Merge #795: Keep focus on "Hide" while ModalOverlay is visible

992b1bb qt: keep focus on "Hide" while ModalOverlay is visible (Jadi)

Pull request description:

  During the initial sync, the Tab moves the focus to the widgets of the main window, even when the ModalOverlay is visible. This creates some weird rectangular *selections on the screen*.

  This PR fixes this by keeping the focus on the "Hide" button while the ModalOverlay is visible.

  Fixes #783

ACKs for top commit:
  pablomartin4btc:
    Concept & approach ACK 992b1bb
  hebasto:
    re-ACK 992b1bb

Tree-SHA512: f702a3fd51db4bc10780bccf76394e35a6b5fb45db72c9c23cd10d777106b08c61077d2d989003838921e76d2cb44f809399f31df76448e4305a6c2a71b5c6a3

Author: hebasto

src/qt/modaloverlay.cpp

@@ -25,6 +25,7 @@ ModalOverlay::ModalOverlay(bool enable_wallet, QWidget* parent)
         parent->installEventFilter(this);
         raise();
     }
+    ui->closeButton->installEventFilter(this);
 
     blockProcessTime.clear();
     setVisible(false);
@@ -60,6 +61,11 @@ bool ModalOverlay::eventFilter(QObject * obj, QEvent * ev) {
             raise();
         }
     }
+
+    if (obj == ui->closeButton && ev->type() == QEvent::FocusOut && layerIsVisible) {
+        ui->closeButton->setFocus(Qt::OtherFocusReason);
+    }
+
     return QWidget::eventFilter(obj, ev);
 }
 
@@ -187,6 +193,10 @@ void ModalOverlay::showHide(bool hide, bool userRequested)
     m_animation.setEndValue(QPoint(0, hide ? height() : 0));
     m_animation.start(QAbstractAnimation::KeepWhenStopped);
     layerIsVisible = !hide;
+
+    if (layerIsVisible) {
+        ui->closeButton->setFocus(Qt::OtherFocusReason);
+    }
 }
 
 void ModalOverlay::closeClicked()