Serial Monitor message history #1404

Author: dwightfowler-cd

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

@@ -6,6 +6,75 @@ import { BoardsServiceProvider } from '../../boards/boards-service-provider';
 import { MonitorModel } from '../../monitor-model';
 import { Unknown } from '../../../common/nls';
 
+class RingList {
+  protected ring: string[];
+  protected size: number;
+  protected begin: number;
+  protected index: number;
+  protected end: number;
+
+  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);
+  }
+
+  public Init(size: number = 100)
+  {
+    this.ring = [];
+    this.size = (size > 0) ? size : 1;
+    this.begin = 0;
+    this.index = 0;
+    this.end = -1;
+  }
+
+  public 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;
+
+    return this.index;
+  }
+
+  public Prev(): string {
+    if (this.ring.length < 1) {
+      return "";
+    }
+
+    if (this.index !== this.begin) {
+      this.index = (this.index > 0) ? --this.index : this.size - 1;
+    }
+
+    return this.ring[this.index];
+  }
+
+  public Next(): string {
+    if (this.ring.length < 1) {
+      return "";
+    }
+
+    if (this.index !== this.end) {
+      this.index = (++this.index < this.size) ? this.index : 0;
+    }
+
+    return this.ring[this.index];
+  }
+
+}
+
 export namespace SerialMonitorSendInput {
   export interface Props {
     readonly boardsServiceProvider: BoardsServiceProvider;
@@ -16,6 +85,7 @@ export namespace SerialMonitorSendInput {
   export interface State {
     text: string;
     connected: boolean;
+    history: RingList;
   }
 }
 
@@ -27,7 +97,7 @@ 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 RingList() };
     this.onChange = this.onChange.bind(this);
     this.onSend = this.onSend.bind(this);
     this.onKeyDown = this.onKeyDown.bind(this);
@@ -110,7 +180,17 @@ 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()});
       }
     }
   }