PLT-2672 Refactored posts view with caching (#3054)

* Refactored posts view to use view controller design

* Add post view caching

* Required updates after rebase

* Fixed bug where current channel not set yet was causing breakage

1 files changed, 128 insertions, 0 deletions

diff --git a/webapp/components/post_view/post_focus_view_controller.jsx b/webapp/components/post_view/post_focus_view_controller.jsx
new file mode 100644
index 000000000..7c1da6566
--- /dev/null
+++ b/webapp/components/post_view/post_focus_view_controller.jsx
@@ -0,0 +1,128 @@
+// Copyright (c) 2015 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import PostList from './components/post_list.jsx';
+import LoadingScreen from 'components/loading_screen.jsx';
+
+import PostStore from 'stores/post_store.jsx';
+import UserStore from 'stores/user_store.jsx';
+import ChannelStore from 'stores/channel_store.jsx';
+
+import Constants from 'utils/constants.jsx';
+const ScrollTypes = Constants.ScrollTypes;
+
+import React from 'react';
+
+export default class PostFocusView extends React.Component {
+    constructor(props) {
+        super(props);
+
+        this.onChannelChange = this.onChannelChange.bind(this);
+        this.onPostsChange = this.onPostsChange.bind(this);
+        this.onUserChange = this.onUserChange.bind(this);
+        this.onPostListScroll = this.onPostListScroll.bind(this);
+
+        const focusedPostId = PostStore.getFocusedPostId();
+
+        const channel = ChannelStore.getCurrent();
+        let profiles = UserStore.getProfiles();
+        if (channel && channel.type === Constants.DM_CHANNEL) {
+            profiles = Object.assign({}, profiles, UserStore.getDirectProfiles());
+        }
+
+        this.state = {
+            postList: PostStore.getVisiblePosts(focusedPostId),
+            currentUser: UserStore.getCurrentUser(),
+            profiles,
+            scrollType: ScrollTypes.POST,
+            currentChannel: ChannelStore.getCurrentId().slice(),
+            scrollPostId: focusedPostId,
+            atTop: PostStore.getVisibilityAtTop(focusedPostId),
+            atBottom: PostStore.getVisibilityAtBottom(focusedPostId)
+        };
+    }
+
+    componentDidMount() {
+        ChannelStore.addChangeListener(this.onChannelChange);
+        PostStore.addChangeListener(this.onPostsChange);
+        UserStore.addChangeListener(this.onUserChange);
+    }
+
+    componentWillUnmount() {
+        ChannelStore.removeChangeListener(this.onChannelChange);
+        PostStore.removeChangeListener(this.onPostsChange);
+        UserStore.removeChangeListener(this.onUserChange);
+    }
+
+    onChannelChange() {
+        const currentChannel = ChannelStore.getCurrentId();
+        if (this.state.currentChannel !== currentChannel) {
+            this.setState({
+                currentChannel: currentChannel.slice(),
+                scrollType: ScrollTypes.POST
+            });
+        }
+    }
+
+    onPostsChange() {
+        const focusedPostId = PostStore.getFocusedPostId();
+        if (focusedPostId == null) {
+            return;
+        }
+
+        this.setState({
+            scrollPostId: focusedPostId,
+            postList: PostStore.getVisiblePosts(focusedPostId),
+            atTop: PostStore.getVisibilityAtTop(focusedPostId),
+            atBottom: PostStore.getVisibilityAtBottom(focusedPostId)
+        });
+    }
+
+    onUserChange() {
+        const channel = ChannelStore.getCurrent();
+        let profiles = UserStore.getProfiles();
+        if (channel && channel.type === Constants.DM_CHANNEL) {
+            profiles = Object.assign({}, profiles, UserStore.getDirectProfiles());
+        }
+        this.setState({currentUser: UserStore.getCurrentUser(), profiles: JSON.parse(JSON.stringify(profiles))});
+    }
+
+    onPostListScroll() {
+        this.setState({scrollType: ScrollTypes.FREE});
+    }
+
+    render() {
+        const postsToHighlight = {};
+        postsToHighlight[this.state.scrollPostId] = true;
+
+        let content;
+        if (this.state.postList == null) {
+            content = (
+                <LoadingScreen
+                    position='absolute'
+                    key='loading'
+                />
+            );
+        } else {
+            content = (
+                <PostList
+                    postList={this.state.postList}
+                    currentUser={this.state.currentUser}
+                    profiles={this.state.profiles}
+                    scrollType={this.state.scrollType}
+                    scrollPostId={this.state.scrollPostId}
+                    postListScrolled={this.onPostListScroll}
+                    showMoreMessagesTop={!this.state.atTop}
+                    showMoreMessagesBottom={!this.state.atBottom}
+                    postsToHighlight={postsToHighlight}
+                />
+            );
+        }
+
+        return (
+            <div id='post-list'>
+                {content}
+            </div>
+        );
+    }
+}