Add pause feature

app/src/actions/Tree.ts

@@ -57,3 +57,13 @@ export const showTree = (tree?: q.Tree<TopicViewModel>) => (dispatch: Dispatch<a
     type: ActionTypes.TREE_SHOW_TREE,
   })
 }
+
+export const togglePause = (tree?: q.Tree<TopicViewModel>) => (dispatch: Dispatch<any>, getState: () => AppState): AnyAction  => {
+  const paused = getState().tree.paused
+  const tree = getState().tree.tree
+  // tree && tree.applyUnmergedChanges()
+
+  return dispatch({
+    type: paused ? ActionTypes.TREE_RESUME_UPDATES : ActionTypes.TREE_PAUSE_UPDATES,
+  })
+}

app/src/components/PauseButton.tsx

@@ -0,0 +1,108 @@
+import * as React from 'react'
+import * as q from '../../../backend/src/Model'
+import CustomIconButton from './CustomIconButton'
+import Pause from '@material-ui/icons/PauseCircleFilled'
+import Resume from '@material-ui/icons/PlayCircleFilled'
+import { AppState } from '../reducers'
+import { bindActionCreators } from 'redux'
+import { connect } from 'react-redux'
+import { treeActions } from '../actions'
+import { StyleRulesCallback, withStyles } from '@material-ui/core/styles'
+import { Tooltip } from '@material-ui/core';
+
+const styles: StyleRulesCallback = theme => ({ })
+
+interface Props {
+  classes: any
+  actions: {
+    tree: typeof treeActions,
+  }
+  paused: boolean
+  tree?: q.Tree<any>
+}
+
+class PauseButton extends React.Component<Props, {changes: number}> {
+  private timer?: any
+  constructor(props: Props) {
+    super(props)
+    this.state = { changes: 0 }
+  }
+
+  public componentDidMount() {
+    this.timer = setInterval(() => {
+      if (!this.props.paused || !this.props.tree) {
+        return
+      }
+
+      const changes = this.props.tree.unmergedChanges()
+      if (this.state.changes !== changes.length) {
+        this.setState({ changes: changes.length })
+      }
+    }, 300)
+  }
+
+  public componentWillUnmount() {
+    this.timer && clearInterval(this.timer)
+  }
+
+  public render() {
+    const { actions, classes } = this.props
+
+    return (
+      <div style={{ display: 'inline-flex' }}>
+        <span>
+          <CustomIconButton onClick={this.props.actions.tree.togglePause} >
+            {this.props.paused ? this.renderResume() : this.renderPause()}
+          </CustomIconButton>
+        </span>
+        {this.props.paused ? this.renderBufferStats() : null}
+      </div>
+    )
+  }
+
+  private renderResume() {
+    return (
+      <Tooltip title="Resumes updating the tree, after applying all recorded changes">
+        <Resume />
+      </Tooltip>
+    )
+  }
+
+  private renderPause() {
+    return (
+      <Tooltip title="Stops all updates, records changes until the buffer is full.">
+        <Pause />
+      </Tooltip>
+    )
+  }
+
+  private renderBufferStats() {
+    if (!this.props.tree) {
+      return
+    }
+
+    return (
+      <span>
+        {this.state.changes} changes<br />
+        buffer at {Math.round(this.props.tree.unmergedChanges().fillState() * 10000) / 100}%
+      </span>
+    )
+  }
+}
+
+const mapStateToProps = (state: AppState) => {
+  return {
+    paused: state.tree.paused,
+    tree: state.tree.tree,
+  }
+}
+
+const mapDispatchToProps = (dispatch: any) => {
+  return {
+    actions: {
+      tree: bindActionCreators(treeActions, dispatch),
+    },
+  }
+}
+
+export default connect(mapStateToProps, mapDispatchToProps)(withStyles(styles)(PauseButton))

app/src/components/TitleBar.tsx

@@ -7,7 +7,7 @@ import Search from '@material-ui/icons/Search'
 import { AppState } from '../reducers'
 import { bindActionCreators } from 'redux'
 import { connect } from 'react-redux'
-import { connectionActions, settingsActions } from '../actions'
+import { connectionActions, settingsActions, treeActions } from '../actions'
 import { fade } from '@material-ui/core/styles/colorManipulator'
 import { StyleRulesCallback, withStyles } from '@material-ui/core/styles'
 import {
@@ -18,6 +18,7 @@ import {
   Toolbar,
   Typography,
 } from '@material-ui/core'
+import PauseButton from './PauseButton';
 
 const styles: StyleRulesCallback = theme => ({
   title: {
@@ -72,7 +73,7 @@ const styles: StyleRulesCallback = theme => ({
   disconnect: {
     margin: 'auto 8px auto auto',
     color: theme.palette.primary.contrastText,
-  }
+  },
 })
 
 interface Props {
@@ -101,10 +102,11 @@ class TitleBar extends React.Component<Props, {}> {
           </IconButton>
           <Typography className={classes.title} variant="h6" color="inherit">MQTT Explorer</Typography>
           {this.renderSearch()}
+          <PauseButton />
           <Button className={classes.disconnect} onClick={actions.connection.disconnect}>
             Disconnect <CloudOff style={{ marginRight: '8px', paddingLeft: '8px' }}/>
           </Button>
-          <ConnectionHealthIndicator />
+          <ConnectionHealthIndicator withBackground={true} />
         </Toolbar>
       </AppBar>
     )

app/src/components/Tree/Tree.tsx

@@ -25,6 +25,7 @@ interface Props {
   autoExpandLimit: number
   highlightTopicUpdates: boolean
   selectTopicWithMouseOver: boolean
+  paused: boolean
 }
 
 interface State {
@@ -78,7 +79,10 @@ class Tree extends React.PureComponent<Props, State> {
         this.updateTimer && clearTimeout(this.updateTimer)
         this.updateTimer = undefined
         this.renderTime = performance.now()
-        this.props.tree && this.props.tree.applyUnmergedChanges()
+
+        if (!this.props.paused) {
+          this.props.tree && this.props.tree.applyUnmergedChanges()
+        }
         window.requestIdleCallback(() => {
           this.setState({ lastUpdate: this.renderTime })
         }, { timeout: 100 })
@@ -126,6 +130,7 @@ class Tree extends React.PureComponent<Props, State> {
 const mapStateToProps = (state: AppState) => {
   return {
     tree: state.tree.tree,
+    paused: state.tree.paused,
     filter: state.tree.filter,
     host: state.connection.host,
     autoExpandLimit: state.settings.autoExpandLimit,

app/src/reducers/Tree.ts

@@ -7,6 +7,7 @@ export interface TreeState {
   tree?: q.Tree<TopicViewModel>
   selectedTopic?: q.TreeNode<TopicViewModel>
   filter?: string
+  paused: boolean
 }
 
 export type Action = ShowTree | SelectTopic
@@ -14,6 +15,8 @@ export type Action = ShowTree | SelectTopic
 export enum ActionTypes {
   TREE_SHOW_TREE = 'TREE_SHOW_TREE',
   TREE_SELECT_TOPIC = 'TREE_SELECT_TOPIC',
+  TREE_RESUME_UPDATES = 'TREE_RESUME_UPDATES',
+  TREE_PAUSE_UPDATES = 'TREE_PAUSE_UPDATES',
 }
 
 export interface ShowTree {
@@ -27,11 +30,26 @@ export interface SelectTopic {
   selectedTopic?: q.TreeNode<TopicViewModel>
 }
 
-const initialState: TreeState = { }
+export interface SetPause {
+  type: ActionTypes.TREE_PAUSE_UPDATES | ActionTypes.TREE_RESUME_UPDATES
+}
+
+const initialState: TreeState = {
+  paused: false,
+}
+
+const setPaused = (pause: boolean) => (state: TreeState, action: ShowTree) => {
+  return {
+    ...state,
+    paused: pause,
+  }
+}
 
 export const treeReducer = createReducer(initialState, {
   TREE_SHOW_TREE: showTree,
   TREE_SELECT_TOPIC: selectTopic,
+  TREE_PAUSE_UPDATES: setPaused(true),
+  TREE_RESUME_UPDATES: setPaused(false),
 })
 
 function showTree(state: TreeState, action: ShowTree) {