From 0f04f9fbb4951c1a81d210f61d0fd0323e32c1b7 Mon Sep 17 00:00:00 2001
From: Daniel Imms <daimms@microsoft.com>
Date: Wed, 17 Jan 2018 14:10:03 -0800
Subject: [PATCH] Rotate rows to ensure an item will be read in nav mode when
 scrolling

---
 src/AccessibilityManager.ts | 19 +++++++++++++++++--
 src/Interfaces.ts           |  2 +-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/AccessibilityManager.ts b/src/AccessibilityManager.ts
index e36efbec..a958d10b 100644
--- a/src/AccessibilityManager.ts
+++ b/src/AccessibilityManager.ts
@@ -187,14 +187,24 @@ export class AccessibilityManager implements IDisposable {
 
   private _renderRows(start: number, end: number): void {
     const buffer: IBuffer = (<any>this._terminal.buffer);
+    const setSize = (buffer.lines.length).toString();
     for (let i = start; i <= end; i++) {
       const lineData = buffer.translateBufferLineToString(buffer.ydisp + i, true);
       this._rowElements[i].textContent = lineData;
-      this._rowElements[i].setAttribute('aria-posinset', (buffer.ydisp + i + 1).toString());
-      this._rowElements[i].setAttribute('aria-setsize', (buffer.lines.length).toString());
+      const posInSet = (buffer.ydisp + i + 1).toString();
+      this._rowElements[i].setAttribute('aria-posinset', posInSet);
+      this._rowElements[i].setAttribute('aria-setsize', setSize);
     }
   }
 
+  public rotateRows(): void {
+    this._rowContainer.removeChild(this._rowElements.shift());
+    const newRowIndex = this._rowElements.length;
+    this._rowElements[newRowIndex] = this._createAccessibilityTreeNode();
+    this._rowContainer.appendChild(this._rowElements[newRowIndex]);
+    this._refreshRowsDimensions();
+  }
+
   private _refreshRowsDimensions(): void {
     const buffer: IBuffer = (<any>this._terminal.buffer);
     const dimensions = this._terminal.renderer.dimensions;
@@ -342,6 +352,11 @@ class NavigationMode implements IDisposable {
   }
 
   private _navigateToElement(absoluteRow: number): void {
+    if (absoluteRow < this._terminal.buffer.ydisp || absoluteRow >= this._terminal.buffer.ydisp + this._terminal.rows) {
+      // Rotate rows to ensure the next focused item is read out correctly
+      this._accessibilityManager.rotateRows();
+    }
+
     absoluteRow = this._terminal.scrollToRow(absoluteRow);
 
     if (this._focusedElement) {
diff --git a/src/Interfaces.ts b/src/Interfaces.ts
index 4dc572d1..a1623a67 100644
--- a/src/Interfaces.ts
+++ b/src/Interfaces.ts
@@ -251,7 +251,7 @@ export interface IEventEmitter {
 export interface IListenerType {
     (data?: any): void;
     listener?: (data?: any) => void;
-};
+}
 
 export interface ILinkMatcherOptions {
   /**