Allow showing rules and background on entire wxListCtrl window

Previously they were both limited to the part occupied by the items
only, add a new method allowing to extend them to the whole client
window area.

See https://github.com/wxWidgets/wxWidgets/pull/2106

include/wx/generic/listctrl.h

@@ -208,6 +208,8 @@ public:
     wxListHeaderWindow  *m_headerWin;
     wxListMainWindow    *m_mainWin;
 
+    void SetListRulesAlternateColourOnBlank(bool state, const wxColour& colour);
+
 protected:
     // Implement base class pure virtual methods.
     long DoInsertColumn(long col, const wxListItem& info) wxOVERRIDE;

include/wx/generic/private/listctrl.h

@@ -775,6 +775,17 @@ public:
         selected ? ++m_selCount : --m_selCount;
     }
 
+    void DrawInReportModeOnBlank ( wxDC *dc,
+                                   const wxRect& rect,
+                                   int lineNumber );
+
+    void SetListRulesAlternateColourOnBlank( const bool state,
+                                             const wxColour& colour)
+    {
+        m_listRulesAlternateColourOnBlank = state;
+        m_alternateColourOnBlank = colour;
+    }
+
 protected:
     // the array of all line objects for a non virtual list control (for the
     // virtual list control we only ever use m_lines[0])
@@ -941,6 +952,13 @@ private:
 
     friend class wxGenericListCtrl;
     friend class wxListCtrlMaxWidthCalculator;
+
+    // tells whether or not to paint empty rows with alternate colour and draw
+    // rulers on empty rows
+    bool m_listRulesAlternateColourOnBlank;
+
+    // colour to paint empty rows (zebra effect)
+    wxColour m_alternateColourOnBlank;
 };
 
 #endif // wxUSE_LISTCTRL

interface/wx/listctrl.h

@@ -1333,6 +1333,30 @@ public:
     */
     void CheckItem(long item, bool check);
 
+    /**
+        When the content of state is true, tells listctrl to draw
+        horizontal and vertical rulers on blank rows and also to
+        paint the background of alternate rows on blank rows, using
+        colour to paint the alternate blank(empty) rows' background.
+
+        As EnableAlternateRowColours(), this method can only be used with
+        controls having ::wxLC_REPORT and ::wxLC_VIRTUAL styles.
+
+        This method is NOT available on Windows.
+
+        @param state
+            if @true, draws horizontal rules and vertical rules on empty rows
+            and uses the colour parameter to paint the background of
+            alternate rows when those rows are blank, empty, with no data.
+        @param colour
+            A valid row background colour to enable alternating rows on
+            blank rows (rows with no data).
+
+        @since 3.1.5
+        @note This method is currently NOT implemented in the Windows version.
+    */
+    void SetListRulesAlternateColourOnBlank(const bool state, const wxColour& colour);
+
 protected:
 
     /**

samples/listctrl/listtest.cpp

@@ -134,6 +134,9 @@ wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(LIST_SET_FG_COL, MyFrame::OnSetFgColour)
     EVT_MENU(LIST_SET_BG_COL, MyFrame::OnSetBgColour)
     EVT_MENU(LIST_ROW_LINES, MyFrame::OnSetRowLines)
+#if !defined(__WXMSW__)
+    EVT_MENU(LIST_ROW_LINES_ON_BLANK, MyFrame::OnSetRowLinesOnBlank)
+#endif
     EVT_MENU(LIST_CUSTOM_HEADER_ATTR, MyFrame::OnCustomHeaderAttr)
     EVT_MENU(LIST_TOGGLE_MULTI_SEL, MyFrame::OnToggleMultiSel)
     EVT_MENU(LIST_SHOW_COL_INFO, MyFrame::OnShowColInfo)
@@ -165,6 +168,9 @@ wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_UPDATE_UI(LIST_TOGGLE_CHECKBOXES, MyFrame::OnUpdateToggleCheckBoxes)
     EVT_UPDATE_UI(LIST_TOGGLE_HEADER, MyFrame::OnUpdateToggleHeader)
     EVT_UPDATE_UI(LIST_ROW_LINES, MyFrame::OnUpdateRowLines)
+#if !defined(__WXMSW__)
+    EVT_UPDATE_UI(LIST_ROW_LINES_ON_BLANK, MyFrame::OnUpdateRowLines)
+#endif
 wxEND_EVENT_TABLE()
 
 // My frame constructor
@@ -277,6 +283,9 @@ MyFrame::MyFrame(const wxString& title)
     menuCol->Append(LIST_SET_FG_COL, "&Foreground colour...");
     menuCol->Append(LIST_SET_BG_COL, "&Background colour...");
     menuCol->AppendCheckItem(LIST_ROW_LINES, "Alternating colours");
+#if !defined(__WXMSW__)
+    menuCol->AppendCheckItem(LIST_ROW_LINES_ON_BLANK, "Alternating colours on Blank");
+#endif
     menuCol->AppendCheckItem(LIST_CUSTOM_HEADER_ATTR, "&Custom header attributes");
 
     wxMenuBar *menubar = new wxMenuBar;
@@ -520,6 +529,9 @@ void MyFrame::RecreateList(long flags, bool withText)
     }
 
     GetMenuBar()->Check(LIST_ROW_LINES, false);
+#if !defined(__WXMSW__)
+    GetMenuBar()->Check(LIST_ROW_LINES_ON_BLANK, false);
+#endif
 
     m_logWindow->Clear();
 }
@@ -940,6 +952,20 @@ void MyFrame::OnSetRowLines(wxCommandEvent& event)
     m_listCtrl->Refresh();
 }
 
+#if !defined(__WXMSW__)
+void MyFrame::OnSetRowLinesOnBlank(wxCommandEvent& event)
+{
+    wxColour color = wxGetColourFromUser(this);
+    m_listCtrl->SetSingleStyle(wxLC_HRULES | wxLC_VRULES, event.IsChecked());
+    if (event.IsChecked())
+        m_listCtrl->SetAlternateRowColour(color);
+    else
+        m_listCtrl->EnableAlternateRowColours(event.IsChecked());
+    m_listCtrl->SetListRulesAlternateColourOnBlank(event.IsChecked(), color);
+    m_listCtrl->Refresh();
+}
+#endif
+
 void MyFrame::OnCustomHeaderAttr(wxCommandEvent& event)
 {
     wxItemAttr attr;

samples/listctrl/listtest.h

@@ -133,6 +133,9 @@ protected:
     void OnSetFgColour(wxCommandEvent& event);
     void OnSetBgColour(wxCommandEvent& event);
     void OnSetRowLines(wxCommandEvent& event);
+#if !defined(__WXMSW__)
+    void OnSetRowLinesOnBlank(wxCommandEvent& event);
+#endif
     void OnCustomHeaderAttr(wxCommandEvent& event);
     void OnToggleMultiSel(wxCommandEvent& event);
     void OnShowColInfo(wxCommandEvent& event);
@@ -223,6 +226,9 @@ enum
     LIST_SET_FG_COL,
     LIST_SET_BG_COL,
     LIST_ROW_LINES,
+#if !defined(__WXMSW__)
+    LIST_ROW_LINES_ON_BLANK,
+#endif
     LIST_CUSTOM_HEADER_ATTR,
     LIST_TOGGLE_MULTI_SEL,
     LIST_TOGGLE_HEADER,

src/generic/listctrl.cpp

@@ -793,6 +793,22 @@ void wxListLineData::Draw(wxDC *dc, bool current)
     }
 }
 
+void wxListMainWindow::DrawInReportModeOnBlank ( wxDC *dc,
+                                                 const wxRect& rect,
+                                                 int lineNumber )
+{
+    // Checks whether or not lineNumber is due to change on its background
+    // colour and fills the row from beginning to end with the colour stored
+    // in the m_alternateColourOnBlank instance variable in affirmative case
+    if ( lineNumber % 2 )
+    {
+        dc->SetBrush(m_alternateColourOnBlank);
+        dc->SetPen(*wxTRANSPARENT_PEN);
+        dc->DrawRectangle(rect);
+    }
+
+}
+
 void wxListLineData::DrawInReportMode( wxDC *dc,
                                        const wxRect& rect,
                                        const wxRect& rectHL,
@@ -1601,6 +1617,9 @@ void wxListMainWindow::Init()
     m_anchor  = (size_t)-1;
 
     m_hasCheckBoxes = false;
+
+    m_listRulesAlternateColourOnBlank = false;
+    m_alternateColourOnBlank = wxColour(176, 235, 212, 0xff);;
 }
 
 wxListMainWindow::wxListMainWindow()
@@ -2072,8 +2091,13 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
         int lineHeight = GetLineHeight();
 
         size_t visibleFrom, visibleTo;
+        size_t visibleEnd;
+        const size_t linesPerPage = (unsigned int) m_linesPerPage;
         GetVisibleLinesRange(&visibleFrom, &visibleTo);
 
+        visibleEnd = (m_listRulesAlternateColourOnBlank &&
+                      linesPerPage > visibleTo ? linesPerPage : visibleTo);
+
         wxRect rectLine;
         int xOrig = dc.LogicalToDeviceX( 0 );
         int yOrig = dc.LogicalToDeviceY( 0 );
@@ -2090,7 +2114,7 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
             GetParent()->GetEventHandler()->ProcessEvent( evCache );
         }
 
-        for ( size_t line = visibleFrom; line <= visibleTo; line++ )
+        for ( size_t line = visibleFrom; line <= visibleEnd; line++ )
         {
             rectLine = GetLineRect(line);
 
@@ -2102,11 +2126,15 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
                 continue;
             }
 
+            if ( line <= visibleTo ) {
                 GetLine(line)->DrawInReportMode( &dc,
                                                  rectLine,
                                                  GetLineHighlightRect(line),
                                                  IsHighlighted(line),
                                                  line == m_current );
+            } else {
+                DrawInReportModeOnBlank( &dc, rectLine, line );
+            }
         }
 
         if ( HasFlag(wxLC_HRULES) )
@@ -2116,7 +2144,7 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
 
             size_t i = visibleFrom;
             if (i == 0) i = 1; // Don't draw the first one
-            for ( ; i <= visibleTo; i++ )
+            for ( ; i <= visibleEnd; i++ )
             {
                 dc.SetPen(pen);
                 dc.SetBrush( *wxTRANSPARENT_BRUSH );
@@ -2125,7 +2153,7 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
             }
 
             // Draw last horizontal rule
-            if ( visibleTo == GetItemCount() - 1 )
+            if ( visibleEnd == GetItemCount() - 1 )
             {
                 dc.SetPen( pen );
                 dc.SetBrush( *wxTRANSPARENT_BRUSH );
@@ -2135,7 +2163,9 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
         }
 
         // Draw vertical rules if required
-        if ( HasFlag(wxLC_VRULES) && !IsEmpty() )
+        if ( HasFlag(wxLC_VRULES) && (m_listRulesAlternateColourOnBlank ||
+                                      ( ! m_listRulesAlternateColourOnBlank
+                                        && !IsEmpty() ) ) )
         {
             wxPen pen(GetRuleColour(), 1, wxPENSTYLE_SOLID);
             wxRect firstItemRect, lastItemRect;
@@ -2146,17 +2176,26 @@ void wxListMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
             dc.SetPen(pen);
             dc.SetBrush(* wxTRANSPARENT_BRUSH);
 
+            int clientHeight, clientWidth;
+            GetSize( &clientWidth, &clientHeight );
+
             for (int col = 0; col < GetColumnCount(); col++)
             {
                 int colWidth = GetColumnWidth(col);
                 x += colWidth;
                 int x_pos = x - dev_x;
                 if (col < GetColumnCount()-1) x_pos -= 2;
+
+                if (m_listRulesAlternateColourOnBlank) {
+                    dc.DrawLine(x_pos, firstItemRect.GetY() - 1 - dev_y,
+                            x_pos, clientHeight);
+                } else {
                     dc.DrawLine(x_pos, firstItemRect.GetY() - 1 - dev_y,
                             x_pos, lastItemRect.GetBottom() + 1 - dev_y);
                 }
             }
         }
+    }
     else // !report
     {
         size_t count = GetItemCount();
@@ -4947,6 +4986,12 @@ bool wxGenericListCtrl::Create(wxWindow *parent,
     return true;
 }
 
+void wxGenericListCtrl::SetListRulesAlternateColourOnBlank(const bool state, const wxColour& colour)
+{
+    if (m_mainWin)
+        m_mainWin->SetListRulesAlternateColourOnBlank(state, colour);
+}
+
 wxBorder wxGenericListCtrl::GetDefaultBorder() const
 {
     return wxBORDER_THEME;