Make it clear that GetSheets() is heavy.

Also removes the side-effect that SCH_SHEET_LIST's
c'tor would sort the list (and write virtual page
numbers) anytime the starting sheet was the root.

Also, definitely don't build a SHEET_LIST (sorted or
otherwise) if you're not even going to use it.

Also don't build SCH_SHEET_LISTs on idle events.  Better
to just always have the Next Sheet button enabled (we
already beep if you click it and there's no next sheet).

Also, use a SCREEN_LIST when you can.  It's much cheaper
to create.

eeschema/annotate.cpp

@@ -39,8 +39,7 @@
 void SCH_EDIT_FRAME::mapExistingAnnotation( std::map<wxString, wxString>& aMap )
 {
     SCH_REFERENCE_LIST references;
-
+    Schematic().BuildUnorderedSheetList().GetSymbols( references );
-    Schematic().GetSheets().GetSymbols( references );
 
     for( size_t i = 0; i < references.GetCount(); i++ )
     {
@@ -62,7 +61,7 @@ void SCH_EDIT_FRAME::DeleteAnnotation( ANNOTATE_SCOPE_T aAnnotateScope, bool aRe
                                        REPORTER& aReporter )
 {
 
-    SCH_SHEET_LIST sheets = Schematic().GetSheets();
+    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
     SCH_SCREEN*    screen = GetScreen();
     SCH_SHEET_PATH currentSheet = GetCurrentSheet();
     SCH_COMMIT     commit( this );
@@ -220,7 +219,7 @@ void SCH_EDIT_FRAME::AnnotateSymbols( SCH_COMMIT* aCommit, ANNOTATE_SCOPE_T  aAn
 
     SCH_REFERENCE_LIST references;
     SCH_SCREENS        screens( Schematic().Root() );
-    SCH_SHEET_LIST     sheets = Schematic().GetSheets();
+    SCH_SHEET_LIST     sheets = Schematic().BuildSheetListSortedByPageNumbers();
     SCH_SHEET_PATH     currentSheet = GetCurrentSheet();
 
 
@@ -464,14 +463,14 @@ int SCH_EDIT_FRAME::CheckAnnotate( ANNOTATION_ERROR_HANDLER aErrorHandler,
 {
     SCH_REFERENCE_LIST  referenceList;
     constexpr bool      includePowerSymbols = false;
-    SCH_SHEET_LIST      sheets = Schematic().GetSheets();
+    SCH_SHEET_LIST      sheets = Schematic().BuildSheetListSortedByPageNumbers();
     SCH_SHEET_PATH      currentSheet = GetCurrentSheet();
 
     // Build the list of symbols
     switch( aAnnotateScope )
     {
     case ANNOTATE_ALL:
-        Schematic().GetSheets().GetSymbols( referenceList );
+        sheets.GetSymbols( referenceList );
         break;
 
     case ANNOTATE_CURRENT_SHEET:

eeschema/connection_graph.cpp

@@ -1367,9 +1367,11 @@ void CONNECTION_GRAPH::buildItemSubGraphs()
     // Recache all bus aliases for later use
     wxCHECK_RET( m_schematic, wxS( "Connection graph cannot be built without schematic pointer" ) );
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->GetUnorderedSheets() )
+    SCH_SCREENS screens( m_schematic->Root() );
+
+    for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
     {
-        for( const std::shared_ptr<BUS_ALIAS>& alias : sheet.LastScreen()->GetBusAliases() )
+        for( const std::shared_ptr<BUS_ALIAS>& alias : screen->GetBusAliases() )
             m_bus_alias_cache[alias->GetName()] = alias;
     }
 
@@ -2084,9 +2086,11 @@ void CONNECTION_GRAPH::buildConnectionGraph( std::function<void( SCH_ITEM* )>* a
     // Recache all bus aliases for later use
     wxCHECK_RET( m_schematic, wxT( "Connection graph cannot be built without schematic pointer" ) );
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->GetUnorderedSheets() )
+    SCH_SCREENS screens( m_schematic->Root() );
+
+    for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
     {
-        for( const std::shared_ptr<BUS_ALIAS>& alias : sheet.LastScreen()->GetBusAliases() )
+        for( const std::shared_ptr<BUS_ALIAS>& alias : screen->GetBusAliases() )
             m_bus_alias_cache[alias->GetName()] = alias;
     }
 

eeschema/cross-probing.cpp

@@ -52,7 +52,7 @@ SCH_ITEM* SCH_EDITOR_CONTROL::FindSymbolAndItem( const wxString* aPath, const wx
     if( !aSearchHierarchy )
         sheetList.push_back( m_frame->GetCurrentSheet() );
     else
-        sheetList = m_frame->Schematic().GetSheets();
+        sheetList = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
 
     for( SCH_SHEET_PATH& sheet : sheetList )
     {
@@ -460,13 +460,8 @@ bool findSymbolsAndPins(
     if( aRecursive )
     {
         // Iterate over children
-        for( const SCH_SHEET_PATH& candidate : aSchematic.GetSheets() )
+        for( const SCH_SHEET_PATH& sheet : SCH_SHEET_LIST( aSheetPath.Last() ) )
-        {
+            findSymbolsAndPins( aSchematic, sheet, aSyncSymMap, aSyncPinMap, aRecursive );
-            if( candidate == aSheetPath || !candidate.IsContainedWithin( aSheetPath ) )
-                continue;
-
-            findSymbolsAndPins( aSchematic, candidate, aSyncSymMap, aSyncPinMap, aRecursive );
-        }
     }
 
     SCH_REFERENCE_LIST references;
@@ -542,12 +537,9 @@ bool sheetContainsOnlyWantedItems(
         return cacheIt->second;
 
     // Iterate over children
-    for( const SCH_SHEET_PATH& candidate : aSchematic.GetSheets() )
+    for( const SCH_SHEET_PATH& sheet : SCH_SHEET_LIST( aSheetPath.Last() ) )
     {
-        if( candidate == aSheetPath || !candidate.IsContainedWithin( aSheetPath ) )
+        bool childRet = sheetContainsOnlyWantedItems( aSchematic, sheet, aSyncSymMap,
-            continue;
-
-        bool childRet = sheetContainsOnlyWantedItems( aSchematic, candidate, aSyncSymMap,
                                                       aSyncPinMap, aCache );
 
         if( !childRet )
@@ -617,7 +609,7 @@ findItemsFromSyncSelection( const SCHEMATIC& aSchematic, const std::string aSync
     std::optional<std::pair<wxString, wxString>>               focusPin;
     std::unordered_map<SCH_SHEET_PATH, std::vector<SCH_ITEM*>> focusItemResults;
 
-    const SCH_SHEET_LIST allSheetsList = aSchematic.GetSheets();
+    const SCH_SHEET_LIST allSheetsList = aSchematic.BuildSheetListSortedByPageNumbers();
 
     // In orderedSheets, the current sheet comes first.
     std::vector<SCH_SHEET_PATH> orderedSheets;

eeschema/dialogs/dialog_change_symbols.cpp

@@ -289,7 +289,7 @@ void DIALOG_CHANGE_SYMBOLS::updateFieldsList()
     std::vector<SCH_FIELD*> libFields;
     std::set<wxString>      fieldNames;
 
-    for( SCH_SHEET_PATH& instance : frame->Schematic().GetUnorderedSheets() )
+    for( SCH_SHEET_PATH& instance : frame->Schematic().BuildUnorderedSheetList() )
     {
         SCH_SCREEN* screen = instance.LastScreen();
 
@@ -483,7 +483,6 @@ int DIALOG_CHANGE_SYMBOLS::processMatchingSymbols( SCH_COMMIT* aCommit )
     wxString    msg;
     int         matchesProcessed = 0;
     SCH_SYMBOL* symbol = nullptr;
-    SCH_SHEET_LIST hierarchy = frame->Schematic().GetSheets();
 
     if( m_mode == MODE::CHANGE )
     {
@@ -495,7 +494,7 @@ int DIALOG_CHANGE_SYMBOLS::processMatchingSymbols( SCH_COMMIT* aCommit )
 
     std::map<SCH_SYMBOL*, SYMBOL_CHANGE_INFO> symbols;
 
-    for( SCH_SHEET_PATH& instance : hierarchy )
+    for( SCH_SHEET_PATH& instance : frame->Schematic().BuildSheetListSortedByPageNumbers() )
     {
         SCH_SCREEN* screen = instance.LastScreen();
 
@@ -796,7 +795,7 @@ wxString DIALOG_CHANGE_SYMBOLS::getSymbolReferences( SCH_SYMBOL& aSymbol,
 
     wxCHECK( parent, msg );
 
-    SCH_SHEET_LIST sheets = parent->Schematic().GetUnorderedSheets();
+    SCH_SHEET_LIST sheets = parent->Schematic().BuildUnorderedSheetList();
 
     for( const SCH_SYMBOL_INSTANCE& instance : aSymbol.GetInstances() )
     {

eeschema/dialogs/dialog_edit_symbols_libid.cpp

@@ -391,13 +391,13 @@ void DIALOG_EDIT_SYMBOLS_LIBID::initDlg()
     // In complex hierarchies, the same symbol is in fact duplicated, but
     // it is listed with different references (one by sheet instance)
     // the list is larger and looks like it contains all symbols.
-    const SCH_SHEET_LIST& sheets = GetParent()->Schematic().GetSheets();
     SCH_REFERENCE_LIST references;
 
     // build the full list of symbols including symbol having no symbol in loaded libs
     // (orphan symbols)
-    sheets.GetSymbols( references, /* include power symbols */ true,
+    GetParent()->Schematic().BuildUnorderedSheetList().GetSymbols( references,
-                       /* include orphan symbols */ true );
+                                                                   true /* include power symbols */,
+                                                                   true /* include orphan symbols */ );
 
     for( unsigned ii = 0; ii < references.GetCount(); ii++ )
     {

eeschema/dialogs/dialog_erc.cpp

@@ -430,8 +430,6 @@ void DIALOG_ERC::OnRunERCClick( wxCommandEvent& event )
     m_deleteAllMarkers->Enable( false );
     m_saveReport->Enable( false );
 
-    sch->GetSheets().AnnotatePowerSymbols();
-
     int itemsNotAnnotated = m_parent->CheckAnnotate(
             []( ERCE_T aType, const wxString& aMsg, SCH_REFERENCE* aItemA, SCH_REFERENCE* aItemB )
             {

eeschema/dialogs/dialog_field_properties.cpp

@@ -672,7 +672,7 @@ void DIALOG_FIELD_PROPERTIES::UpdateField( SCH_COMMIT* aCommit, SCH_FIELD* aFiel
             int      unit = symbol->GetUnit();
             LIB_ID   libId = symbol->GetLibId();
 
-            for( SCH_SHEET_PATH& sheet : editFrame->Schematic().GetUnorderedSheets() )
+            for( SCH_SHEET_PATH& sheet : editFrame->Schematic().BuildUnorderedSheetList() )
             {
                 SCH_SCREEN*              screen = sheet.LastScreen();
                 std::vector<SCH_SYMBOL*> otherUnits;

eeschema/dialogs/dialog_global_edit_text_and_graphics.cpp

@@ -580,7 +580,7 @@ bool DIALOG_GLOBAL_EDIT_TEXT_AND_GRAPHICS::TransferDataFromWindow()
     SCH_COMMIT     commit( m_parent );
 
     // Go through sheets
-    for( const SCH_SHEET_PATH& sheetPath : m_parent->Schematic().GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheetPath : m_parent->Schematic().BuildUnorderedSheetList() )
     {
         SCH_SCREEN* screen = sheetPath.LastScreen();
 

eeschema/dialogs/dialog_sheet_properties.cpp

@@ -363,7 +363,8 @@ bool DIALOG_SHEET_PROPERTIES::TransferDataFromWindow()
             currentScreen->SetFileName( wxEmptyString );
 
         // One last validity check (and potential repair) just to be sure to be sure
-        SCH_SHEET_LIST repairedList( &m_frame->Schematic().Root(), true );
+        SCH_SHEET_LIST repairedList;
+        repairedList.BuildSheetList( &m_frame->Schematic().Root(), true );
     }
 
     wxString newSheetname = m_fields->at( SHEETNAME ).GetText();

eeschema/dialogs/dialog_symbol_fields_table.cpp

@@ -176,7 +176,7 @@ DIALOG_SYMBOL_FIELDS_TABLE::DIALOG_SYMBOL_FIELDS_TABLE( SCH_EDIT_FRAME* parent )
         m_schSettings( parent->Schematic().Settings() )
 {
     // Get all symbols from the list of schematic sheets
-    m_parent->Schematic().GetUnorderedSheets().GetSymbols( m_symbolsList, false );
+    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( m_symbolsList, false );
 
     m_bRefresh->SetBitmap( KiBitmapBundle( BITMAPS::small_refresh ) );
     m_bRefreshPreview->SetBitmap( KiBitmapBundle( BITMAPS::small_refresh ) );
@@ -2211,10 +2211,8 @@ void DIALOG_SYMBOL_FIELDS_TABLE::savePresetsToSchematic()
 void DIALOG_SYMBOL_FIELDS_TABLE::OnSchItemsAdded( SCHEMATIC&              aSch,
                                                   std::vector<SCH_ITEM*>& aSchItem )
 {
-    SCH_SHEET_LIST     allSheets = m_parent->Schematic().GetUnorderedSheets();
     SCH_REFERENCE_LIST allRefs;
-
+    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( allRefs );
-    allSheets.GetSymbols( allRefs );
 
     for( SCH_ITEM* item : aSchItem )
     {
@@ -2282,10 +2280,8 @@ void DIALOG_SYMBOL_FIELDS_TABLE::OnSchItemsRemoved( SCHEMATIC&              aSch
 void DIALOG_SYMBOL_FIELDS_TABLE::OnSchItemsChanged( SCHEMATIC&              aSch,
                                                     std::vector<SCH_ITEM*>& aSchItem )
 {
-    SCH_SHEET_LIST     allSheets = m_parent->Schematic().GetUnorderedSheets();
     SCH_REFERENCE_LIST allRefs;
-
+    m_parent->Schematic().BuildUnorderedSheetList().GetSymbols( allRefs );
-    allSheets.GetSymbols( allRefs );
 
     for( SCH_ITEM* item : aSchItem )
     {
@@ -2363,7 +2359,6 @@ SCH_REFERENCE_LIST
 DIALOG_SYMBOL_FIELDS_TABLE::getSymbolReferences( SCH_SYMBOL*         aSymbol,
                                                  SCH_REFERENCE_LIST& aCachedRefs )
 {
-    SCH_SHEET_LIST     allSheets = m_parent->Schematic().GetUnorderedSheets();
     SCH_REFERENCE_LIST symbolRefs;
 
     for( size_t i = 0; i < aCachedRefs.GetCount(); i++ )
@@ -2383,7 +2378,7 @@ DIALOG_SYMBOL_FIELDS_TABLE::getSymbolReferences( SCH_SYMBOL*         aSymbol,
 
 SCH_REFERENCE_LIST DIALOG_SYMBOL_FIELDS_TABLE::getSheetSymbolReferences( SCH_SHEET& aSheet )
 {
-    SCH_SHEET_LIST     allSheets = m_parent->Schematic().GetUnorderedSheets();
+    SCH_SHEET_LIST     allSheets = m_parent->Schematic().BuildUnorderedSheetList();
     SCH_REFERENCE_LIST sheetRefs;
 
     // We need to operate on all instances of the sheet

eeschema/dialogs/dialog_symbol_properties.cpp

@@ -785,7 +785,7 @@ bool DIALOG_SYMBOL_PROPERTIES::TransferDataFromWindow()
         int      unit = m_symbol->GetUnit();
         LIB_ID   libId = m_symbol->GetLibId();
 
-        for( SCH_SHEET_PATH& sheet : GetParent()->Schematic().GetUnorderedSheets() )
+        for( SCH_SHEET_PATH& sheet : GetParent()->Schematic().BuildUnorderedSheetList() )
         {
             SCH_SCREEN*              screen = sheet.LastScreen();
             std::vector<SCH_SYMBOL*> otherUnits;

eeschema/dialogs/dialog_table_properties.cpp

@@ -242,7 +242,7 @@ void DIALOG_TABLE_PROPERTIES::getContextualTextVars( const wxString& aCrossRef,
         SCH_REFERENCE_LIST refs;
         SCH_SYMBOL*        refSymbol = nullptr;
 
-        m_frame->Schematic().GetUnorderedSheets().GetSymbols( refs );
+        m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( refs );
 
         for( int jj = 0; jj < (int) refs.GetCount(); jj++ )
         {

eeschema/dialogs/dialog_text_properties.cpp

@@ -164,9 +164,9 @@ DIALOG_TEXT_PROPERTIES::DIALOG_TEXT_PROPERTIES( SCH_BASE_FRAME* aParent, SCH_ITE
 
     if( SCH_EDIT_FRAME* schematicEditor = dynamic_cast<SCH_EDIT_FRAME*>( m_frame ) )
     {
-        SCH_SHEET_LIST sheetList = schematicEditor->Schematic().GetSheets();
+        const SCHEMATIC& schematic = schematicEditor->Schematic();
 
-        for( const SCH_SHEET_PATH& sheet : sheetList )
+        for( const SCH_SHEET_PATH& sheet : schematic.BuildSheetListSortedByPageNumbers() )
         {
             wxString sheetPageNum = sheet.GetPageNumber();
             wxString sheetName = sheet.size() == 1 ? _( "<root sheet>" )
@@ -229,10 +229,8 @@ void DIALOG_TEXT_PROPERTIES::getContextualTextVars( const wxString& aCrossRef,
 
         if( schematic )
         {
-            SCH_SHEET_LIST     sheets = m_currentItem->Schematic()->GetSheets();
             SCH_REFERENCE_LIST refs;
-
+            schematic->BuildUnorderedSheetList().GetSymbols( refs );
-            sheets.GetSymbols( refs );
 
             for( int jj = 0; jj < (int) refs.GetCount(); jj++ )
             {

eeschema/eeschema.cpp

@@ -91,14 +91,16 @@ static std::unique_ptr<SCHEMATIC> readSchematicFromFile( const std::string& aFil
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
         screen->UpdateLocalLibSymbolLinks();
 
-    SCH_SHEET_LIST sheets = schematic->GetSheets();
+    SCH_SHEET_LIST sheets = schematic->BuildSheetListSortedByPageNumbers();
 
     // Restore all of the loaded symbol instances from the root sheet screen.
     sheets.UpdateSymbolInstanceData( schematic->RootScreen()->GetSymbolInstances() );
 
     if( schematic->RootScreen()->GetFileFormatVersionAtLoad() < 20230221 )
+    {
         for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
             screen->FixLegacyPowerSymbolMismatches();
+    }
 
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
         screen->MigrateSimModels();

eeschema/eeschema_helpers.cpp

@@ -151,7 +151,7 @@ SCHEMATIC* EESCHEMA_HELPERS::LoadSchematic( wxString& aFileName, SCH_IO_MGR::SCH
         return nullptr;
     }
 
-    SCH_SHEET_LIST sheetList = schematic->GetSheets();
+    SCH_SHEET_LIST sheetList = schematic->BuildSheetListSortedByPageNumbers();
     SCH_SCREENS    screens( schematic->Root() );
 
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )

eeschema/eeschema_jobs_handler.cpp

@@ -249,7 +249,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportNetlist( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->GetSheets().GetSymbols( referenceList );
+    sch->BuildUnorderedSheetList().GetSymbols( referenceList );
 
     if( referenceList.GetCount() > 0 )
     {
@@ -362,7 +362,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportBom( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->GetSheets().GetSymbols( referenceList, false, false );
+    sch->BuildUnorderedSheetList().GetSymbols( referenceList, false, false );
 
     if( referenceList.GetCount() > 0 )
     {
@@ -618,7 +618,7 @@ int EESCHEMA_JOBS_HANDLER::JobExportPythonBom( JOB* aJob )
 
     // Annotation warning check
     SCH_REFERENCE_LIST referenceList;
-    sch->GetSheets().GetSymbols( referenceList );
+    sch->BuildUnorderedSheetList().GetSymbols( referenceList );
 
     if( referenceList.GetCount() > 0 )
     {

eeschema/erc/erc.cpp

@@ -1363,11 +1363,11 @@ int ERC_TESTER::TestRuleAreaOverlappingRuleAreasERC(
 void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aEditFrame,
                            KIFACE* aCvPcb, PROJECT* aProject, PROGRESS_REPORTER* aProgressReporter )
 {
-    ERC_SETTINGS& settings = m_schematic->ErcSettings();
+    m_sheetList.AnnotatePowerSymbols();
 
     // Test duplicate sheet names inside a given sheet.  While one can have multiple references
     // to the same file, each must have a unique name.
-    if( settings.IsTestEnabled( ERCE_DUPLICATE_SHEET_NAME ) )
+    if( m_settings.IsTestEnabled( ERCE_DUPLICATE_SHEET_NAME ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking sheet names..." ) );
@@ -1375,7 +1375,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestDuplicateSheetNames( true );
     }
 
-    if( settings.IsTestEnabled( ERCE_BUS_ALIAS_CONFLICT ) )
+    if( m_settings.IsTestEnabled( ERCE_BUS_ALIAS_CONFLICT ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking bus conflicts..." ) );
@@ -1401,7 +1401,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
     if( aProgressReporter )
         aProgressReporter->AdvancePhase( _( "Checking rule areas..." ) );
 
-    if( settings.IsTestEnabled( ERCE_OVERLAPPING_RULE_AREAS ) )
+    if( m_settings.IsTestEnabled( ERCE_OVERLAPPING_RULE_AREAS ) )
     {
         RunRuleAreaERC();
     }
@@ -1410,7 +1410,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         aProgressReporter->AdvancePhase( _( "Checking units..." ) );
 
     // Test is all units of each multiunit symbol have the same footprint assigned.
-    if( settings.IsTestEnabled( ERCE_DIFFERENT_UNIT_FP ) )
+    if( m_settings.IsTestEnabled( ERCE_DIFFERENT_UNIT_FP ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking footprints..." ) );
@@ -1418,10 +1418,10 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestMultiunitFootprints();
     }
 
-    if( settings.IsTestEnabled( ERCE_MISSING_UNIT )
+    if( m_settings.IsTestEnabled( ERCE_MISSING_UNIT )
-        || settings.IsTestEnabled( ERCE_MISSING_INPUT_PIN )
+        || m_settings.IsTestEnabled( ERCE_MISSING_INPUT_PIN )
-        || settings.IsTestEnabled( ERCE_MISSING_POWER_INPUT_PIN )
+        || m_settings.IsTestEnabled( ERCE_MISSING_POWER_INPUT_PIN )
-        || settings.IsTestEnabled( ERCE_MISSING_BIDI_PIN ) )
+        || m_settings.IsTestEnabled( ERCE_MISSING_BIDI_PIN ) )
     {
         TestMissingUnits();
     }
@@ -1429,20 +1429,20 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
     if( aProgressReporter )
         aProgressReporter->AdvancePhase( _( "Checking pins..." ) );
 
-    if( settings.IsTestEnabled( ERCE_DIFFERENT_UNIT_NET ) )
+    if( m_settings.IsTestEnabled( ERCE_DIFFERENT_UNIT_NET ) )
         TestMultUnitPinConflicts();
 
     // Test pins on each net against the pin connection table
-    if( settings.IsTestEnabled( ERCE_PIN_TO_PIN_ERROR )
+    if( m_settings.IsTestEnabled( ERCE_PIN_TO_PIN_ERROR )
-        || settings.IsTestEnabled( ERCE_POWERPIN_NOT_DRIVEN )
+        || m_settings.IsTestEnabled( ERCE_POWERPIN_NOT_DRIVEN )
-        || settings.IsTestEnabled( ERCE_PIN_NOT_DRIVEN ) )
+        || m_settings.IsTestEnabled( ERCE_PIN_NOT_DRIVEN ) )
     {
         TestPinToPin();
     }
 
     // Test similar labels (i;e. labels which are identical when
     // using case insensitive comparisons)
-    if( settings.IsTestEnabled( ERCE_SIMILAR_LABELS ) )
+    if( m_settings.IsTestEnabled( ERCE_SIMILAR_LABELS ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking labels..." ) );
@@ -1450,7 +1450,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestSimilarLabels();
     }
 
-    if( settings.IsTestEnabled( ERCE_UNRESOLVED_VARIABLE ) )
+    if( m_settings.IsTestEnabled( ERCE_UNRESOLVED_VARIABLE ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for unresolved variables..." ) );
@@ -1458,7 +1458,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestTextVars( aDrawingSheet );
     }
 
-    if( settings.IsTestEnabled( ERCE_SIMULATION_MODEL ) )
+    if( m_settings.IsTestEnabled( ERCE_SIMULATION_MODEL ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking SPICE models..." ) );
@@ -1466,7 +1466,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestSimModelIssues();
     }
 
-    if( settings.IsTestEnabled( ERCE_NOCONNECT_CONNECTED ) )
+    if( m_settings.IsTestEnabled( ERCE_NOCONNECT_CONNECTED ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking no connect pins for connections..." ) );
@@ -1474,8 +1474,8 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestNoConnectPins();
     }
 
-    if( settings.IsTestEnabled( ERCE_LIB_SYMBOL_ISSUES )
+    if( m_settings.IsTestEnabled( ERCE_LIB_SYMBOL_ISSUES )
-        || settings.IsTestEnabled( ERCE_LIB_SYMBOL_MISMATCH ) )
+        || m_settings.IsTestEnabled( ERCE_LIB_SYMBOL_MISMATCH ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for library symbol issues..." ) );
@@ -1483,7 +1483,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestLibSymbolIssues();
     }
 
-    if( settings.IsTestEnabled( ERCE_FOOTPRINT_LINK_ISSUES ) && aCvPcb )
+    if( m_settings.IsTestEnabled( ERCE_FOOTPRINT_LINK_ISSUES ) && aCvPcb )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for footprint link issues..." ) );
@@ -1491,7 +1491,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestFootprintLinkIssues( aCvPcb, aProject );
     }
 
-    if( settings.IsTestEnabled( ERCE_ENDPOINT_OFF_GRID ) )
+    if( m_settings.IsTestEnabled( ERCE_ENDPOINT_OFF_GRID ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for off grid pins and wires..." ) );
@@ -1499,7 +1499,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestOffGridEndpoints();
     }
 
-    if( settings.IsTestEnabled( ERCE_FOUR_WAY_JUNCTION ) )
+    if( m_settings.IsTestEnabled( ERCE_FOUR_WAY_JUNCTION ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for four way junctions..." ) );
@@ -1507,7 +1507,7 @@ void ERC_TESTER::RunTests( DS_PROXY_VIEW_ITEM* aDrawingSheet, SCH_EDIT_FRAME* aE
         TestFourWayJunction();
     }
 
-    if( settings.IsTestEnabled( ERCE_UNDEFINED_NETCLASS ) )
+    if( m_settings.IsTestEnabled( ERCE_UNDEFINED_NETCLASS ) )
     {
         if( aProgressReporter )
             aProgressReporter->AdvancePhase( _( "Checking for undefined netclasses..." ) );

eeschema/erc/erc.h

@@ -55,7 +55,7 @@ public:
     ERC_TESTER( SCHEMATIC* aSchematic ) :
             m_schematic( aSchematic ),
             m_settings( aSchematic->ErcSettings() ),
-            m_sheetList( aSchematic->GetSheets() ),
+            m_sheetList( aSchematic->BuildSheetListSortedByPageNumbers() ),
             m_screens( aSchematic->Root() ),
             m_nets( aSchematic->ConnectionGraph()->GetNetMap() )
     {

eeschema/erc/erc_report.cpp

@@ -53,7 +53,7 @@ wxString ERC_REPORT::GetTextReport()
     int            err_count = 0;
     int            warn_count = 0;
     int            total_count = 0;
-    SCH_SHEET_LIST sheetList = m_sch->GetSheets();
+    SCH_SHEET_LIST sheetList = m_sch->BuildSheetListSortedByPageNumbers();
 
     sheetList.FillItemMap( itemMap );
 
@@ -124,7 +124,7 @@ bool ERC_REPORT::WriteJsonReport( const wxString& aFullFileName )
     int            err_count = 0;
     int            warn_count = 0;
     int            total_count = 0;
-    SCH_SHEET_LIST sheetList = m_sch->GetSheets();
+    SCH_SHEET_LIST sheetList = m_sch->BuildSheetListSortedByPageNumbers();
     sheetList.FillItemMap( itemMap );
 
     ERC_SETTINGS& settings = m_sch->ErcSettings();

eeschema/erc/erc_settings.cpp

@@ -292,7 +292,7 @@ void SHEETLIST_ERC_ITEMS_PROVIDER::visitMarkers( std::function<void( SCH_MARKER*
 {
     std::set<SCH_SCREEN*> seenScreens;
 
-    for( const SCH_SHEET_PATH& sheet : m_schematic->GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildUnorderedSheetList() )
     {
         bool firstTime = seenScreens.count( sheet.LastScreen() ) == 0;
 

eeschema/files-io.cpp

@@ -329,7 +329,7 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
 
         // It's possible the schematic parser fixed errors due to bugs so warn the user
         // that the schematic has been fixed (modified).
-        SCH_SHEET_LIST sheetList = Schematic().GetSheets();
+        SCH_SHEET_LIST sheetList = Schematic().BuildSheetListSortedByPageNumbers();
 
         if( sheetList.IsModified() )
         {
@@ -513,8 +513,8 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
             }
         }
 
-        schematic.PruneOrphanedSymbolInstances( Prj().GetProjectName(), Schematic().GetSheets() );
+        schematic.PruneOrphanedSymbolInstances( Prj().GetProjectName(), sheetList );
-        schematic.PruneOrphanedSheetInstances( Prj().GetProjectName(), Schematic().GetSheets() );
+        schematic.PruneOrphanedSheetInstances( Prj().GetProjectName(), sheetList );
 
         Schematic().ConnectionGraph()->Reset();
 
@@ -1074,7 +1074,7 @@ bool SCH_EDIT_FRAME::SaveProject( bool aSaveAs )
         }
 
         // Attempt to make sheet file name paths relative to the new root schematic path.
-        for( SCH_SHEET_PATH& sheet : Schematic().GetUnorderedSheets() )
+        for( SCH_SHEET_PATH& sheet : Schematic().BuildUnorderedSheetList() )
         {
             if( !sheet.Last()->IsRootSheet() )
                 sheet.MakeFilePathRelativeToParentSheet();
@@ -1237,7 +1237,7 @@ bool SCH_EDIT_FRAME::SaveProject( bool aSaveAs )
     std::vector<FILE_INFO_PAIR>& sheets = Prj().GetProjectFile().GetSheets();
     sheets.clear();
 
-    for( SCH_SHEET_PATH& sheetPath : Schematic().GetSheets() )
+    for( SCH_SHEET_PATH& sheetPath : Schematic().BuildUnorderedSheetList() )
     {
         SCH_SHEET* sheet = sheetPath.Last();
 
@@ -1365,7 +1365,6 @@ bool SCH_EDIT_FRAME::importFile( const wxString& aFileName, int aFileType,
 {
     wxFileName             filename( aFileName );
     wxFileName             newfilename;
-    SCH_SHEET_LIST         sheetList = Schematic().GetSheets();
     SCH_IO_MGR::SCH_FILE_T fileType = (SCH_IO_MGR::SCH_FILE_T) aFileType;
 
     wxCommandEvent changingEvt( EDA_EVT_SCHEMATIC_CHANGING );

eeschema/net_navigator.cpp

@@ -267,7 +267,7 @@ void SCH_EDIT_FRAME::RefreshNetNavigator( const NET_NAVIGATOR_ITEM_DATA* aSelect
     if( !m_netNavigator->IsShown() )
         return;
 
-    bool   singleSheetSchematic = m_schematic->GetUnorderedSheets().size() == 1;
+    bool   singleSheetSchematic = m_schematic->BuildUnorderedSheetList().size() == 1;
     size_t nodeCnt = 0;
 
     m_netNavigator->Freeze();

eeschema/netlist_exporters/netlist_exporter_allegro.cpp

@@ -136,14 +136,12 @@ void NETLIST_EXPORTER_ALLEGRO::extractComponentsInfo()
     m_referencesAlreadyFound.Clear();
     m_libParts.clear();
 
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
-
-    for( unsigned ii = 0; ii < sheetList.size(); ii++ )
     {
-        SCH_SHEET_PATH sheet = sheetList[ii];
         m_schematic->SetCurrentSheet( sheet );
 
-        auto cmp = [sheet]( SCH_SYMBOL* a, SCH_SYMBOL* b )
+        auto cmp =
+                [sheet]( SCH_SYMBOL* a, SCH_SYMBOL* b )
                 {
                     return ( StrNumCmp( a->GetRef( &sheet, false ),
                                         b->GetRef( &sheet, false ), true ) < 0 );
@@ -174,7 +172,7 @@ void NETLIST_EXPORTER_ALLEGRO::extractComponentsInfo()
 
         for( EDA_ITEM* item : ordered_symbols )
         {
-            SCH_SYMBOL* symbol = findNextSymbol( item, &sheet );
+            SCH_SYMBOL* symbol = findNextSymbol( item, sheet );
 
             if( !symbol || symbol->GetExcludedFromBoard() )
                 continue;

eeschema/netlist_exporters/netlist_exporter_base.cpp

@@ -79,10 +79,10 @@ wxString NETLIST_EXPORTER_BASE::MakeCommandLine( const wxString& aFormatString,
 }
 
 
-SCH_SYMBOL* NETLIST_EXPORTER_BASE::findNextSymbol( EDA_ITEM* aItem, SCH_SHEET_PATH* aSheetPath )
+SCH_SYMBOL* NETLIST_EXPORTER_BASE::findNextSymbol( EDA_ITEM* aItem,
+                                                   const SCH_SHEET_PATH& aSheetPath )
 {
     wxCHECK( aItem, nullptr );
-    wxCHECK( aSheetPath, nullptr );
 
     wxString ref;
 
@@ -94,12 +94,12 @@ SCH_SYMBOL* NETLIST_EXPORTER_BASE::findNextSymbol( EDA_ITEM* aItem, SCH_SHEET_PA
 
     // Power symbols and other symbols which have the reference starting with "#" are not
     // included in netlist (pseudo or virtual symbols)
-    ref = symbol->GetRef( aSheetPath );
+    ref = symbol->GetRef( &aSheetPath );
 
     if( ref[0] == wxChar( '#' ) )
         return nullptr;
 
-    SCH_SCREEN* screen = aSheetPath->LastScreen();
+    SCH_SCREEN* screen = aSheetPath.LastScreen();
 
     wxCHECK( screen, nullptr );
 
@@ -126,14 +126,14 @@ SCH_SYMBOL* NETLIST_EXPORTER_BASE::findNextSymbol( EDA_ITEM* aItem, SCH_SHEET_PA
 
 
 std::vector<PIN_INFO> NETLIST_EXPORTER_BASE::CreatePinList( SCH_SYMBOL* aSymbol,
-                                                            SCH_SHEET_PATH* aSheetPath,
+                                                            const SCH_SHEET_PATH& aSheetPath,
                                                             bool aKeepUnconnectedPins )
 {
     std::vector<PIN_INFO> pins;
 
     wxCHECK( aSymbol, pins );
 
-    wxString              ref( aSymbol->GetRef( aSheetPath ) );
+    wxString ref( aSymbol->GetRef( &aSheetPath ) );
 
     // Power symbols and other symbols which have the reference starting with "#" are not
     // included in netlist (pseudo or virtual symbols)
@@ -161,15 +161,15 @@ std::vector<PIN_INFO> NETLIST_EXPORTER_BASE::CreatePinList( SCH_SYMBOL* aSymbol,
     {
         CONNECTION_GRAPH* graph = m_schematic->ConnectionGraph();
 
-        for( const SCH_PIN* pin : aSymbol->GetPins( aSheetPath ) )
+        for( const SCH_PIN* pin : aSymbol->GetPins( &aSheetPath ) )
         {
-            if( SCH_CONNECTION* conn = pin->Connection( aSheetPath ) )
+            if( SCH_CONNECTION* conn = pin->Connection( &aSheetPath ) )
             {
                 const wxString& netName = conn->Name();
 
                 if( !aKeepUnconnectedPins )     // Skip unconnected pins if requested
                 {
-                    CONNECTION_SUBGRAPH* sg = graph->FindSubgraphByName( netName, *aSheetPath );
+                    CONNECTION_SUBGRAPH* sg = graph->FindSubgraphByName( netName, aSheetPath );
 
                     if( !sg || sg->GetNoConnect() || sg->GetItems().size() < 2 )
                         continue;
@@ -231,21 +231,18 @@ void NETLIST_EXPORTER_BASE::eraseDuplicatePins( std::vector<PIN_INFO>& aPins )
 
 
 void NETLIST_EXPORTER_BASE::findAllUnitsOfSymbol( SCH_SYMBOL* aSchSymbol,
-                                                  SCH_SHEET_PATH* aSheetPath,
+                                                  const SCH_SHEET_PATH& aSheetPath,
                                                   std::vector<PIN_INFO>& aPins,
                                                   bool aKeepUnconnectedPins )
 {
-    wxString    ref = aSchSymbol->GetRef( aSheetPath );
+    wxString ref = aSchSymbol->GetRef( &aSheetPath );
     wxString ref2;
 
-    SCH_SHEET_LIST    sheetList = m_schematic->GetSheets();
     CONNECTION_GRAPH* graph = m_schematic->ConnectionGraph();
 
-    for( unsigned i = 0;  i < sheetList.size();  i++ )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
     {
-        SCH_SHEET_PATH& sheet = sheetList[i];
+        for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
-
-        for( SCH_ITEM* item : sheetList[i].LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
             SCH_SYMBOL* comp2 = static_cast<SCH_SYMBOL*>( item );
 

eeschema/netlist_exporters/netlist_exporter_base.h

@@ -147,7 +147,7 @@ protected:
      * if aKeepUnconnectedPins = false, unconnected pins will be removed from list
      * but usually we need all pins in netlists.
      */
-    std::vector<PIN_INFO> CreatePinList( SCH_SYMBOL* aSymbol, SCH_SHEET_PATH* aSheetPath,
+    std::vector<PIN_INFO> CreatePinList( SCH_SYMBOL* aSymbol, const SCH_SHEET_PATH& aSheetPath,
                                          bool aKeepUnconnectedPins );
 
     /**
@@ -159,7 +159,7 @@ protected:
      * @param aSheetPath is the sheet to check the symbol for
      * @return the symbol if it should be processed, or nullptr
      */
-    SCH_SYMBOL* findNextSymbol( EDA_ITEM* aItem, SCH_SHEET_PATH* aSheetPath );
+    SCH_SYMBOL* findNextSymbol( EDA_ITEM* aItem, const SCH_SHEET_PATH& aSheetPath );
 
     /**
      * Erase duplicate pins.
@@ -181,7 +181,7 @@ protected:
      * if aKeepUnconnectedPins = false, unconnected pins will be removed from list
      * but usually we need all pins in netlists.
      */
-    void findAllUnitsOfSymbol( SCH_SYMBOL* aSchSymbol, SCH_SHEET_PATH* aSheetPath,
+    void findAllUnitsOfSymbol( SCH_SYMBOL* aSchSymbol, const SCH_SHEET_PATH& aSheetPath,
                                std::vector<PIN_INFO>& aPins, bool aKeepUnconnectedPins );
 
     /// Used for "multiple symbols per package" symbols to avoid processing a lib symbol more than

eeschema/netlist_exporters/netlist_exporter_cadstar.cpp

@@ -65,13 +65,11 @@ bool NETLIST_EXPORTER_CADSTAR::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
-
-    for( unsigned i = 0; i < sheetList.size(); i++ )
     {
-        for( SCH_ITEM* item : sheetList[i].LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
+        for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
-            symbol = findNextSymbol( item, &sheetList[ i ] );
+            symbol = findNextSymbol( item, sheet );
 
             if( !symbol )
                 continue;
@@ -79,16 +77,16 @@ bool NETLIST_EXPORTER_CADSTAR::WriteNetlist( const wxString& aOutFileName,
             if( symbol->GetExcludedFromBoard() )
                 continue;
 
-            footprint = symbol->GetFootprintFieldText( true, &sheetList[ i ], false );
+            footprint = symbol->GetFootprintFieldText( true, &sheet, false );
 
             if( footprint.IsEmpty() )
                 footprint = "$noname";
 
-            msg = symbol->GetRef( &sheetList[i] );
+            msg = symbol->GetRef( &sheet );
             ret |= fprintf( f, "%s     ", TO_UTF8( StartCmpDesc ) );
             ret |= fprintf( f, "%s", TO_UTF8( msg ) );
 
-            msg = symbol->GetValue( true, &sheetList[ i ], false );
+            msg = symbol->GetValue( true, &sheet, false );
             msg.Replace( wxT( " " ), wxT( "_" ) );
             ret |= fprintf( f, "     \"%s\"", TO_UTF8( msg ) );
             ret |= fprintf( f, "     \"%s\"", TO_UTF8( footprint ) );

eeschema/netlist_exporters/netlist_exporter_orcadpcb2.cpp

@@ -62,16 +62,12 @@ bool NETLIST_EXPORTER_ORCADPCB2::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
-
-    for( unsigned i = 0;  i < sheetList.size();  i++ )
     {
-        SCH_SHEET_PATH sheet = sheetList[i];
-
         // Process symbol attributes
         for( EDA_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
-            SCH_SYMBOL* symbol = findNextSymbol( item, &sheet );
+            SCH_SYMBOL* symbol = findNextSymbol( item, sheet );
 
             if( !symbol )
                 continue;
@@ -79,7 +75,7 @@ bool NETLIST_EXPORTER_ORCADPCB2::WriteNetlist( const wxString& aOutFileName,
             if( symbol->GetExcludedFromBoard() )
                 continue;
 
-            std::vector<PIN_INFO> pins = CreatePinList( symbol, &sheet, true );
+            std::vector<PIN_INFO> pins = CreatePinList( symbol, sheet, true );
 
             if( symbol->GetLibSymbolRef()
                   && symbol->GetLibSymbolRef()->GetFPFilters().GetCount() != 0  )

eeschema/netlist_exporters/netlist_exporter_pads.cpp

@@ -55,13 +55,11 @@ bool NETLIST_EXPORTER_PADS::WriteNetlist( const wxString& aOutFileName,
     // Create netlist footprints section
     m_referencesAlreadyFound.Clear();
 
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
-
-    for( unsigned i = 0; i < sheetList.size(); i++ )
     {
-        for( SCH_ITEM* item : sheetList[i].LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
+        for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
-            symbol = findNextSymbol( item, &sheetList[ i ] );
+            symbol = findNextSymbol( item, sheet );
 
             if( !symbol )
                 continue;
@@ -69,7 +67,7 @@ bool NETLIST_EXPORTER_PADS::WriteNetlist( const wxString& aOutFileName,
             if( symbol->GetExcludedFromBoard() )
                 continue;
 
-            footprint = symbol->GetFootprintFieldText( true, &sheetList[ i ], false );
+            footprint = symbol->GetFootprintFieldText( true, &sheet, false );
 
             footprint = footprint.Trim( true );
             footprint = footprint.Trim( false );
@@ -78,13 +76,13 @@ bool NETLIST_EXPORTER_PADS::WriteNetlist( const wxString& aOutFileName,
             if( footprint.IsEmpty() )
             {
                 // fall back to value field
-                footprint = symbol->GetValue( true, &sheetList[i], false );
+                footprint = symbol->GetValue( true, &sheet, false );
                 footprint.Replace( wxT( " " ), wxT( "_" ) );
                 footprint = footprint.Trim( true );
                 footprint = footprint.Trim( false );
             }
 
-            msg = symbol->GetRef( &sheetList[i] );
+            msg = symbol->GetRef( &sheet );
             ret |= fprintf( f, "%-16s %s\n", TO_UTF8( msg ), TO_UTF8( footprint ) );
         }
     }

eeschema/netlist_exporters/netlist_exporter_spice.cpp

@@ -202,17 +202,17 @@ bool NETLIST_EXPORTER_SPICE::ReadSchematicAndLibraries( unsigned aNetlistOptions
         wxRemoveFile( thisFile.GetFullPath() );
     }
 
-    for( SCH_SHEET_PATH& sheet : GetSheets( aNetlistOptions ) )
+    for( SCH_SHEET_PATH& sheet : BuildSheetList( aNetlistOptions ) )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {
-            SCH_SYMBOL* symbol = findNextSymbol( item, &sheet );
+            SCH_SYMBOL* symbol = findNextSymbol( item, sheet );
 
             if( !symbol || symbol->GetExcludedFromSim() )
                 continue;
 
             SPICE_ITEM            spiceItem;
-            std::vector<PIN_INFO> pins = CreatePinList( symbol, &sheet, true );
+            std::vector<PIN_INFO> pins = CreatePinList( symbol, sheet, true );
 
             for( const SCH_FIELD& field : symbol->GetFields() )
             {
@@ -324,7 +324,7 @@ void NETLIST_EXPORTER_SPICE::ReadDirectives( unsigned aNetlistOptions )
 
     m_directives.clear();
 
-    for( const SCH_SHEET_PATH& sheet : GetSheets( aNetlistOptions ) )
+    for( const SCH_SHEET_PATH& sheet : BuildSheetList( aNetlistOptions ) )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items() )
         {
@@ -725,14 +725,14 @@ std::string NETLIST_EXPORTER_SPICE::GenerateItemPinNetName( const std::string& a
 }
 
 
-SCH_SHEET_LIST NETLIST_EXPORTER_SPICE::GetSheets( unsigned aNetlistOptions ) const
+SCH_SHEET_LIST NETLIST_EXPORTER_SPICE::BuildSheetList( unsigned aNetlistOptions ) const
 {
     SCH_SHEET_LIST sheets;
 
     if( aNetlistOptions & OPTION_CUR_SHEET_AS_ROOT )
         sheets = SCH_SHEET_LIST( m_schematic->CurrentSheet().Last() );
     else
-        sheets = SCH_SHEET_LIST( m_schematic->GetSheets() );
+        sheets = m_schematic->BuildSheetListSortedByPageNumbers();
 
     alg::delete_if( sheets,
                     [&]( const SCH_SHEET_PATH& sheet )

eeschema/netlist_exporters/netlist_exporter_spice.h

@@ -143,7 +143,7 @@ protected:
     /**
      * Return the paths of exported sheets (either all or the current one).
      */
-    SCH_SHEET_LIST GetSheets( unsigned aNetlistOptions = 0 ) const;
+    SCH_SHEET_LIST BuildSheetList( unsigned aNetlistOptions = 0 ) const;
 
 private:
     void readRefName( SCH_SHEET_PATH& aSheet, SCH_SYMBOL& aSymbol, SPICE_ITEM& aItem,

eeschema/netlist_exporters/netlist_exporter_spice_model.cpp

@@ -89,7 +89,7 @@ std::string NETLIST_EXPORTER_SPICE_MODEL::GenerateItemPinNetName( const std::str
 
 void NETLIST_EXPORTER_SPICE_MODEL::readPorts( unsigned aNetlistOptions )
 {
-    for( const SCH_SHEET_PATH& sheet : GetSheets( aNetlistOptions ) )
+    for( const SCH_SHEET_PATH& sheet : BuildSheetList( aNetlistOptions ) )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_HIER_LABEL_T ) )
         {

eeschema/netlist_exporters/netlist_exporter_xml.cpp

@@ -93,7 +93,8 @@ XNODE* NETLIST_EXPORTER_XML::makeRoot( unsigned aCtl )
 
 
 void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
-                                            SCH_SHEET_PATH* aSheet )
+                                            const SCH_SHEET_PATH& aSheet,
+                                            const SCH_SHEET_LIST& aSheetList )
 {
     wxString                     value;
     wxString                     footprint;
@@ -111,41 +112,40 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
         // any non blank fields in all units and use the first non-blank field
         // for each unique field name.
 
-        wxString ref = aSymbol->GetRef( aSheet );
+        wxString ref = aSymbol->GetRef( &aSheet );
 
-        SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+        int minUnit = aSymbol->GetUnitSelection( &aSheet );
-        int minUnit = aSymbol->GetUnitSelection( aSheet );
 
-        for( unsigned i = 0;  i < sheetList.size();  i++ )
+        for( const SCH_SHEET_PATH& sheet : aSheetList )
         {
-            for( SCH_ITEM* item : sheetList[i].LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
+            for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
             {
                 SCH_SYMBOL* symbol2 = static_cast<SCH_SYMBOL*>( item );
 
-                wxString ref2 = symbol2->GetRef( &sheetList[i] );
+                wxString ref2 = symbol2->GetRef( &sheet );
 
                 if( ref2.CmpNoCase( ref ) != 0 )
                     continue;
 
-                int unit = symbol2->GetUnitSelection( aSheet );
+                int unit = symbol2->GetUnitSelection( &aSheet );
 
                 // The lowest unit number wins.  User should only set fields in any one unit.
 
                 // Value
-                candidate = symbol2->GetValue( m_resolveTextVars, &sheetList[i], false );
+                candidate = symbol2->GetValue( m_resolveTextVars, &sheet, false );
 
                 if( !candidate.IsEmpty() && ( unit < minUnit || value.IsEmpty() ) )
                     value = candidate;
 
                 // Footprint
-                candidate = symbol2->GetFootprintFieldText( m_resolveTextVars, &sheetList[i], false );
+                candidate = symbol2->GetFootprintFieldText( m_resolveTextVars, &sheet, false );
 
                 if( !candidate.IsEmpty() && ( unit < minUnit || footprint.IsEmpty() ) )
                     footprint = candidate;
 
                 // Datasheet
                 candidate = m_resolveTextVars
-                                ? symbol2->GetField( DATASHEET_FIELD )->GetShownText( &sheetList[i], false )
+                                ? symbol2->GetField( DATASHEET_FIELD )->GetShownText( &sheet, false )
                                 : symbol2->GetField( DATASHEET_FIELD )->GetText();
 
                 if( !candidate.IsEmpty() && ( unit < minUnit || datasheet.IsEmpty() ) )
@@ -153,7 +153,7 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
 
                 // Description
                 candidate = m_resolveTextVars
-                                ? symbol2->GetField( DESCRIPTION_FIELD )->GetShownText( &sheetList[i], false )
+                                ? symbol2->GetField( DESCRIPTION_FIELD )->GetShownText( &sheet, false )
                                 : symbol2->GetField( DESCRIPTION_FIELD )->GetText();
 
                 if( !candidate.IsEmpty() && ( unit < minUnit || description.IsEmpty() ) )
@@ -167,7 +167,7 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
                     if( unit < minUnit || fields.count( f.GetName() ) == 0 )
                     {
                         if( m_resolveTextVars )
-                            fields[f.GetName()] = f.GetShownText( aSheet, false );
+                            fields[f.GetName()] = f.GetShownText( &aSheet, false );
                         else
                             fields[f.GetName()] = f.GetText();
                     }
@@ -179,21 +179,21 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
     }
     else
     {
-        value = aSymbol->GetValue( m_resolveTextVars, aSheet, false );
+        value = aSymbol->GetValue( m_resolveTextVars, &aSheet, false );
-        footprint = aSymbol->GetFootprintFieldText( m_resolveTextVars, aSheet, false );
+        footprint = aSymbol->GetFootprintFieldText( m_resolveTextVars, &aSheet, false );
 
         SCH_FIELD* datasheetField = aSymbol->GetField( DATASHEET_FIELD );
         SCH_FIELD* descriptionField = aSymbol->GetField( DESCRIPTION_FIELD );
 
         // Datasheet
         if( m_resolveTextVars )
-            datasheet = datasheetField->GetShownText( aSheet, false );
+            datasheet = datasheetField->GetShownText( &aSheet, false );
         else
             datasheet = datasheetField->GetText();
 
         // Description
         if( m_resolveTextVars )
-            description = descriptionField->GetShownText( aSheet, false );
+            description = descriptionField->GetShownText( &aSheet, false );
         else
             description = descriptionField->GetText();
 
@@ -202,7 +202,7 @@ void NETLIST_EXPORTER_XML::addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol,
             const SCH_FIELD& f = aSymbol->GetFields()[ ii ];
 
             if( m_resolveTextVars )
-                fields[f.GetName()] = f.GetShownText( aSheet, false );
+                fields[f.GetName()] = f.GetShownText( &aSheet, false );
             else
                 fields[f.GetName()] = f.GetText();
         }
@@ -246,21 +246,20 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
     m_referencesAlreadyFound.Clear();
     m_libParts.clear();
 
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
     SCH_SHEET_PATH currentSheet = m_schematic->CurrentSheet();
+    SCH_SHEET_LIST sheetList = m_schematic->BuildSheetListSortedByPageNumbers();
 
     // Output is xml, so there is no reason to remove spaces from the field values.
     // And XML element names need not be translated to various languages.
 
-    for( unsigned ii = 0; ii < sheetList.size(); ii++ )
+    for( const SCH_SHEET_PATH& sheet : sheetList )
     {
-        SCH_SHEET_PATH sheet = sheetList[ii];
-
         // Change schematic CurrentSheet in each iteration to allow hierarchical
         // resolution of text variables in sheet fields.
         m_schematic->SetCurrentSheet( sheet );
 
-        auto cmp = [sheet]( SCH_SYMBOL* a, SCH_SYMBOL* b )
+        auto cmp =
+                [sheet]( SCH_SYMBOL* a, SCH_SYMBOL* b )
                 {
                     return ( StrNumCmp( a->GetRef( &sheet, false ),
                                         b->GetRef( &sheet, false ), true ) < 0 );
@@ -291,7 +290,7 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
 
         for( EDA_ITEM* item : ordered_symbols )
         {
-            SCH_SYMBOL* symbol = findNextSymbol( item, &sheet );
+            SCH_SYMBOL* symbol = findNextSymbol( item, sheet );
             bool        forBOM = aCtl & GNL_OPT_BOM;
             bool        forBoard = aCtl & GNL_OPT_KICAD;
 
@@ -312,7 +311,7 @@ XNODE* NETLIST_EXPORTER_XML::makeSymbols( unsigned aCtl )
             xcomps->AddChild( xcomp = node( wxT( "comp" ) ) );
 
             xcomp->AddAttribute( wxT( "ref" ), symbol->GetRef( &sheet ) );
-            addSymbolFields( xcomp, symbol, &sheet );
+            addSymbolFields( xcomp, symbol, sheet, sheetList );
 
             XNODE*  xlibsource;
             xcomp->AddChild( xlibsource = node( wxT( "libsource" ) ) );
@@ -476,21 +475,19 @@ XNODE* NETLIST_EXPORTER_XML::makeDesignHeader()
     /*
      *  Export the sheets information
      */
-    SCH_SHEET_LIST sheetList = m_schematic->GetSheets();
+    unsigned sheetIndex = 1;     // Human readable index
 
-    for( unsigned i = 0;  i < sheetList.size();  i++ )
+    for( const SCH_SHEET_PATH& sheet : m_schematic->BuildSheetListSortedByPageNumbers() )
     {
-        screen = sheetList[i].LastScreen();
+        screen = sheet.LastScreen();
 
         xdesign->AddChild( xsheet = node( wxT( "sheet" ) ) );
 
         // get the string representation of the sheet index number.
-        // Note that sheet->GetIndex() is zero index base and we need to increment the
+        sheetTxt.Printf( wxT( "%u" ), sheetIndex++ );
-        // number by one to make it human readable
-        sheetTxt.Printf( wxT( "%u" ), i + 1 );
         xsheet->AddAttribute( wxT( "number" ), sheetTxt );
-        xsheet->AddAttribute( wxT( "name" ), sheetList[i].PathHumanReadable() );
+        xsheet->AddAttribute( wxT( "name" ), sheet.PathHumanReadable() );
-        xsheet->AddAttribute( wxT( "tstamps" ), sheetList[i].PathAsString() );
+        xsheet->AddAttribute( wxT( "tstamps" ), sheet.PathAsString() );
 
         TITLE_BLOCK tb = screen->GetTitleBlock();
         PROJECT*    prj = &m_schematic->Prj();

eeschema/netlist_exporters/netlist_exporter_xml.h

@@ -130,7 +130,8 @@ protected:
      */
     XNODE* makeLibraries();
 
-    void addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol, SCH_SHEET_PATH* aSheet );
+    void addSymbolFields( XNODE* aNode, SCH_SYMBOL* aSymbol, const SCH_SHEET_PATH& aSheet,
+                          const SCH_SHEET_LIST& aSheetList);
 
     bool                m_resolveTextVars;   // Export textVar references resolved
 

eeschema/netlist_exporters/netlist_generator.cpp

@@ -50,7 +50,7 @@ bool SCH_EDIT_FRAME::WriteNetListFile( int aFormat, const wxString& aFullFileNam
                                        unsigned aNetlistOptions, REPORTER* aReporter )
 {
     // Ensure all power symbols have a valid reference
-    Schematic().GetSheets().AnnotatePowerSymbols();
+    Schematic().BuildSheetListSortedByPageNumbers().AnnotatePowerSymbols();
 
     if( !ReadyToNetlist( _( "Exporting netlist requires a fully annotated schematic." ) ) )
         return false;
@@ -192,7 +192,7 @@ bool SCH_EDIT_FRAME::WriteNetListFile( int aFormat, const wxString& aFullFileNam
 bool SCH_EDIT_FRAME::ReadyToNetlist( const wxString& aAnnotateMessage )
 {
     // Ensure all power symbols have a valid reference
-    Schematic().GetSheets().AnnotatePowerSymbols();
+    Schematic().BuildSheetListSortedByPageNumbers().AnnotatePowerSymbols();
 
     // Symbols must be annotated
     if( CheckAnnotate( []( ERCE_T, const wxString&, SCH_REFERENCE*, SCH_REFERENCE* ) {} ) )

eeschema/printing/sch_printout.cpp

@@ -69,7 +69,7 @@ bool SCH_PRINTOUT::OnBeginDocument( int startPage, int endPage )
 
 bool SCH_PRINTOUT::OnPrintPage( int page )
 {
-    SCH_SHEET_LIST sheetList = m_parent->Schematic().GetSheets();
+    SCH_SHEET_LIST sheetList = m_parent->Schematic().BuildSheetListSortedByPageNumbers();
 
     wxCHECK_MSG( page >= 1 && page <= (int)sheetList.size(), false,
                  wxT( "Cannot print invalid page number." ) );

eeschema/sch_commit.cpp

@@ -567,7 +567,7 @@ void SCH_COMMIT::Revert()
                 {
                     // Lazy eval of sheet list; this is expensive even when unsorted
                     if( sheets.empty() )
-                        sheets = schematic->GetUnorderedSheets();
+                        sheets = schematic->BuildUnorderedSheetList();
 
                     SCH_SHEET_PATH sheet = sheets.FindSheetForScreen( screen );
                     symbol->SetRef( &sheet, field->GetText() );

eeschema/sch_edit_frame.cpp

@@ -178,7 +178,10 @@ SCH_EDIT_FRAME::SCH_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent ) :
 
     // NB: also links the schematic to the loaded project
     CreateScreens();
-    SetCurrentSheet( Schematic().GetSheets()[0] );
+
+    SCH_SHEET_PATH root;
+    root.push_back( &Schematic().Root() );
+    SetCurrentSheet( root );
 
     setupTools();
     setupUIConditions();
@@ -714,20 +717,6 @@ void SCH_EDIT_FRAME::setupUIConditions()
                 return navigateTool && navigateTool->CanGoUp();
             };
 
-    auto navSchematicHasPreviousSheet =
-            [this]( const SELECTION& aSel )
-            {
-                SCH_NAVIGATE_TOOL* navigateTool = m_toolManager->GetTool<SCH_NAVIGATE_TOOL>();
-                return navigateTool && navigateTool->CanGoPrevious();
-            };
-
-    auto navSchematicHasNextSheet =
-            [this]( const SELECTION& aSel )
-            {
-                SCH_NAVIGATE_TOOL* navigateTool = m_toolManager->GetTool<SCH_NAVIGATE_TOOL>();
-                return navigateTool && navigateTool->CanGoNext();
-            };
-
     mgr->SetConditions( EE_ACTIONS::leaveSheet,            ENABLE( belowRootSheetCondition ) );
 
     /* Some of these are bound by default to arrow keys which will get a different action if we
@@ -738,8 +727,6 @@ void SCH_EDIT_FRAME::setupUIConditions()
     mgr->SetConditions( EE_ACTIONS::navigateBack,          ENABLE( navHistoryHsBackward ) );
      */
 
-    mgr->SetConditions( EE_ACTIONS::navigatePrevious,      ENABLE( navSchematicHasPreviousSheet ) );
-    mgr->SetConditions( EE_ACTIONS::navigateNext,          ENABLE( navSchematicHasNextSheet ) );
     mgr->SetConditions( EE_ACTIONS::remapSymbols,          ENABLE( remapSymbolsCondition ) );
     mgr->SetConditions( EE_ACTIONS::toggleHiddenPins,      CHECK( showHiddenPinsCond ) );
     mgr->SetConditions( EE_ACTIONS::toggleHiddenFields,    CHECK( showHiddenFieldsCond ) );
@@ -1011,7 +998,7 @@ bool SCH_EDIT_FRAME::canCloseWindow( wxCloseEvent& aEvent )
 
 void SCH_EDIT_FRAME::doCloseWindow()
 {
-    SCH_SHEET_LIST sheetlist = Schematic().GetUnorderedSheets();
+    SCH_SHEET_LIST sheetlist = Schematic().BuildUnorderedSheetList();
 
     // Shutdown all running tools
     if( m_toolManager )
@@ -1723,7 +1710,7 @@ void SCH_EDIT_FRAME::RecalculateConnections( SCH_COMMIT* aCommit, SCH_CLEANUP_FL
     wxString            highlightedConn = GetHighlightedConnection();
     bool                hasHighlightedConn = !highlightedConn.IsEmpty();
     SCHEMATIC_SETTINGS& settings = Schematic().Settings();
-    SCH_SHEET_LIST      list = Schematic().GetSheets();
+    SCH_SHEET_LIST      list = Schematic().BuildSheetListSortedByPageNumbers();
     SCH_COMMIT          localCommit( m_toolManager );
 
     if( !aCommit )
@@ -2199,7 +2186,7 @@ const BOX2I SCH_EDIT_FRAME::GetDocumentExtents( bool aIncludeAllVisible ) const
 
 bool SCH_EDIT_FRAME::IsContentModified() const
 {
-    return Schematic().GetUnorderedSheets().IsModified();
+    return Schematic().BuildUnorderedSheetList().IsModified();
 }
 
 
@@ -2271,7 +2258,8 @@ void SCH_EDIT_FRAME::SaveSymbolToSchematic( const LIB_SYMBOL& aSymbol,
                                             const KIID& aSchematicSymbolUUID )
 {
     SCH_SHEET_PATH principalPath;
-    SCH_ITEM*      item = Schematic().GetSheets().GetItem( aSchematicSymbolUUID, &principalPath );
+    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
+    SCH_ITEM*      item = sheets.GetItem( aSchematicSymbolUUID, &principalPath );
     SCH_SYMBOL*    principalSymbol = dynamic_cast<SCH_SYMBOL*>( item );
     SCH_COMMIT     commit( m_toolManager );
 
@@ -2285,7 +2273,7 @@ void SCH_EDIT_FRAME::SaveSymbolToSchematic( const LIB_SYMBOL& aSymbol,
 
     std::vector< std::pair<SCH_SYMBOL*, SCH_SHEET_PATH> > allUnits;
 
-    for( const SCH_SHEET_PATH& path : Schematic().GetSheets() )
+    for( const SCH_SHEET_PATH& path : sheets )
     {
         for( SCH_ITEM* candidate : path.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {

eeschema/sch_field.cpp

@@ -858,7 +858,7 @@ void SCH_FIELD::OnScintillaCharAdded( SCINTILLA_TRICKS* aScintillaTricks,
                 SCH_REFERENCE_LIST refs;
                 SCH_SYMBOL*        refSymbol = nullptr;
 
-                schematic->GetUnorderedSheets().GetSymbols( refs );
+                schematic->BuildUnorderedSheetList().GetSymbols( refs );
 
                 for( size_t jj = 0; jj < refs.GetCount(); jj++ )
                 {

eeschema/sch_io/cadstar/sch_io_cadstar_archive.cpp

@@ -141,7 +141,7 @@ SCH_SHEET* SCH_IO_CADSTAR_ARCHIVE::LoadSchematicFile( const wxString&        aFi
     sch_plugin->SaveLibrary( libFileName.GetFullPath() );
 
     // Link up all symbols in the design to the newly created library
-    for( SCH_SHEET_PATH& sheet : aSchematic->GetSheets() )
+    for( SCH_SHEET_PATH& sheet : aSchematic->BuildUnorderedSheetList() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_SYMBOL_T ) )
         {

eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.cpp

@@ -362,6 +362,7 @@ void SCH_IO_KICAD_SEXPR::Format( SCH_SHEET* aSheet )
     wxCHECK_RET( aSheet != nullptr, "NULL SCH_SHEET* object." );
     wxCHECK_RET( m_schematic != nullptr, "NULL SCHEMATIC* object." );
 
+    SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
     SCH_SCREEN* screen = aSheet->GetScreen();
 
     wxCHECK( screen, /* void */ );
@@ -426,7 +427,7 @@ void SCH_IO_KICAD_SEXPR::Format( SCH_SHEET* aSheet )
         {
         case SCH_SYMBOL_T:
             m_out->Print( 0, "\n" );
-            saveSymbol( static_cast<SCH_SYMBOL*>( item ), *m_schematic, 1, false );
+            saveSymbol( static_cast<SCH_SYMBOL*>( item ), *m_schematic, sheets, 1, false );
             break;
 
         case SCH_BITMAP_T:
@@ -435,7 +436,7 @@ void SCH_IO_KICAD_SEXPR::Format( SCH_SHEET* aSheet )
 
         case SCH_SHEET_T:
             m_out->Print( 0, "\n" );
-            saveSheet( static_cast<SCH_SHEET*>( item ), 1 );
+            saveSheet( static_cast<SCH_SHEET*>( item ), sheets, 1 );
             break;
 
         case SCH_JUNCTION_T:
@@ -516,7 +517,7 @@ void SCH_IO_KICAD_SEXPR::Format( EE_SELECTION* aSelection, SCH_SHEET_PATH* aSele
     wxCHECK( aSelection && aSelectionPath && aFormatter, /* void */ );
 
     LOCALE_IO toggle;
-    SCH_SHEET_LIST fullHierarchy = aSchematic.GetSheets();
+    SCH_SHEET_LIST sheets = aSchematic.BuildSheetListSortedByPageNumbers();
 
     m_schematic = &aSchematic;
     m_out = aFormatter;
@@ -580,7 +581,7 @@ void SCH_IO_KICAD_SEXPR::Format( EE_SELECTION* aSelection, SCH_SHEET_PATH* aSele
             break;
 
         case SCH_SHEET_T:
-            saveSheet( static_cast< SCH_SHEET* >( item ), 0 );
+            saveSheet( static_cast< SCH_SHEET* >( item ), sheets, 0 );
             break;
 
         case SCH_JUNCTION_T:
@@ -647,6 +648,7 @@ void SCH_IO_KICAD_SEXPR::Format( EE_SELECTION* aSelection, SCH_SHEET_PATH* aSele
 
 
 void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSchematic,
+                                     const SCH_SHEET_LIST& aSheetList,
                                      int aNestLevel, bool aForClipboard,
                                      const SCH_SHEET_PATH* aRelativePath )
 {
@@ -711,9 +713,8 @@ void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSche
 
     // The symbol unit is always set to the first instance regardless of the current sheet
     // instance to prevent file churn.
-    int unit = ( aSymbol->GetInstances().size() == 0 ) ?
+    int unit = ( aSymbol->GetInstances().size() == 0 ) ? aSymbol->GetUnit()
-               aSymbol->GetUnit() :
+                                                       : aSymbol->GetInstances()[0].m_Unit;
-               aSymbol->GetInstances()[0].m_Unit;
 
     if( aForClipboard && aRelativePath )
     {
@@ -819,7 +820,6 @@ void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSche
         wxString projectName;
         KIID lastProjectUuid;
         KIID rootSheetUuid = aSchematic.Root().m_Uuid;
-        SCH_SHEET_LIST fullHierarchy = aSchematic.GetSheets();
 
         for( const SCH_SYMBOL_INSTANCE& inst : aSymbol->GetInstances() )
         {
@@ -830,7 +830,7 @@ void SCH_IO_KICAD_SEXPR::saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSche
             // path, don't save it.  This prevents large amounts of orphaned instance data for the
             // current project from accumulating in the schematic files.
             bool isOrphaned = ( inst.m_Path[0] == rootSheetUuid )
-                              && !fullHierarchy.GetSheetPathByKIIDPath( inst.m_Path );
+                              && !aSheetList.GetSheetPathByKIIDPath( inst.m_Path );
 
             // Keep all instance data when copying to the clipboard.  They may be needed on paste.
             if( !aForClipboard && isOrphaned )
@@ -998,7 +998,8 @@ void SCH_IO_KICAD_SEXPR::saveBitmap( SCH_BITMAP* aBitmap, int aNestLevel )
 }
 
 
-void SCH_IO_KICAD_SEXPR::saveSheet( SCH_SHEET* aSheet, int aNestLevel )
+void SCH_IO_KICAD_SEXPR::saveSheet( SCH_SHEET* aSheet, const SCH_SHEET_LIST& aSheetList,
+                                    int aNestLevel )
 {
     wxCHECK_RET( aSheet != nullptr && m_out != nullptr, "" );
 
@@ -1081,7 +1082,6 @@ void SCH_IO_KICAD_SEXPR::saveSheet( SCH_SHEET* aSheet, int aNestLevel )
 
         KIID lastProjectUuid;
         KIID rootSheetUuid = m_schematic->Root().m_Uuid;
-        SCH_SHEET_LIST fullHierarchy = m_schematic->GetSheets();
         bool project_open = false;
 
         for( size_t i = 0; i < sheetInstances.size(); i++ )
@@ -1092,7 +1092,7 @@ void SCH_IO_KICAD_SEXPR::saveSheet( SCH_SHEET* aSheet, int aNestLevel )
             //
             // Keep all instance data when copying to the clipboard.  It may be needed on paste.
             if( ( sheetInstances[i].m_Path[0] == rootSheetUuid )
-              && !fullHierarchy.GetSheetPathByKIIDPath( sheetInstances[i].m_Path, false ) )
+              && !aSheetList.GetSheetPathByKIIDPath( sheetInstances[i].m_Path, false ) )
             {
                 if( project_open && ( ( i + 1 == sheetInstances.size() )
                   || lastProjectUuid != sheetInstances[i+1].m_Path[0] ) )

eeschema/sch_io/kicad_sexpr/sch_io_kicad_sexpr.h

@@ -142,11 +142,12 @@ private:
     void loadHierarchy( const SCH_SHEET_PATH& aParentSheetPath, SCH_SHEET* aSheet );
     void loadFile( const wxString& aFileName, SCH_SHEET* aSheet );
 
-    void saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSchematic, int aNestLevel,
+    void saveSymbol( SCH_SYMBOL* aSymbol, const SCHEMATIC& aSchematic,
+                     const SCH_SHEET_LIST& aSheetList, int aNestLevel,
                      bool aForClipboard, const SCH_SHEET_PATH* aRelativePath = nullptr );
     void saveField( SCH_FIELD* aField, int aNestLevel );
     void saveBitmap( SCH_BITMAP* aBitmap, int aNestLevel );
-    void saveSheet( SCH_SHEET* aSheet, int aNestLevel );
+    void saveSheet( SCH_SHEET* aSheet, const SCH_SHEET_LIST& aSheetList, int aNestLevel );
     void saveJunction( SCH_JUNCTION* aJunction, int aNestLevel );
     void saveNoConnect( SCH_NO_CONNECT* aNoConnect, int aNestLevel );
     void saveBusEntry( SCH_BUS_ENTRY_BASE* aBusEntry, int aNestLevel );

eeschema/sch_screen.cpp

@@ -1756,7 +1756,7 @@ void SCH_SCREENS::ClearAnnotationOfNewSheetPaths( SCH_SHEET_LIST& aInitialSheetP
 
     // Search for new sheet paths, not existing in aInitialSheetPathList
     // and existing in sheetpathList
-    for( SCH_SHEET_PATH& sheetpath : sch->GetSheets() )
+    for( SCH_SHEET_PATH& sheetpath : sch->BuildSheetListSortedByPageNumbers() )
     {
         bool path_exists = false;
 
@@ -1896,7 +1896,7 @@ void SCH_SCREENS::UpdateSymbolLinks( REPORTER* aReporter )
 
     wxCHECK_RET( sch, "Null schematic in SCH_SCREENS::UpdateSymbolLinks" );
 
-    SCH_SHEET_LIST sheets = sch->GetSheets();
+    SCH_SHEET_LIST sheets = sch->BuildSheetListSortedByPageNumbers();
 
     // All of the library symbols have been replaced with copies so the connection graph
     // pointers are stale.
@@ -1995,7 +1995,7 @@ void SCH_SCREENS::BuildClientSheetPathList()
     for( SCH_SCREEN* curr_screen = GetFirst(); curr_screen; curr_screen = GetNext() )
         curr_screen->GetClientSheetPaths().clear();
 
-    for( SCH_SHEET_PATH& sheetpath : sch->GetSheets() )
+    for( SCH_SHEET_PATH& sheetpath : sch->BuildSheetListSortedByPageNumbers() )
     {
         SCH_SCREEN* used_screen = sheetpath.LastScreen();
 

eeschema/sch_sheet.cpp

@@ -297,7 +297,7 @@ bool SCH_SHEET::ResolveTextVar( const SCH_SHEET_PATH* aPath, wxString* token, in
     }
     else if( token->IsSameAs( wxT( "##" ) ) )
     {
-        *token = wxString::Format( wxT( "%d" ), (int) schematic->GetUnorderedSheets().size() );
+        *token = wxString::Format( wxT( "%d" ), (int) schematic->BuildUnorderedSheetList().size() );
         return true;
     }
     else if( token->IsSameAs( wxT( "SHEETPATH" ) ) )

eeschema/sch_sheet_path.cpp

@@ -711,15 +711,10 @@ void SCH_SHEET_PATH::MakeFilePathRelativeToParentSheet()
 }
 
 
-SCH_SHEET_LIST::SCH_SHEET_LIST( SCH_SHEET* aSheet, bool aCheckIntegrity )
+SCH_SHEET_LIST::SCH_SHEET_LIST( SCH_SHEET* aSheet )
 {
     if( aSheet != nullptr )
-    {
+        BuildSheetList( aSheet, false );
-        BuildSheetList( aSheet, aCheckIntegrity );
-
-        if( aSheet->IsRootSheet() )
-            SortByPageNumbers();
-    }
 }
 
 

eeschema/sch_sheet_path.h

@@ -471,7 +471,7 @@ public:
      *
      * If aSheet == NULL, then this is an empty hierarchy which the user can populate.
      */
-    SCH_SHEET_LIST( SCH_SHEET* aSheet = nullptr, bool aCheckIntegrity = false );
+    SCH_SHEET_LIST( SCH_SHEET* aSheet = nullptr );
 
     ~SCH_SHEET_LIST() {}
 
@@ -595,7 +595,7 @@ public:
      *
      * If \a aSheet is the root sheet, the full sheet path and sheet list are built.
      *
-     * The list will be ordered as per #SCH_SCREEN::GetSheets which results in sheets being ordered
+     * The list will be ordered as per #SCH_SCREEN::BuildSheetList which results in sheets being ordered
      * in the legacy way of using the X and Y positions of the sheets.
      *
      * @see #SortByPageNumbers to sort by page numbers

eeschema/schematic.cpp

@@ -72,7 +72,7 @@ SCHEMATIC::SCHEMATIC( PROJECT* aPrj ) :
                 int      unit = symbol->GetUnit();
                 LIB_ID   libId = symbol->GetLibId();
 
-                for( SCH_SHEET_PATH& sheet : GetUnorderedSheets() )
+                for( SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
                 {
                     std::vector<SCH_SYMBOL*> otherUnits;
 
@@ -302,7 +302,7 @@ ERC_SETTINGS& SCHEMATIC::ErcSettings() const
 
 std::vector<SCH_MARKER*> SCHEMATIC::ResolveERCExclusions()
 {
-    SCH_SHEET_LIST sheetList = GetSheets();
+    SCH_SHEET_LIST sheetList = BuildUnorderedSheetList();
     ERC_SETTINGS&  settings  = ErcSettings();
 
     // Migrate legacy marker exclusions to new format to ensure exclusion matching functions across
@@ -384,7 +384,7 @@ std::vector<SCH_MARKER*> SCHEMATIC::ResolveERCExclusions()
 
 std::shared_ptr<BUS_ALIAS> SCHEMATIC::GetBusAlias( const wxString& aLabel ) const
 {
-    for( const SCH_SHEET_PATH& sheet : GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
     {
         for( const std::shared_ptr<BUS_ALIAS>& alias : sheet.LastScreen()->GetBusAliases() )
         {
@@ -454,7 +454,7 @@ std::map<int, wxString> SCHEMATIC::GetVirtualPageToSheetNamesMap() const
 {
     std::map<int, wxString> namesMap;
 
-    for( const SCH_SHEET_PATH& sheet : GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
     {
         if( sheet.size() == 1 )
             namesMap[sheet.GetVirtualPageNumber()] = _( "<root sheet>" );
@@ -470,7 +470,7 @@ std::map<int, wxString> SCHEMATIC::GetVirtualPageToSheetPagesMap() const
 {
     std::map<int, wxString> pagesMap;
 
-    for( const SCH_SHEET_PATH& sheet : GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : BuildUnorderedSheetList() )
         pagesMap[sheet.GetVirtualPageNumber()] = sheet.GetPageNumber();
 
     return pagesMap;
@@ -518,7 +518,7 @@ wxString SCHEMATIC::ConvertRefsToKIIDs( const wxString& aSource ) const
                 wxString           ref = token.BeforeFirst( ':', &remainder );
                 SCH_REFERENCE_LIST references;
 
-                GetUnorderedSheets().GetSymbols( references );
+                BuildUnorderedSheetList().GetSymbols( references );
 
                 for( size_t jj = 0; jj < references.GetCount(); jj++ )
                 {
@@ -641,7 +641,7 @@ void SCHEMATIC::SetSheetNumberAndCount()
 
     // @todo Remove all pseudo page number system is left over from prior to real page number
     //       implementation.
-    for( const SCH_SHEET_PATH& sheet : GetSheets() )
+    for( const SCH_SHEET_PATH& sheet : BuildSheetListSortedByPageNumbers() )
     {
         if( sheet.Path() == current_sheetpath ) // Current sheet path found
             break;
@@ -664,7 +664,7 @@ void SCHEMATIC::RecomputeIntersheetRefs( const std::function<void( SCH_GLOBALLAB
 
     pageRefsMap.clear();
 
-    for( const SCH_SHEET_PATH& sheet : GetSheets() )
+    for( const SCH_SHEET_PATH& sheet : BuildSheetListSortedByPageNumbers() )
     {
         for( SCH_ITEM* item : sheet.LastScreen()->Items().OfType( SCH_GLOBAL_LABEL_T ) )
         {
@@ -802,7 +802,8 @@ void SCHEMATIC::RemoveAllListeners()
 
 void SCHEMATIC::RecordERCExclusions()
 {
-    SCH_SHEET_LIST sheetList = GetSheets();
+    // Use a sorted sheetList to reduce file churn
+    SCH_SHEET_LIST sheetList = BuildSheetListSortedByPageNumbers();
     ERC_SETTINGS&  ercSettings = ErcSettings();
 
     ercSettings.m_ErcExclusions.clear();
@@ -827,7 +828,7 @@ void SCHEMATIC::RecordERCExclusions()
 
 void SCHEMATIC::ResolveERCExclusionsPostUpdate()
 {
-    SCH_SHEET_LIST sheetList = GetUnorderedSheets();
+    SCH_SHEET_LIST sheetList = BuildUnorderedSheetList();
 
     for( SCH_MARKER* marker : ResolveERCExclusions() )
     {

eeschema/schematic.h

@@ -43,7 +43,7 @@ public:
     virtual ~SCHEMATIC_IFACE() {};
 
     virtual CONNECTION_GRAPH* ConnectionGraph() const = 0;
-    virtual SCH_SHEET_LIST GetSheets() const = 0;
+    virtual SCH_SHEET_LIST BuildSheetListSortedByPageNumbers() const = 0;
     virtual void SetCurrentSheet( const SCH_SHEET_PATH& aPath ) = 0;
     virtual SCH_SHEET_PATH& CurrentSheet() const = 0;
     virtual wxString GetFileName() const = 0;
@@ -92,17 +92,12 @@ public:
 
     const std::map<wxString, wxString>* GetProperties() { return &m_properties; }
 
-    /**
+    SCH_SHEET_LIST BuildSheetListSortedByPageNumbers() const override
-     * Builds and returns an updated schematic hierarchy
-     * TODO: can this be cached?
-     * @return a SCH_SHEET_LIST containing the schematic hierarchy
-     */
-    SCH_SHEET_LIST GetSheets() const override
     {
         return SCH_SHEET_LIST( m_rootSheet );
     }
 
-    SCH_SHEET_LIST GetUnorderedSheets() const
+    SCH_SHEET_LIST BuildUnorderedSheetList() const
     {
         SCH_SHEET_LIST sheets;
         sheets.BuildSheetList( m_rootSheet, false );
@@ -111,7 +106,7 @@ public:
 
     SCH_ITEM* GetItem( const KIID& aID, SCH_SHEET_PATH* aPathOut = nullptr ) const
     {
-        return GetUnorderedSheets().GetItem( aID, aPathOut );
+        return BuildUnorderedSheetList().GetItem( aID, aPathOut );
     }
 
     SCH_SHEET& Root() const

eeschema/schematic_undo_redo.cpp

@@ -374,7 +374,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
         {
             // Lazy eval of sheet list; this is expensive even when unsorted
             if( sheets.empty() )
-                sheets = m_schematic->GetUnorderedSheets();
+                sheets = m_schematic->BuildUnorderedSheetList();
 
             SCH_SHEET_PATH undoSheet = sheets.FindSheetForScreen( screen );
 
@@ -435,7 +435,7 @@ void SCH_EDIT_FRAME::PutDataInPreviousState( PICKED_ITEMS_LIST* aList )
                     {
                         // Lazy eval of sheet list; this is expensive even when unsorted
                         if( sheets.empty() )
-                            sheets = m_schematic->GetUnorderedSheets();
+                            sheets = m_schematic->BuildUnorderedSheetList();
 
                         SCH_SHEET_PATH sheet = sheets.FindSheetForScreen( screen );
                         symbol->SetRef( &sheet, field->GetText() );

eeschema/sheet.cpp

@@ -53,8 +53,8 @@ bool SCH_EDIT_FRAME::CheckSheetForRecursion( SCH_SHEET* aSheet, SCH_SHEET_PATH*
     wxASSERT( aSheet && aCurrentSheet );
 
     wxString msg;
-    SCH_SHEET_LIST hierarchy = Schematic().GetSheets();  // The full schematic sheet hierarchy.
+    SCH_SHEET_LIST schematicSheets = Schematic().BuildUnorderedSheetList();
-    SCH_SHEET_LIST sheetHierarchy( aSheet );  // This is the hierarchy of the loaded file.
+    SCH_SHEET_LIST loadedSheets( aSheet );  // This is the schematicSheets of the loaded file.
 
     wxString destFilePath = aCurrentSheet->LastScreen()->GetFileName();
 
@@ -68,11 +68,11 @@ bool SCH_EDIT_FRAME::CheckSheetForRecursion( SCH_SHEET* aSheet, SCH_SHEET_PATH*
     // something is seriously broken.
     wxASSERT( wxFileName( destFilePath ).IsAbsolute() );
 
-    if( hierarchy.TestForRecursion( sheetHierarchy, destFilePath ) )
+    if( schematicSheets.TestForRecursion( loadedSheets, destFilePath ) )
     {
         msg.Printf( _( "The sheet changes cannot be made because the destination sheet already "
                        "has the sheet '%s' or one of its subsheets as a parent somewhere in the "
-                       "schematic hierarchy." ),
+                       "schematic schematicSheets." ),
                     destFilePath );
         DisplayError( this, msg );
         return true;
@@ -275,8 +275,8 @@ bool SCH_EDIT_FRAME::LoadSheetFromFile( SCH_SHEET* aSheet, SCH_SHEET_PATH* aCurr
         }
     }
 
-    SCH_SHEET_LIST sheetHierarchy( tmpSheet.get() );    // This is the hierarchy of the loaded file.
+    SCH_SHEET_LIST loadedSheets( tmpSheet.get() );
-    SCH_SHEET_LIST hierarchy = Schematic().GetSheets(); // This is the schematic sheet hierarchy.
+    SCH_SHEET_LIST schematicSheets = Schematic().BuildUnorderedSheetList();
 
     // Make sure any new sheet changes do not cause any recursion issues.
     if( CheckSheetForRecursion( tmpSheet.get(), aCurrentSheet )
@@ -565,17 +565,17 @@ bool SCH_EDIT_FRAME::LoadSheetFromFile( SCH_SHEET* aSheet, SCH_SHEET_PATH* aCurr
         {
             // If the loaded schematic is a root sheet for another project, update the symbol
             // instances.
-            sheetHierarchy.UpdateSymbolInstanceData( newScreen->GetSymbolInstances());
+            loadedSheets.UpdateSymbolInstanceData( newScreen->GetSymbolInstances());
         }
     }
 
     newScreen->MigrateSimModels();
 
     // Attempt to create new symbol instances using the instance data loaded above.
-    sheetHierarchy.AddNewSymbolInstances( *aCurrentSheet, Prj().GetProjectName() );
+    loadedSheets.AddNewSymbolInstances( *aCurrentSheet, Prj().GetProjectName() );
 
     // Add new sheet instance data.
-    sheetHierarchy.AddNewSheetInstances( *aCurrentSheet, hierarchy.GetLastVirtualPageNumber() );
+    loadedSheets.AddNewSheetInstances( *aCurrentSheet, schematicSheets.GetLastVirtualPageNumber() );
 
     // It is finally safe to add or append the imported schematic.
     if( aSheet->GetScreen() == nullptr )
@@ -693,7 +693,7 @@ void SCH_EDIT_FRAME::DrawCurrentSheetToClipboard()
 bool SCH_EDIT_FRAME::AllowCaseSensitiveFileNameClashes( const wxString& aOldName, const wxString& aSchematicFileName )
 {
     wxString       msg;
-    SCH_SHEET_LIST sheets( &Schematic().Root() );
+    SCH_SHEET_LIST sheets = Schematic().BuildUnorderedSheetList();
     wxFileName     fn = aSchematicFileName;
 
     wxCHECK( fn.IsAbsolute(), false );

eeschema/tools/assign_footprints.cpp

@@ -45,11 +45,10 @@ void SCH_EDITOR_CONTROL::AssignFootprints( const std::string& aChangedSetOfRefer
 {
     // Build a flat list of symbols in schematic:
     SCH_REFERENCE_LIST refs;
-    SCH_SHEET_LIST      sheets    = m_frame->Schematic().GetSheets();
     bool               isChanged = false;
     bool               appendToUndoList = false;
 
-    sheets.GetSymbols( refs, false );
+    m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( refs, false );
 
     DSNLEXER lexer( aChangedSetOfReferences, From_UTF8( __func__ ) );
     PTREE    doc;
@@ -129,9 +128,7 @@ bool SCH_EDITOR_CONTROL::processCmpToFootprintLinkFile( const wxString& aFullFil
 {
     // Build a flat list of symbols in schematic:
     SCH_REFERENCE_LIST referencesList;
-    SCH_SHEET_LIST      sheetList = m_frame->Schematic().GetSheets();
+    m_frame->Schematic().BuildUnorderedSheetList().GetSymbols( referencesList, false );
-
-    sheetList.GetSymbols( referencesList, false );
 
     FILE* cmpFile = wxFopen( aFullFilename, wxT( "rt" ) );
 

eeschema/tools/backannotate.cpp

@@ -80,7 +80,7 @@ bool BACK_ANNOTATE::BackAnnotateSymbols( const std::string& aNetlist )
 
     getPcbModulesFromString( aNetlist );
 
-    SCH_SHEET_LIST sheets = m_frame->Schematic().GetSheets();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
     sheets.GetSymbols( m_refs, false );
     sheets.GetMultiUnitSymbols( m_multiUnitsRefs );
 

eeschema/tools/sch_drawing_tools.cpp

@@ -145,7 +145,7 @@ int SCH_DRAWING_TOOLS::PlaceSymbol( const TOOL_EVENT& aEvent )
 
     // First we need to get all instances of this sheet so we can annotate
     // whatever symbols we place on all copies
-    SCH_SHEET_LIST hierarchy = m_frame->Schematic().GetSheets();
+    SCH_SHEET_LIST hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
     SCH_SHEET_LIST newInstances =
             hierarchy.FindAllSheetsForScreen( m_frame->GetCurrentSheet().LastScreen() );
     newInstances.SortByPageNumbers();

eeschema/tools/sch_edit_tool.cpp

@@ -1872,7 +1872,8 @@ int SCH_EDIT_TOOL::Properties( const TOOL_EVENT& aEvent )
         // Keep track of existing sheet paths. EditSheet() can modify this list.
         // Note that we use the validity checking/repairing version here just to make sure
         // we've got a valid hierarchy to begin with.
-        SCH_SHEET_LIST originalHierarchy( &m_frame->Schematic().Root(), true );
+        SCH_SHEET_LIST originalHierarchy;
+        originalHierarchy.BuildSheetList( &m_frame->Schematic().Root(), true );
 
         SCH_COMMIT commit( m_toolMgr );
         commit.Modify( sheet, m_frame->GetScreen() );

eeschema/tools/sch_editor_control.cpp

@@ -359,8 +359,9 @@ int SCH_EDITOR_CONTROL::ExportSymbolsToLibrary( const TOOL_EVENT& aEvent )
 
     bool createNew = aEvent.IsAction( &EE_ACTIONS::exportSymbolsToNewLibrary );
 
+    SCH_SHEET_LIST     sheets = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
     SCH_REFERENCE_LIST symbols;
-    m_frame->Schematic().GetSheets().GetSymbols( symbols, savePowerSymbols );
+    sheets.GetSymbols( symbols, savePowerSymbols );
 
     std::map<LIB_ID, LIB_SYMBOL*> libSymbols;
     std::map<LIB_ID, std::vector<SCH_SYMBOL*>> symbolMap;
@@ -519,7 +520,6 @@ int SCH_EDITOR_CONTROL::ExportSymbolsToLibrary( const TOOL_EVENT& aEvent )
     if( append )
     {
         std::set<SCH_SCREEN*> processedScreens;
-        SCH_SHEET_LIST        sheets = m_frame->Schematic().GetSheets();
 
         for( SCH_SHEET_PATH& sheet : sheets )
         {
@@ -1344,7 +1344,6 @@ bool SCH_EDITOR_CONTROL::doCopy( bool aUseDuplicateClipboard )
 
     STRING_FORMATTER   formatter;
     SCH_IO_KICAD_SEXPR plugin;
-    SCH_SHEET_LIST     hierarchy = schematic.GetSheets();
     SCH_SHEET_PATH     selPath = m_frame->GetCurrentSheet();
 
     plugin.Format( &selection, &selPath, schematic, &formatter, true );
@@ -1676,7 +1675,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
     EDA_ITEMS              loadedItems;
     std::vector<SCH_ITEM*> sortedLoadedItems;
     bool                   sheetsPasted = false;
-    SCH_SHEET_LIST         hierarchy = m_frame->Schematic().GetSheets();
+    SCH_SHEET_LIST         hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
     SCH_SHEET_PATH&        pasteRoot = m_frame->GetCurrentSheet();
     wxFileName             destFn = pasteRoot.Last()->GetFileName();
 
@@ -1838,7 +1837,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
             // Update hierarchy to include any other sheets we already added, avoiding
             // duplicate sheet names
-            hierarchy = m_frame->Schematic().GetSheets();
+            hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
 
             //@todo: it might be better to just iterate through the sheet names
             // in this screen instead of the whole hierarchy.
@@ -1988,7 +1987,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
 
         // Get a version with correct sheet numbers since we've pasted sheets,
         // we'll need this when annotating next
-        hierarchy = m_frame->Schematic().GetSheets();
+        hierarchy = m_frame->Schematic().BuildSheetListSortedByPageNumbers();
     }
 
     std::map<SCH_SHEET_PATH, SCH_REFERENCE_LIST> annotatedSymbols;
@@ -2077,12 +2076,11 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
     // schematic file.
     prunePastedSymbolInstances();
 
+    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
     SCH_SCREENS    allScreens( m_frame->Schematic().Root() );
 
-    allScreens.PruneOrphanedSymbolInstances( m_frame->Prj().GetProjectName(),
+    allScreens.PruneOrphanedSymbolInstances( m_frame->Prj().GetProjectName(), sheets );
-                                             m_frame->Schematic().GetSheets() );
+    allScreens.PruneOrphanedSheetInstances( m_frame->Prj().GetProjectName(), sheets );
-    allScreens.PruneOrphanedSheetInstances( m_frame->Prj().GetProjectName(),
-                                            m_frame->Schematic().GetSheets() );
 
     // Now clear the previous selection, select the pasted items, and fire up the "move" tool.
     m_toolMgr->RunAction( EE_ACTIONS::clearSelection );
@@ -2610,6 +2608,8 @@ int SCH_EDITOR_CONTROL::RepairSchematic( const TOOL_EVENT& aEvent )
     std::map<KIID, EDA_ITEM*> ids;
     int                       duplicates = 0;
 
+    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
+
     auto processItem =
             [&]( EDA_ITEM* aItem )
             {
@@ -2627,7 +2627,7 @@ int SCH_EDITOR_CONTROL::RepairSchematic( const TOOL_EVENT& aEvent )
     // Symbol IDs are the most important, so give them the first crack at "claiming" a
     // particular KIID.
 
-    for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : sheets )
     {
         SCH_SCREEN* screen = sheet.LastScreen();
 
@@ -2640,7 +2640,7 @@ int SCH_EDITOR_CONTROL::RepairSchematic( const TOOL_EVENT& aEvent )
         }
     }
 
-    for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().GetUnorderedSheets() )
+    for( const SCH_SHEET_PATH& sheet : sheets )
     {
         SCH_SCREEN* screen = sheet.LastScreen();
 

eeschema/tools/sch_find_replace_tool.cpp

@@ -431,7 +431,7 @@ int SCH_FIND_REPLACE_TOOL::ReplaceAll( const TOOL_EVENT& aEvent )
     }
     else
     {
-        SCH_SHEET_LIST allSheets = m_frame->Schematic().GetUnorderedSheets();
+        SCH_SHEET_LIST allSheets = m_frame->Schematic().BuildUnorderedSheetList();
         SCH_SCREENS    screens( m_frame->Schematic().Root() );
 
         for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )

eeschema/tools/sch_navigate_tool.cpp

@@ -42,7 +42,7 @@ void SCH_NAVIGATE_TOOL::ResetHistory()
 
 void SCH_NAVIGATE_TOOL::CleanHistory()
 {
-    SCH_SHEET_LIST sheets = m_frame->Schematic().GetSheets();
+    SCH_SHEET_LIST sheets = m_frame->Schematic().BuildUnorderedSheetList();
 
     // Search through our history, and removing any entries
     // that the no longer point to a sheet on the schematic
@@ -69,7 +69,7 @@ void SCH_NAVIGATE_TOOL::HypertextCommand( const wxString& href )
     }
     else if( EDA_TEXT::IsGotoPageHref( href, &destPage ) && !destPage.IsEmpty() )
     {
-        for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().GetSheets() )
+        for( const SCH_SHEET_PATH& sheet : m_frame->Schematic().BuildSheetListSortedByPageNumbers() )
         {
             if( sheet.GetPageNumber() == destPage )
             {
@@ -147,7 +147,7 @@ int SCH_NAVIGATE_TOOL::Previous( const TOOL_EVENT& aEvent )
     if( CanGoPrevious() )
     {
         int targetSheet = m_frame->GetCurrentSheet().GetVirtualPageNumber() - 1;
-        changeSheet( m_frame->Schematic().GetSheets().at( targetSheet - 1 ) );
+        changeSheet( m_frame->Schematic().BuildSheetListSortedByPageNumbers().at( targetSheet - 1 ) );
     }
     else
     {
@@ -163,7 +163,7 @@ int SCH_NAVIGATE_TOOL::Next( const TOOL_EVENT& aEvent )
     if( CanGoNext() )
     {
         int targetSheet = m_frame->GetCurrentSheet().GetVirtualPageNumber() + 1;
-        changeSheet( m_frame->Schematic().GetSheets().at( targetSheet - 1 ) );
+        changeSheet( m_frame->Schematic().BuildSheetListSortedByPageNumbers().at( targetSheet - 1 ) );
     }
     else
     {
@@ -201,7 +201,7 @@ bool SCH_NAVIGATE_TOOL::CanGoPrevious()
 bool SCH_NAVIGATE_TOOL::CanGoNext()
 {
     return m_frame->GetCurrentSheet().GetVirtualPageNumber()
-           < (int) m_frame->Schematic().GetUnorderedSheets().size();
+           < (int) m_frame->Schematic().BuildUnorderedSheetList().size();
 }
 
 

qa/schematic_utils/eeschema_test_utils.cpp

@@ -61,7 +61,7 @@ void KI_TEST::SCHEMATIC_TEST_FIXTURE::LoadSchematic( const wxString& aBaseName )
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
         screen->UpdateLocalLibSymbolLinks();
 
-    SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+    SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
     // Restore all of the loaded symbol instances from the root sheet screen.
     if( m_schematic.RootScreen()->GetFileFormatVersionAtLoad() < 20221002 )

qa/schematic_utils/schematic_file_util.cpp

@@ -149,7 +149,7 @@ void LoadSchematic( SETTINGS_MANAGER& aSettingsManager, const wxString& aRelPath
     for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
         screen->UpdateLocalLibSymbolLinks();
 
-    SCH_SHEET_LIST sheets = aSchematic->GetSheets();
+    SCH_SHEET_LIST sheets = aSchematic->BuildSheetListSortedByPageNumbers();
 
     // Restore all of the loaded symbol instances from the root sheet screen.
     sheets.UpdateSymbolInstanceData( aSchematic->RootScreen()->GetSymbolInstances() );

qa/tests/eeschema/erc/test_erc_global_labels.cpp

@@ -61,7 +61,8 @@ BOOST_FIXTURE_TEST_CASE( ERCGlobalLabels, ERC_REGRESSION_TEST_FIXTURE )
         settings.m_ERCSeverities[ERCE_LIB_SYMBOL_ISSUES] = RPT_SEVERITY_IGNORE;
         settings.m_ERCSeverities[ERCE_LIB_SYMBOL_MISMATCH] = RPT_SEVERITY_IGNORE;
 
-        m_schematic->ConnectionGraph()->Recalculate( m_schematic->GetSheets(), true );
+        SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+        m_schematic->ConnectionGraph()->Recalculate( sheets, true );
         m_schematic->ConnectionGraph()->RunERC();
 
         ERC_TESTER tester( m_schematic.get() );
@@ -107,7 +108,8 @@ BOOST_FIXTURE_TEST_CASE( ERCSingleGlobalLabels, ERC_REGRESSION_TEST_FIXTURE )
         settings.m_ERCSeverities[ERCE_GLOBLABEL] = RPT_SEVERITY_IGNORE;
         settings.m_ERCSeverities[ERCE_SINGLE_GLOBAL_LABEL] = RPT_SEVERITY_ERROR;
 
-        m_schematic->ConnectionGraph()->Recalculate( m_schematic->GetSheets(), true );
+        SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+        m_schematic->ConnectionGraph()->Recalculate( sheets, true );
         m_schematic->ConnectionGraph()->RunERC();
 
         ERC_TESTER tester( m_schematic.get() );

qa/tests/eeschema/erc/test_erc_rule_areas.cpp

@@ -74,7 +74,9 @@ BOOST_FIXTURE_TEST_CASE( ERCRuleAreaNetClasseDirectives, ERC_REGRESSION_TEST_FIX
             allScreens.insert( screen );
 
         SCH_RULE_AREA::UpdateRuleAreasInScreens( allScreens, nullptr );
-        m_schematic->ConnectionGraph()->Recalculate( m_schematic->GetSheets(), true );
+
+        SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+        m_schematic->ConnectionGraph()->Recalculate( sheets, true );
         m_schematic->ConnectionGraph()->RunERC();
 
         errors.SetSeverities( RPT_SEVERITY_ERROR | RPT_SEVERITY_WARNING );
@@ -117,12 +119,13 @@ BOOST_FIXTURE_TEST_CASE( ERCRuleAreaOverlaps, ERC_REGRESSION_TEST_FIXTURE )
         SCH_SCREENS                     screens( m_schematic->Root() );
         screens.BuildClientSheetPathList();
 
-        for( SCH_SCREEN* screen = screens.GetFirst(); screen != nullptr;
+        for( SCH_SCREEN* screen = screens.GetFirst(); screen; screen = screens.GetNext() )
-             screen = screens.GetNext() )
             allScreens.insert( screen );
 
         SCH_RULE_AREA::UpdateRuleAreasInScreens( allScreens, nullptr );
-        m_schematic->ConnectionGraph()->Recalculate( m_schematic->GetSheets(), true );
+
+        SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
+        m_schematic->ConnectionGraph()->Recalculate( sheets, true );
 
         ERC_TESTER tester( m_schematic.get() );
         tester.RunRuleAreaERC();

qa/tests/eeschema/test_incremental_netlister.cpp

@@ -67,7 +67,7 @@ BOOST_FIXTURE_TEST_CASE( RemoveAddItems, INCREMENTAL_NETLIST_TEST_FIXTURE )
     {
         KI_TEST::LoadSchematic( m_settingsManager, test, m_schematic );
 
-        SCH_SHEET_LIST sheets = m_schematic->GetSheets();
+        SCH_SHEET_LIST sheets = m_schematic->BuildSheetListSortedByPageNumbers();
 
         for( const SCH_SHEET_PATH& path : sheets )
         {

qa/tests/eeschema/test_sch_netclass.cpp

@@ -33,8 +33,7 @@ BOOST_AUTO_TEST_CASE( TestSubsheetNetclass )
 {
     LoadSchematic( "issue14494" );
 
-    SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+    SCH_SHEET_PATH path = m_schematic.BuildSheetListSortedByPageNumbers().at( 1 );
-    SCH_SHEET_PATH path = sheets.at( 1 );
     SCH_SCREEN*    screen = path.GetSheet( 1 )->GetScreen();
 
     for( SCH_ITEM* item : screen->Items().OfType( SCH_HIER_LABEL_T ) )

qa/tests/eeschema/test_sch_reference_list.cpp

@@ -80,10 +80,8 @@ void TEST_SCH_REFERENCE_LIST_FIXTURE::loadTestCase( wxString aSchematicRelativeP
 SCH_SYMBOL* TEST_SCH_REFERENCE_LIST_FIXTURE::getSymbolByKIID( wxString        aKIID,
                                                               SCH_SHEET_PATH* aSymbolPath )
 {
-    SCH_SHEET_LIST sheets = m_schematic.GetSheets();
-
     KIID        symKIID( aKIID );
-    SCH_ITEM*   foundItem = sheets.GetItem( symKIID, aSymbolPath );
+    SCH_ITEM*   foundItem = m_schematic.GetItem( symKIID, aSymbolPath );
     SCH_SYMBOL* symbol = dynamic_cast<SCH_SYMBOL*>( foundItem );
 
     return symbol;
@@ -95,7 +93,7 @@ SCH_REFERENCE_LIST TEST_SCH_REFERENCE_LIST_FIXTURE::getAdditionalRefs()
     // Build List of additional references to pass into Annotate()
     SCH_REFERENCE_LIST allRefs, additionalRefs;
 
-    m_schematic.GetSheets().GetSymbols( allRefs );
+    m_schematic.BuildSheetListSortedByPageNumbers().GetSymbols( allRefs );
 
     for( size_t i = 0; i < allRefs.GetCount(); ++i )
     {

qa/tests/eeschema/test_sch_sheet_list.cpp

@@ -49,7 +49,7 @@ BOOST_AUTO_TEST_CASE( TestSheetListPageProperties )
 {
     LoadSchematic( "complex_hierarchy/complex_hierarchy" );
 
-    SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+    SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
     BOOST_CHECK( sheets.AllSheetPageNumbersEmpty() );
 
@@ -69,7 +69,7 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         // Check the Sub Sheet has the expected page numbers
         LoadSchematic( "complex_hierarchy_shared/ampli_ht/ampli_ht" );
 
-        SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+        SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
         BOOST_CHECK_EQUAL( sheets.size(), 2 );
         BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "i" );
@@ -81,7 +81,7 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         // Check the parent sheet has the expected page numbers
         LoadSchematic( "complex_hierarchy_shared/complex_hierarchy" );
 
-        SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+        SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
         BOOST_CHECK_EQUAL( sheets.size(), 5 );
         BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "1" );
@@ -93,7 +93,7 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
 
     BOOST_TEST_CONTEXT( "Modify page numbers in root sheet" )
     {
-        SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+        SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
         // Amend Page numbers
         sheets.at( 0 ).SetPageNumber( "A" );
@@ -129,7 +129,7 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
 
         LoadSchematic( "complex_hierarchy_shared/temp/complex_hierarchy" );
 
-        sheets = m_schematic.GetSheets();
+        sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
         BOOST_CHECK_EQUAL( sheets.size(), 5 );
         BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "A" );
@@ -154,7 +154,7 @@ BOOST_AUTO_TEST_CASE( TestEditPageNumbersInSharedDesign )
         // (This should not have been modified after editing the root sheet)
         LoadSchematic( "complex_hierarchy_shared/ampli_ht/ampli_ht" );
 
-        SCH_SHEET_LIST sheets = m_schematic.GetSheets();
+        SCH_SHEET_LIST sheets = m_schematic.BuildSheetListSortedByPageNumbers();
 
         BOOST_CHECK_EQUAL( sheets.size(), 2 );
         BOOST_CHECK_EQUAL( sheets.at( 0 ).GetPageNumber(), "i" );