Missing alias file tracking out of AudacityApp, into new files...

... which reduces the need for including AudacityApp.h

src/MissingAliasFileDialog.cpp

@@ -0,0 +1,133 @@
+/*********************************************************************
+
+\class MissingAliasFileDialog
+\brief Special case of ErrorDialog for reporting missing alias files.
+
+*//*******************************************************************/
+
+#include "MissingAliasFileDialog.h"
+
+#include <mutex>
+
+#include "BlockFile.h"
+#include "DirManager.h"
+#include "Project.h"
+#include "widgets/ErrorDialog.h"
+
+// special case for alias missing dialog because we keep track of if it exists.
+class MissingAliasFileDialog final : public ErrorDialog
+{
+   public:
+   MissingAliasFileDialog(AudacityProject *parent,
+      const wxString & dlogTitle,
+      const wxString & message,
+      const wxString & helpURL,
+      const bool Close = true, const bool modal = true);
+   virtual ~MissingAliasFileDialog();
+};
+
+
+MissingAliasFileDialog::MissingAliasFileDialog(AudacityProject *parent,
+      const wxString & dlogTitle,
+      const wxString & message,
+      const wxString & helpURL,
+      const bool Close, const bool modal):
+ErrorDialog(parent, dlogTitle, message, helpURL, Close, modal)
+{
+   parent->SetMissingAliasFileDialog(this);
+}
+
+MissingAliasFileDialog::~MissingAliasFileDialog()
+{
+   static_cast<AudacityProject *>(GetParent())
+      ->SetMissingAliasFileDialog( nullptr );
+}
+
+namespace MissingAliasFilesDialog {
+   
+   namespace{
+      bool                 m_missingAliasFilesWarningShouldShow{ true };
+      std::weak_ptr< AudacityProject > m_LastMissingBlockFileProject;
+      wxString             m_LastMissingBlockFilePath;
+      std::mutex m_LastMissingBlockFileLock;
+   }
+   
+   using Lock = std::unique_lock< std::mutex >;
+   
+   void Show(AudacityProject *parent,
+             const wxString &dlogTitle,
+             const wxString &message,
+             const wxString &helpPage,
+             const bool Close)
+   {
+      wxASSERT(parent); // to justify safenew
+      ErrorDialog *dlog = safenew MissingAliasFileDialog(parent, dlogTitle, message, helpPage, Close, false);
+      // Don't center because in many cases (effect, export, etc) there will be a progress bar in the center that blocks this.
+      // instead put it just above or on the top of the project.
+      wxPoint point;
+      point.x = 0;
+      
+      point.y = parent ? parent->GetPosition().y - 200 : 100;
+      
+      if (point.y < 100)
+         point.y = 100;
+      dlog->SetPosition(point);
+      dlog->CentreOnParent(wxHORIZONTAL);
+      
+      // This needs to be modeless because user may need to
+      // stop playback AND read dialog's instructions.
+      dlog->Show();
+      // ANSWER-ME: Vigilant Sentry flags this method as not deleting dlog, so a mem leak.
+      // PRL: answer is that the parent window guarantees destruction of the dialog
+      // but in practice Destroy() in OnOK does that
+   }
+   
+   void Mark(const AliasBlockFile *b)
+   {
+      Lock lock{ m_LastMissingBlockFileLock };
+      if (b) {
+         size_t numProjects = gAudacityProjects.size();
+         for (size_t ii = 0; ii < numProjects; ++ii) {
+            // search each project for the blockfile
+            if (gAudacityProjects[ii]->GetDirManager()->ContainsBlockFile(b)) {
+               m_LastMissingBlockFileProject = gAudacityProjects[ii];
+               break;
+            }
+         }
+      }
+      else
+         m_LastMissingBlockFileProject = {};
+      
+      if (b)
+         m_LastMissingBlockFilePath = b->GetAliasedFileName().GetFullPath();
+      else
+         m_LastMissingBlockFilePath = wxString{};
+   }
+   
+   std::pair< wxString, std::shared_ptr<AudacityProject> > Marked()
+   {
+      Lock lock{ m_LastMissingBlockFileLock };
+      return { m_LastMissingBlockFilePath, m_LastMissingBlockFileProject.lock() };
+   }
+   
+   bool ShouldShow()
+   {
+      Lock lock{ m_LastMissingBlockFileLock };
+      auto ptr = m_LastMissingBlockFileProject.lock();
+      return ptr && m_missingAliasFilesWarningShouldShow;
+   }
+   
+   void SetShouldShow(bool b)
+   {
+      // Note that this is can be called by both the main thread and other threads.
+      // I don't believe we need a mutex because we are checking zero vs non-zero,
+      // and the setting from other threads will always be non-zero (true), and the
+      // setting from the main thread is always false.
+      m_missingAliasFilesWarningShouldShow = b;
+      // reset the warnings as they were probably marked by a previous run
+      if (m_missingAliasFilesWarningShouldShow) {
+         Mark( nullptr );
+      }
+   }
+   
+}