Add the option to use alternating row colors in tables/grids

ADDED: Option to use alternating row colors in tables/grids

Fixes https://gitlab.com/kicad/code/kicad/-/issues/16739

common/dialogs/panel_common_settings.cpp

@@ -190,6 +190,8 @@ bool PANEL_COMMON_SETTINGS::TransferDataFromWindow()
 
     commonSettings->m_Appearance.show_scrollbars = m_showScrollbars->GetValue();
 
+    commonSettings->m_Appearance.grid_striping = m_gridStriping->GetValue();
+
     double dimmingPercent = 80;
     m_highContrastCtrl->GetValue().ToDouble( &dimmingPercent );
     commonSettings->m_Appearance.hicontrast_dimming_factor = dimmingPercent / 100.0f;
@@ -276,6 +278,8 @@ void PANEL_COMMON_SETTINGS::applySettingsToPanel( COMMON_SETTINGS& aSettings )
     m_checkBoxIconsInMenus->SetValue( aSettings.m_Appearance.use_icons_in_menus );
     m_scaleFonts->SetValue( aSettings.m_Appearance.apply_icon_scale_to_fonts );
 
+    m_gridStriping->SetValue( aSettings.m_Appearance.grid_striping );
+
     double dimmingPercent = aSettings.m_Appearance.hicontrast_dimming_factor * 100.0f;
     m_highContrastCtrl->SetValue( wxString::Format( "%.0f", dimmingPercent ) );
 

common/dialogs/panel_common_settings_base.cpp

@@ -1,5 +1,5 @@
 ///////////////////////////////////////////////////////////////////////////
-// C++ code generated with wxFormBuilder (version 3.10.1-0-g8feb16b3)
+// C++ code generated with wxFormBuilder (version 4.0.0-0-g0efcecf-dirty)
 // http://www.wxformbuilder.org/
 //
 // PLEASE DO *NOT* EDIT THIS FILE!
@@ -159,6 +159,11 @@ PANEL_COMMON_SETTINGS_BASE::PANEL_COMMON_SETTINGS_BASE( wxWindow* parent, wxWind
 
 	bSizer14->Add( m_hotkeyFeedback, 0, wxBOTTOM|wxLEFT|wxRIGHT, 5 );
 
+	m_gridStriping = new wxCheckBox( this, wxID_ANY, _("Use alternating row colors in tables"), wxDefaultPosition, wxDefaultSize, 0 );
+	m_gridStriping->SetToolTip( _("When enabled, use a different color for every other table row") );
+
+	bSizer14->Add( m_gridStriping, 0, wxBOTTOM|wxLEFT|wxRIGHT, 5 );
+
 
 	bUserInterfaceSizer->Add( bSizer14, 0, wxEXPAND, 5 );
 

common/dialogs/panel_common_settings_base.h

@@ -1,5 +1,5 @@
 ///////////////////////////////////////////////////////////////////////////
-// C++ code generated with wxFormBuilder (version 3.10.1-0-g8feb16b3)
+// C++ code generated with wxFormBuilder (version 4.0.0-0-g0efcecf-dirty)
 // http://www.wxformbuilder.org/
 //
 // PLEASE DO *NOT* EDIT THIS FILE!
@@ -63,6 +63,7 @@ class PANEL_COMMON_SETTINGS_BASE : public RESETTABLE_PANEL
 		wxCheckBox* m_showScrollbars;
 		wxCheckBox* m_focusFollowSchPcb;
 		wxCheckBox* m_hotkeyFeedback;
+		wxCheckBox* m_gridStriping;
 		wxStaticText* m_stIconTheme;
 		wxRadioButton* m_rbIconThemeLight;
 		wxRadioButton* m_rbIconThemeDark;

common/gal/color4d.cpp

@@ -601,3 +601,27 @@ int COLOR4D::Compare( const COLOR4D& aRhs ) const
 
     return 0;
 }
+
+
+double COLOR4D::RelativeLuminance() const
+{
+    // Formula from https://www.w3.org/TR/WCAG21/#dfn-relative-luminance
+    double cr = ( r <= 0.04045 ) ? ( r / 12.92 ) : std::pow( ( r + 0.055 ) / 1.055, 2.4 );
+    double cg = ( g <= 0.04045 ) ? ( g / 12.92 ) : std::pow( ( g + 0.055 ) / 1.055, 2.4 );
+    double cb = ( b <= 0.04045 ) ? ( b / 12.92 ) : std::pow( ( b + 0.055 ) / 1.055, 2.4 );
+
+    return 0.2126 * cr + 0.7152 * cg + 0.0722 * cb;
+}
+
+
+double COLOR4D::ContrastRatio( const COLOR4D& aLeft, const COLOR4D& aRight )
+{
+    // Formula from https://www.w3.org/TR/WCAG21/#dfn-contrast-ratio
+    double aRL = aLeft.RelativeLuminance();
+    double bRL = aRight.RelativeLuminance();
+
+    if( aRL > bRL )
+        return ( aRL + 0.05 ) / ( bRL + 0.05 );
+    else
+        return ( bRL + 0.05 ) / ( aRL + 0.05 );
+}

common/settings/common_settings.cpp

@@ -99,6 +99,9 @@ COMMON_SETTINGS::COMMON_SETTINGS() :
     m_params.emplace_back( new PARAM<int>( "appearance.toolbar_icon_size",
             &m_Appearance.toolbar_icon_size, 24, 16, 64 ) );
 
+    m_params.emplace_back( new PARAM<bool>( "appearance.grid_striping",
+            &m_Appearance.grid_striping, false ) );
+
     m_params.emplace_back( new PARAM<bool>( "auto_backup.enabled", &m_Backup.enabled, true ) );
 
     m_params.emplace_back( new PARAM<bool>( "auto_backup.backup_on_autosave",

common/widgets/wx_grid.cpp

@@ -21,6 +21,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  */
 
+#include <wx/colour.h>
 #include <wx/tokenzr.h>
 #include <wx/dc.h>
 #include <wx/settings.h>
@@ -30,6 +31,10 @@
 #include <algorithm>
 #include <core/kicad_algo.h>
 #include <gal/color4d.h>
+#include <kiplatform/ui.h>
+
+#include <pgm_base.h>
+#include <settings/common_settings.h>
 
 #define MIN_GRIDCELL_MARGIN FromDIP( 3 )
 
@@ -94,6 +99,59 @@ public:
 };
 
 
+/**
+ * Attribute provider that provides attributes (or modifies the existing attribute) to alternate a row color
+ * between the odd and even rows.
+ */
+class WX_GRID_ALT_ROW_COLOR_PROVIDER : public wxGridCellAttrProvider
+{
+public:
+    WX_GRID_ALT_ROW_COLOR_PROVIDER( const wxColor& aBaseColor ) : wxGridCellAttrProvider(),
+        m_attrOdd( new wxGridCellAttr() )
+    {
+        UpdateColors( aBaseColor );
+    }
+
+
+    void UpdateColors( const wxColor& aBaseColor )
+    {
+        // Choose the default color, taking into account if the dark mode theme is enabled
+        wxColor rowColor = aBaseColor.ChangeLightness( KIPLATFORM::UI::IsDarkTheme() ? 105 : 95 );
+
+        m_attrOdd->SetBackgroundColour( rowColor );
+    }
+
+
+    wxGridCellAttr* GetAttr( int row, int col,
+                             wxGridCellAttr::wxAttrKind  kind ) const override
+    {
+        wxGridCellAttrPtr cellAttr( wxGridCellAttrProvider::GetAttr( row, col, kind ) );
+
+        // Just pass through the cell attribute on even rows
+        if( row % 2 )
+            return cellAttr.release();
+
+        if( !cellAttr )
+        {
+            cellAttr = m_attrOdd;
+        }
+        else
+        {
+            if( !cellAttr->HasBackgroundColour() )
+            {
+                cellAttr = cellAttr->Clone();
+                cellAttr->SetBackgroundColour( m_attrOdd->GetBackgroundColour() );
+            }
+        }
+
+        return cellAttr.release();
+    }
+
+private:
+    wxGridCellAttrPtr m_attrOdd;
+};
+
+
 WX_GRID::WX_GRID( wxWindow *parent, wxWindowID id, const wxPoint& pos, const wxSize& size,
                   long style, const wxString& name ) :
         wxGrid( parent, id, pos, size, style, name ),
@@ -179,6 +237,8 @@ void WX_GRID::SetTable( wxGridTableBase* aTable, bool aTakeOwnership )
 
     delete[] formBuilderColWidths;
 
+    EnableAlternateRowColors( Pgm().GetCommonSettings()->m_Appearance.grid_striping );
+
     Connect( wxEVT_GRID_COL_MOVE, wxGridEventHandler( WX_GRID::onGridColMove ), nullptr, this );
     Connect( wxEVT_GRID_SELECT_CELL, wxGridEventHandler( WX_GRID::onGridCellSelect ), nullptr, this );
 
@@ -186,6 +246,25 @@ void WX_GRID::SetTable( wxGridTableBase* aTable, bool aTakeOwnership )
 }
 
 
+void WX_GRID::EnableAlternateRowColors( bool aEnable )
+{
+    wxGridTableBase* table = wxGrid::GetTable();
+
+    wxCHECK_MSG( table, /* void */,
+                 "Tried to enable alternate row colors without a table assigned to the grid" );
+
+    if( aEnable )
+    {
+        wxColor color = wxGrid::GetDefaultCellBackgroundColour();
+        table->SetAttrProvider( new WX_GRID_ALT_ROW_COLOR_PROVIDER( color ) );
+    }
+    else
+    {
+        table->SetAttrProvider( nullptr );
+    }
+}
+
+
 void WX_GRID::onGridCellSelect( wxGridEvent& aEvent )
 {
     // Highlight the selected cell.

include/gal/color4d.h

@@ -189,7 +189,7 @@ public:
      * @param aOutLightness is conversion result for value component (0 ... 1.0).
      * @note saturation is set to 0.0 for black color if r = g = b,
      */
-    void ToHSL( double& aOutHue, double& aOutSaturation, double& aOutValue ) const;
+    void ToHSL( double& aOutHue, double& aOutSaturation, double& aOutLightness ) const;
 
     /**
      * Change currently used color to the one given by hue, saturation and lightness parameters.
@@ -367,6 +367,22 @@ public:
 
     int Compare( const COLOR4D& aRhs ) const;
 
+    /**
+     * Compute the relative luminance of a color using the formula from WCAG21.
+     *
+     * @return relative luminance between 0 and 1 where 0 is darkest black and 1 is lightest white.
+     */
+    double RelativeLuminance() const;
+
+    /**
+     * Compute the contrast ration between two colors using the formula from WCAG21.
+     *
+     * @param aLeft is the first color to use in the ratio
+     * @param aRight is the second color to use in the ratio
+     * @return contrast ratio between 1.0:1 and 21.0:1 between the two colors.
+     */
+    static double ContrastRatio( const COLOR4D& aLeft, const COLOR4D& aRight );
+
     /**
      * Returns a legacy color ID that is closest to the given 8-bit RGB values.
      */

include/settings/common_settings.h

@@ -57,6 +57,7 @@ public:
         double     hicontrast_dimming_factor;
         int        text_editor_zoom;
         int        toolbar_icon_size;
+        bool       grid_striping;
     };
 
     struct AUTO_BACKUP

include/widgets/wx_grid.h

@@ -58,6 +58,14 @@ public:
      */
     void SetLabelFont( const wxFont& aFont );   // Yes, we're hiding a non-virtual method
 
+    /**
+     * Enable alternate row highlighting, where every odd row has a different background
+     * color than the even rows.s
+     *
+     * @param aEnable flag to specify to enable alternate row striping in the grid
+     */
+    void EnableAlternateRowColors( bool aEnable = true );
+
     /**
      * Get a tokenized string containing the shown column indexes.
      * Tokens are separated by spaces.