System.Windows.Forms.ContainerControl.PerformValidation C# (CSharp) Method

		private Control PerformValidation (ContainerControl top_container, bool postpone_validation, ArrayList validation_chain, 
				Control topmost_under_root)
		{
			validation_failed = false;

			if (postpone_validation) {
				AddValidationChain (top_container, validation_chain);
				return null;
			}

			// if not null, pending chain has always one element or more
			if (top_container.pending_validation_chain != null) {
				// if the topmost node in the enter chain is exactly the topmost
				// int the validation chain, remove it, as .net does
				int last_idx = top_container.pending_validation_chain.Count - 1;
				if (topmost_under_root == top_container.pending_validation_chain [last_idx])
					top_container.pending_validation_chain.RemoveAt (last_idx);

				AddValidationChain (top_container, validation_chain);
				validation_chain = top_container.pending_validation_chain;
				top_container.pending_validation_chain = null;
			}

			for (int i = 0; i < validation_chain.Count; i ++) {
				if (!ValidateControl ((Control)validation_chain[i])) {
					validation_failed = true;
					return (Control)validation_chain[i];
				}
			}

			return null;
		}