Veto window closure during scanner discovery in the background.

Resources/InsaneWidget/XInsaneWidget.cpp

@@ -422,10 +422,9 @@ void XInsaneWidget::Setup(wxConfig * config, TimeredStatusBar * sb)
   btnScan->Enable(false);
   btnScan->Bind ( wxEVT_RIGHT_UP, &XInsaneWidget::OnBtnScanRightClick, this );
   btnScan->Bind ( wxEVT_LEFT_UP, &XInsaneWidget::OnBtnScanClick, this );
-  m_backgroundScannerDiscoveryEvh = std::make_unique<BackgroundScannerDiscoveryEVH>(this);
-  BackgroundScannerDiscovery * backgroundDiscovery = new BackgroundScannerDiscovery ( m_scannerWidget.get(),
-                                                                                      m_backgroundScannerDiscoveryEvh.get());
-  backgroundDiscovery->Run();
+  m_backgroundDiscovery = new BackgroundScannerDiscovery ( m_scannerWidget.get(),
+                                                          new BackgroundScannerDiscoveryEVH(this)); // Takes ownership.
+  m_backgroundDiscovery->Run();
 }
 
 
@@ -581,5 +580,14 @@ void XInsaneWidget::CancelScanning()
 
 void XInsaneWidget::EnableScanButton(bool enable)
 {
+  // Called from BackgroundScannerDiscoveryEVH::Done() only;
   btnScan->Enable(enable);
+  m_backgroundDiscovery = nullptr;
+}
+
+bool XInsaneWidget::IsScannerDiscoveryRunning()
+{
+  if (!m_backgroundDiscovery)
+    return false;
+  return m_backgroundDiscovery->IsRunning();
 }

Resources/InsaneWidget/XInsaneWidget.h

@@ -23,7 +23,7 @@
 #include <memory>
 #include <vector>
 
-class BackgroundScannerDiscoveryEVH;
+class BackgroundScannerDiscovery; // Is a wxThread.
 class ScanProjectHandler; // An event handler extending InsaneWorkerEvent.
 class XStampWidget;
 struct StampDescriptor;
@@ -66,6 +66,7 @@ public:
   void CancelScanning();
   void EnableScanButton(bool enable); // For CallAfter.
   void Setup(wxConfig * config, TimeredStatusBar * sb);
+  bool IsScannerDiscoveryRunning();
 private:
   wxConfig * m_config;
   wxWeakRef<TimeredStatusBar> m_sb;
@@ -81,7 +82,7 @@ private:
   // Available devices and minimal options.
   std::unique_ptr<XScannerWidget> m_scannerWidget;
   std::unique_ptr<InsaneWorker> m_insaneWorker;
-  std::unique_ptr<BackgroundScannerDiscoveryEVH> m_backgroundScannerDiscoveryEvh;
+  BackgroundScannerDiscovery * m_backgroundDiscovery;
   std::unique_ptr<ScanProjectHandler> m_scanProject;
 
   bool m_doubleSided = false;

Resources/InsaneWidget/XScannerWidget.cpp

@@ -311,7 +311,10 @@ wxThread::ExitCode BackgroundScannerDiscovery::Entry()
     evt.SetShow ( true );
     m_owner->OnActivated ( evt );
     if (m_evh)
+    {
       m_evh->OnDone();
+      wxDELETE(m_evh);
+    }
   }
   return ( wxThread::ExitCode ) 0;
 }
@@ -321,3 +324,5 @@ wxThread::ExitCode BackgroundScannerDiscovery::Entry()
 void BackgroundScannerDiscoveryEvent::OnDone()
 {}
 
+BackgroundScannerDiscoveryEvent::~BackgroundScannerDiscoveryEvent() = default;
+

Resources/InsaneWidget/XScannerWidget.h

@@ -99,7 +99,7 @@ public:
   BackgroundScannerDiscovery ( XScannerWidget * owner, BackgroundScannerDiscoveryEvent * evh )
   {
     m_owner = owner;
-    m_evh = evh;
+    m_evh = evh; // Owned here.
   }
   virtual ~BackgroundScannerDiscovery() {};
   virtual ExitCode Entry();
@@ -112,6 +112,7 @@ class BackgroundScannerDiscoveryEvent
 {
 public:
   virtual void OnDone();
+  virtual ~BackgroundScannerDiscoveryEvent();
 
 };