter *pa, const QRectF &rect)
 {
-    drawTitleBarIcon(pa, rect, QLatin1String("window_menu"));
+    const QPen pen = pa->pen();
+    pa->setPen(Qt::NoPen);
+    pa->drawRect(rect);
+    QRect content_rect(0, 0, rect.width() / 5, rect.height() / 5);
+    content_rect.moveCenter(rect.center().toPoint());
+    pa->setPen(pen);
+
+    pa->setRenderHint(QPainter::Antialiasing, pa->device()->devicePixelRatioF() > 1.0);
+    pa->drawLine(content_rect.x(), content_rect.y(), content_rect.topRight().x() - 2, content_rect.topRight().y());
+    pa->drawLine(content_rect.bottomLeft(), content_rect.bottomRight());
+
+    qreal y = content_rect.center().y();
+    pa->drawLine(content_rect.x(), y, content_rect.topRight().x(), y);
 }
 
 void drawTitleBarMinButton(QPainter *pa, const QRectF &rect)