SHF: Small: Foundations for User Interface Programming

超过三分之一的程序代码是用来实现用户界面的，而这些代码包含了更大部分的缺陷。这并不奇怪;用户界面代码很少是可重用的，并且当前的基于事件处理的用户界面编程方法要求程序员管理大量的细节;这些细节太多而不能一致地产生正确和丰富的用户界面行为。所有的计算机用户都会经历这种影响：用户界面卡住，行为不合逻辑，丢失信息，缺乏关键或有用的功能，或者只是令人困惑。 结果是用户沮丧和浪费精力，当对所有用户进行聚合时是非常显著的成本，并且当对他或她的所有计算机使用进行聚合时甚至对一个用户也是显著的。这个项目寻求用户界面编程的进步，研究一种声明式方法，其中用户界面的许多行为可以表示为编码在软件库中的可重用算法。这极大地减少了应用程序员需要关注的细节;应用程序特定的“事件处理”代码根本不需要。我们的目标是显着降低生产高质量的用户界面的成本，并间接地通过更好的用户界面，使我们与计算机的交互更少的挫折和更producible.The建议的声明式编程方法是基于多路数据流约束系统，这是适用于模型的数据直接操纵的用户界面和数据内的依赖关系。该项目旨在表明，一旦一个应用程序设计师指定这样的约束系统，并将其连接到用户界面的视觉元素，一个大类的接口的行为可以从可重用的算法参数化的约束系统。 这样的行为的示例包括基于用户在其他用户界面元素上的交互来更新元素的值、启用和禁用用户界面元素、通过并发执行由用户的交互触发的计算来保持用户界面最大响应、管理用户界面的结构的改变、以及正确地编排所有上述内容。

More than one-third of all program code exists to implement user interfaces and this code contains an even larger portion of all defects. This is no surprise; user interface code is seldom reusable and current event-handling-based approaches to user interface programming require programmers to manage a large number of details; too many to consistently produce correct and rich user interface behaviors. The impact is experienced by all computer users: user interfaces get stuck, behave illogically, lose information, lack crucial or useful functionality, or are simply confusing. The result is user frustration and wasted effort, a very significant cost when aggregated over all users, and significant even to one user when aggregated over all of his or her computer use. This project seeks advances in user interface programming, studying a declarative approach where many behaviors of user interfaces can be expressed as reusable algorithms encoded in software libraries. This drastically reduces the details that an application programmer needs to be concerned with; application-specific "event handling" code is not necessary at all. The goal is to significantly reduce the cost of producing high quality user interfaces, and, indirectly through better user interfaces, to make our interactions with computers less frustrating and more productive.The proposed declarative programming approach is based on multi-way data-flow constraint systems, which are applied to model the data directly manipulated by user interfaces and the dependencies within that data. The project seeks to show that once an application programmer specifies such a constraint system and connects it to the visual elements of a user interface, a large class of the interface's behavior can be derived from reusable algorithms parametrized over the constraint system. Examples of such behaviors include updating values of elements based on user interaction on other user interface elements, enabling and disabling user interface elements, keeping the user interface maximally responsive by concurrently executing computations triggered by users' interactions, managing changes in the structure of the user interface, and correctly orchestrating all of the above.