boolean widget & some documentation (#396)

src/components/Widgets.js

@@ -25,6 +25,7 @@ import ObjectControl from './Widgets/ObjectControl';
 import ObjectPreview from './Widgets/ObjectPreview';
 import RelationControl from './Widgets/RelationControl';
 import RelationPreview from './Widgets/RelationPreview';
+import BooleanControl from './Widgets/BooleanControl';
 
 
 registry.registerWidget('string', StringControl, StringPreview);
@@ -39,6 +40,7 @@ registry.registerWidget('datetime', DateTimeControl, DateTimePreview);
 registry.registerWidget('select', SelectControl, SelectPreview);
 registry.registerWidget('object', ObjectControl, ObjectPreview);
 registry.registerWidget('relation', RelationControl, RelationPreview);
+registry.registerWidget('boolean', BooleanControl);
 registry.registerWidget('unknown', UnknownControl, UnknownPreview);
 
 export function resolveWidget(name) { // eslint-disable-line

src/components/Widgets/BooleanControl.js

@@ -0,0 +1,23 @@
+import React, { PropTypes } from 'react';
+import ImmutablePropTypes from "react-immutable-proptypes";
+import Switch from 'react-toolbox/lib/switch';
+
+export default class BooleanControl extends React.Component {
+  render() {
+    const { value, field, forId, onChange } = this.props;
+    return (
+      <Switch
+        id={forId}
+        checked={value === undefined ? field.get('defaultValue', false) : value}
+        onChange={onChange}
+      />
+    );
+  }
+}
+
+BooleanControl.propTypes = {
+  field: ImmutablePropTypes.map.isRequired,
+  onChange: PropTypes.func.isRequired,
+  forID: PropTypes.string.isRequired,
+  value: PropTypes.bool,
+};