Added Message History to Serial Monitor

Author: nmzaheer

Diff for: arduino-ide-extension/src/browser/serial/monitor/serial-monitor-send-input.tsx

@@ -6,6 +6,88 @@ import { BoardsServiceProvider } from '../../boards/boards-service-provider';
 import { MonitorModel } from '../../monitor-model';
 import { Unknown } from '../../../common/nls';
 
+class HistoryList {
+  private ring: string[];
+  private size: number;
+  private begin: number;
+  private index: number;
+  private end: number;
+  private traverse: boolean;
+
+  constructor(size: number = 100) {
+    this.init = this.init.bind(this);
+    this.push = this.push.bind(this);
+    this.prev = this.prev.bind(this);
+    this.next = this.next.bind(this);
+    this.init(size);
+  }
+  private init(size: number = 100) {
+    this.ring = [];
+    this.size = (size > 0) ? size : 1;
+    this.begin = 0;
+    this.index = 0;
+    this.end = -1;
+    this.traverse = false;
+  }
+
+  push(val: string): number {
+    this.end++;
+    if (this.ring.length >= this.size) {
+      if (this.end >= this.size)
+        this.end = 0;
+      if (this.end === this.begin) {
+        this.begin++;
+        if (this.begin >= this.size)
+          this.begin = 0;
+      }
+    }
+    this.ring[this.end] = val;
+    this.index = this.end;
+    this.traverse = false;
+    return this.index;
+  }
+
+  prev(): string {
+    if (this.ring.length < 1) {
+      return '';
+    }
+    if (this.index === this.end) {
+      this.traverse = true;
+      this.index--;
+      return this.ring[this.end];
+    }
+    if (this.index !== this.begin) {
+      if (this.traverse) {
+        this.traverse = false;
+      }
+      else
+        this.index = (this.index > 0) ? --this.index : this.size - 1;
+    }
+
+    return this.ring[this.index];
+  }
+
+  next(): string {
+    if (this.ring.length < 1) {
+      return '';
+    }
+    if (this.index !== this.end) {
+      this.traverse = true;
+      this.index = (++this.index < this.size) ? this.index : 0;
+      return this.ring[this.index];
+    }
+    else {
+      if (!this.traverse) {
+        return '';
+      }
+      else {
+        this.traverse = false;
+        return this.ring[this.index];
+      }
+    }
+  }
+}
+
 export namespace SerialMonitorSendInput {
   export interface Props {
     readonly boardsServiceProvider: BoardsServiceProvider;
@@ -16,6 +98,7 @@ export namespace SerialMonitorSendInput {
   export interface State {
     text: string;
     connected: boolean;
+    history: HistoryList;
   }
 }
 
@@ -27,7 +110,7 @@ export class SerialMonitorSendInput extends React.Component<
 
   constructor(props: Readonly<SerialMonitorSendInput.Props>) {
     super(props);
-    this.state = { text: '', connected: true };
+    this.state = { text: '', connected: true, history: new HistoryList() };
     this.onChange = this.onChange.bind(this);
     this.onSend = this.onSend.bind(this);
     this.onKeyDown = this.onKeyDown.bind(this);
@@ -110,8 +193,23 @@ export class SerialMonitorSendInput extends React.Component<
     if (keyCode) {
       const { key } = keyCode;
       if (key === Key.ENTER) {
+        // NOTE: order of operations is critical here. Push the current state.text
+        // onto the history stack before sending. After sending, state.text is empty
+        // and you'd end up pushing '' onto the history stack.
+        if (this.state.text.length > 0) {
+          this.state.history.push(this.state.text);
+        }
         this.onSend();
+      } 
+      else if (key === Key.ARROW_UP) {
+        this.setState({ text: this.state.history.prev()});
+      } 
+      else if (key === Key.ARROW_DOWN) {
+        this.setState({ text: this.state.history.next()});
+      }
+      else if (key === Key.ESCAPE) {
+        this.setState({ text: ''});
       }
     }
   }
-}
+}