82 lines
4.3 KiB
Plaintext
82 lines
4.3 KiB
Plaintext
/** @~english
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@page pg-mv-model Model-View framework
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@brief A overview of the Model-View framework
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@section Glossary
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@li view: widget dedicated to show the data. It could be a graph, list etc.
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@li model: abstraction and combination of data.
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@li data: things that needed to be delivered or shown. It could be a array of
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votage values which is sampled from a AD in an interval. Or it could be the
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attributes of all the files in a folder.
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@section Design considerations and implementations
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@li one model can respond to more than one views. one view can connect to
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more than one models.
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@li It is guaranteed that the change events of a model will be sent to all
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the registered views.
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@li Because there are so many formats of data, Model-View neither specify the
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format data is stored nor try to abstract them. The only thing stored in
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model is a pointer to the underlaying data. It is the responsibility of
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inherited classed to implement the boxing/un-boxing operations.
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@li Data can be multi-dimensional. The "dimension" does not only means
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dimension geometry. It can also means attributes. For example, a folder could
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have two attributes which are name and icon. So it's two-dimensional. If take
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the size into consideration, it will be three-dimensional. The size of
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dimension is saved in model. Each dimension is correspond to a pointer to some
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sort of data. Model can save many of them. As above, model does not make
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assumptions on the underlaying data structure. It only provide mechanism, not
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policy and leave that to the inherited classes.
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@section Events
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@li model has a record of registered views. When data changes, model notify
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views the change by sending events. The event contains the id of the model,
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the id of target view, the scope of changed data.
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@li views can handle the event by retrieve data from model, and update
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themselves according to the scope that data has changed. The connected model
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views should have the same presentation of data structure. Views should also
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restore all the models it interested. In the case of repainting, it should
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re-retrieve data from those models.
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@li model send events by rtgui_send. So it's suitable for the synchronization
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between threads and even could be used in ISR.
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*/
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/** @~chinese
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@page pg-mv-model Model-View 框架
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@brief 对于 Model-View 框架的简介
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@section 名词解释
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@li view：用于显示数据的控件。可以是诸如图表控件、列表控件的控件。
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@li model：对于数据的组合和抽象。
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@li 数据：需要显示或传递的数据。它可以是每隔一段时间就从AD读取的电压值，也可
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以是一个目录下所有文件的属性列表。
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@section 设计原则和实现
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@li 一个 model 可以对应多个view。一个view可以对应多个 model。
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@li 保证 model 的更新事件会同时发送到所有注册的 view 上。
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@li 因为数据的形式与内容千差万别，所以 Model-View 不规定数据的存储形式，也不对其进
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行抽象。只在 model 中保留指向第一个数据的指针。打包/解包由从m odel/view 派生出
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的子类实现。
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@li 数据源可以是多维的。这里的维度指的不只是几何的维度，而且可以是属性。比如
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一个目录，它可以有名称、图标两个属性，那么它就是两维的。如果加入大小这个属性
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，就是三维的。 model 内部存储数据的维度大小。一个维度对应一个数据首地址的指针
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。model 中可以存储多个数据首地址。model 对底层数据结构不作假设。只提供机制，不
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提供策略。只保证能够多维，但把具体的实现方式留给子类实现。
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@subsection 事件
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@li model 内部记录对自己感兴趣的 view。在数据变化时，用事件通知所有相关 view。事
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件内容包含：自己的 id；目标 view 的 id；所变化数据的 index 范围。
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@li view 收到事件之后通过 model id 拿到数据并根据事件中的变化范围更新自己。对于
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指针的数据类型转换需要自己实现并保证和 model 一致。view 内部保存与自己相关的
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model id，在需要重绘的时候要从所有相关 model 提取数据。
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@li model 通过 rtgui_send 给 view 发送事件。使得这个模型适用于线程间同步，也
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可以在中断上下文里通知事件的发生。
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*/
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