From 6541202d427401ef9ffff87c2d7c1840dd6ac337 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Tue, 15 Jul 2025 15:22:18 +0100
Subject: [PATCH] Repair COMMON_TOOLS to know about frame-specific
 WINDOW_SETTINGS

Remove the older architectures for ensuring non-empty
grids and zooms

Move new architecture to PARAM_LIST::Load,
and add zoom support

Fixes https://gitlab.com/kicad/code/kicad/-/issues/21318
---
 common/settings/app_settings.cpp      | 69 ++++++++++++++++++++++++---
 common/tool/common_tools.cpp          | 47 ++++++++----------
 eeschema/eeschema_config.cpp          |  7 ---
 gerbview/gerbview_frame.cpp           | 38 +--------------
 include/settings/app_settings.h       |  2 +
 include/settings/parameters.h         | 30 +++++++-----
 pagelayout_editor/pl_editor_frame.cpp | 20 --------
 pcbnew/footprint_chooser_frame.cpp    | 10 ++--
 pcbnew/footprint_preview_panel.cpp    | 14 ------
 pcbnew/pcb_base_frame.cpp             | 14 ------
 10 files changed, 112 insertions(+), 139 deletions(-)

diff --git a/common/settings/app_settings.cpp b/common/settings/app_settings.cpp
index e3a13936ce..6051f77500 100644
--- a/common/settings/app_settings.cpp
+++ b/common/settings/app_settings.cpp
@@ -29,6 +29,7 @@
 #include <settings/common_settings.h>
 #include <settings/grid_settings.h>
 #include <settings/parameters.h>
+#include <zoom_defines.h>
 
 
 APP_SETTINGS_BASE::APP_SETTINGS_BASE( const std::string& aFilename, int aSchemaVersion ) :
@@ -432,7 +433,7 @@ void APP_SETTINGS_BASE::addParamsForWindow( WINDOW_SETTINGS* aWindow, const std:
                                                     &aWindow->state.display, 0 ) );
 
     m_params.emplace_back( new PARAM_LIST<double>( aJsonPath + ".zoom_factors",
-            &aWindow->zoom_factors, {} ) );
+            &aWindow->zoom_factors, DefaultZoomList(), true /* resetIfEmpty */ ) );
 
     m_params.emplace_back( new PARAM<bool>( aJsonPath + ".grid.axes_enabled",
             &aWindow->grid.axes_enabled, false ) );
@@ -453,11 +454,7 @@ void APP_SETTINGS_BASE::addParamsForWindow( WINDOW_SETTINGS* aWindow, const std:
     }
 
     m_params.emplace_back( new PARAM_LIST<GRID>( aJsonPath + ".grid.sizes", &aWindow->grid.grids,
-                                                 DefaultGridSizeList() ) );
-
-    // Force grids to have at least 1 entry.  If not, reset to default.
-    if( aWindow->grid.grids.empty() )
-        aWindow->grid.grids = DefaultGridSizeList();
+                                                 DefaultGridSizeList(), true /* resetIfEmpty */ ) );
 
     m_params.emplace_back( new PARAM<int>( aJsonPath + ".grid.last_size",
             &aWindow->grid.last_size_idx, defaultGridIdx ) );
@@ -551,6 +548,30 @@ void APP_SETTINGS_BASE::addParamsForWindow( WINDOW_SETTINGS* aWindow, const std:
 }
 
 
+const std::vector<double> APP_SETTINGS_BASE::DefaultZoomList() const
+{
+    if( m_filename == wxS( "eeschema" ) || m_filename == wxS( "symbol_editor" ) )
+    {
+        return { ZOOM_LIST_EESCHEMA };
+    }
+    else if( m_filename == wxS( "pl_editor" ) )
+    {
+        return { ZOOM_LIST_PL_EDITOR };
+    }
+    else if( m_filename == wxS( "gerbview" ) )
+    {
+        return { ZOOM_LIST_GERBVIEW };
+    }
+    else
+    {
+        if( ADVANCED_CFG::GetCfg().m_HyperZoom )
+            return { ZOOM_LIST_PCBNEW_HYPER };
+        else
+            return { ZOOM_LIST_PCBNEW };
+    }
+}
+
+
 const std::vector<GRID> APP_SETTINGS_BASE::DefaultGridSizeList() const
 {
     if( m_filename == wxS( "eeschema" ) || m_filename == wxS( "symbol_editor" ) )
@@ -560,6 +581,42 @@ const std::vector<GRID> APP_SETTINGS_BASE::DefaultGridSizeList() const
                  GRID{ wxEmptyString, wxS( "25 mil" ), wxS( "25 mil" ) },
                  GRID{ wxEmptyString, wxS( "10 mil" ), wxS( "10 mil" ) } };
     }
+    else if( m_filename == wxS( "pl_editor" ) )
+    {
+        return { GRID{ wxEmptyString, wxS( "5.00 mm" ), wxS( "5.00 mm" ) },
+                 GRID{ wxEmptyString, wxS( "2.50 mm" ), wxS( "2.50 mm" ) },
+                 GRID{ wxEmptyString, wxS( "2.00 mm" ), wxS( "2.00 mm" ) },
+                 GRID{ wxEmptyString, wxS( "1.00 mm" ), wxS( "1.00 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.50 mm" ), wxS( "0.50 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.25 mm" ), wxS( "0.25 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.20 mm" ), wxS( "0.20 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.10 mm" ), wxS( "0.10 mm" ) } };
+    }
+    else if( m_filename == wxS( "gerbview" ) )
+    {
+        return { GRID{ wxEmptyString, wxS( "100 mil" ), wxS( "100 mil" ) },
+                 GRID{ wxEmptyString, wxS( "50 mil" ), wxS( "50 mil" ) },
+                 GRID{ wxEmptyString, wxS( "25 mil" ), wxS( "25 mil" ) },
+                 GRID{ wxEmptyString, wxS( "20 mil" ), wxS( "20 mil" ) },
+                 GRID{ wxEmptyString, wxS( "10 mil" ), wxS( "10 mil" ) },
+                 GRID{ wxEmptyString, wxS( "5 mil" ), wxS( "5 mil" ) },
+                 GRID{ wxEmptyString, wxS( "2.5 mil" ), wxS( "2.5 mil" ) },
+                 GRID{ wxEmptyString, wxS( "2 mil" ), wxS( "2 mil" ) },
+                 GRID{ wxEmptyString, wxS( "1 mil" ), wxS( "1 mil" ) },
+                 GRID{ wxEmptyString, wxS( "0.5 mil" ), wxS( "0.5 mil" ) },
+                 GRID{ wxEmptyString, wxS( "0.2 mil" ), wxS( "0.2 mil" ) },
+                 GRID{ wxEmptyString, wxS( "0.1 mil" ), wxS( "0.1 mil" ) },
+                 GRID{ wxEmptyString, wxS( "5.0 mm" ), wxS( "5.0 mm" ) },
+                 GRID{ wxEmptyString, wxS( "1.5 mm" ), wxS( "2.5 mm" ) },
+                 GRID{ wxEmptyString, wxS( "1.0 mm" ), wxS( "1.0 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.5 mm" ), wxS( "0.5 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.25 mm" ), wxS( "0.25 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.2 mm" ), wxS( "0.2 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.1 mm" ), wxS( "0.1 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.05 mm" ), wxS( "0.0 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.025 mm" ), wxS( "0.0 mm" ) },
+                 GRID{ wxEmptyString, wxS( "0.01 mm" ), wxS( "0.0 mm" ) } };
+    }
     else
     {
         return { GRID{ wxEmptyString, wxS( "1000 mil" ), wxS( "1000 mil" ) },
diff --git a/common/tool/common_tools.cpp b/common/tool/common_tools.cpp
index 179e88a3a9..a6531a72c8 100644
--- a/common/tool/common_tools.cpp
+++ b/common/tool/common_tools.cpp
@@ -64,18 +64,15 @@ void COMMON_TOOLS::Reset( RESET_REASON aReason )
     if( aReason == RESET_REASON::SHUTDOWN )
         return;
 
-    GRID_SETTINGS& settings = m_toolMgr->GetSettings()->m_Window.grid;
+    GRID_SETTINGS& settings = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid;
     EDA_IU_SCALE   scale = m_frame->GetIuScale();
 
     for( GRID& gridDef : settings.grids )
     {
-        double gridSizeX = EDA_UNIT_UTILS::UI::DoubleValueFromString( scale, EDA_UNITS::MM,
-                                                                      gridDef.x );
-        double gridSizeY = EDA_UNIT_UTILS::UI::DoubleValueFromString( scale, EDA_UNITS::MM,
-                                                                      gridDef.y );
+        double gridSizeX = EDA_UNIT_UTILS::UI::DoubleValueFromString( scale, EDA_UNITS::MM, gridDef.x );
+        double gridSizeY = EDA_UNIT_UTILS::UI::DoubleValueFromString( scale, EDA_UNITS::MM, gridDef.y );
 
-        m_grids.emplace_back( KiROUND<double, int>( gridSizeX ),
-                              KiROUND<double, int>( gridSizeY ) );
+        m_grids.emplace_back( KiROUND<double, int>( gridSizeX ), KiROUND<double, int>( gridSizeY ) );
     }
 
     OnGridChanged( false );
@@ -251,7 +248,7 @@ int COMMON_TOOLS::doZoomInOut( bool aDirection, bool aCenterOnCursor )
         zoom /= 1.3;
 
     // Now look for the next closest menu step
-    std::vector<double>& zoomList = m_toolMgr->GetSettings()->m_Window.zoom_factors;
+    std::vector<double>& zoomList = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->zoom_factors;
     int idx;
 
     if( aDirection )
@@ -458,13 +455,7 @@ int COMMON_TOOLS::ZoomPreset( const TOOL_EVENT& aEvent )
 // Note: idx == 0 is Auto; idx == 1 is first entry in zoomList
 int COMMON_TOOLS::doZoomToPreset( int idx, bool aCenterOnCursor )
 {
-    std::vector<double>& zoomList = m_toolMgr->GetSettings()->m_Window.zoom_factors;
-
-    if( zoomList.empty() ) // When called from footprint chooser, zoomList is empty for some reason
-        zoomList = m_frame->config()->m_Window.zoom_factors;
-    // or: zoomList = Kiface().KifaceSettings()->m_Window.zoom_factors;
-
-    wxCHECK( !zoomList.empty(), 0 ); // To avoid a crash lower on scale from Fp Chooser panel
+    std::vector<double>& zoomList = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->zoom_factors;
 
     if( idx == 0 )      // Zoom Auto
     {
@@ -498,7 +489,7 @@ int COMMON_TOOLS::doZoomToPreset( int idx, bool aCenterOnCursor )
 
 int COMMON_TOOLS::GridNext( const TOOL_EVENT& aEvent )
 {
-    int& currentGrid = m_toolMgr->GetSettings()->m_Window.grid.last_size_idx;
+    int& currentGrid = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.last_size_idx;
 
     currentGrid++;
 
@@ -511,7 +502,7 @@ int COMMON_TOOLS::GridNext( const TOOL_EVENT& aEvent )
 
 int COMMON_TOOLS::GridPrev( const TOOL_EVENT& aEvent )
 {
-    int& currentGrid = m_toolMgr->GetSettings()->m_Window.grid.last_size_idx;
+    int& currentGrid = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.last_size_idx;
 
     currentGrid--;
 
@@ -530,7 +521,7 @@ int COMMON_TOOLS::GridPreset( const TOOL_EVENT& aEvent )
 
 int COMMON_TOOLS::GridPreset( int idx, bool aFromHotkey )
 {
-    int& currentGrid = m_toolMgr->GetSettings()->m_Window.grid.last_size_idx;
+    int& currentGrid = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.last_size_idx;
 
     currentGrid = std::clamp( idx, 0, (int) m_grids.size() - 1 );
 
@@ -540,7 +531,7 @@ int COMMON_TOOLS::GridPreset( int idx, bool aFromHotkey )
 
 int COMMON_TOOLS::OnGridChanged( bool aFromHotkey )
 {
-    int& currentGrid = m_toolMgr->GetSettings()->m_Window.grid.last_size_idx;
+    int& currentGrid = m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.last_size_idx;
 
     currentGrid = std::max( 0, std::min( currentGrid, static_cast<int>( m_grids.size() ) - 1 ) );
 
@@ -550,7 +541,7 @@ int COMMON_TOOLS::OnGridChanged( bool aFromHotkey )
 
     // Update GAL canvas from screen
     getView()->GetGAL()->SetGridSize( m_grids[ currentGrid ] );
-    getView()->GetGAL()->SetGridVisibility( m_toolMgr->GetSettings()->m_Window.grid.show );
+    getView()->GetGAL()->SetGridVisibility( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.show );
     getView()->MarkTargetDirty( KIGFX::TARGET_NONCACHED );
 
     // Put cursor on new grid
@@ -567,25 +558,25 @@ int COMMON_TOOLS::OnGridChanged( bool aFromHotkey )
 
 int COMMON_TOOLS::GridFast1( const TOOL_EVENT& aEvent )
 {
-    return GridPreset( m_frame->config()->m_Window.grid.fast_grid_1, true );
+    return GridPreset( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.fast_grid_1, true );
 }
 
 
 int COMMON_TOOLS::GridFast2( const TOOL_EVENT& aEvent )
 {
-    return GridPreset( m_frame->config()->m_Window.grid.fast_grid_2, true );
+    return GridPreset( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.fast_grid_2, true );
 }
 
 
 int COMMON_TOOLS::GridFastCycle( const TOOL_EVENT& aEvent )
 {
-    if( m_toolMgr->GetSettings()->m_Window.grid.last_size_idx
-        == m_frame->config()->m_Window.grid.fast_grid_1 )
+    if( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.last_size_idx
+        == m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.fast_grid_1 )
     {
-        return GridPreset( m_frame->config()->m_Window.grid.fast_grid_2, true );
+        return GridPreset( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.fast_grid_2, true );
     }
 
-    return GridPreset( m_frame->config()->m_Window.grid.fast_grid_1, true );
+    return GridPreset( m_frame->GetWindowSettings( m_toolMgr->GetSettings() )->grid.fast_grid_1, true );
 }
 
 
@@ -707,7 +698,7 @@ int COMMON_TOOLS::ToggleCursor( const TOOL_EVENT& aEvent )
     auto& galOpts = m_frame->GetGalDisplayOptions();
 
     galOpts.m_forceDisplayCursor = !galOpts.m_forceDisplayCursor;
-    galOpts.WriteConfig( m_toolMgr->GetSettings()->m_Window );
+    galOpts.WriteConfig( *m_frame->GetWindowSettings( m_toolMgr->GetSettings() ) );
     galOpts.NotifyChanged();
 
     return 0;
@@ -719,7 +710,7 @@ int COMMON_TOOLS::ToggleCursorStyle( const TOOL_EVENT& aEvent )
     GAL_DISPLAY_OPTIONS_IMPL& galOpts = m_frame->GetGalDisplayOptions();
 
     galOpts.m_fullscreenCursor = !galOpts.m_fullscreenCursor;
-    galOpts.WriteConfig( m_toolMgr->GetSettings()->m_Window );
+    galOpts.WriteConfig( *m_frame->GetWindowSettings( m_toolMgr->GetSettings() ) );
     galOpts.NotifyChanged();
 
     return 0;
diff --git a/eeschema/eeschema_config.cpp b/eeschema/eeschema_config.cpp
index 762b4403b6..8963c6db46 100644
--- a/eeschema/eeschema_config.cpp
+++ b/eeschema/eeschema_config.cpp
@@ -43,7 +43,6 @@
 #include <settings/settings_manager.h>
 #include <wildcards_and_files_ext.h>
 #include <drawing_sheet/ds_data_model.h>
-#include <zoom_defines.h>
 #include <sim/spice_settings.h>
 #include <tool/tool_manager.h>
 #include <tools/sch_selection_tool.h>
@@ -357,9 +356,6 @@ void SCH_BASE_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
 
     EDA_DRAW_FRAME::LoadSettings( aCfg );
 
-    if( aCfg->m_Window.grid.grids.empty() )
-        aCfg->m_Window.grid.grids = aCfg->DefaultGridSizeList();
-
     // Move legacy user grids to grid list
     if( !aCfg->m_Window.grid.user_grid_x.empty() )
     {
@@ -378,9 +374,6 @@ void SCH_BASE_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
 
     if( aCfg->m_Window.grid.fast_grid_2 > (int) aCfg->m_Window.grid.grids.size() )
         aCfg->m_Window.grid.fast_grid_2 = 2;
-
-    if( aCfg->m_Window.zoom_factors.empty() )
-        aCfg->m_Window.zoom_factors = { ZOOM_LIST_EESCHEMA };
 }
 
 
diff --git a/gerbview/gerbview_frame.cpp b/gerbview/gerbview_frame.cpp
index 7db3aba93b..0a4ea36e10 100644
--- a/gerbview/gerbview_frame.cpp
+++ b/gerbview/gerbview_frame.cpp
@@ -58,7 +58,6 @@
 #include "widgets/gerbview_layer_widget.h"
 #include "widgets/dcode_selection_box.h"
 #include <dialog_draw_layers_settings.h>
-#include <zoom_defines.h>
 
 #include <navlib/nl_gerbview_plugin.h>
 #include <wx/log.h>
@@ -317,44 +316,11 @@ void GERBVIEW_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
 {
     EDA_DRAW_FRAME::LoadSettings( aCfg );
 
-    if( aCfg->m_Window.grid.grids.empty() )
-    {
-        aCfg->m_Window.grid.grids = { GRID{ wxEmptyString, wxS( "100 mil" ), wxS( "100 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "50 mil" ), wxS( "50 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "25 mil" ), wxS( "25 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "20 mil" ), wxS( "20 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "10 mil" ), wxS( "10 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "5 mil" ), wxS( "5 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "2.5 mil" ), wxS( "2.5 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "2 mil" ), wxS( "2 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "1 mil" ), wxS( "1 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "0.5 mil" ), wxS( "0.5 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "0.2 mil" ), wxS( "0.2 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "0.1 mil" ), wxS( "0.1 mil" ) },
-                                      GRID{ wxEmptyString, wxS( "5.0 mm" ), wxS( "5.0 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "1.5 mm" ), wxS( "2.5 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "1.0 mm" ), wxS( "1.0 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.5 mm" ), wxS( "0.5 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.25 mm" ), wxS( "0.25 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.2 mm" ), wxS( "0.2 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.1 mm" ), wxS( "0.1 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.05 mm" ), wxS( "0.0 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.025 mm" ), wxS( "0.0 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.01 mm" ), wxS( "0.0 mm" ) } };
-    }
-
-    if( aCfg->m_Window.zoom_factors.empty() )
-    {
-        aCfg->m_Window.zoom_factors = { ZOOM_LIST_GERBVIEW };
-    }
-
     GERBVIEW_SETTINGS* cfg = dynamic_cast<GERBVIEW_SETTINGS*>( aCfg );
     wxCHECK( cfg, /*void*/ );
 
-    SetElementVisibility( LAYER_GERBVIEW_DRAWINGSHEET,
-                          cfg->m_Appearance.show_border_and_titleblock );
-    SetElementVisibility( LAYER_GERBVIEW_PAGE_LIMITS,
-                          cfg->m_Display.m_DisplayPageLimits );
+    SetElementVisibility( LAYER_GERBVIEW_DRAWINGSHEET, cfg->m_Appearance.show_border_and_titleblock );
+    SetElementVisibility( LAYER_GERBVIEW_PAGE_LIMITS, cfg->m_Display.m_DisplayPageLimits );
 
     PAGE_INFO pageInfo( wxT( "GERBER" ) );
     pageInfo.SetType( cfg->m_Appearance.page_type );
diff --git a/include/settings/app_settings.h b/include/settings/app_settings.h
index 54698093d9..464d81980f 100644
--- a/include/settings/app_settings.h
+++ b/include/settings/app_settings.h
@@ -208,6 +208,8 @@ public:
 
     const std::vector<GRID> DefaultGridSizeList() const;
 
+    const std::vector<double> DefaultZoomList() const;
+
 public:
     CROSS_PROBING_SETTINGS m_CrossProbing;
 
diff --git a/include/settings/parameters.h b/include/settings/parameters.h
index 2129e5b9f1..fdffdb3cce 100644
--- a/include/settings/parameters.h
+++ b/include/settings/parameters.h
@@ -476,17 +476,19 @@ class PARAM_LIST : public PARAM_BASE
 {
 public:
     PARAM_LIST( const std::string& aJsonPath, std::vector<Type>* aPtr,
-                std::initializer_list<Type> aDefault, bool aReadOnly = false ) :
-            PARAM_BASE( aJsonPath, aReadOnly ),
+                std::initializer_list<Type> aDefault, bool aResetIfEmpty = false ) :
+            PARAM_BASE( aJsonPath, false ),
             m_ptr( aPtr ),
-            m_default( aDefault )
+            m_default( aDefault ),
+            m_resetIfEmpty( aResetIfEmpty )
     { }
 
     PARAM_LIST( const std::string& aJsonPath, std::vector<Type>* aPtr,
-                std::vector<Type> aDefault, bool aReadOnly = false ) :
-            PARAM_BASE( aJsonPath, aReadOnly ),
+                std::vector<Type> aDefault, bool aResetIfEmpty = false ) :
+            PARAM_BASE( aJsonPath, false ),
             m_ptr( aPtr ),
-            m_default( std::move( aDefault ) )
+            m_default( std::move( aDefault ) ),
+            m_resetIfEmpty( aResetIfEmpty )
     { }
 
     void Load( const JSON_SETTINGS& aSettings, bool aResetIfMissing = true ) const override
@@ -504,10 +506,15 @@ public:
                     val.push_back( el.value().get<Type>() );
             }
 
-            *m_ptr = val;
+            if( val.empty() && m_resetIfEmpty )
+                *m_ptr = m_default;
+            else
+                *m_ptr = val;
         }
         else if( aResetIfMissing )
+        {
             *m_ptr = m_default;
+        }
     }
 
     void Store( JSON_SETTINGS* aSettings ) const override
@@ -555,6 +562,7 @@ public:
 protected:
     std::vector<Type>* m_ptr;
     std::vector<Type>  m_default;
+    bool               m_resetIfEmpty;
 };
 
 
@@ -667,13 +675,13 @@ class KICOMMON_API PARAM_PATH_LIST : public PARAM_LIST<wxString>
 {
 public:
     PARAM_PATH_LIST( const std::string& aJsonPath, std::vector<wxString>* aPtr,
-                     std::initializer_list<wxString> aDefault, bool aReadOnly = false ) :
-            PARAM_LIST( aJsonPath, aPtr, aDefault, aReadOnly )
+                     std::initializer_list<wxString> aDefault ) :
+            PARAM_LIST( aJsonPath, aPtr, aDefault )
     { }
 
     PARAM_PATH_LIST( const std::string& aJsonPath, std::vector<wxString>* aPtr,
-                     std::vector<wxString> aDefault, bool aReadOnly = false ) :
-            PARAM_LIST( aJsonPath, aPtr, aDefault, aReadOnly )
+                     std::vector<wxString> aDefault ) :
+            PARAM_LIST( aJsonPath, aPtr, aDefault )
     { }
 
     void Load( const JSON_SETTINGS& aSettings, bool aResetIfMissing = true ) const override
diff --git a/pagelayout_editor/pl_editor_frame.cpp b/pagelayout_editor/pl_editor_frame.cpp
index 829d0c087c..3ec5844bbc 100644
--- a/pagelayout_editor/pl_editor_frame.cpp
+++ b/pagelayout_editor/pl_editor_frame.cpp
@@ -58,7 +58,6 @@
 #include "invoke_pl_editor_dialog.h"
 #include "tools/pl_editor_control.h"
 #include <view/view_controls.h>
-#include <zoom_defines.h>
 
 #include <wx/filedlg.h>
 #include <wx/print.h>
@@ -518,25 +517,6 @@ void PL_EDITOR_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
 {
     EDA_DRAW_FRAME::LoadSettings( aCfg );
 
-    if( aCfg->m_Window.grid.grids.empty() )
-    {
-        aCfg->m_Window.grid.grids = { GRID{ wxEmptyString, wxS( "5.00 mm" ), wxS( "5.00 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "2.50 mm" ), wxS( "2.50 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "2.00 mm" ), wxS( "2.00 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "1.00 mm" ), wxS( "1.00 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.50 mm" ), wxS( "0.50 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.25 mm" ), wxS( "0.25 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.20 mm" ), wxS( "0.20 mm" ) },
-                                      GRID{ wxEmptyString, wxS( "0.10 mm" ), wxS( "0.10 mm" ) } };
-    }
-
-    // Currently values read from config file are not used because the user cannot
-    // change this config
-    // if( aCfg->m_Window.zoom_factors.empty() )
-    {
-        aCfg->m_Window.zoom_factors = { ZOOM_LIST_PL_EDITOR };
-    }
-
     PL_EDITOR_SETTINGS* cfg = dynamic_cast<PL_EDITOR_SETTINGS*>( aCfg );
     wxCHECK( cfg, /*void*/ );
 
diff --git a/pcbnew/footprint_chooser_frame.cpp b/pcbnew/footprint_chooser_frame.cpp
index 75b25a446b..e576b64d41 100644
--- a/pcbnew/footprint_chooser_frame.cpp
+++ b/pcbnew/footprint_chooser_frame.cpp
@@ -44,6 +44,7 @@
 #include <tools/pcb_actions.h>
 #include <tools/pcb_picker_tool.h>
 #include <tools/pcb_viewer_tools.h>
+#include "settings/cvpcb_settings.h"
 #include "wx/display.h"
 #include <footprint_preview_panel.h>
 #include <3d_canvas/eda_3d_canvas.h>
@@ -437,10 +438,13 @@ void FOOTPRINT_CHOOSER_FRAME::doCloseWindow()
 
 WINDOW_SETTINGS* FOOTPRINT_CHOOSER_FRAME::GetWindowSettings( APP_SETTINGS_BASE* aCfg )
 {
-    PCBNEW_SETTINGS* cfg = dynamic_cast<PCBNEW_SETTINGS*>( aCfg );
-    wxCHECK_MSG( cfg, nullptr, wxT( "config not existing" ) );
+    if( PCBNEW_SETTINGS* pcb_cfg = dynamic_cast<PCBNEW_SETTINGS*>( aCfg ) )
+        return &pcb_cfg->m_FootprintViewer;
+    else if( CVPCB_SETTINGS* cvpcb_cfg = dynamic_cast<CVPCB_SETTINGS*>( aCfg ) )
+        return &cvpcb_cfg->m_FootprintViewer;
 
-    return &cfg->m_FootprintViewer;
+    wxFAIL_MSG( wxT( "FOOTPRINT_CHOOSER not running with PCBNEW_SETTINGS or CVPCB_SETTINGS" ) );
+    return &aCfg->m_Window;     // non-null fail-safe
 }
 
 
diff --git a/pcbnew/footprint_preview_panel.cpp b/pcbnew/footprint_preview_panel.cpp
index 0e58e337a1..f4db7553ec 100644
--- a/pcbnew/footprint_preview_panel.cpp
+++ b/pcbnew/footprint_preview_panel.cpp
@@ -43,7 +43,6 @@
 #include <settings/settings_manager.h>
 #include <view/view.h>
 #include <wx/stattext.h>
-#include <zoom_defines.h>
 #include <dialog_shim.h>
 #include <project_pcb.h>
 
@@ -243,19 +242,6 @@ FOOTPRINT_PREVIEW_PANEL* FOOTPRINT_PREVIEW_PANEL::New( KIWAY* aKiway, wxWindow*
 {
     PCBNEW_SETTINGS* cfg = Pgm().GetSettingsManager().GetAppSettings<PCBNEW_SETTINGS>( "pcbnew" );
 
-    if( cfg->m_Window.grid.grids.empty() )
-        cfg->m_Window.grid.grids = cfg->DefaultGridSizeList();
-
-    // Currently values read from config file are not used because the user cannot
-    // change this config
-    //if( cfg->m_Window.zoom_factors.empty() )
-    {
-        if( ADVANCED_CFG::GetCfg().m_HyperZoom )
-            cfg->m_Window.zoom_factors = { ZOOM_LIST_PCBNEW_HYPER };
-        else
-            cfg->m_Window.zoom_factors = { ZOOM_LIST_PCBNEW };
-    }
-
     std::unique_ptr<GAL_DISPLAY_OPTIONS_IMPL> gal_opts;
 
     gal_opts = std::make_unique<GAL_DISPLAY_OPTIONS_IMPL>();
diff --git a/pcbnew/pcb_base_frame.cpp b/pcbnew/pcb_base_frame.cpp
index 5d2f45bac4..d38fbe3234 100644
--- a/pcbnew/pcb_base_frame.cpp
+++ b/pcbnew/pcb_base_frame.cpp
@@ -53,7 +53,6 @@
 #include <pgm_base.h>
 #include <project_pcb.h>
 #include <wildcards_and_files_ext.h>
-#include <zoom_defines.h>
 
 #include <math/vector2d.h>
 #include <math/vector2wx.h>
@@ -814,9 +813,6 @@ void PCB_BASE_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
 {
     EDA_DRAW_FRAME::LoadSettings( aCfg );
 
-    if( aCfg->m_Window.grid.grids.empty() )
-        aCfg->m_Window.grid.grids = aCfg->DefaultGridSizeList();
-
     // Move legacy user grids to grid list
     if( !aCfg->m_Window.grid.user_grid_x.empty() )
     {
@@ -826,16 +822,6 @@ void PCB_BASE_FRAME::LoadSettings( APP_SETTINGS_BASE* aCfg )
         aCfg->m_Window.grid.user_grid_y = wxEmptyString;
     }
 
-    // Currently values read from config file are not used because the user cannot
-    // change this config
-    // if( aCfg->m_Window.zoom_factors.empty() )
-    {
-        if( ADVANCED_CFG::GetCfg().m_HyperZoom )
-            aCfg->m_Window.zoom_factors = { ZOOM_LIST_PCBNEW_HYPER };
-        else
-            aCfg->m_Window.zoom_factors = { ZOOM_LIST_PCBNEW };
-    }
-
     // Some, but not all, derived classes have a PCBNEW_SETTINGS.
     if( PCBNEW_SETTINGS* pcbnew_cfg = dynamic_cast<PCBNEW_SETTINGS*>( aCfg ) )
         m_polarCoords = pcbnew_cfg->m_PolarCoords;