Move fn.dart into /sky/framework

sky/examples/fn/lib/component.dart

-// Copyright 2015 The Chromium Authors. 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 fn;
-
-List<Component> _dirtyComponents = new List<Component>();
-bool _renderScheduled = false;
-
-void _renderDirtyComponents() {
-  Stopwatch sw = new Stopwatch()..start();
-
-  _dirtyComponents.sort((a, b) => a._order - b._order);
-  for (var comp in _dirtyComponents) {
-    comp._renderIfDirty();
-  }
-
-  _dirtyComponents.clear();
-  _renderScheduled = false;
-  sw.stop();
-  print("Render took ${sw.elapsedMicroseconds} microseconds");
-}
-
-void _scheduleComponentForRender(Component c) {
-  _dirtyComponents.add(c);
-
-  if (!_renderScheduled) {
-    _renderScheduled = true;
-    new Future.microtask(_renderDirtyComponents);
-  }
-}
-
-abstract class Component extends Node {
-  bool _dirty = true; // components begin dirty because they haven't rendered.
-  Node _rendered = null;
-  bool _removed = false;
-  final int _order;
-  static int _currentOrder = 0;
-  bool _stateful;
-  static Component _currentlyRendering;
-
-  Component({ Object key, bool stateful })
-      : _stateful = stateful != null ? stateful : false,
-        _order = _currentOrder + 1,
-        super(key:key);
-
-  void willUnmount() {}
-
-  void _remove() {
-    assert(_rendered != null);
-    assert(_root != null);
-    willUnmount();
-    _rendered._remove();
-    _rendered = null;
-    _root = null;
-    _removed = true;
-  }
-
-  // TODO(rafaelw): It seems wrong to expose DOM at all. This is presently
-  // needed to get sizing info.
-  sky.Node getRoot() => _root;
-
-  bool _sync(Node old, sky.Node host, sky.Node insertBefore) {
-    Component oldComponent = old as Component;
-
-    if (oldComponent == null || oldComponent == this) {
-      _renderInternal(host, insertBefore);
-      return false;
-    }
-
-    assert(oldComponent != null);
-    assert(_dirty);
-    assert(_rendered == null);
-
-    if (oldComponent._stateful) {
-      _stateful = false; // prevent iloop from _renderInternal below.
-
-      reflect.copyPublicFields(this, oldComponent);
-
-      oldComponent._dirty = true;
-      _dirty = false;
-
-      oldComponent._renderInternal(host, insertBefore);
-      return true;  // Must retain old component
-    }
-
-    _rendered = oldComponent._rendered;
-    _renderInternal(host, insertBefore);
-    return false;
-  }
-
-  void _renderInternal(sky.Node host, sky.Node insertBefore) {
-    if (!_dirty) {
-      assert(_rendered != null);
-      return;
-    }
-
-    var oldRendered = _rendered;
-    int lastOrder = _currentOrder;
-    _currentOrder = _order;
-    _currentlyRendering = this;
-    _rendered = render();
-    _currentlyRendering = null;
-    _currentOrder = lastOrder;
-
-    _rendered.events.addAll(events);
-
-    _dirty = false;
-
-    // TODO(rafaelw): This prevents components from returning different node
-    // types as their root node at different times. Consider relaxing.
-    assert(oldRendered == null ||
-           _rendered.runtimeType == oldRendered.runtimeType);
-
-    if (_rendered._sync(oldRendered, host, insertBefore)) {
-      _rendered = oldRendered; // retain stateful component
-    }
-    _root = _rendered._root;
-    assert(_rendered._root is sky.Node);
-  }
-
-  void _renderIfDirty() {
-    assert(_rendered != null);
-    assert(!_removed);
-
-    var rendered = _rendered;
-    while (rendered is Component) {
-      rendered = rendered._rendered;
-    }
-    sky.Node root = rendered._root;
-
-    _renderInternal(root.parentNode, root.nextSibling);
-  }
-
-  void setState(Function fn()) {
-    assert(_rendered != null); // cannot setState before mounting.
-    _stateful = true;
-    fn();
-    if (_currentlyRendering != this) {
-      _dirty = true;
-      _scheduleComponentForRender(this);
-    }
-  }
-
-  Node render();
-}
-
-abstract class App extends Component {
-  sky.Node _host = null;
-  App()
-    : super(stateful: true) {
-
-    _host = sky.document.createElement('div');
-    sky.document.appendChild(_host);
-
-    new Future.microtask(() {
-      Stopwatch sw = new Stopwatch()..start();
-      _sync(null, _host, null);
-      assert(_root is sky.Node);
-      sw.stop();
-      print("Initial render: ${sw.elapsedMicroseconds} microseconds");
-    });
-  }
-}