Fix Properties panel to reference the correct frame

The properties editors are global but the frame that they reference is
not static, so we need to be able to update the frame reference when
restarting pcb editor from the main window.  This updates the frame,
being careful to remove the signalling when closing pcbnew but keeping
the instance of the editor in place.

Fixes https://gitlab.com/kicad/code/kicad/issues/12297

common/properties/pg_editors.cpp

@@ -39,9 +39,27 @@ PG_UNIT_EDITOR::~PG_UNIT_EDITOR()
 }
 
 
+void PG_UNIT_EDITOR::UpdateFrame( EDA_DRAW_FRAME* aFrame )
+{
+    m_frame = aFrame;
+
+    if( aFrame )
+    {
+        m_unitBinder = std::make_unique<PROPERTY_EDITOR_UNIT_BINDER>( m_frame );
+        m_unitBinder->SetUnits( m_frame->GetUserUnits() );
+    }
+    else
+    {
+        m_unitBinder = nullptr;
+    }
+}
+
+
 wxPGWindowList PG_UNIT_EDITOR::CreateControls( wxPropertyGrid* aPropGrid, wxPGProperty* aProperty,
                                                const wxPoint& aPos, const wxSize& aSize ) const
 {
+    wxASSERT( m_unitBinder );
+
     wxPGWindowList ret = wxPGTextCtrlEditor::CreateControls( aPropGrid, aProperty, aPos, aSize );
 
     m_unitBinder->SetControl( ret.m_primary );
@@ -57,6 +75,8 @@ wxPGWindowList PG_UNIT_EDITOR::CreateControls( wxPropertyGrid* aPropGrid, wxPGPr
 bool PG_UNIT_EDITOR::GetValueFromControl( wxVariant& aVariant, wxPGProperty* aProperty,
                                           wxWindow* aCtrl ) const
 {
+    wxASSERT( m_unitBinder );
+
     wxTextCtrl* textCtrl = dynamic_cast<wxTextCtrl*>( aCtrl );
     wxCHECK_MSG( textCtrl, false, "PG_UNIT_EDITOR requires a text control!" );
     wxString textVal = textCtrl->GetValue();

include/properties/pg_editors.h

@@ -35,13 +35,22 @@ public:
 
     virtual ~PG_UNIT_EDITOR();
 
-    wxString GetName() const override { return wxT( "UnitEditor" ); }
+    wxString GetName() const override { return wxT( "KiCadUnitEditor" ); }
 
     wxPGWindowList CreateControls( wxPropertyGrid* aPropGrid, wxPGProperty* aProperty,
                                    const wxPoint& aPos, const wxSize& aSize ) const override;
 
     bool GetValueFromControl( wxVariant& aVariant, wxPGProperty* aProperty,
                               wxWindow* aCtrl ) const override;
+
+    /**
+     * When restarting an editor, the instance of PG_UNIT_EDITOR may be the same
+     * but the referenced frame is different.  This re-binds the frame to the editor
+     * and associated controls
+     * @param aFrame New frame to bind
+     */
+    void UpdateFrame( EDA_DRAW_FRAME* aFrame );
+
 protected:
     EDA_DRAW_FRAME* m_frame;
 

pcbnew/widgets/pcb_properties_panel.cpp

@@ -39,23 +39,35 @@ PCB_PROPERTIES_PANEL::PCB_PROPERTIES_PANEL( wxWindow* aParent, PCB_EDIT_FRAME* a
     : PROPERTIES_PANEL( aParent, aFrame ), m_frame( aFrame ), m_propMgr( PROPERTY_MANAGER::Instance() )
 {
     m_propMgr.Rebuild();
+    bool found = false;
+
+    PG_UNIT_EDITOR* new_editor = new PG_UNIT_EDITOR( m_frame );
+
+    if( wxPGGlobalVars )
+    {
+        auto it = wxPGGlobalVars->m_mapEditorClasses.find( new_editor->GetName() );
+
+        if( it != wxPGGlobalVars->m_mapEditorClasses.end() )
+        {
+            m_editor = static_cast<PG_UNIT_EDITOR*>( it->second );
+            m_editor->UpdateFrame( m_frame );
+            found = true;
+        }
+    }
+
+    if( found )
+        delete new_editor;
+    else
+        m_editor = static_cast<PG_UNIT_EDITOR*>( wxPropertyGrid::RegisterEditorClass( new_editor ) );
+
 
-    m_editor = wxPropertyGrid::RegisterEditorClass( new PG_UNIT_EDITOR( m_frame ) );
 }
 
 
 
 PCB_PROPERTIES_PANEL::~PCB_PROPERTIES_PANEL()
 {
-    auto it = wxPGGlobalVars->m_mapEditorClasses.find( m_editor->GetName() );
-
-    if( it != wxPGGlobalVars->m_mapEditorClasses.end() )
-    {
-        wxPGGlobalVars->m_mapEditorClasses.erase( it );
-
-        delete static_cast<PG_UNIT_EDITOR*>( it->second );
-        it->second = nullptr;
-    }
+    m_editor->UpdateFrame( nullptr );
 }
 
 

pcbnew/widgets/pcb_properties_panel.h

@@ -27,7 +27,7 @@ class SELECTION;
 class BOARD;
 class PCB_EDIT_FRAME;
 class PROPERTY_MANAGER;
-class wxPGEditor;
+class PG_UNIT_EDITOR;
 
 class PCB_PROPERTIES_PANEL : public PROPERTIES_PANEL
 {
@@ -48,7 +48,7 @@ protected:
 
     PCB_EDIT_FRAME* m_frame;
     PROPERTY_MANAGER& m_propMgr;
-    wxPGEditor* m_editor;
+    PG_UNIT_EDITOR* m_editor;
 
     wxPGChoices m_nets;
 };