Move DND context to LoggedInView

so that we can drag things from any part of the logged in app to
another. (Specifically GroupView and TagPanel).

src/components/structures/LoggedInView.js

@@ -19,6 +19,7 @@ limitations under the License.
 import * as Matrix from 'matrix-js-sdk';
 import React from 'react';
 import PropTypes from 'prop-types';
+import { DragDropContext } from 'react-beautiful-dnd';
 
 import { KeyCode, isOnlyCtrlOrCmdKeyEvent } from '../../Keyboard';
 import Notifier from '../../Notifier';
@@ -30,6 +31,9 @@ import sessionStore from '../../stores/SessionStore';
 import MatrixClientPeg from '../../MatrixClientPeg';
 import SettingsStore from "../../settings/SettingsStore";
 
+import TagOrderActions from '../../actions/TagOrderActions';
+import RoomListActions from '../../actions/RoomListActions';
+
 /**
  * This is what our MatrixChat shows when we are logged in. The precise view is
  * determined by the page_type property.
@@ -207,6 +211,50 @@ const LoggedInView = React.createClass({
         }
     },
 
+    _onDragEnd: function(result) {
+        // Dragged to an invalid destination, not onto a droppable
+        if (!result.destination) {
+            return;
+        }
+
+        const dest = result.destination.droppableId;
+
+        if (dest === 'tag-panel-droppable') {
+            // Could be "GroupTile +groupId:domain"
+            const draggableId = result.draggableId.split(' ').pop();
+
+            // Dispatch synchronously so that the TagPanel receives an
+            // optimistic update from TagOrderStore before the previous
+            // state is shown.
+            dis.dispatch(TagOrderActions.moveTag(
+                this._matrixClient,
+                draggableId,
+                result.destination.index,
+            ), true);
+        } else if (dest.startsWith('room-sub-list-droppable_')) {
+            this._onRoomTileEndDrag(result);
+        }
+    },
+
+    _onRoomTileEndDrag: function(result) {
+        let newTag = result.destination.droppableId.split('_')[1];
+        let prevTag = result.source.droppableId.split('_')[1];
+        if (newTag === 'undefined') newTag = undefined;
+        if (prevTag === 'undefined') prevTag = undefined;
+
+        const roomId = result.draggableId.split('_')[1];
+
+        const oldIndex = result.source.index;
+        const newIndex = result.destination.index;
+
+        dis.dispatch(RoomListActions.tagRoom(
+            this._matrixClient,
+            this._matrixClient.getRoom(roomId),
+            prevTag, newTag,
+            oldIndex, newIndex,
+        ), true);
+    },
+
     render: function() {
         const LeftPanel = sdk.getComponent('structures.LeftPanel');
         const RightPanel = sdk.getComponent('structures.RightPanel');
@@ -328,6 +376,7 @@ const LoggedInView = React.createClass({
         return (
             <div className='mx_MatrixChat_wrapper'>
                 { topBar }
+                <DragDropContext onDragEnd={this._onDragEnd}>
                     <div className={bodyClasses}>
                         <LeftPanel
                             collapsed={this.props.collapseLhs || false}
@@ -338,6 +387,7 @@ const LoggedInView = React.createClass({
                         </main>
                         { right_panel }
                     </div>
+                </DragDropContext>
             </div>
         );
     },