visualisations: Fix close action

Pressing the close button on the window sends a close event, where other methods
of exiting visualization just hide the window. If shown again after close, the
window will be empty. To fix this, handle and reject the close event. Call hide
instead.

src/visualisations/visualisationcontainer.cpp

@@ -21,6 +21,7 @@
 #include "visualisationoverlay.h"
 #include "visualisationselector.h"
 #include "engines/gstengine.h"
+#include "core/logging.h"
 #include "ui/iconloader.h"
 #include "ui/screensaver.h"
 
@@ -151,6 +152,7 @@ void VisualisationContainer::SetEngine(GstEngine* engine) {
 }
 
 void VisualisationContainer::showEvent(QShowEvent* e) {
+  qLog(Debug) << "Showing visualization";
   if (!initialised_) {
     if (!QGLFormat::hasOpenGL()) {
       hide();
@@ -171,12 +173,19 @@ void VisualisationContainer::showEvent(QShowEvent* e) {
 }
 
 void VisualisationContainer::hideEvent(QHideEvent* e) {
+  qLog(Debug) << "Hiding visualization";
   QGraphicsView::hideEvent(e);
   update_timer_.stop();
 
   if (engine_) engine_->RemoveBufferConsumer(vis_);
 }
 
+void VisualisationContainer::closeEvent(QCloseEvent* e) {
+  // Don't close the window. Just hide it.
+  e->ignore();
+  hide();
+}
+
 void VisualisationContainer::resizeEvent(QResizeEvent* e) {
   QGraphicsView::resizeEvent(e);
   SizeChanged();

src/visualisations/visualisationcontainer.h

@@ -60,6 +60,7 @@ class VisualisationContainer : public QGraphicsView {
   // QWidget
   void showEvent(QShowEvent* e);
   void hideEvent(QHideEvent* e);
+  void closeEvent(QCloseEvent* e);
   void resizeEvent(QResizeEvent* e);
   void timerEvent(QTimerEvent* e);
   void mouseMoveEvent(QMouseEvent* e);