Don't send SELECTED events for an already selected item in wxGTK wxListBox.

Bring wxGTK in line with wxMSW behaviour and avoid sending the
wxEVT_COMMAND_LISTBOX_SELECTED events when the user clicks on an already
selected item.

Refactor wxMSW code to extract the logic to avoid such events into a reusable
in other ports wxListBoxBase::DoChangeSingleSelection() function. Also add
wxListBox::GTKOnSelectionChanged() to wxGTK to avoid having to make the new
function public just so that it could be called by GTK callback and make the
previously existing CalcAndSendEvent() protected as well.

This fixes a unit test failure in ListBoxTestCase::ClickEvents() under wxGTK.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65935 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/listbox.h

@@ -100,6 +100,8 @@ public:
     void GTKDisableEvents();
     void GTKEnableEvents();
 
+    void GTKOnSelectionChanged();
+
 protected:
     virtual void DoClear();
     virtual void DoDeleteOneItem(unsigned int n);

include/wx/listbox.h

@@ -49,7 +49,7 @@ public:
 
     // multiple selection logic
     virtual bool IsSelected(int n) const = 0;
-    virtual void SetSelection(int n) { DoSetSelection(n, true); }
+    virtual void SetSelection(int n);
     void SetSelection(int n, bool select) { DoSetSelection(n, select); }
     void Deselect(int n) { DoSetSelection(n, false); }
     void DeselectAll(int itemToLeaveSelected = -1);
@@ -96,11 +96,6 @@ public:
     int HitTest(int x, int y) const { return DoListHitTest(wxPoint(x, y)); }
 
 
-    // For generating events in multiple and extended mode: compare the current
-    // selections with the previously recorded ones (in m_oldSelections) and
-    // send the appropriate event if they differ, otherwise just return false.
-    bool CalcAndSendEvent();
-
 protected:
     virtual void DoSetFirstItem(int n) = 0;
 
@@ -110,6 +105,17 @@ protected:
     virtual int DoListHitTest(const wxPoint& WXUNUSED(point)) const
         { return wxNOT_FOUND; }
 
+    // Helper for the code generating events in single selection mode: updates
+    // m_oldSelections and return true if the selection really changed.
+    // Otherwise just returns false.
+    bool DoChangeSingleSelection(int item);
+
+    // Helper for generating events in multiple and extended mode: compare the
+    // current selections with the previously recorded ones (in
+    // m_oldSelections) and send the appropriate event if they differ,
+    // otherwise just return false.
+    bool CalcAndSendEvent();
+
     // Send a listbox (de)selection or double click event.
     //
     // Returns true if the event was processed.
@@ -118,6 +124,9 @@ protected:
     // Array storing the indices of all selected items that we already notified
     // the user code about for multi selection list boxes.
     //
+    // For single selection list boxes, we reuse this array to store the single
+    // currently selected item, this is used by DoChangeSingleSelection().
+    //
     // TODO-OPT: wxSelectionStore would be more efficient for big list boxes.
     wxArrayInt m_oldSelections;
 

src/common/lboxcmn.cpp

@@ -59,6 +59,14 @@ bool wxListBoxBase::SetStringSelection(const wxString& s, bool select)
     return true;
 }
 
+void wxListBoxBase::SetSelection(int n)
+{
+    if ( !HasMultipleSelection() )
+        DoChangeSingleSelection(n);
+
+    DoSetSelection(n, true);
+}
+
 void wxListBoxBase::DeselectAll(int itemToLeaveSelected)
 {
     if ( HasMultipleSelection() )
@@ -114,6 +122,24 @@ bool wxListBoxBase::SendEvent(wxEventType evtType, int item, bool selected)
     return HandleWindowEvent(event);
 }
 
+bool wxListBoxBase::DoChangeSingleSelection(int item)
+{
+    // As we don't use m_oldSelections in single selection mode, we store the
+    // last item that we notified the user about in it in this case because we
+    // need to remember it to be able to filter out the dummy selection changes
+    // that we get when the user clicks on an already selected item.
+    if ( !m_oldSelections.empty() && *m_oldSelections.begin() == item )
+    {
+        // Same item as the last time.
+        return false;
+    }
+
+    m_oldSelections.clear();
+    m_oldSelections.push_back(item);
+
+    return true;
+}
+
 bool wxListBoxBase::CalcAndSendEvent()
 {
     wxArrayInt selections;

src/gtk/listbox.cpp

@@ -119,49 +119,9 @@ gtk_listitem_changed_callback(GtkTreeSelection * WXUNUSED(selection),
 {
     if (g_blockEventsOnDrag) return;
 
-    if (listbox->HasFlag(wxLB_MULTIPLE | wxLB_EXTENDED))
-    {
-        listbox->CalcAndSendEvent();
-    }
-    else // single selection
-    {
-        wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, listbox->GetId() );
-        event.SetEventObject( listbox );
-
-        int index = listbox->GetSelection();
-        if (index == wxNOT_FOUND)
-        {
-            // indicate that this is a deselection
-            event.SetExtraLong( 0 );
-            event.SetInt( -1 );
-
-            listbox->HandleWindowEvent( event );
-
-            return;
-        }
-        else
-        {
-            GtkTreeEntry* entry = listbox->GTKGetEntry( index );
-
-            // indicate that this is a selection
-            event.SetExtraLong( 1 );
-
-            event.SetInt( index );
-            event.SetString(wxConvUTF8.cMB2WX(gtk_tree_entry_get_label(entry)));
-
-            if ( listbox->HasClientObjectData() )
-                event.SetClientObject(
-                    (wxClientData*) gtk_tree_entry_get_userdata(entry)
-                                 );
-            else if ( listbox->HasClientUntypedData() )
-                event.SetClientData( gtk_tree_entry_get_userdata(entry) );
-
-            listbox->HandleWindowEvent( event );
-
-            g_object_unref (entry);
-        }
-    }
+    listbox->GTKOnSelectionChanged();
 }
+
 }
 
 //-----------------------------------------------------------------------------
@@ -761,6 +721,55 @@ int wxListBox::FindString( const wxString &item, bool bCase ) const
 // selection
 // ----------------------------------------------------------------------------
 
+void wxListBox::GTKOnSelectionChanged()
+{
+    if ( HasFlag(wxLB_MULTIPLE | wxLB_EXTENDED) )
+    {
+        CalcAndSendEvent();
+    }
+    else // single selection
+    {
+        const int index = GetSelection();
+        if ( !DoChangeSingleSelection(index) )
+            return;
+
+        wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, GetId() );
+        event.SetEventObject( this );
+
+        if (index == wxNOT_FOUND)
+        {
+            // indicate that this is a deselection
+            event.SetExtraLong( 0 );
+            event.SetInt( -1 );
+
+            HandleWindowEvent( event );
+
+            return;
+        }
+        else
+        {
+            GtkTreeEntry* entry = GTKGetEntry( index );
+
+            // indicate that this is a selection
+            event.SetExtraLong( 1 );
+
+            event.SetInt( index );
+            event.SetString(wxConvUTF8.cMB2WX(gtk_tree_entry_get_label(entry)));
+
+            if ( HasClientObjectData() )
+                event.SetClientObject(
+                    (wxClientData*) gtk_tree_entry_get_userdata(entry)
+                                 );
+            else if ( HasClientUntypedData() )
+                event.SetClientData( gtk_tree_entry_get_userdata(entry) );
+
+            HandleWindowEvent( event );
+
+            g_object_unref (entry);
+        }
+    }
+}
+
 int wxListBox::GetSelection() const
 {
     wxCHECK_MSG( m_treeview != NULL, wxNOT_FOUND, wxT("invalid listbox"));

src/msw/listbox.cpp

@@ -689,20 +689,10 @@ bool wxListBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
     if ( n == wxNOT_FOUND )
        return false;
 
-    // As we don't use m_oldSelections in single selection mode, we store the
-    // last item that we notified the user about in it in this case because we
-    // need to remember it to be able to filter out the dummy LBN_SELCHANGE
-    // messages that we get when the user clicks on an already selected item.
     if ( param == LBN_SELCHANGE )
     {
-        if ( !m_oldSelections.empty() && *m_oldSelections.begin() == n )
-        {
-            // Same item as the last time.
+        if ( !DoChangeSingleSelection(n) )
             return false;
-        }
-
-        m_oldSelections.clear();
-        m_oldSelections.push_back(n);
     }
 
     // Do generate an event otherwise.