From 9a7f1bb7e19cb7efa227b987b7a44d6db027f00a Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 15:24:45 +0100
Subject: [PATCH 01/12] Introduce context menu to determine drag-and-drop
 operation

---
 src/gui/efgdisplay.cc | 143 ++++++++++++++++++++++++++++--------------
 src/gui/efgdisplay.h  |   3 +
 2 files changed, 98 insertions(+), 48 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index 5ab177bc7..1bad50a18 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -119,6 +119,7 @@ class PlayerDropTarget : public wxTextDropTarget {
   bool OnDropSetOutcome(const GameNode &p_node, const wxString &p_text);
   bool OnDropMoveOutcome(const GameNode &p_node, const wxString &p_text);
   bool OnDropCopyOutcome(const GameNode &p_node, const wxString &p_text);
+  bool OnDropTreeNode(const GameNode &p_node, const wxString &p_text, const wxPoint &p_pos);
 
 public:
   explicit PlayerDropTarget(EfgDisplay *p_owner)
@@ -255,6 +256,20 @@ bool PlayerDropTarget::OnDropCopyOutcome(const GameNode &p_node, const wxString
   return true;
 }
 
+bool PlayerDropTarget::OnDropTreeNode(const GameNode &p_node, const wxString &p_text,
+                                      const wxPoint &p_pos)
+{
+  long n;
+  p_text.Right(p_text.Length() - 1).ToLong(&n);
+
+  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
+  if (!srcNode || srcNode == p_node || srcNode->IsTerminal()) {
+    return false;
+  }
+
+  return m_owner->ShowTreeDropMenu(p_node, srcNode, p_pos);
+}
+
 bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_text)
 {
   const Game efg = m_owner->GetDocument()->GetGame();
@@ -281,6 +296,8 @@ bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_te
 
   try {
     switch (static_cast<char>(p_text[0])) {
+    case 'N':
+      return OnDropTreeNode(node, p_text, wxPoint(p_x, p_y));
     case 'P':
       return OnDropPlayer(node, p_text);
     case 'C':
@@ -361,6 +378,75 @@ void EfgDisplay::MakeMenus()
   m_nodeMenu->Append(GBT_MENU_EDIT_GAME, _("&Game properties"), _("Edit properties of the game"));
 }
 
+bool EfgDisplay::ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
+                                  const wxPoint &p_pos)
+{
+  if (!p_targetNode || !p_sourceNode || p_sourceNode->IsTerminal()) {
+    return false;
+  }
+
+  const bool canCopyOrMoveTree = p_targetNode->IsTerminal();
+  const bool canUseSameInfoset =
+      (!p_targetNode->IsTerminal() &&
+       p_targetNode->GetChildren().size() == p_sourceNode->GetChildren().size()) ||
+      p_targetNode->IsTerminal();
+
+  if (!canCopyOrMoveTree && !canUseSameInfoset) {
+    return false;
+  }
+
+  const int copyTreeId = wxWindow::NewControlId();
+  const int moveTreeId = wxWindow::NewControlId();
+  const int infosetId = wxWindow::NewControlId();
+
+  wxMenu menu;
+
+  if (canCopyOrMoveTree) {
+    menu.Append(copyTreeId, _("Copy subtree here"));
+    menu.Append(moveTreeId, _("Move subtree here"));
+  }
+
+  if (canUseSameInfoset) {
+    if (!menu.GetMenuItems().empty()) {
+      menu.AppendSeparator();
+    }
+
+    if (p_targetNode->IsTerminal()) {
+      menu.Append(infosetId, _("Insert move using same information set"));
+    }
+    else {
+      menu.Append(infosetId, _("Put node in same information set"));
+    }
+  }
+
+  const int selection = GetPopupMenuSelectionFromUser(menu, p_pos);
+
+  try {
+    if (selection == copyTreeId) {
+      m_doc->DoCopyTree(p_targetNode, p_sourceNode);
+      return true;
+    }
+    if (selection == moveTreeId) {
+      m_doc->DoMoveTree(p_targetNode, p_sourceNode);
+      return true;
+    }
+    if (selection == infosetId) {
+      if (!p_targetNode->IsTerminal()) {
+        m_doc->DoSetInfoset(p_targetNode, p_sourceNode->GetInfoset());
+      }
+      else {
+        m_doc->DoAppendMove(p_targetNode, p_sourceNode->GetInfoset());
+      }
+      return true;
+    }
+  }
+  catch (std::exception &ex) {
+    ExceptionDialog(this, ex.what()).ShowModal();
+  }
+
+  return false;
+}
+
 //---------------------------------------------------------------------
 //                  EfgDisplay: Event-hook members
 //---------------------------------------------------------------------
@@ -977,61 +1063,22 @@ void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
     GameNode node = m_layout.NodeHitTest(x, y);
 
     if (node && !node->IsTerminal()) {
-      const GamePlayer player = node->GetPlayer();
-      if (p_event.ControlDown()) {
-        // Copy subtree
-        const wxBitmap bitmap(tree_xpm);
+      const wxBitmap bitmap(tree_xpm);
 #if defined(__WXMSW__) or defined(__WXMAC__)
-        const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-        wxIcon image;
-        image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
-        wxString label;
-        label << "C" << node->GetNumber();
-        wxTextDataObject textData(label);
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(true);
-      }
-      else if (p_event.ShiftDown()) {
-        // Copy move (information set)
-        // This should be the pawn icon!
-        const wxBitmap bitmap(move_xpm);
-#if defined(__WXMSW__) or defined(__WXMAC__)
-        const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-        wxIcon image;
-        image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
-        wxString label;
-        label << "I" << node->GetNumber();
-        wxTextDataObject textData(label);
-
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(wxDrag_DefaultMove);
-      }
-      else {
-        // Move subtree
-        const wxBitmap bitmap(tree_xpm);
-#if defined(__WXMSW__) or defined(__WXMAC__)
-        const auto image = wxCursor(bitmap.ConvertToImage());
+      const auto image = wxCursor(bitmap.ConvertToImage());
 #else
-        wxIcon image;
-        image.CopyFromBitmap(bitmap);
+      wxIcon image;
+      image.CopyFromBitmap(bitmap);
 #endif // _WXMSW__
 
-        wxString label;
-        label << "M" << node->GetNumber();
-        wxTextDataObject textData(label);
+      wxString label;
+      label << "N" << node->GetNumber();
+      wxTextDataObject textData(label);
 
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(wxDrag_DefaultMove);
-      }
+      wxDropSource source(textData, this, image, image, image);
+      /*wxDragResult result =*/source.DoDragDrop(wxDrag_DefaultMove);
       return;
     }
-
     node = m_layout.OutcomeHitTest(x, y);
 
     if (node && node->GetOutcome()) {
diff --git a/src/gui/efgdisplay.h b/src/gui/efgdisplay.h
index 3f10e8d69..7ef2d7fcd 100644
--- a/src/gui/efgdisplay.h
+++ b/src/gui/efgdisplay.h
@@ -109,6 +109,9 @@ class EfgDisplay final : public wxScrolledWindow, public GameView {
 
   void EnsureNodeVisible(const GameNode &);
 
+  bool ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
+                        const wxPoint &p_pos);
+
   DECLARE_EVENT_TABLE()
 };
 } // namespace Gambit::GUI

From 82a6ec231c4ec2a8830733f549fb7ad7e791745c Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 15:27:47 +0100
Subject: [PATCH 02/12] Remove unused code

---
 src/gui/efgdisplay.cc | 59 -------------------------------------------
 1 file changed, 59 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index 1bad50a18..6b615485d 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -113,9 +113,6 @@ class PlayerDropTarget : public wxTextDropTarget {
   GameDocument *m_model;
 
   bool OnDropPlayer(const GameNode &p_node, const wxString &p_text);
-  bool OnDropCopyNode(const GameNode &p_node, const wxString &p_text);
-  bool OnDropMoveNode(const GameNode &p_node, const wxString &p_text);
-  bool OnDropInfoset(const GameNode &p_node, const wxString &p_text);
   bool OnDropSetOutcome(const GameNode &p_node, const wxString &p_text);
   bool OnDropMoveOutcome(const GameNode &p_node, const wxString &p_text);
   bool OnDropCopyOutcome(const GameNode &p_node, const wxString &p_text);
@@ -170,55 +167,6 @@ bool PlayerDropTarget::OnDropPlayer(const GameNode &p_node, const wxString &p_te
   return true;
 }
 
-bool PlayerDropTarget::OnDropCopyNode(const GameNode &p_node, const wxString &p_text)
-{
-  long n;
-  p_text.Right(p_text.Length() - 1).ToLong(&n);
-  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode) {
-    return false;
-  }
-  if (p_node->IsTerminal() && !srcNode->IsTerminal()) {
-    m_model->DoCopyTree(p_node, srcNode);
-    return true;
-  }
-  return false;
-}
-
-bool PlayerDropTarget::OnDropMoveNode(const GameNode &p_node, const wxString &p_text)
-{
-  long n;
-  p_text.Right(p_text.Length() - 1).ToLong(&n);
-  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode) {
-    return false;
-  }
-  if (p_node->IsTerminal() && !srcNode->IsTerminal()) {
-    m_model->DoMoveTree(p_node, srcNode);
-    return true;
-  }
-  return false;
-}
-
-bool PlayerDropTarget::OnDropInfoset(const GameNode &p_node, const wxString &p_text)
-{
-  long n;
-  p_text.Right(p_text.Length() - 1).ToLong(&n);
-  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode) {
-    return false;
-  }
-  if (!p_node->IsTerminal() && p_node->GetChildren().size() == srcNode->GetChildren().size()) {
-    m_model->DoSetInfoset(p_node, srcNode->GetInfoset());
-    return true;
-  }
-  else if (p_node->IsTerminal() && !srcNode->IsTerminal()) {
-    m_model->DoAppendMove(p_node, srcNode->GetInfoset());
-    return true;
-  }
-  return false;
-}
-
 bool PlayerDropTarget::OnDropSetOutcome(const GameNode &p_node, const wxString &p_text)
 {
   long n;
@@ -300,12 +248,6 @@ bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_te
       return OnDropTreeNode(node, p_text, wxPoint(p_x, p_y));
     case 'P':
       return OnDropPlayer(node, p_text);
-    case 'C':
-      return OnDropCopyNode(node, p_text);
-    case 'M':
-      return OnDropMoveNode(node, p_text);
-    case 'I':
-      return OnDropInfoset(node, p_text);
     case 'O':
       return OnDropSetOutcome(node, p_text);
     case 'o':
@@ -1050,7 +992,6 @@ void EfgDisplay::OnMagnify(wxMouseEvent &p_event)
 }
 
 #include "bitmaps/tree.xpm"
-#include "bitmaps/move.xpm"
 
 void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
 {

From 79b0d826590db8efe9d40933573cfdc500476ae9 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 15:47:39 +0100
Subject: [PATCH 03/12] Remove custom cursor for tree drags

---
 src/gui/efgdisplay.cc | 77 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 57 insertions(+), 20 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index 6b615485d..a37d4a576 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -223,16 +223,7 @@ bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_te
   const Game efg = m_owner->GetDocument()->GetGame();
 
   int x, y;
-#if defined(__WXMSW__)
-  // The +12 here is designed to effectively make the hot spot on
-  // the cursor the center of the cursor image (they're currently
-  // 24 pixels wide).
-  m_owner->CalcUnscrolledPosition(p_x + 12, p_y + 12, &x, &y);
-#else
-  // Under GTK, there is an angle in the upper left-hand corner which
-  // serves to identify the hot spot.  Thus, no adjustment is used
   m_owner->CalcUnscrolledPosition(p_x, p_y, &x, &y);
-#endif // __WXMSW__ or defined(__WXMAC__)
 
   x = m_owner->DeviceToLayout(x);
   y = m_owner->DeviceToLayout(y);
@@ -991,7 +982,61 @@ void EfgDisplay::OnMagnify(wxMouseEvent &p_event)
   }
 }
 
-#include "bitmaps/tree.xpm"
+namespace {
+
+wxCursor MakeTreeDragCursor()
+{
+  constexpr int width = 24;
+  constexpr int height = 24;
+
+  wxBitmap bitmap(width, height, 32);
+
+  {
+    wxMemoryDC dc(bitmap);
+    dc.SetBackground(*wxTRANSPARENT_BRUSH);
+    dc.Clear();
+
+    const wxColour stroke(70, 70, 70);
+    const wxColour fill(255, 255, 255);
+
+    dc.SetPen(wxPen(stroke, 2));
+    dc.SetBrush(wxBrush(fill, wxBRUSHSTYLE_SOLID));
+
+    // Simple subtree glyph: one parent node and two children.
+    dc.DrawCircle(7, 5, 3);
+    dc.DrawCircle(7, 18, 3);
+    dc.DrawCircle(18, 18, 3);
+
+    dc.SetPen(wxPen(stroke, 1));
+    dc.DrawLine(7, 8, 7, 15);
+    dc.DrawLine(10, 18, 15, 18);
+
+    dc.SelectObject(wxNullBitmap);
+  }
+
+  wxImage image = bitmap.ConvertToImage();
+  if (image.HasAlpha()) {
+    // Good.
+  }
+  else {
+    image.InitAlpha();
+  }
+
+  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, 0);
+  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, 0);
+
+  return wxCursor(image);
+}
+
+wxCursor MakeDragCursor(const wxBitmap &p_bitmap, int p_hotspotX, int p_hotspotY)
+{
+  wxImage image = p_bitmap.ConvertToImage();
+  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, p_hotspotX);
+  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, p_hotspotY);
+  return wxCursor(image);
+}
+
+} // namespace
 
 void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
 {
@@ -1004,20 +1049,12 @@ void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
     GameNode node = m_layout.NodeHitTest(x, y);
 
     if (node && !node->IsTerminal()) {
-      const wxBitmap bitmap(tree_xpm);
-#if defined(__WXMSW__) or defined(__WXMAC__)
-      const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-      wxIcon image;
-      image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
       wxString label;
       label << "N" << node->GetNumber();
       wxTextDataObject textData(label);
 
-      wxDropSource source(textData, this, image, image, image);
-      /*wxDragResult result =*/source.DoDragDrop(wxDrag_DefaultMove);
+      wxDropSource source(textData, this);
+      source.DoDragDrop(wxDrag_DefaultMove);
       return;
     }
     node = m_layout.OutcomeHitTest(x, y);

From 1501aa3ff447c98b3b2d309425200f32acf7a807 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 15:53:49 +0100
Subject: [PATCH 04/12] Simplify outcome DnD

---
 src/gui/efgdisplay.cc | 198 ++++++++++++------------------------------
 src/gui/efgdisplay.h  |   2 +
 2 files changed, 57 insertions(+), 143 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index a37d4a576..bc5a523fa 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -81,29 +81,6 @@ void TreePayoffEditor::OnChar(wxKeyEvent &p_event)
   }
 }
 
-//--------------------------------------------------------------------------
-//                       Bitmap drawing functions
-//--------------------------------------------------------------------------
-
-static wxBitmap MakeOutcomeBitmap()
-{
-  wxBitmap bitmap(24, 24);
-  wxMemoryDC dc;
-  dc.SelectObject(bitmap);
-  dc.Clear();
-  dc.SetPen(wxPen(*wxBLACK, 1, wxPENSTYLE_SOLID));
-  // Make a gold-colored background
-  dc.SetBrush(wxBrush(wxColour(255, 215, 0), wxBRUSHSTYLE_SOLID));
-  dc.DrawCircle(12, 12, 10);
-  dc.SetFont(wxFont(12, wxFONTFAMILY_SWISS, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD));
-  dc.SetTextForeground(wxColour(0, 192, 0));
-
-  int width, height;
-  dc.GetTextExtent(wxT("u"), &width, &height);
-  dc.DrawText(wxT("u"), 12 - width / 2, 12 - height / 2);
-  return bitmap;
-}
-
 //--------------------------------------------------------------------------
 //                      class PlayerDropTarget
 //--------------------------------------------------------------------------
@@ -113,9 +90,7 @@ class PlayerDropTarget : public wxTextDropTarget {
   GameDocument *m_model;
 
   bool OnDropPlayer(const GameNode &p_node, const wxString &p_text);
-  bool OnDropSetOutcome(const GameNode &p_node, const wxString &p_text);
-  bool OnDropMoveOutcome(const GameNode &p_node, const wxString &p_text);
-  bool OnDropCopyOutcome(const GameNode &p_node, const wxString &p_text);
+  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);
 
 public:
@@ -167,41 +142,18 @@ bool PlayerDropTarget::OnDropPlayer(const GameNode &p_node, const wxString &p_te
   return true;
 }
 
-bool PlayerDropTarget::OnDropSetOutcome(const GameNode &p_node, const wxString &p_text)
+bool PlayerDropTarget::OnDropOutcome(const GameNode &p_node, const wxString &p_text,
+                                     const wxPoint &p_pos)
 {
   long n;
   p_text.Right(p_text.Length() - 1).ToLong(&n);
-  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode || p_node == srcNode) {
-    return false;
-  }
-  m_model->DoSetOutcome(p_node, srcNode->GetOutcome());
-  return true;
-}
 
-bool PlayerDropTarget::OnDropMoveOutcome(const GameNode &p_node, const wxString &p_text)
-{
-  long n;
-  p_text.Right(p_text.Length() - 1).ToLong(&n);
   const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode || p_node == srcNode) {
+  if (!srcNode || srcNode == p_node || !srcNode->GetOutcome()) {
     return false;
   }
-  m_model->DoSetOutcome(p_node, srcNode->GetOutcome());
-  m_model->DoSetOutcome(srcNode, nullptr);
-  return true;
-}
 
-bool PlayerDropTarget::OnDropCopyOutcome(const GameNode &p_node, const wxString &p_text)
-{
-  long n;
-  p_text.Right(p_text.Length() - 1).ToLong(&n);
-  const GameNode srcNode = GetNode(m_model->GetGame()->GetRoot(), n);
-  if (!srcNode || p_node == srcNode) {
-    return false;
-  }
-  m_model->DoCopyOutcome(p_node, srcNode->GetOutcome());
-  return true;
+  return m_owner->ShowOutcomeDropMenu(p_node, srcNode, p_pos);
 }
 
 bool PlayerDropTarget::OnDropTreeNode(const GameNode &p_node, const wxString &p_text,
@@ -240,11 +192,7 @@ bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_te
     case 'P':
       return OnDropPlayer(node, p_text);
     case 'O':
-      return OnDropSetOutcome(node, p_text);
-    case 'o':
-      return OnDropMoveOutcome(node, p_text);
-    case 'p':
-      return OnDropCopyOutcome(node, p_text);
+      return OnDropOutcome(node, p_text, wxPoint(p_x, p_y));
     default:
       return false;
     }
@@ -380,6 +328,48 @@ bool EfgDisplay::ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &
   return false;
 }
 
+bool EfgDisplay::ShowOutcomeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
+                                     const wxPoint &p_pos)
+{
+  if (!p_targetNode || !p_sourceNode || p_targetNode == p_sourceNode ||
+      !p_sourceNode->GetOutcome()) {
+    return false;
+  }
+
+  const int useSameOutcomeId = wxWindow::NewControlId();
+  const int copyOutcomeId = wxWindow::NewControlId();
+  const int moveOutcomeId = wxWindow::NewControlId();
+
+  wxMenu menu;
+  menu.Append(useSameOutcomeId, _("Use same outcome here"));
+  menu.Append(copyOutcomeId, _("Copy outcome here"));
+  menu.AppendSeparator();
+  menu.Append(moveOutcomeId, _("Move outcome here"));
+
+  const int selection = GetPopupMenuSelectionFromUser(menu, p_pos);
+
+  try {
+    if (selection == useSameOutcomeId) {
+      m_doc->DoSetOutcome(p_targetNode, p_sourceNode->GetOutcome());
+      return true;
+    }
+    if (selection == copyOutcomeId) {
+      m_doc->DoCopyOutcome(p_targetNode, p_sourceNode->GetOutcome());
+      return true;
+    }
+    if (selection == moveOutcomeId) {
+      m_doc->DoSetOutcome(p_targetNode, p_sourceNode->GetOutcome());
+      m_doc->DoSetOutcome(p_sourceNode, nullptr);
+      return true;
+    }
+  }
+  catch (std::exception &ex) {
+    ExceptionDialog(this, ex.what()).ShowModal();
+  }
+
+  return false;
+}
+
 //---------------------------------------------------------------------
 //                  EfgDisplay: Event-hook members
 //---------------------------------------------------------------------
@@ -982,62 +972,6 @@ void EfgDisplay::OnMagnify(wxMouseEvent &p_event)
   }
 }
 
-namespace {
-
-wxCursor MakeTreeDragCursor()
-{
-  constexpr int width = 24;
-  constexpr int height = 24;
-
-  wxBitmap bitmap(width, height, 32);
-
-  {
-    wxMemoryDC dc(bitmap);
-    dc.SetBackground(*wxTRANSPARENT_BRUSH);
-    dc.Clear();
-
-    const wxColour stroke(70, 70, 70);
-    const wxColour fill(255, 255, 255);
-
-    dc.SetPen(wxPen(stroke, 2));
-    dc.SetBrush(wxBrush(fill, wxBRUSHSTYLE_SOLID));
-
-    // Simple subtree glyph: one parent node and two children.
-    dc.DrawCircle(7, 5, 3);
-    dc.DrawCircle(7, 18, 3);
-    dc.DrawCircle(18, 18, 3);
-
-    dc.SetPen(wxPen(stroke, 1));
-    dc.DrawLine(7, 8, 7, 15);
-    dc.DrawLine(10, 18, 15, 18);
-
-    dc.SelectObject(wxNullBitmap);
-  }
-
-  wxImage image = bitmap.ConvertToImage();
-  if (image.HasAlpha()) {
-    // Good.
-  }
-  else {
-    image.InitAlpha();
-  }
-
-  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, 0);
-  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, 0);
-
-  return wxCursor(image);
-}
-
-wxCursor MakeDragCursor(const wxBitmap &p_bitmap, int p_hotspotX, int p_hotspotY)
-{
-  wxImage image = p_bitmap.ConvertToImage();
-  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, p_hotspotX);
-  image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, p_hotspotY);
-  return wxCursor(image);
-}
-
-} // namespace
-
 void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
 {
   if (p_event.LeftIsDown() && p_event.Dragging()) {
@@ -1057,38 +991,16 @@ void EfgDisplay::OnMouseMotion(wxMouseEvent &p_event)
       source.DoDragDrop(wxDrag_DefaultMove);
       return;
     }
+
     node = m_layout.OutcomeHitTest(x, y);
 
     if (node && node->GetOutcome()) {
-      const wxBitmap bitmap = MakeOutcomeBitmap();
-#if defined(__WXMSW__) or defined(__WXMAC__)
-      const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-      wxIcon image;
-      image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
-      if (p_event.ControlDown()) {
-        wxString label;
-        label << "O" << node->GetNumber();
-        wxTextDataObject textData(label);
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(true);
-      }
-      else if (p_event.ShiftDown()) {
-        wxString label;
-        label << "p" << node->GetNumber();
-        wxTextDataObject textData(label);
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(true);
-      }
-      else {
-        wxString label;
-        label << "o" << node->GetNumber();
-        wxTextDataObject textData(label);
-        wxDropSource source(textData, this, image, image, image);
-        /*wxDragResult result =*/source.DoDragDrop(wxDrag_DefaultMove);
-      }
+      wxString label;
+      label << "O" << node->GetNumber();
+      wxTextDataObject textData(label);
+
+      wxDropSource source(textData, this);
+      source.DoDragDrop(wxDrag_DefaultMove);
     }
   }
 }
diff --git a/src/gui/efgdisplay.h b/src/gui/efgdisplay.h
index 7ef2d7fcd..b7df8c124 100644
--- a/src/gui/efgdisplay.h
+++ b/src/gui/efgdisplay.h
@@ -111,6 +111,8 @@ class EfgDisplay final : public wxScrolledWindow, public GameView {
 
   bool ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
                         const wxPoint &p_pos);
+  bool ShowOutcomeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
+                           const wxPoint &p_pos);
 
   DECLARE_EVENT_TABLE()
 };

From 2184f83c2062e17ac55dbc803eddb4259760203e Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 16:16:25 +0100
Subject: [PATCH 05/12] Remove DnD cursors for player drag as well

---
 src/gui/efgdisplay.cc |  1 -
 src/gui/efgpanel.cc   | 12 +-----------
 src/gui/nfgpanel.cc   | 12 +-----------
 3 files changed, 2 insertions(+), 23 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index bc5a523fa..4ee455049 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -27,7 +27,6 @@
 #include <wx/wx.h>
 #endif              // WX_PRECOMP
 #include <wx/dnd.h> // for drag-and-drop support
-#include <wx/image.h>
 
 #include "gambit.h"
 
diff --git a/src/gui/efgpanel.cc b/src/gui/efgpanel.cc
index 4767fb47b..a58950f2e 100644
--- a/src/gui/efgpanel.cc
+++ b/src/gui/efgpanel.cc
@@ -27,7 +27,6 @@
 #include <wx/wx.h>
 #endif                   // WX_PRECOMP
 #include <wx/dnd.h>      // for drag-and-drop features
-#include <wx/image.h>    // for creating drag-and-drop cursor
 #include <wx/print.h>    // for printing support
 #include <wx/colordlg.h> // for picking player colors
 #include <wx/dcsvg.h>    // for SVG output
@@ -66,19 +65,10 @@ gbtTreePlayerIcon::gbtTreePlayerIcon(wxWindow *p_parent, int p_player)
 
 void gbtTreePlayerIcon::OnLeftClick(wxMouseEvent &)
 {
-  const wxBitmap bitmap(person_xpm);
-
-#if defined(__WXMSW__) or defined(__WXMAC__)
-  const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-  wxIcon image;
-  image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
   wxString label;
   label << "P" << m_player;
   wxTextDataObject textData(label);
-  wxDropSource source(textData, this, image, image, image);
+  wxDropSource source(textData, this);
   source.DoDragDrop(wxDrag_DefaultMove);
 }
 
diff --git a/src/gui/nfgpanel.cc b/src/gui/nfgpanel.cc
index c72df8620..91de60321 100644
--- a/src/gui/nfgpanel.cc
+++ b/src/gui/nfgpanel.cc
@@ -25,7 +25,6 @@
 #include <wx/wx.h>
 #endif                   // WX_PRECOMP
 #include <wx/dnd.h>      // for drag-and-drop features
-#include <wx/image.h>    // for creating drag-and-drop cursor
 #include <wx/colordlg.h> // for picking player colors
 
 #include "gamedoc.h"
@@ -62,19 +61,10 @@ TablePlayerIcon::TablePlayerIcon(wxWindow *p_parent, int p_player)
 
 void TablePlayerIcon::OnLeftClick(wxMouseEvent &)
 {
-  const wxBitmap bitmap(person_xpm);
-
-#if defined(__WXMSW__) or defined(__WXMAC__)
-  const auto image = wxCursor(bitmap.ConvertToImage());
-#else
-  wxIcon image;
-  image.CopyFromBitmap(bitmap);
-#endif // _WXMSW__
-
   wxString label;
   label << "P" << m_player;
   wxTextDataObject textData(label);
-  wxDropSource source(textData, this, image, image, image);
+  wxDropSource source(textData, this);
   source.DoDragDrop(wxDrag_DefaultMove);
 }
 

From f198dfc15ba7224ae16da1e58b83f5d9316f695a Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Fri, 5 Jun 2026 16:22:23 +0100
Subject: [PATCH 06/12] Update drag-and-drop documentation

---
 doc/gui.efg.rst | 46 ++++++++++------------------------------------
 1 file changed, 10 insertions(+), 36 deletions(-)

diff --git a/doc/gui.efg.rst b/doc/gui.efg.rst
index a863bdb1e..6566580d0 100644
--- a/doc/gui.efg.rst
+++ b/doc/gui.efg.rst
@@ -84,27 +84,11 @@ the tree. It is often efficient to create the structure once, and then
 copy it as needed elsewhere.
 
 Gambit provides a convenient idiom for this. Clicking on any
-nonterminal node and dragging to any terminal node implements a move
-operation, which moves the entire subtree rooted at the original,
-nonterminal node to the terminal node.
-
-To turn the operation into a copy operation:
-
-+ On Windows and Linux systems, hold down the :kbd:`Ctrl` key during
-  the operation.
-+ On OS X, hold down the :kbd:`Cmd` key when starting the
-  drag operation, then release prior to dropping.
-
-The entire subtree rooted at the original node is copied,
-starting at the terminal node. In this copy operation, each node in
-the copied image is placed in the same information set as the
-corresponding node in the original subtree.
-
-Copying a subtree to a terminal node in that subtree is also
-supported. In this case, the copying operation is halted when reaching
-the terminal node, to avoid an infinite loop. Thus, this feature
-can also be helpful in constructing multiple-stage games.
-
+nonterminal node and dragging to another node results in a context-aware
+popup menu.  Depending on the destination node, this menu offers
+the option of copying the subtree rooted at the original node, moving
+it entirely, or placing the destination node in the same information set
+as the source node.
 
 
 Removing parts of a game tree
@@ -204,21 +188,11 @@ payoff by pressing the :kbd:`Tab` key both stores the changes to the
 player's payoff, and advances the editor to the payoff for the next
 player at that outcome.
 
-Outcomes may also be moved or copied using a drag-and-drop idiom.
-Left-clicking and dragging an outcome to another node moves the
-outcome from the original node to the target node. Copying an outcome
-may be accomplished by doing this same action while holding down the
-Control (:kbd:`Ctrl`) key on the keyboard.
-
-
-
-When using the copy idiom described above, the action assigns the same
-outcome to both the involved nodes. Therefore, if subsequently the
-payoffs of the outcome are edited, the payoffs at both nodes will be
-modified. To copy the outcome in such a way that the outcome at the
-target node is a different outcome from the one at the source, but
-with the same payoffs, hold down the :kbd:`Shift` key instead of the
-:kbd:`Control` key while dragging.
+Outcomes may also be moved or copied using drag-and-drop.
+Left-clicking and dragging an outcome to another node pops up a
+context-aware menu which allows the outcome to be moved or copied, or
+to create a new outcome with the same payoffs as the original one at
+the new node.
 
 To remove an outcome from a node, click on the node, and
 select :menuselection:`Edit --> Remove outcome`.

From 7d23aca696aecc60333cb75a103b043e21f35b93 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Wed, 17 Jun 2026 10:10:57 +0100
Subject: [PATCH 07/12] Added context menu for dropping player

---
 src/gui/efgdisplay.cc | 70 ++++++++++++++++++++++++++++++++++---------
 src/gui/efgdisplay.h  |  2 ++
 2 files changed, 58 insertions(+), 14 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index 4ee455049..e8f2b1cfc 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -88,7 +88,7 @@ class PlayerDropTarget : public wxTextDropTarget {
   EfgDisplay *m_owner;
   GameDocument *m_model;
 
-  bool OnDropPlayer(const GameNode &p_node, const wxString &p_text);
+  bool OnDropPlayer(const GameNode &p_node, const wxString &p_text, const wxPoint &p_pos);
   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);
 
@@ -123,22 +123,18 @@ static GameNode GetNode(const GameNode &p_node, int p_id)
   }
 }
 
-bool PlayerDropTarget::OnDropPlayer(const GameNode &p_node, const wxString &p_text)
+bool PlayerDropTarget::OnDropPlayer(const GameNode &p_node, const wxString &p_text,
+                                    const wxPoint &p_pos)
 {
   long pl;
-  p_text.Right(p_text.Length() - 1).ToLong(&pl);
+  if (!p_text.Right(p_text.Length() - 1).ToLong(&pl)) {
+    return false;
+  }
+
   const Game efg = m_model->GetGame();
   const GamePlayer player = ((pl == 0) ? efg->GetChance() : efg->GetPlayer(pl));
-  if (p_node->IsTerminal()) {
-    m_model->DoInsertMove(p_node, player, 2);
-  }
-  else if (p_node->GetPlayer() == player) {
-    m_model->DoInsertAction(p_node);
-  }
-  else {
-    m_model->DoSetPlayer(p_node, player);
-  }
-  return true;
+
+  return m_owner->ShowPlayerDropMenu(p_node, player, p_pos);
 }
 
 bool PlayerDropTarget::OnDropOutcome(const GameNode &p_node, const wxString &p_text,
@@ -189,7 +185,7 @@ bool PlayerDropTarget::OnDropText(wxCoord p_x, wxCoord p_y, const wxString &p_te
     case 'N':
       return OnDropTreeNode(node, p_text, wxPoint(p_x, p_y));
     case 'P':
-      return OnDropPlayer(node, p_text);
+      return OnDropPlayer(node, p_text, wxPoint(p_x, p_y));
     case 'O':
       return OnDropOutcome(node, p_text, wxPoint(p_x, p_y));
     default:
@@ -258,6 +254,52 @@ void EfgDisplay::MakeMenus()
   m_nodeMenu->Append(GBT_MENU_EDIT_GAME, _("&Game properties"), _("Edit properties of the game"));
 }
 
+bool EfgDisplay::ShowPlayerDropMenu(const GameNode &p_targetNode, const GamePlayer &p_player,
+                                    const wxPoint &p_pos)
+{
+  if (!p_targetNode || !p_player) {
+    return false;
+  }
+
+  const int operationId = wxWindow::NewControlId();
+
+  wxMenu menu;
+
+  if (p_targetNode->IsTerminal()) {
+    menu.Append(operationId, _("Insert move for this player"));
+  }
+  else if (p_targetNode->GetPlayer() == p_player) {
+    menu.Append(operationId, _("Insert action at this move"));
+  }
+  else {
+    menu.Append(operationId, _("Assign this move to this player"));
+  }
+
+  const int selection = GetPopupMenuSelectionFromUser(menu, p_pos);
+  if (selection != operationId) {
+    return false;
+  }
+
+  try {
+    if (p_targetNode->IsTerminal()) {
+      m_doc->DoInsertMove(p_targetNode, p_player, 2);
+    }
+    else if (p_targetNode->GetPlayer() == p_player) {
+      m_doc->DoInsertAction(p_targetNode);
+    }
+    else {
+      m_doc->DoSetPlayer(p_targetNode, p_player);
+    }
+
+    return true;
+  }
+  catch (std::exception &ex) {
+    ExceptionDialog(this, ex.what()).ShowModal();
+  }
+
+  return false;
+}
+
 bool EfgDisplay::ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
                                   const wxPoint &p_pos)
 {
diff --git a/src/gui/efgdisplay.h b/src/gui/efgdisplay.h
index b7df8c124..268349e23 100644
--- a/src/gui/efgdisplay.h
+++ b/src/gui/efgdisplay.h
@@ -109,6 +109,8 @@ class EfgDisplay final : public wxScrolledWindow, public GameView {
 
   void EnsureNodeVisible(const GameNode &);
 
+  bool ShowPlayerDropMenu(const GameNode &p_targetNode, const GamePlayer &p_player,
+                          const wxPoint &p_pos);
   bool ShowTreeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,
                         const wxPoint &p_pos);
   bool ShowOutcomeDropMenu(const GameNode &p_targetNode, const GameNode &p_sourceNode,

From e54cbd56be68dbb35f4b86afd5b2c3fc924879aa Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Wed, 17 Jun 2026 10:14:57 +0100
Subject: [PATCH 08/12] Remove unneeded elses and nesting

---
 src/gui/efgdisplay.cc | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/gui/efgdisplay.cc b/src/gui/efgdisplay.cc
index e8f2b1cfc..3bcbd6a1d 100644
--- a/src/gui/efgdisplay.cc
+++ b/src/gui/efgdisplay.cc
@@ -110,17 +110,15 @@ static GameNode GetNode(const GameNode &p_node, int p_id)
   if (p_node->GetNumber() == p_id) {
     return p_node;
   }
-  else if (p_node->IsTerminal()) {
+  if (p_node->IsTerminal()) {
     return nullptr;
   }
-  else {
-    for (const auto &child : p_node->GetChildren()) {
-      if (const auto node = GetNode(child, p_id)) {
-        return node;
-      }
+  for (const auto &child : p_node->GetChildren()) {
+    if (const auto node = GetNode(child, p_id)) {
+      return node;
     }
-    return nullptr;
   }
+  return nullptr;
 }
 
 bool PlayerDropTarget::OnDropPlayer(const GameNode &p_node, const wxString &p_text,

From c675f546a4ebc86c186723f3c8c44af089958ab8 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Wed, 17 Jun 2026 10:29:51 +0100
Subject: [PATCH 09/12] Add context menu for strategic form drag and drop

---
 src/gui/nfgtable.cc | 153 ++++++++++++++++++++++++++++++++------------
 1 file changed, 112 insertions(+), 41 deletions(-)

diff --git a/src/gui/nfgtable.cc b/src/gui/nfgtable.cc
index add5f6df4..193c2da50 100644
--- a/src/gui/nfgtable.cc
+++ b/src/gui/nfgtable.cc
@@ -113,7 +113,7 @@ void TableWidgetBase::OnCellLeftClick(wxSheetEvent &p_event)
 }
 
 //=========================================================================
-//                class gbtTableWidgetDropTarget
+//                class TableWidgetDropTarget
 //=========================================================================
 
 //!
@@ -121,12 +121,11 @@ void TableWidgetBase::OnCellLeftClick(wxSheetEvent &p_event)
 //! communicates the location and text of the drop to its owner for
 //! further processing
 //!
-class gbtTableWidgetDropTarget : public wxTextDropTarget {
-private:
+class TableWidgetDropTarget : public wxTextDropTarget {
   TableWidgetBase *m_owner;
 
 public:
-  explicit gbtTableWidgetDropTarget(TableWidgetBase *p_owner) : m_owner(p_owner) {}
+  explicit TableWidgetDropTarget(TableWidgetBase *p_owner) : m_owner(p_owner) {}
 
   bool OnDropText(wxCoord x, wxCoord y, const wxString &p_text) override
   {
@@ -159,10 +158,13 @@ class RowPlayerWidget final : public TableWidgetBase {
 
   void OnCellRightClick(wxSheetEvent &);
 
+  bool ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
+                          const wxPoint &p_pos);
+
 public:
   /// @name Lifecycle
   //@{
-  /// Constructorw
+  /// Constructor
   RowPlayerWidget(TableWidget *p_parent);
   //@}
 
@@ -187,7 +189,7 @@ RowPlayerWidget::RowPlayerWidget(TableWidget *p_parent)
   SetScrollBarMode(SB_NEVER);
   SetGridLineColour(*wxBLACK);
 
-  wxWindow::SetDropTarget(new gbtTableWidgetDropTarget(this));
+  wxWindow::SetDropTarget(new TableWidgetDropTarget(this));
 
   Connect(GetId(), wxEVT_SHEET_CELL_RIGHT_DOWN,
           reinterpret_cast<wxEventFunction>(wxStaticCastEvent(
@@ -322,28 +324,61 @@ void RowPlayerWidget::OnUpdate()
   Refresh();
 }
 
+bool RowPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
+                                         const wxPoint &p_pos)
+{
+  const int placePlayerId = wxWindow::NewControlId();
+
+  wxMenu menu;
+  menu.Append(placePlayerId, p_label);
+
+  const int selection = GetPopupMenuSelectionFromUser(menu, p_pos);
+  if (selection != placePlayerId) {
+    return false;
+  }
+
+  try {
+    m_table->SetRowPlayer(p_index, p_player);
+    return true;
+  }
+  catch (std::exception &ex) {
+    ExceptionDialog(this, ex.what()).ShowModal();
+  }
+
+  return false;
+}
+
 bool RowPlayerWidget::DropText(wxCoord p_x, wxCoord p_y, const wxString &p_text)
 {
-  if (p_text[0] == 'P') {
-    long pl;
-    p_text.Right(p_text.Length() - 1).ToLong(&pl);
+  if (p_text.empty() || p_text[0] != 'P') {
+    return false;
+  }
 
-    if (m_table->NumRowPlayers() == 0) {
-      m_table->SetRowPlayer(1, pl);
-      return true;
-    }
+  long player;
+  if (!p_text.Right(p_text.Length() - 1).ToLong(&player)) {
+    return false;
+  }
 
-    for (int col = 0; col < GetNumberCols(); col++) {
-      const wxRect rect = CellToRect(wxSheetCoords(0, col));
+  if (m_table->NumRowPlayers() == 0) {
+    return ShowPlayerDropMenu(1, static_cast<int>(player), _("Use as row player"),
+                              wxPoint(p_x, p_y));
+  }
 
-      if (p_x >= rect.x && p_x < rect.x + rect.width / 2) {
-        m_table->SetRowPlayer(col + 1, pl);
-        return true;
-      }
-      else if (p_x >= rect.x + rect.width / 2 && p_x < rect.x + rect.width) {
-        m_table->SetRowPlayer(col + 2, pl);
-        return true;
-      }
+  for (int col = 0; col < GetNumberCols(); col++) {
+    const wxRect rect = CellToRect(wxSheetCoords(0, col));
+    const int existingPlayer = m_table->GetRowHeaderPlayer(col);
+    const wxString playerLabel = wxString::Format(_("Player %d"), existingPlayer);
+
+    if (p_x >= rect.x && p_x < rect.x + rect.width / 2) {
+      return ShowPlayerDropMenu(col + 1, static_cast<int>(player),
+                                wxString::Format(_("Place before %s"), playerLabel),
+                                wxPoint(p_x, p_y));
+    }
+
+    if (p_x >= rect.x + rect.width / 2 && p_x < rect.x + rect.width) {
+      return ShowPlayerDropMenu(col + 2, static_cast<int>(player),
+                                wxString::Format(_("Place after %s"), playerLabel),
+                                wxPoint(p_x, p_y));
     }
   }
 
@@ -375,6 +410,9 @@ class ColPlayerWidget final : public TableWidgetBase {
 
   void OnCellRightClick(wxSheetEvent &);
 
+  bool ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
+                          const wxPoint &p_pos);
+
 public:
   /// @name Lifecycle
   //@{
@@ -404,7 +442,7 @@ ColPlayerWidget::ColPlayerWidget(TableWidget *p_parent)
   SetGridLineColour(*wxBLACK);
   wxWindow::SetBackgroundColour(*wxLIGHT_GREY);
 
-  wxWindow::SetDropTarget(new gbtTableWidgetDropTarget(this));
+  wxWindow::SetDropTarget(new TableWidgetDropTarget(this));
 
   Connect(GetId(), wxEVT_SHEET_CELL_RIGHT_DOWN,
           reinterpret_cast<wxEventFunction>(wxStaticCastEvent(
@@ -540,28 +578,61 @@ void ColPlayerWidget::DrawCell(wxDC &p_dc, const wxSheetCoords &p_coords)
   }
 }
 
+bool ColPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
+                                         const wxPoint &p_pos)
+{
+  const int placePlayerId = wxWindow::NewControlId();
+
+  wxMenu menu;
+  menu.Append(placePlayerId, p_label);
+
+  const int selection = GetPopupMenuSelectionFromUser(menu, p_pos);
+  if (selection != placePlayerId) {
+    return false;
+  }
+
+  try {
+    m_table->SetColPlayer(p_index, p_player);
+    return true;
+  }
+  catch (std::exception &ex) {
+    ExceptionDialog(this, ex.what()).ShowModal();
+  }
+
+  return false;
+}
+
 bool ColPlayerWidget::DropText(wxCoord p_x, wxCoord p_y, const wxString &p_text)
 {
-  if (p_text[0] == 'P') {
-    long pl;
-    p_text.Right(p_text.Length() - 1).ToLong(&pl);
+  if (p_text.empty() || p_text[0] != 'P') {
+    return false;
+  }
 
-    if (m_table->NumColPlayers() == 0) {
-      m_table->SetColPlayer(1, pl);
-      return true;
-    }
+  long player;
+  if (!p_text.Right(p_text.Length() - 1).ToLong(&player)) {
+    return false;
+  }
 
-    for (int row = 0; row < GetNumberRows(); row++) {
-      const wxRect rect = CellToRect(wxSheetCoords(row, 0));
+  if (m_table->NumColPlayers() == 0) {
+    return ShowPlayerDropMenu(1, static_cast<int>(player), _("Use as column player"),
+                              wxPoint(p_x, p_y));
+  }
 
-      if (p_y >= rect.y && p_y < rect.y + rect.height / 2) {
-        m_table->SetColPlayer(row + 1, pl);
-        return true;
-      }
-      else if (p_y >= rect.y + rect.height / 2 && p_y < rect.y + rect.height) {
-        m_table->SetColPlayer(row + 2, pl);
-        return true;
-      }
+  for (int row = 0; row < GetNumberRows(); row++) {
+    const wxRect rect = CellToRect(wxSheetCoords(row, 0));
+    const int existingPlayer = m_table->GetColHeaderPlayer(row);
+    const wxString playerLabel = wxString::Format(_("Player %d"), existingPlayer);
+
+    if (p_y >= rect.y && p_y < rect.y + rect.height / 2) {
+      return ShowPlayerDropMenu(row + 1, static_cast<int>(player),
+                                wxString::Format(_("Place before %s"), playerLabel),
+                                wxPoint(p_x, p_y));
+    }
+
+    if (p_y >= rect.y + rect.height / 2 && p_y < rect.y + rect.height) {
+      return ShowPlayerDropMenu(row + 2, static_cast<int>(player),
+                                wxString::Format(_("Place after %s"), playerLabel),
+                                wxPoint(p_x, p_y));
     }
   }
 

From cf510d89d1a01c77dab4b58da6626bcd4bcb09b3 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Wed, 17 Jun 2026 10:36:57 +0100
Subject: [PATCH 10/12] Suppress popup if normal form DnD operation is a no-op

---
 src/gui/nfgtable.cc | 32 ++++++++++++++++++++++++++++++++
 src/gui/nfgtable.h  |  2 ++
 2 files changed, 34 insertions(+)

diff --git a/src/gui/nfgtable.cc b/src/gui/nfgtable.cc
index 193c2da50..b1beaa088 100644
--- a/src/gui/nfgtable.cc
+++ b/src/gui/nfgtable.cc
@@ -327,6 +327,10 @@ void RowPlayerWidget::OnUpdate()
 bool RowPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
                                          const wxPoint &p_pos)
 {
+  if (m_table->IsRowPlayerPlacementNoOp(p_index, p_player)) {
+    return false;
+  }
+
   const int placePlayerId = wxWindow::NewControlId();
 
   wxMenu menu;
@@ -581,6 +585,10 @@ void ColPlayerWidget::DrawCell(wxDC &p_dc, const wxSheetCoords &p_coords)
 bool ColPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxString &p_label,
                                          const wxPoint &p_pos)
 {
+  if (m_table->IsColPlayerPlacementNoOp(p_index, p_player)) {
+    return false;
+  }
+
   const int placePlayerId = wxWindow::NewControlId();
 
   wxMenu menu;
@@ -1164,6 +1172,30 @@ bool TableWidget::ShowDominance() const { return m_nfgPanel->IsDominanceShown();
 //                      TableWidget: View state
 //=========================================================================
 
+bool TableWidget::IsRowPlayerPlacementNoOp(int p_index, int p_player) const
+{
+  for (int col = 0; col < NumRowPlayers(); ++col) {
+    if (GetRowHeaderPlayer(col) == p_player) {
+      const int currentIndex = col + 1;
+      return p_index == currentIndex || p_index == currentIndex + 1;
+    }
+  }
+
+  return false;
+}
+
+bool TableWidget::IsColPlayerPlacementNoOp(int p_index, int p_player) const
+{
+  for (int row = 0; row < NumColPlayers(); ++row) {
+    if (GetColHeaderPlayer(row) == p_player) {
+      const int currentIndex = row + 1;
+      return p_index == currentIndex || p_index == currentIndex + 1;
+    }
+  }
+
+  return false;
+}
+
 void TableWidget::SetRowPlayer(int index, int pl)
 {
   m_layout->SetRowPlayer(index, pl);
diff --git a/src/gui/nfgtable.h b/src/gui/nfgtable.h
index 34bc459b8..8ceb1f92a 100644
--- a/src/gui/nfgtable.h
+++ b/src/gui/nfgtable.h
@@ -305,6 +305,8 @@ class TableWidget final : public wxPanel {
 
   /// Are we showing dominance indicators or not?
   bool ShowDominance() const;
+  bool IsRowPlayerPlacementNoOp(int p_index, int p_player) const;
+  bool IsColPlayerPlacementNoOp(int p_index, int p_player) const;
   //@}
 
   /// @name View state

From f7b4c9b792b141f5afde2ac5f37203010cfd7e67 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Wed, 17 Jun 2026 11:25:23 +0100
Subject: [PATCH 11/12] Change no-op behaviour to silently accept rather than
 reject

---
 src/gui/nfgtable.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/gui/nfgtable.cc b/src/gui/nfgtable.cc
index b1beaa088..74df50984 100644
--- a/src/gui/nfgtable.cc
+++ b/src/gui/nfgtable.cc
@@ -328,7 +328,7 @@ bool RowPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxStri
                                          const wxPoint &p_pos)
 {
   if (m_table->IsRowPlayerPlacementNoOp(p_index, p_player)) {
-    return false;
+    return true;
   }
 
   const int placePlayerId = wxWindow::NewControlId();
@@ -586,7 +586,7 @@ bool ColPlayerWidget::ShowPlayerDropMenu(int p_index, int p_player, const wxStri
                                          const wxPoint &p_pos)
 {
   if (m_table->IsColPlayerPlacementNoOp(p_index, p_player)) {
-    return false;
+    return true;
   }
 
   const int placePlayerId = wxWindow::NewControlId();

From adbf752219efcf822f6797ea9225ff4346673f69 Mon Sep 17 00:00:00 2001
From: Theodore Turocy <ted.turocy@gmail.com>
Date: Thu, 18 Jun 2026 13:55:22 +0100
Subject: [PATCH 12/12] Rewrite documentation section on pivoting strategic
 game.

---
 doc/gui.nfg.rst | 181 +++++++++++++++++++++++++-----------------------
 1 file changed, 96 insertions(+), 85 deletions(-)

diff --git a/doc/gui.nfg.rst b/doc/gui.nfg.rst
index af0f289c5..3631bd74c 100644
--- a/doc/gui.nfg.rst
+++ b/doc/gui.nfg.rst
@@ -22,91 +22,102 @@ game, select :menuselection:`File --> New --> Strategic game`,
 or click the new strategic game icon on the toolbar.
 
 
-
-Navigating a strategic game
----------------------------
-
-Gambit displays a strategic game in table form. All players are
-assigned to be either row players or column players, and the payoffs
-for each entry in the strategic game table correspond to the payoffs
-corresponding to the situation in which all the row players play the
-strategy specified on that row for them, and all the column players
-play the strategy specified on that column for them.
-
-.. image::  screens/pd1.*
-            :width: 33%
-            :alt: a prisoner's dilemma game
-            :align: right
-            :target: _images/pd1.png
-
-For games with two players, this presentation is by default configured
-to be similar to the standard presenation of strategic games as
-tables, in which one player is assigned to be the "row" player and the
-other the "column" player. However, Gambit permits a more flexible
-assignment, in which multiple players can be assigned to the rows and
-multiple players to the columns. This is of particular use for games
-with more than two players. In print, a three-player strategic game is
-usually presented as a collection of tables, with one player choosing
-the row, the second the column, and the third the table. Gambit
-presents such games by hierarchially listing the strategies of one or
-more players on both rows and columns.
-
-The hierarchical presentation of the table is similar to that of a
-pivot table.
-Here, Alice,
-shown in red, has her strategies listed on the rows of the table, and
-Bob, shown in blue, has his strategies listed on the columns of the
-table.
-
-The assignment of players to row and column roles is fully
-customizable. To change the assignment of a player, drag the person
-icon appearing to the left of the player's name on the player toolbar
-to either of the areas in the payoff table displaying the strategy
-labels.
-
-.. image::  screens/pd2.*
-            :width: 33%
-            :alt: a prisoner's dilemma game, with contingencies in
-                  list style
-            :align: right
-            :target: _images/pd2.png
-
-For example, dragging the player icon from the left of Bob's name in
-the list of players and dropping it on the right side of Alice's
-strategy label column changes the display of the game as in
-Here, the strategies are shown in a
-hierarchical format, enumerating the outcomes of the game first by
-Alice's (red) strategy choice, then by Bob's (blue) strategy choice.
-
-Alternatively, the game can be displayed by listing the outcomes with
-Bob's strategy choice first, then Alice's. Drag Bob's player icon and
-drop it on the left side of Alice's strategy choices, and the game
-display changes to organize the outcomes first by Bob's action, then
-by Alice's.
-
-The same dragging operation can be used to assign players to the
-columns. Assigning multiple players to the columns gives the same
-hierarchical presentation of those players' strategies. Dropping a
-player above another player's strategy labels assigns him to a higher
-level of the column player hierarchy; dropping a player below another
-player's strategy labels assigns him to a lower level of the column
-player hierarchy.
-
-.. image::  screens/pd3.*
-            :width: 33%
-            :alt: another view of the same prisoner's dilemma game.
-            :align: right
-            :target: _images/pd3.png
-
-As the assignment of players in the row and column
-hierarchies changes, the ordering of the payoffs in each cell of the
-table also changes. In all cases, the color-coding of the entries
-identifies the player to whom each payoff corresponds. The ordering
-convention is chosen so that for a two player game in which one player
-is a row player and the other a column player, the row player's payoff
-is shown first, followed by the column player, which is the most
-common convention in print.
-
+Displaying a strategic game
+===========================
+
+Gambit displays a strategic game as a table. Each cell represents one
+strategy profile: one strategy choice for every player. The cell shows
+the payoffs that result when the players choose the strategies named by
+that cell's row and column labels.
+
+For a two-player game, Gambit initially uses the familiar matrix
+arrangement. One player's strategies label the rows, and the other
+player's strategies label the columns.
+
+.. image:: screens/pd1.*
+   :width: 50%
+   :alt: A two-player strategic game with Alice's strategies on the rows and Bob's strategies on the columns.
+   :align: center
+   :target: _images/pd1.png
+
+Each row-and-column combination identifies one strategy profile. For
+example, a cell in the row labelled ``Cooperate`` and the column
+labelled ``Defect`` represents the outcome in which the row player
+chooses ``Cooperate`` and the column player chooses ``Defect``.
+
+The payoffs in each cell are colour-coded by player. In the standard
+two-player arrangement, Gambit displays the row player's payoff first
+and the column player's payoff second.
+
+
+Row and column hierarchies
+--------------------------
+
+Games with more than two players require more than one strategy label
+to identify each row or column. Gambit handles this by allowing several
+players to be assigned to the rows, several players to be assigned to
+the columns, or both.
+
+When several players are assigned to the same side of the table, their
+strategy labels form a hierarchy. Each level groups together the
+strategy combinations belonging to the players below it. This is
+similar to the hierarchical row and column labels used in a pivot table
+or a table with a multi-level index.
+
+For example, suppose Alice and Bob are both assigned to the rows. If
+Alice is above Bob in the row hierarchy, Gambit first groups the rows
+by Alice's strategy and then lists Bob's strategies within each group.
+
+.. image:: screens/pd2.*
+   :width: 50%
+   :alt: A strategic game with Alice and Bob arranged as two levels of hierarchical row labels.
+   :align: center
+   :target: _images/pd2.png
+
+Reversing their order groups the rows first by Bob's strategy and then
+by Alice's. The strategy profiles and payoffs do not change; only their
+arrangement in the table changes.
+
+The same principle applies to the columns. A player placed at a higher
+level of the column hierarchy forms the outer grouping, while players
+at lower levels form groups within it.
+
+This arrangement provides a single table view of games that are often
+printed as a collection of separate payoff matrices. For example, a
+three-player game can be displayed with one player on the rows and two
+players in a column hierarchy, rather than as a separate matrix for
+each strategy of the third player.
+
+
+Rearranging the table
+---------------------
+
+To change the table arrangement, drag a player from the player list to
+the row-label or column-label area.
+
+When the drop menu appears, choose where to place the player in the row
+or column hierarchy. Gambit updates the display without changing the
+game itself.
+
+The available positions depend on the current arrangement. Placing a
+player before another player makes the moved player a higher level in
+the hierarchy; placing the player after another player makes the moved
+player a lower level.
+
+.. image:: screens/pd3.*
+   :width: 50%
+   :alt: The same strategic game displayed with a different ordering of its hierarchical strategy labels.
+   :align: center
+   :target: _images/pd3.png
+
+Changing the row and column hierarchies may also change the order in
+which payoffs appear within each cell. The colour of each payoff
+continues to identify the player to whom it belongs.
+
+.. note::
+
+   Rearranging the table changes only the presentation of the game. It
+   does not change the players, strategies, outcomes, or payoffs.
 
 
 Changing players and strategies