Avoid showing 2 tooltips simultaneously in wxMSW wxListCtrl

Only show the built-in control tooltips if we're not showing any custom
ones.

Closes https://github.com/wxWidgets/wxWidgets/pull/1500

Closes #10492.

include/wx/msw/listctrl.h

@@ -390,6 +390,9 @@ protected:
         { return MSWGetBestViewRect(width, -1).y; }
     virtual int DoGetBestClientWidth(int height) const wxOVERRIDE
         { return MSWGetBestViewRect(-1, height).x; }
+#if wxUSE_TOOLTIPS
+    virtual void DoSetToolTip(wxToolTip *tip) wxOVERRIDE;
+#endif // wxUSE_TOOLTIPS
 
     wxSize MSWGetBestViewRect(int x, int y) const;
 

src/msw/listctrl.cpp

@@ -327,7 +327,6 @@ void wxListCtrl::MSWSetExListStyles()
     // we want to have some non default extended
     // styles because it's prettier (and also because wxGTK does it like this)
     int exStyle =
-        LVS_EX_LABELTIP |
         LVS_EX_FULLROWSELECT |
         LVS_EX_SUBITEMIMAGES |
         // normally this should be governed by a style as it's probably not
@@ -335,6 +334,13 @@ void wxListCtrl::MSWSetExListStyles()
         // it seems better to enable it by default than disable
         LVS_EX_HEADERDRAGDROP;
 
+    // Showing the tooltip items not fitting into the control is nice, but not
+    // really compatible with having custom tooltips, as this could result in
+    // showing 2 tooltips simultaneously, which would be confusing. So only
+    // enable this style if there is no risk of this happening.
+    if ( !GetToolTip() )
+        exStyle |= LVS_EX_LABELTIP;
+
     if ( wxApp::GetComCtl32Version() >= 600 )
     {
         // We must enable double buffering when using the system theme to avoid
@@ -3605,4 +3611,16 @@ static void wxConvertToMSWListCol(HWND hwndList,
     }
 }
 
+#if wxUSE_TOOLTIPS
+
+void wxListCtrl::DoSetToolTip(wxToolTip *tip)
+{
+    wxWindow::DoSetToolTip(tip);
+
+    // Add or remove LVS_EX_LABELTIP style as necessary.
+    MSWSetExListStyles();
+}
+
+#endif // wxUSE_TOOLTIPS
+
 #endif // wxUSE_LISTCTRL