Merge branch 'listctrl-col-count'

Ensure wxListCtrl::GetColumnCount() behaves consistently on all
platforms with wxLC_LIST style.

See #22497.

Closes #22482.

interface/wx/listctrl.h

@@ -566,6 +566,11 @@ public:
 
     /**
         Returns the number of columns.
+
+        The control can have multiple columns only in wxLC_REPORT mode. In
+        wxLC_LIST mode this function returns 1, as a list is still considered
+        to have a (single) column. In wxLC_SMALL_ICON and wxLC_ICON modes, it
+        returns 0 as there are no columns at all.
     */
     int GetColumnCount() const;
 

src/generic/listctrl.cpp

@@ -2331,8 +2331,10 @@ void wxListMainWindow::SendNotify( size_t line,
                                    wxEventType command,
                                    const wxPoint& point )
 {
-    wxListEvent le( command, GetParent()->GetId() );
+    wxGenericListCtrl* const listctrl = GetListCtrl();
-    le.SetEventObject( GetParent() );
+
+    wxListEvent le( command, listctrl->GetId() );
+    le.SetEventObject( listctrl );
 
     le.m_item.m_itemId =
     le.m_itemIndex = line;
@@ -2349,12 +2351,12 @@ void wxListMainWindow::SendNotify( size_t line,
 
     // provide information about the (first column of the) item in the event if
     // we have a valid item and any columns at all
-    if ( line != (size_t)-1 && GetColumnCount() )
+    if ( line != (size_t)-1 && listctrl->GetColumnCount() )
     {
         GetLine(line)->GetItem( 0, le.m_item );
     }
 
-    GetParent()->GetEventHandler()->ProcessEvent( le );
+    listctrl->GetEventHandler()->ProcessEvent( le );
 }
 
 bool wxListMainWindow::ChangeCurrentWithoutEvent(size_t current)
@@ -4906,6 +4908,10 @@ void wxGenericListCtrl::Init()
 
 wxGenericListCtrl::~wxGenericListCtrl()
 {
+    // Don't wait until the base class does it because our subwindows expect
+    // their parent window to be a wxListCtrl, but this won't be the case any
+    // more when we get to the base class dtor (it will be only a wxWindow).
+    DestroyChildren();
 }
 
 void wxGenericListCtrl::CreateOrDestroyHeaderWindowAsNeeded()
@@ -5353,7 +5359,11 @@ int wxGenericListCtrl::GetItemCount() const
 
 int wxGenericListCtrl::GetColumnCount() const
 {
-    return m_mainWin->GetColumnCount();
+    // wxLC_LIST is special as we want to return 1 for it, for compatibility
+    // with the native wxMSW version and not the real number of columns, which
+    // is 0. For the other non-wxLC_REPORT modes returning 0 is fine, however,
+    // as wxMSW does it too.
+    return HasFlag(wxLC_LIST) ? 1 : m_mainWin->GetColumnCount();
 }
 
 void wxGenericListCtrl::SetItemSpacing( int spacing, bool isSmall )

tests/controls/listctrltest.cpp

@@ -48,10 +48,12 @@ private:
         WXUISIM_TEST( ColumnClick );
         WXUISIM_TEST( ColumnDrag );
         CPPUNIT_TEST( SubitemRect );
+        CPPUNIT_TEST( ColumnCount );
     CPPUNIT_TEST_SUITE_END();
 
     void EditLabel();
     void SubitemRect();
+    void ColumnCount();
 #if wxUSE_UIACTIONSIMULATOR
     // Column events are only supported in wxListCtrl currently so we test them
     // here rather than in ListBaseTest
@@ -139,6 +141,33 @@ void ListCtrlTestCase::SubitemRect()
     CHECK(rectLabel.GetRight() == rectItem.GetRight());
 }
 
+void ListCtrlTestCase::ColumnCount()
+{
+    CHECK(m_list->GetColumnCount() == 0);
+    m_list->InsertColumn(0, "Column 0");
+    m_list->InsertColumn(1, "Column 1");
+    CHECK(m_list->GetColumnCount() == 2);
+
+    // Recreate the control in other modes to check the count there as well.
+    delete m_list;
+    m_list = new wxListCtrl(wxTheApp->GetTopWindow(), wxID_ANY,
+                            wxDefaultPosition, wxDefaultSize,
+                            wxLC_LIST);
+    CHECK(m_list->GetColumnCount() == 1);
+
+    delete m_list;
+    m_list = new wxListCtrl(wxTheApp->GetTopWindow(), wxID_ANY,
+                            wxDefaultPosition, wxDefaultSize,
+                            wxLC_ICON);
+    CHECK(m_list->GetColumnCount() == 0);
+
+    delete m_list;
+    m_list = new wxListCtrl(wxTheApp->GetTopWindow(), wxID_ANY,
+                            wxDefaultPosition, wxDefaultSize,
+                            wxLC_SMALL_ICON);
+    CHECK(m_list->GetColumnCount() == 0);
+}
+
 #if wxUSE_UIACTIONSIMULATOR
 void ListCtrlTestCase::ColumnDrag()
 {