tturocy · Aug 20, 2026 · Aug 19, 2026 · Aug 20, 2026
diff --git a/src/gui/app.cc b/src/gui/app.cc
@@ -2,7 +2,7 @@
 // This file is part of Gambit
 // Copyright (c) 1994-2026, The Gambit Project (https://www.gambit-project.org)
 //
-// FILE: src/gui/gambit.cc
+// FILE: src/gui/app.cc
 // Implementation of main wxApp class
 //
 // This program is free software; you can redistribute it and/or modify
@@ -20,8 +20,6 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 //
 
-#include <fstream>
-
 #include <wx/wxprec.h>
 #ifndef WX_PRECOMP
 #include <wx/wx.h>
@@ -181,48 +179,35 @@ class FileErrorDialog final : public wxDialog {
 
 AppLoadResult Application::LoadFile(const wxString &p_filename, wxWindow *p_parent)
 {
-  std::ifstream infile(p_filename.mb_str());
-  if (!infile.good()) {
+  const auto [result, doc] = GameDocument::Load(p_filename);
+
+  switch (result) {
+  case GameDocument::LoadResult::OpenFailed:
     FileErrorDialog(p_parent, _("Unable to open file"),
                     _("Gambit could not open this file for reading."), p_filename)
         .ShowModal();
     return AppLoadResult::OpenFailed;
-  }
 
-  auto *doc = new GameDocument(NewTree());
-  if (doc->LoadWorkspace(p_filename)) {
-    doc->SetFilename(p_filename);
-    m_fileHistory.AddFileToHistory(p_filename);
-    m_fileHistory.Save(*wxConfigBase::Get());
-    (void)new GameFrame(nullptr, doc);
-    return AppLoadResult::Success;
-  }
-  delete doc;
-
-  try {
-    const Game game = ReadGame(infile);
-    if (game->IsAgg()) {
-      FileErrorDialog(p_parent, _("Unsupported game representation"),
-                      _("Action graph games are not currently supported by the "
-                        "graphical interface."),
-                      p_filename)
-          .ShowModal();
-      return AppLoadResult::UnsupportedRepresentation;
-    }
+  case GameDocument::LoadResult::ParseFailed:
+    FileErrorDialog(p_parent, _("Unable to read file"),
+                    _("File is not in a format Gambit recognizes."), p_filename)
+        .ShowModal();
+    return AppLoadResult::ParseFailed;
 
+  case GameDocument::LoadResult::UnsupportedRepresentation:
+    FileErrorDialog(p_parent, _("Unsupported game representation"),
+                    _("Action graph games are not currently supported by the "
+                      "graphical interface."),
+                    p_filename)
+        .ShowModal();
+    return AppLoadResult::UnsupportedRepresentation;
+
+  case GameDocument::LoadResult::Success:
     m_fileHistory.AddFileToHistory(p_filename);
     m_fileHistory.Save(*wxConfigBase::Get());
-    doc = new GameDocument(game);
-    doc->SetFilename(p_filename);
     (void)new GameFrame(nullptr, doc);
     return AppLoadResult::Success;
   }
-  catch (InvalidFileException &) {
-    FileErrorDialog(p_parent, _("Unable to read file"),
-                    _("File is not in a format Gambit recognizes."), p_filename)
-        .ShowModal();
-    return AppLoadResult::ParseFailed;
-  }
 }
 
 void Application::SetCurrentDir(const wxString &p_dir)

diff --git a/src/gui/dlefglogit.cc b/src/gui/dlefglogit.cc
@@ -46,14 +46,14 @@ namespace Gambit::GUI {
 //! isn't resized/repainted on every single profile received.
 //!
 class LogitBehavTable final : public wxGridTableBase {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   Array<double> m_lambdas;
   Array<std::shared_ptr<MixedBehaviorProfile<double>>> m_profiles;
   int m_numCols{0};
   int m_numRows{0};
 
 public:
-  explicit LogitBehavTable(GameDocument *p_doc) : m_doc(p_doc) {}
+  explicit LogitBehavTable(const std::shared_ptr<GameDocument> &p_doc) : m_doc(p_doc) {}
 
   int GetNumberRows() override { return m_numRows; }
   int GetNumberCols() override { return m_numCols; }
@@ -172,7 +172,7 @@ class LogitBehavGrid final : public wxGrid {
   //@}
 
 public:
-  LogitBehavGrid(wxWindow *p_parent, GameDocument *p_doc)
+  LogitBehavGrid(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
     : wxGrid(p_parent, wxID_ANY), m_gridTable(new LogitBehavTable(p_doc))
   {
     SetTable(m_gridTable, true);
@@ -258,7 +258,7 @@ class LogitBehavThreadRunner final : public wxThread {
   void RequestCancel() { m_cancel.RequestCancel(); }
 };
 
-LogitBehavDialog::LogitBehavDialog(wxWindow *p_parent, GameDocument *p_doc)
+LogitBehavDialog::LogitBehavDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
   : wxDialog(p_parent, wxID_ANY, wxT("Compute quantal response equilibria"), wxDefaultPosition),
     m_doc(p_doc), m_behavList(new LogitBehavGrid(this, m_doc))
 {

diff --git a/src/gui/dlefglogit.h b/src/gui/dlefglogit.h
@@ -30,7 +30,7 @@ class LogitBehavGrid;
 class LogitBehavThreadRunner;
 
 class LogitBehavDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   std::unique_ptr<LogitBehavThreadRunner> m_runner;
   LogitBehavGrid *m_behavList;
   wxStaticText *m_statusText;
@@ -47,7 +47,7 @@ class LogitBehavDialog final : public wxDialog {
   void Start();
 
 public:
-  LogitBehavDialog(wxWindow *p_parent, GameDocument *p_doc);
+  LogitBehavDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc);
   ~LogitBehavDialog() override;
 };
 

diff --git a/src/gui/dlgameprop.cc b/src/gui/dlgameprop.cc
@@ -75,7 +75,7 @@ class PlayerLabelPanel final : public wxPanel {
   };
 
 private:
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   std::vector<Row> m_rows;
   wxColour m_defaultBg;
   std::function<void()> m_onChanged;
@@ -87,7 +87,7 @@ class PlayerLabelPanel final : public wxPanel {
   wxBitmapButton *MakeColorButton(int p_index);
 
 public:
-  PlayerLabelPanel(wxWindow *p_parent, GameDocument *p_doc,
+  PlayerLabelPanel(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc,
                    const std::function<void()> &p_onChanged);
 
   int NumRows() const { return static_cast<int>(m_rows.size()); }
@@ -106,7 +106,7 @@ class PlayerLabelPanel final : public wxPanel {
   wxString ValidateLabels();
 };
 
-PlayerLabelPanel::PlayerLabelPanel(wxWindow *p_parent, GameDocument *p_doc,
+PlayerLabelPanel::PlayerLabelPanel(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc,
                                    const std::function<void()> &p_onChanged)
   : wxPanel(p_parent, wxID_ANY), m_doc(p_doc), m_onChanged(p_onChanged)
 {
@@ -247,7 +247,8 @@ wxString PlayerLabelPanel::ValidateLabels()
 //                   class GamePropertiesDialog
 //========================================================================
 
-GamePropertiesDialog::GamePropertiesDialog(wxWindow *p_parent, GameDocument *p_doc)
+GamePropertiesDialog::GamePropertiesDialog(wxWindow *p_parent,
+                                           const std::shared_ptr<GameDocument> &p_doc)
   : wxDialog(p_parent, wxID_ANY, _("Game properties"), wxDefaultPosition, wxDefaultSize,
              wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER),
     m_doc(p_doc)

diff --git a/src/gui/dlgameprop.h b/src/gui/dlgameprop.h
@@ -28,7 +28,7 @@ namespace Gambit::GUI {
 class PlayerLabelPanel;
 
 class GamePropertiesDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   wxTextCtrl *m_title, *m_comment;
   PlayerLabelPanel *m_playerPanel;
   wxStaticText *m_errorText;
@@ -37,7 +37,7 @@ class GamePropertiesDialog final : public wxDialog {
 
 public:
   // Lifecycle
-  GamePropertiesDialog(wxWindow *p_parent, GameDocument *p_doc);
+  GamePropertiesDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc);
 
   // Data access (only valid when ShowModal() returns with wxID_OK)
   wxString GetTitle() const override { return m_title->GetValue(); }

diff --git a/src/gui/dlinsertmove.cc b/src/gui/dlinsertmove.cc
@@ -32,7 +32,7 @@ namespace Gambit::GUI {
 //                   InsertMoveDialog: Member functions
 //=========================================================================
 
-InsertMoveDialog::InsertMoveDialog(wxWindow *p_parent, GameDocument *p_doc)
+InsertMoveDialog::InsertMoveDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
   : wxDialog(p_parent, wxID_ANY, _("Insert Move"), wxDefaultPosition), m_doc(p_doc)
 {
   m_playerItem = new wxChoice(this, wxID_ANY);

diff --git a/src/gui/dlinsertmove.h b/src/gui/dlinsertmove.h
@@ -29,7 +29,7 @@
 namespace Gambit::GUI {
 
 class InsertMoveDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
 
   wxChoice *m_playerItem, *m_infosetItem;
   wxSpinCtrl *m_actions;
@@ -39,7 +39,7 @@ class InsertMoveDialog final : public wxDialog {
 
 public:
   // Constructor
-  InsertMoveDialog(wxWindow *, GameDocument *);
+  InsertMoveDialog(wxWindow *, const std::shared_ptr<GameDocument> &);
 
   // Data access (only valid if ShowModal() returns wxID_OK.
   // If GetInfoset() returns null, user selected "new infoset"

diff --git a/src/gui/dlnash.cc b/src/gui/dlnash.cc
@@ -291,7 +291,7 @@ wxString ParameterDescription(const NashMethodSpec &p_method)
 
 } // namespace
 
-NashChoiceDialog::NashChoiceDialog(wxWindow *p_parent, GameDocument *p_doc)
+NashChoiceDialog::NashChoiceDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
   : wxDialog(p_parent, wxID_ANY, wxT("Compute Nash equilibria"), wxDefaultPosition), m_doc(p_doc)
 {
   auto *topSizer = new wxBoxSizer(wxVERTICAL);
@@ -432,10 +432,10 @@ std::shared_ptr<AnalysisOutput> NashChoiceDialog::GetCommand() const
   const bool useBehavior = computation.representation == NashRepresentation::Behavior;
   std::shared_ptr<AnalysisOutput> output;
   if (UsesRationalOutput(computation.method)) {
-    output = std::make_shared<AnalysisProfileList<Rational>>(m_doc, useBehavior);
+    output = std::make_shared<AnalysisProfileList<Rational>>(m_doc.get(), useBehavior);
   }
   else {
-    output = std::make_shared<AnalysisProfileList<double>>(m_doc, useBehavior);
+    output = std::make_shared<AnalysisProfileList<double>>(m_doc.get(), useBehavior);
   }
 
   wxString count;

diff --git a/src/gui/dlnash.h b/src/gui/dlnash.h
@@ -27,7 +27,7 @@
 
 namespace Gambit::GUI {
 class NashChoiceDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   wxChoice *m_countChoice, *m_methodChoice, *m_repChoice;
 
   // Event handlers
@@ -38,7 +38,7 @@ class NashChoiceDialog final : public wxDialog {
   NashComputationSpec GetComputation() const;
 
 public:
-  NashChoiceDialog(wxWindow *, GameDocument *);
+  NashChoiceDialog(wxWindow *, const std::shared_ptr<GameDocument> &);
 
   std::shared_ptr<AnalysisOutput> GetCommand() const;
 

diff --git a/src/gui/dlnashmon.cc b/src/gui/dlnashmon.cc
@@ -302,7 +302,7 @@ class SolverThreadRunner final : public wxThread {
 };
 
 class NashMonitorDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   std::unique_ptr<class ExternalProcessRunner> m_runner;
   std::unique_ptr<class SolverThreadRunner> m_threadRunner;
   wxWindow *m_profileList;
@@ -354,11 +354,12 @@ class NashMonitorDialog final : public wxDialog {
   }
 
 public:
-  NashMonitorDialog(wxWindow *p_parent, GameDocument *p_doc,
+  NashMonitorDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc,
                     const std::shared_ptr<AnalysisOutput> &p_command);
 };
 
-NashMonitorDialog::NashMonitorDialog(wxWindow *p_parent, GameDocument *p_doc,
+NashMonitorDialog::NashMonitorDialog(wxWindow *p_parent,
+                                     const std::shared_ptr<GameDocument> &p_doc,
                                      const std::shared_ptr<AnalysisOutput> &p_command)
   : wxDialog(p_parent, wxID_ANY, wxT("Computing Nash equilibria"), wxDefaultPosition),
     m_doc(p_doc), m_output(p_command)
@@ -547,7 +548,7 @@ void NashMonitorDialog::OnClose(wxCloseEvent &p_event)
 
 namespace Gambit::GUI {
 
-void ShowNashMonitorDialog(wxWindow *p_parent, GameDocument *p_doc,
+void ShowNashMonitorDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc,
                            const std::shared_ptr<AnalysisOutput> &p_command)
 {
   NashMonitorDialog dialog(p_parent, p_doc, p_command);

diff --git a/src/gui/dlnfglogit.cc b/src/gui/dlnfglogit.cc
@@ -46,14 +46,14 @@ namespace Gambit::GUI {
 //! isn't resized/repainted on every single profile received.
 //!
 class LogitMixedTable final : public wxGridTableBase {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   Array<double> m_lambdas;
   Array<std::shared_ptr<MixedStrategyProfile<double>>> m_profiles;
   int m_numCols{0};
   int m_numRows{0};
 
 public:
-  explicit LogitMixedTable(GameDocument *p_doc) : m_doc(p_doc) {}
+  explicit LogitMixedTable(const std::shared_ptr<GameDocument> &p_doc) : m_doc(p_doc) {}
 
   int GetNumberRows() override { return m_numRows; }
   int GetNumberCols() override { return m_numCols; }
@@ -175,7 +175,7 @@ class LogitMixedGrid final : public wxGrid {
   //@}
 
 public:
-  LogitMixedGrid(wxWindow *p_parent, GameDocument *p_doc)
+  LogitMixedGrid(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
     : wxGrid(p_parent, wxID_ANY), m_gridTable(new LogitMixedTable(p_doc))
   {
     SetTable(m_gridTable, true);
@@ -261,7 +261,7 @@ class LogitMixedThreadRunner final : public wxThread {
   void RequestCancel() { m_cancel.RequestCancel(); }
 };
 
-LogitMixedDialog::LogitMixedDialog(wxWindow *p_parent, GameDocument *p_doc)
+LogitMixedDialog::LogitMixedDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
   : wxDialog(p_parent, wxID_ANY, wxT("Compute quantal response equilibria"), wxDefaultPosition),
     m_doc(p_doc), m_mixedList(new LogitMixedGrid(this, m_doc))
 {
@@ -412,7 +412,7 @@ void LogitMixedDialog::OnSave(wxCommandEvent &)
   }
 }
 
-void LogitStrategic(wxWindow *p_parent, GameDocument *p_doc)
+void LogitStrategic(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
 {
   LogitMixedDialog(p_parent, p_doc).ShowModal();
 }

diff --git a/src/gui/dlnfglogit.h b/src/gui/dlnfglogit.h
@@ -30,7 +30,7 @@ class LogitMixedGrid;
 class LogitMixedThreadRunner;
 
 class LogitMixedDialog final : public wxDialog {
-  GameDocument *m_doc;
+  std::shared_ptr<GameDocument> m_doc;
   std::unique_ptr<LogitMixedThreadRunner> m_runner;
   LogitMixedGrid *m_mixedList;
   wxStaticText *m_statusText;
@@ -47,11 +47,11 @@ class LogitMixedDialog final : public wxDialog {
   void Start();
 
 public:
-  LogitMixedDialog(wxWindow *p_parent, GameDocument *p_doc);
+  LogitMixedDialog(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc);
   ~LogitMixedDialog() override;
 };
 
-void LogitStrategic(wxWindow *p_parent, GameDocument *p_doc);
+void LogitStrategic(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc);
 
 } // namespace Gambit::GUI
 

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
@@ -62,7 +62,7 @@ END_EVENT_TABLE()
 //                EfgDisplay: Constructor and destructor
 //----------------------------------------------------------------------
 
-EfgDisplay::EfgDisplay(wxWindow *p_parent, GameDocument *p_doc)
+EfgDisplay::EfgDisplay(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc)
   : wxScrolledWindow(p_parent), GameView(p_doc), m_layout(p_doc), m_zoom(100)
 {
   wxWindow::SetBackgroundColour(wxColour(250, 250, 250));

diff --git a/src/gui/efgdisplay.h b/src/gui/efgdisplay.h
@@ -125,7 +125,7 @@ class EfgDisplay final : public wxScrolledWindow, public GameView {
   void ZoomByFactor(double p_factor, const wxPoint &p_clientPoint);
 
 public:
-  EfgDisplay(wxWindow *p_parent, GameDocument *p_doc);
+  EfgDisplay(wxWindow *p_parent, const std::shared_ptr<GameDocument> &p_doc);
 
   void OnDraw(wxDC &dc) override;
   void OnDraw(wxDC &, double);

diff --git a/src/gui/efgdragdrop.cc b/src/gui/efgdragdrop.cc
@@ -41,7 +41,7 @@ namespace Gambit::GUI {
 
 class TreeDropTarget : public wxTextDropTarget {
   EfgDisplay *m_owner;
-  GameDocument *m_model;
+  std::shared_ptr<GameDocument> m_model;
 
   bool OnDropOutcome(const GameNode &p_node, const wxString &p_text, const wxPoint &p_pos);
   bool OnDropTreeNode(const GameNode &p_node, const wxString &p_text, const wxPoint &p_pos);

diff --git a/src/gui/efglayout.h b/src/gui/efglayout.h
@@ -177,7 +177,7 @@ class TreeLayout final : public GameView {
   void BuildNodeList(const Game &);
 
 public:
-  explicit TreeLayout(GameDocument *p_doc) : GameView(p_doc) {}
+  explicit TreeLayout(const std::shared_ptr<GameDocument> &p_doc) : GameView(p_doc) {}
   ~TreeLayout() override = default;
 
   void Layout(const Game &);