| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| /** |
| * These classes provide bindings between Android widgets and Syncbase data. For the reasons |
| * outlined in {@link io.v.rx.syncbase}, Vanadium state distribution with Syncbase would ideally be |
| * done with pure FRP <a href="https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93viewmodel" |
| * target="_blank">MVVM</a>, with distributed state elements modeled in Syncbase. |
| * <p> |
| * <img src="doc-files/mvvm.png"> |
| * <p> |
| * <b>Fig: Ideal MVVM for distributed apps</b> |
| * <p> |
| * However, while this is easily accomplished with |
| * <a href="https://flutter.io/" target="_blank">Flutter</a>, the Baku Toolkit would need to |
| * implement an Android viewmodel layer to achieve the same for Android Java, which starts to amount |
| * to reimplementing Flutter for Java. Instead, the Baku Android Toolkit offers data bindings that |
| * allow Syncbase to drive more conventional Android Java UI widgets, and to allow those widgets to |
| * update distributed state in Syncbase. |
| * <p> |
| * <img src="doc-files/bindings.png"> |
| * <p> |
| * <b>Fig: Baku data bindings without viewmodel</b> |
| * <p> |
| * Even though these data bindings are not true MVVM, app developers are encouraged to treat them |
| * declaratively, and to make use of pure functional transformations wherever possible to simplify |
| * their code. Imperative code is however still useful for Android initialization, implementing |
| * reactive widget update logic, and writing to Syncbase. |
| * <p> |
| * Data bindings are offered to client applications via builders. Many facets of bindings are |
| * derived from their usage context. For example, {@code bindTo(...)} methods perform type |
| * introspection to construct appropriate binding types for the widget being bound (and possibly the |
| * row type being bound to). In the future, we may add a plug-in to preprocess Android layout markup |
| * similar to the <a href="http://developer.android.com/tools/data-binding/guide.html" |
| * target="_blank">Android Data Binding Library</a>. |
| * <p> |
| * At present, for simplicity, each data binding that reads from Syncbase has its own Syncbase watch |
| * stream. If this ends up wasting resources and degrading performance, we can optimize to minimize |
| * the number of watch streams and broadcast filtered streams to each data binding. |
| * <p> |
| * Offering data bindings rather than pure functional MVVM transforms does introduce some |
| * coordination concerns between read and write bindings. Strategies for dealing with coordination |
| * are included in the toolkit. |
| */ |
| package io.v.baku.toolkit.bind; |
