Final CL to kill off client/samples .

client/samples/swarm/SwarmState.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * The top-level class for the UI state. UI state is essentially a "model" from
- * the view's perspective but whose data just describes the UI itself. It
- * contains data like the currently selected story, etc.
- */
-// TODO(jimhug): Split the two classes here into framework and app-specific.
-class SwarmState extends UIState {
-  /** Core data source for the app. */
-  final Sections _dataModel;
-
-  /**
-   * Which article the user is currently viewing, or null if they aren't
-   * viewing an Article.
-   */
-  final ObservableValue<Article> currentArticle;
-  /**
-   * Which article the user currently has selected (for traversing articles
-   * via keyboard shortcuts).
-   */
-  final ObservableValue<Article> selectedArticle;
-
-  /**
-   * True if the story view is maximized and the top and bottom UI elements
-   * are hidden.
-   */
-  final ObservableValue<bool> storyMaximized;
-
-  /**
-   * True if the maximized story, if any, is being displayed in text mode
-   * rather than as an embedded web-page.
-   */
-  final ObservableValue<bool> storyTextMode;
-
-  /**
-   * Which article the user currently has selected (by keyboard shortcuts),
-   * or null if an article isn't selected by the keyboard.
-   */
-  BiIterator<Article> _articleIterator;
-
-  /**
-   * Which feed is currently selected (for keyboard shortcuts).
-   */
-  BiIterator<Feed> _feedIterator;
-
-  /**
-   * Which section is currently selected (for keyboard shortcuts).
-   */
-  BiIterator<Section> _sectionIterator;
-
-  SwarmState(this._dataModel)
-    : super(),
-      currentArticle = new ObservableValue<Article>(null),
-      selectedArticle = new ObservableValue<Article>(null),
-      storyMaximized = new ObservableValue<bool>(false),
-      storyTextMode = new ObservableValue<bool>(true) {
-    startHistoryTracking();
-    // TODO(efortuna): consider having this class just hold observable
-    // currentIndecies instead of iterators with observablevalues..
-    _sectionIterator = new BiIterator<Section>(_dataModel.sections); 
-    _feedIterator = new BiIterator<Feed>(_sectionIterator.current.feeds);
-    _articleIterator = 
-        new BiIterator<Article>(_feedIterator.current.articles);
-
-    currentArticle.addChangeListener((e) {
-      _articleIterator.jumpToValue(currentArticle.value);
-    });
-  }
-
-  /**
-   * Registers an event to fire on any state change
-   *
-   * TODO(jmesserly): fix this so we don't have to enumerate all of our fields
-   * again. One idea here is UIState becomes Observable, Observables have
-   * parents and notifications bubble up the parent chain.
-   */
-  void addChangeListener(ChangeListener listener) {
-    _sectionIterator.currentIndex.addChangeListener(listener);
-    _feedIterator.currentIndex.addChangeListener(listener);
-    _articleIterator.currentIndex.addChangeListener(listener);
-    currentArticle.addChangeListener(listener);
-  }
-
-  Map<String, String> toHistory() {
-    final data = {};
-    data['section'] = currentSection.id;
-    data['feed'] = currentFeed.id;
-    if (currentArticle.value != null) {
-      data['article'] = currentArticle.value.id;
-    }
-    return data;
-  }
-
-  void loadFromHistory(Map values) {
-    // TODO(jimhug): There's a better way of doing this...
-    if (values['section'] != null) {
-      _sectionIterator.jumpToValue(_dataModel.
-          findSectionById(values['section']));
-    } else {
-      _sectionIterator = new BiIterator<Section>(_dataModel.sections); 
-    }
-    if (values['feed'] != null && currentSection != null) {
-      _feedIterator.jumpToValue(currentSection.findFeed(values['feed']));
-    } else {
-      _feedIterator = new BiIterator<Feed>(_sectionIterator.current.feeds);
-    }
-    if (values['article'] != null && currentFeed != null) {
-      currentArticle.value = currentFeed.findArticle(values['article']);
-      _articleIterator.jumpToValue(currentArticle.value);
-    } else {
-      _articleIterator = 
-          new BiIterator<Article>(_feedIterator.current.articles);
-      currentArticle.value = null;
-    }
-
-    storyMaximized.value = false;
-  }
-
-  /**
-   * Move the currentArticle pointer to the next item in the Feed.
-   */
-  void goToNextArticle() {
-    currentArticle.value =  _articleIterator.next();
-    selectedArticle.value = _articleIterator.current;
-  }
-
-  /**
-   * Move the currentArticle pointer to the previous item in the Feed.
-   */
-  void goToPreviousArticle() {
-    currentArticle.value = _articleIterator.previous();
-    selectedArticle.value = _articleIterator.current;
-  }
-
-  /**
-   * Move the selectedArticle pointer to the next item in the Feed.
-   */
-  void goToNextSelectedArticle() {
-    selectedArticle.value = _articleIterator.next();
-  }
-
-  /**
-   * Move the selectedArticle pointer to the previous item in the Feed.
-   */
-  void goToPreviousSelectedArticle() {
-    selectedArticle.value = _articleIterator.previous();
-  }
-
-  /**
-   * Move the pointers for selectedArticle to point to the next
-   * Feed. 
-   */
-  void goToNextFeed() {
-    var newFeed = _feedIterator.next();
-    int oldIndex = _articleIterator.currentIndex.value;
-
-    _articleIterator = new BiIterator<Article>(newFeed.articles, 
-        _articleIterator.currentIndex.listeners);
-
-    _articleIterator.currentIndex.value = oldIndex;
-    selectedArticle.value = _articleIterator.current;
-  }
-
-  /**
-   * Move the pointers for selectedArticle to point to the previous
-   * DataSource. 
-   */
-  void goToPreviousFeed() {
-    var newFeed = _feedIterator.previous();
-    int oldIndex = _articleIterator.currentIndex.value;
-
-    _articleIterator = new BiIterator<Article>(newFeed.articles,
-        _articleIterator.currentIndex.listeners);
-    _articleIterator.currentIndex.value = oldIndex;
-    selectedArticle.value = _articleIterator.current;
-   }
-
-  /**
-   * Move to the next section (page) of feeds in the UI.
-   * @param index the previous index (how far down in a given feed)
-   * from the Source we are moving from.
-   * This method takes sliderMenu in the event that it needs to move 
-   * to a previous section, it can notify the UI to update.
-   */
-  void goToNextSection(SliderMenu sliderMenu) {
-    //TODO(efortuna): move sections?
-    var oldSection = currentSection;
-    int oldIndex = _articleIterator.currentIndex.value;
-    sliderMenu.selectNext(true);
-    // This check prevents our selector from wrapping around when we try to 
-    // go to the "next section", but we're already at the last section.
-    if (oldSection != _sectionIterator.current) {
-      _feedIterator = new BiIterator<Feed>(_sectionIterator.current.feeds,
-          _feedIterator.currentIndex.listeners);
-      _articleIterator =
-          new BiIterator<Article>(_feedIterator.current.articles,
-          _articleIterator.currentIndex.listeners);
-      _articleIterator.currentIndex.value = oldIndex;    
-      selectedArticle.value = _articleIterator.current;
-    }
-  }
-
-  /**
-   * Move to the previous section (page) of feeds in the UI.
-   * @param index the previous index (how far down in a given feed)
-   * from the Source we are moving from.
-   * @param oldSection the original starting section (before the slider
-   * menu moved)
-   * This method takes sliderMenu in the event that it needs to move 
-   * to a previous section, it can notify the UI to update.
-   */
-  void goToPreviousSection(SliderMenu sliderMenu) {
-    //TODO(efortuna): don't pass sliderMenu here. Just update in view!
-    var oldSection = currentSection;
-    int oldIndex = _articleIterator.currentIndex.value;
-    sliderMenu.selectPrevious(true);
-
-    // This check prevents our selector from wrapping around when we try to 
-    // go to the "previous section", but we're already at the first section.
-    if (oldSection != _sectionIterator.current) {
-      _feedIterator = new BiIterator<Feed>(_sectionIterator.current.feeds,
-          _feedIterator.currentIndex.listeners);
-      // Jump to back of feed set if we are moving backwards through sections.
-      _feedIterator.currentIndex.value = _feedIterator.list.length - 1;
-      _articleIterator =
-          new BiIterator<Article>(_feedIterator.current.articles,
-          _articleIterator.currentIndex.listeners);
-      _articleIterator.currentIndex.value = oldIndex;
-      selectedArticle.value = _articleIterator.current;
-    }
-  }
-
-  /**
-   * Set the selected story as the current story (for viewing in the larger
-   * Story View.)
-   */
-  void selectStoryAsCurrent() {
-    currentArticle.value = _articleIterator.current;
-    selectedArticle.value = _articleIterator.current;
-  }
-
-  /**
-   * Remove our currentArticle selection, to move back to the Main Grid view.
-   */
-  void clearCurrentArticle() {
-    currentArticle.value = null;
-  }
-
-  /**
-   * Set the selectedArticle as the first item in that section (UI page).
-   */
-  void goToFirstArticleInSection() {
-    selectedArticle.value = _articleIterator.current;
-  }
-
-  /**
-   * Returns true if the UI is currently in the Story View state.
-   */
-  bool get inMainView() => currentArticle.value == null;
-
-  /**
-   * Returns true if we currently have an Article selected (for keyboard
-   * shortcuts browsing).
-   */
-  bool get hasArticleSelected() => selectedArticle.value != null;
-
-  /**
-   * Mark the current article as read
-   */
-  bool markCurrentAsRead() {
-    currentArticle.value.unread.value = false;
-  }
-
-  /**
-   * The user has moved to a new section (page). This can occur either
-   * if the user clicked on a section page, or used keyboard shortcuts.
-   * The default behavior is to move to the first article in the first 
-   * column. The location of the selected item depends on the previous
-   * selected item location if the user used keyboard shortcuts. These 
-   * are manipulated in goToPrevious/NextSection().
-   */
-  void moveToNewSection(String sectionTitle) {
-    _sectionIterator.currentIndex.value = 
-        _dataModel.findSectionIndex(sectionTitle);
-    _feedIterator = new BiIterator<Feed>(_sectionIterator.current.feeds,
-        _feedIterator.currentIndex.listeners);
-    _articleIterator =
-        new BiIterator<Article>(_feedIterator.current.articles,
-        _articleIterator.currentIndex.listeners);
-  }
-
-  Section get currentSection() => _sectionIterator.current;
-  Feed get currentFeed() => _feedIterator.current;
-}