trigger aftertest on OpportunityLineItem (after Delete) {

 Set<Id> oppIds = new Set<Id>();
 Set<Id> pbeIds = new Set<Id>();
 
 //Create three sets so we can track what products are on what opps.
 Set<Id> kioskSoftwareOpps = new Set<Id>();
 Set<Id> kioskHardwareOpps = new Set<Id>();
 Set<Id> webSoftwareOpps = new Set<Id>();

 //------------variables above can be reused so only the logice below should go in the after delete part.
    
 //since this is after delete we need to use trigger.old and there are trigger.new is null
 for(OpportunityLineItem  oli : trigger.old){
     oppIds.add(oli.id);
 }
    
 //We need to go get all the olis for the opps from which one was deleted
 List<OpportunityLineItem> olis = [select Id, PricebookEntryId from OpportunityLineItem where OpportunityId IN :oppIds];
 
 for(OpportunityLineItem oli : olis){
  pbeIds.add(oli.pricebookEntryId);
 }
 
 Map<Id, PricebookEntry> entries = new Map<Id, PricebookEntry>([select product2.product_group__c from pricebookentry where id in :pbeIds]);
 
 for(OpportunityLineItem nOLI : olis){
  //lets get the product family from the map
  String productGroup = entries.get(nOLI.pricebookEntryId).product2.Product_Group__c;
  
  //You'll want to break these up so you can keep track of what products are on what opp. 
  if(productGroup == 'Kiosk Software') {
   oppIds.add(nOLI.OpportunityId);
   kioskSoftwareOpps.add(nOLI.OpportunityId);
  }
  
  if(productGroup == 'Kiosk Hardware'){
   oppIds.add(nOLI.OpportunityId);
   kioskHardwareOpps.add(nOLI.OpportunityId);
  }
  
  if(productGroup == 'Web Software') {
   oppIds.add(nOLI.OpportunityId);
   webSoftwareOpps.add(nOLI.OpportunityId);
  }
 }
 
 //now we re-evaluate
  for(Opportunity opp : [select Id, Has_Kiosk_Hardware__c, Has_Kiosk_Software__c, Has_Web_Software__c from Opportunity where ID IN :oppIds]){
   
   //before we re-evaluate set all the checkboxes to false
   opp.Has_Kiosk_Software__c = false;
   opp.Has_Kiost_Hardware__c = false;
   opp.Has_Web_Software__c = false;
      
   //Here we check the sets above to see if the opps contains one of the product families
   if(kioskSoftwareOpps.contains(opp.Id){
      Has_Kiosk_Software__c = true;
   }
   
   if(kioskHardwareOpps.contains(opp.Id){
      Has_Kiosk_Hardware__c = true;
   }
   
   if(webSoftwareOpps.contains(opp.Id){
      Has_Web_Software__c = true;
   }
   
   oppsToUpdate.add(opp);
  
  }
  
  if(oppsToUpdate.size() > 0){
   update oppsToUpdate;
  }

}