| // 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. |
| |
| part of swarmlib; |
| |
| /** |
| * A simple news reader in Dart. |
| */ |
| class Swarm extends App { |
| /** |
| * Flag to insure the onLoad isn't called when callback from initializeFromUrl |
| * could occur before the document's onload event. |
| */ |
| bool onLoadFired; |
| |
| /** Collections of datafeeds to show per page. */ |
| Sections sections; |
| |
| /** The front page of the app. */ |
| FrontView frontView; |
| |
| /** Observable UI state. */ |
| SwarmState state; |
| |
| Swarm({bool useCannedData: false}) : onLoadFired = false { |
| Sections.initializeFromUrl(useCannedData, (currSections) { |
| sections = currSections; |
| state = new SwarmState(sections); |
| setupApp(); |
| }); |
| // Catch user keypresses and decide whether to use them for the |
| // Streams app or pass them on to the browser. |
| document.onKeyUp.listen((e) { |
| if (frontView != null) { |
| frontView.processKeyEvent(e); |
| } |
| }); |
| } |
| |
| /** |
| * Tells each data source to check the server for the latest data. |
| */ |
| void refresh() { |
| sections.refresh(); |
| |
| // Hook up listeners about any data source additions or deletions. We don't |
| // differentiate additions or deletions just the fact that data feeds have |
| // changed. We might want more fidelity later. |
| sections.sectionTitles.forEach((title) { |
| Section section = sections.findSection(title); |
| // TODO(terry): addChangeListener needs to return an id so previous |
| // listener can be removed, otherwise anonymous functions |
| // can't easily be used. See b/5063673 |
| section.feeds.addChangeListener((data) { |
| // TODO(jacobr): implement this. |
| print("Refresh sections not impl yet."); |
| }); |
| }); |
| } |
| |
| /** The page load event handler. */ |
| void onLoad() { |
| onLoadFired = true; |
| super.onLoad(); |
| setupApp(); |
| } |
| |
| /** |
| * Setup the application's world. |
| */ |
| void setupApp() { |
| // TODO(terry): Should be able to spinup the app w/o waiting for data. |
| // If the document is already loaded so we can setup the app anytime. |
| // Otherwise, we'll wait to setup the world until the document is ready |
| // to render. |
| if (onLoadFired && state != null) { |
| render(); |
| // This call loads the initial data. |
| refresh(); |
| eraseSplashScreen(); |
| } |
| } |
| |
| void render() { |
| frontView = new FrontView(this); |
| frontView.addToDocument(document.body); |
| } |
| } |