samer@4: % disposables - Manage resources that need to be disposed of cleanly
samer@4: %
samer@4: % This is implemented as a message handler to be used as follows:
samer@4: %
samer@4: % >> ref=disposables('reg',x)  % register x as a disposable returning reference ref
samer@4: % >> disposables('dereg',ref)  % deregister (but do not dispose) of registered object
samer@4: % >> dx=disposables('get')     % get cell array of all registered objects
samer@4: % >> disposables('dispose')    % dispose of and deregister all disposables
samer@4: %
samer@4: % In most cases, you will not need to use this function as resources should
samer@4: % be disposed of correctly by the functions that acquire them. However, if
samer@4: % things go wrong or the user presses Ctrl-C, some objects might not be
samer@4: % disposed of properly and cause problems later. In this case, a call to
samer@4: % disposables('dispose') should take care of it.
samer@4: 
samer@4: function varargout=disposables(msg,varargin)
samer@4: 	persistent registry
samer@4: 
samer@4: 	switch(msg)
samer@4: 		case 'reg', 
samer@4: 			obj=varargin{1};
samer@4: 			registry = [registry, obj]; 
samer@4: 			varargout{1}=obj;
samer@4: 		case 'dereg', 
samer@4: 			obj=varargin{1};
samer@42: 			if ~isempty(registry)
samer@42: 				idx=find(registry==obj);
samer@42: 				registry=registry([1:idx-1,idx+1:length(registry)]);
samer@42: 			end
samer@4: 		case 'get'
samer@4: 			varargout{1}=registry;
samer@4: 		case 'dispose'
samer@4: 			for i=1:length(registry)
samer@4: 				registry(i).dispose();
samer@4: 			end
samer@4: 			registry=[];
samer@4: 	end
samer@4: end
samer@4: