Update the current row after item deletion in generic wxDataViewCtrl.

Also change the code changing the current item to collect the range checks
inside OnVerticalNavigation() itself instead of doing them in the caller.

Closes #14802.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72906 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/datavgen.cpp

@@ -612,7 +612,7 @@ public:
     void OnPaint( wxPaintEvent &event );
     void OnCharHook( wxKeyEvent &event );
     void OnChar( wxKeyEvent &event );
-    void OnVerticalNavigation(unsigned int newCurrent, const wxKeyEvent& event);
+    void OnVerticalNavigation(int delta, const wxKeyEvent& event);
     void OnLeftKey();
     void OnRightKey();
     void OnMouse( wxMouseEvent &event );
@@ -1397,7 +1397,7 @@ wxDataViewMainWindow::wxDataViewMainWindow( wxDataViewCtrl *parent, wxWindowID i
     m_currentCol = NULL;
     m_currentColSetByKeyboard = false;
     m_useCellFocus = false;
-    m_currentRow = 0;
+    m_currentRow = (unsigned)-1;
 
 #ifdef __WXMSW__
     // We would like to use the same line height that Explorer uses. This is
@@ -2398,7 +2398,7 @@ bool wxDataViewMainWindow::ItemDeleted(const wxDataViewItem& parent,
     }
 
     // Change the current row to the last row if the current exceed the max row number
-    if( m_currentRow > GetRowCount() )
+    if ( m_currentRow >= GetRowCount() )
         ChangeCurrentRow(m_count - 1);
 
     GetOwner()->InvalidateColBestWidths();
@@ -2472,6 +2472,7 @@ bool wxDataViewMainWindow::Cleared()
 {
     DestroyTree();
     m_selection.Clear();
+    m_currentRow = (unsigned)-1;
 
     if (GetModel())
     {
@@ -3002,6 +3003,9 @@ wxDataViewTreeNode * wxDataViewMainWindow::GetTreeNodeByRow(unsigned int row) co
 {
     wxASSERT( !IsVirtualList() );
 
+    if ( row == (unsigned)-1 )
+        return NULL;
+
     RowToTreeNodeJob job( row , -2, m_root );
     Walker( m_root , job );
     return job.GetResult();
@@ -3704,13 +3708,11 @@ void wxDataViewMainWindow::OnChar( wxKeyEvent &event )
             break;
 
         case WXK_UP:
-            if ( m_currentRow > 0 )
+            OnVerticalNavigation( -1, event );
-                OnVerticalNavigation( m_currentRow - 1, event );
             break;
 
         case WXK_DOWN:
-            if ( m_currentRow + 1 < GetRowCount() )
+            OnVerticalNavigation( +1, event );
-                OnVerticalNavigation( m_currentRow + 1, event );
             break;
         // Add the process for tree expanding/collapsing
         case WXK_LEFT:
@@ -3722,37 +3724,19 @@ void wxDataViewMainWindow::OnChar( wxKeyEvent &event )
             break;
 
         case WXK_END:
-        {
+            OnVerticalNavigation( +(int)GetRowCount(), event );
-            if (!IsEmpty())
-                OnVerticalNavigation( GetRowCount() - 1, event );
             break;
-        }
+
         case WXK_HOME:
-            if (!IsEmpty())
+            OnVerticalNavigation( -(int)GetRowCount(), event );
-                OnVerticalNavigation( 0, event );
             break;
 
         case WXK_PAGEUP:
-            {
+            OnVerticalNavigation( -(pageSize - 1), event );
-                int steps = pageSize - 1;
-                int index = m_currentRow - steps;
-                if (index < 0)
-                    index = 0;
-
-                OnVerticalNavigation( index, event );
-            }
             break;
 
         case WXK_PAGEDOWN:
-            {
+            OnVerticalNavigation( +(pageSize - 1), event );
-                int steps = pageSize - 1;
-                unsigned int index = m_currentRow + steps;
-                unsigned int count = GetRowCount();
-                if ( index >= count )
-                    index = count - 1;
-
-                OnVerticalNavigation( index, event );
-            }
             break;
 
         default:
@@ -3760,16 +3744,24 @@ void wxDataViewMainWindow::OnChar( wxKeyEvent &event )
     }
 }
 
-void wxDataViewMainWindow::OnVerticalNavigation(unsigned int newCurrent, const wxKeyEvent& event)
+void wxDataViewMainWindow::OnVerticalNavigation(int delta, const wxKeyEvent& event)
 {
-    wxCHECK_RET( newCurrent < GetRowCount(),
-                wxT("invalid item index in OnVerticalNavigation()") );
-
     // if there is no selection, we cannot move it anywhere
-    if (!HasCurrentRow())
+    if (!HasCurrentRow() || IsEmpty())
         return;
 
+    int newRow = (int)m_currentRow + delta;
+
+    // let's keep the new row inside the allowed range
+    if ( newRow < 0 )
+        newRow = 0;
+
+    const int rowCount = (int)GetRowCount();
+    if ( newRow >= rowCount )
+        newRow = rowCount - 1;
+
     unsigned int oldCurrent = m_currentRow;
+    unsigned int newCurrent = (unsigned int)newRow;
 
     // in single selection we just ignore Shift as we can't select several
     // items anyhow
@@ -3821,6 +3813,8 @@ void wxDataViewMainWindow::OnLeftKey()
     else
     {
         wxDataViewTreeNode* node = GetTreeNodeByRow(m_currentRow);
+        if ( !node )
+            return;
 
         if ( TryAdvanceCurrentColumn(node, /*forward=*/false) )
             return;
@@ -3863,6 +3857,8 @@ void wxDataViewMainWindow::OnRightKey()
     else
     {
         wxDataViewTreeNode* node = GetTreeNodeByRow(m_currentRow);
+        if ( !node )
+            return;
 
         if ( node->HasChildren() )
         {