getTabIndex method
      
dynamic
getTabIndex(
    
    
- dynamic label,
- dynamic context,
- dynamic tabName
Implementation
getTabIndex(label, context, tabName) {
  myLogAll('getTabIndex');
  for (int i = 0; i < _tabList[tabName][gData].length; i++) {
    if (_tabList[tabName][gData][i][gLabel] == label) {
      return i;
    }
  }
  return -1;
}