{"id":14933,"date":"2022-06-13T17:40:04","date_gmt":"2022-06-13T21:40:04","guid":{"rendered":"https:\/\/carleton.ca\/scs\/?page_id=14933"},"modified":"2026-06-09T10:12:36","modified_gmt":"2026-06-09T14:12:36","slug":"tr-190-coordinators-a-mechanism-for-monitoring-and-controlling-interactions-between-groups-of-objects","status":"publish","type":"page","link":"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1991\/tr-190-coordinators-a-mechanism-for-monitoring-and-controlling-interactions-between-groups-of-objects\/","title":{"rendered":"TR-190: Coordinators: A Mechanism for Monitoring and Controlling Interactions Between Groups of Objects"},"content":{"rendered":"\n<section class=\"w-screen px-6 cu-section cu-section--white ml-offset-center md:px-8 lg:px-14\">\n    <div class=\"space-y-6 cu-max-w-child-5xl  md:space-y-10 cu-prose-first-last\">\n\n            <div class=\"cu-textmedia flex flex-col lg:flex-row mx-auto gap-6 md:gap-10 my-6 md:my-12 first:mt-0 max-w-5xl\">\n        <div class=\"justify-start cu-textmedia-content cu-prose-first-last\" style=\"flex: 0 0 100%;\">\n            <header class=\"font-light prose-xl cu-pageheader md:prose-2xl cu-component-updated cu-prose-first-last\">\n                                    <h1 class=\"cu-prose-first-last font-semibold !mt-2 mb-4 md:mb-6 relative after:absolute after:h-px after:bottom-0 after:bg-cu-red after:left-px text-3xl md:text-4xl lg:text-5xl lg:leading-[3.5rem] pb-5 after:w-10 text-cu-black-700 not-prose\">\n                        TR-190: Coordinators: A Mechanism for Monitoring and Controlling Interactions Between Groups of Objects\n                    <\/h1>\n                \n                                \n                            <\/header>\n\n                    <\/div>\n\n            <\/div>\n\n    <\/div>\n<\/section>\n\n\n\n<p>Carleton University<br><a href=\"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1991\/\">Technical Report<\/a>&nbsp;<strong>TR-190<\/strong><br>April 1991<\/p>\n\n\n\n<h2 id=\"coordinators-a-mechanism-for-monitoring-and-controlling-interactions-between-groups-of-objects\" class=\"wp-block-heading\">Coordinators: A Mechanism for Monitoring and Controlling Interactions Between Groups of Objects<\/h2>\n\n\n\n<p>Wilf R. LaLonde, Paul White, Kevin McGuire<\/p>\n\n\n\n<h3 id=\"abstract\" class=\"wp-block-heading\">Abstract<\/h3>\n\n\n\n<p>Coordinators are mechanisms for explicitly specifying the important message traffic between groups of interacting objects and subsequently monitoring, intercepting, and massaging this message traffic to ensure proper communication. In general, they are useful in applications that require monitoring, statistics gathering, and coordination. Nevertheless, they were designed primarily to solve some outstanding problems in user-interface classes that hinder reusability.<\/p>\n\n\n\n<p>Coordinators provide an explicit description of the important message traffic enabling users to quickly understand the important interaction messages. It replaces the change\/update mechanism in the model-view\u00adcontroller paradigm with one that makes the change messages more explicit. It permits arbitrary models to be plugged-in without having to instrument them with \u201cself changed:\u201d messages. It also permits new interaction structures to be constructed out of simpler building blocks and makes the building blocks more reusable. For example, it would permit components of complex windows like browsers to be reused in application specific browsers without having to duplicate the inherent functionality.<\/p>\n\n\n\n<p><a href=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/TR-190.pdf\">TR-190.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Carleton UniversityTechnical Report&nbsp;TR-190April 1991 Coordinators: A Mechanism for Monitoring and Controlling Interactions Between Groups of Objects Wilf R. LaLonde, Paul White, Kevin McGuire Abstract Coordinators are mechanisms for explicitly specifying the important message traffic between groups of interacting objects and subsequently monitoring, intercepting, and massaging this message traffic to ensure proper communication. In general, they [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":11908,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_cu_dining_location_slug":"","footnotes":"","_links_to":"","_links_to_target":""},"cu_page_type":[],"class_list":["post-14933","page","type-page","status-publish","hentry"],"acf":{"cu_post_thumbnail":""},"_links":{"self":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/14933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/comments?post=14933"}],"version-history":[{"count":2,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/14933\/revisions"}],"predecessor-version":[{"id":24520,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/14933\/revisions\/24520"}],"up":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/11908"}],"wp:attachment":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/media?parent=14933"}],"wp:term":[{"taxonomy":"cu_page_type","embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/cu_page_type?post=14933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}