Fix Icon button focus issue on DeepinOS

Author: mominul

src/frontend/TopBar.cpp

@@ -361,8 +361,17 @@ bool TopBar::eventFilter(QObject *object, QEvent *event) {
       event->accept();
     } else if (event->type() == QEvent::MouseMove) {
       if (canMoveTopbar) {
-        if(!this->windowHandle()->startSystemMove()){
-            QMouseEvent *e = (QMouseEvent *) event;
+        QMouseEvent *e = (QMouseEvent *) event;
+        if (!(e->buttons() & Qt::LeftButton)) {
+            // Mouse release event was missed; stop dragging.
+            canMoveTopbar = false;
+            ui->buttonIcon->setCursor(Qt::ArrowCursor);
+        } else if(this->windowHandle()->startSystemMove()){
+            // The window manager now owns the drag and will consume the
+            // mouse release event, so reset our drag state immediately.
+            canMoveTopbar = false;
+            ui->buttonIcon->setCursor(Qt::ArrowCursor);
+        } else {
             ui->buttonIcon->setCursor(Qt::ClosedHandCursor);
             move(e->globalX() - pressedMouseX, e->globalY() - pressedMouseY);
         }

src/frontend/TopBar.ui

@@ -37,6 +37,11 @@ QPushButton {
     margin: 2px;
     color: rgba(0, 0, 0, 0.7);
     font-size: 18px;
+    outline: none;
+}
+
+QPushButton:focus {
+    outline: none;
 }
 
 QPushButton:hover {