Merge branch 'mac-lbox-sel-events'

Fix Mac wxListBox selection behaviour and events.

See https://github.com/wxWidgets/wxWidgets/pull/847

include/wx/osx/listbox.h

@@ -122,9 +122,11 @@ public:
 
     wxListWidgetImpl* GetListPeer() const;
 
-    bool MacGetBlockEvents() const { return m_blockEvents; }
-
     virtual void HandleLineEvent( unsigned int n, bool doubleClick );
+
+    // This is called by wxNSTableView
+    void MacHandleSelectionChange(int row);
+
 protected:
     // callback for derived classes which may have to insert additional data
     // at a certain line - which cannot be predetermined for sorted list data

src/osx/cocoa/listbox.mm

@@ -297,24 +297,12 @@ protected:
 
     int row = [self selectedRow];
 
-    if (row == -1) 
-    {
-        // no row selected
-    } 
-    else 
-    {
-        wxWidgetCocoaImpl* impl = (wxWidgetCocoaImpl* ) wxWidgetImpl::FindFromWXWidget( self );
-        wxListBox *list = static_cast<wxListBox*> ( impl->GetWXPeer());
-        wxCHECK_RET( list != NULL , wxT("Listbox expected"));
+    wxWidgetCocoaImpl* impl = (wxWidgetCocoaImpl* ) wxWidgetImpl::FindFromWXWidget( self );
+    wxListBox* const list = wxDynamicCast(impl->GetWXPeer(), wxListBox);
+    wxCHECK_RET( list != NULL , "Associated control should be a wxListBox" );
 
-        if ((row < 0) || (row > (int) list->GetCount()))  // OS X can select an item below the last item
-            return;
-
-        if ( !list->MacGetBlockEvents() )
-            list->HandleLineEvent( row, false );
-    }
-
-} 
+    list->MacHandleSelectionChange(row);
+}
 
 - (void)setFont:(NSFont *)aFont
 {

src/osx/listbox_osx.cpp

@@ -420,6 +420,40 @@ void wxListBox::HandleLineEvent( unsigned int n, bool doubleClick )
     HandleWindowEvent(event);
 }
 
+void wxListBox::MacHandleSelectionChange(int row)
+{
+    if ( m_blockEvents )
+        return;
+
+    // Correct notification events for multiselection list.
+    if ( HasMultipleSelection() )
+    {
+        CalcAndSendEvent();
+        return;
+    }
+
+    // OS X can select an item below the last item. In that case keep the old
+    // selection because in wxWidgets API there is no notification event for
+    // removing the selection from a single-selection list box.
+    //
+    // Otherwise call DoChangeSingleSelection so GetOldSelection() will return
+    // the correct value if row < 0 later.
+    const int count = static_cast<int>(GetCount());
+    if ( row < 0 || row >= count )
+    {
+        if ( !m_oldSelections.empty() )
+        {
+            const int oldsel = m_oldSelections[0];
+            if ( oldsel >= 0 && oldsel < count )
+                SetSelection(oldsel);
+        }
+    }
+    else if ( DoChangeSingleSelection(row) )
+    {
+        HandleLineEvent( row, false );
+    }
+}
+
 //
 // common list cell value operations
 //