Support serializing tabs

Author: Tyriar

addons/xterm-addon-serialize/src/SerializeAddon.api.ts

@@ -260,10 +260,16 @@ describe('SerializeAddon', () => {
   it('serialize tabs correctly', async () =>  {
     const lines = [
       'a\tb',
-      'foo\tbar\tbaz'
+      'aa\tc',
+      'aaa\td'
+    ];
+    const expected = [
+      'a\x1b[7Cb',
+      'aa\x1b[6Cc',
+      'aaa\x1b[5Cd'
     ];
     await writeSync(page, lines.join('\\r\\n'));
-    assert.equal(await page.evaluate(`serializeAddon.serialize();`), lines.join('\r\n'));
+    assert.equal(await page.evaluate(`serializeAddon.serialize();`), expected.join('\r\n'));
   });
 });
 

addons/xterm-addon-serialize/src/SerializeAddon.ts

@@ -79,6 +79,7 @@ class StringSerializeHandler extends BaseSerializeHandler {
   private _rowIndex: number = 0;
   private _allRows: string[] = new Array<string>();
   private _currentRow: string = '';
+  private _nullCellCount: number = 0;
   private _sgrSeq: number[] = [];
 
   constructor(buffer: IBuffer) {
@@ -92,6 +93,7 @@ class StringSerializeHandler extends BaseSerializeHandler {
   protected _lineEnd(row: number): void {
     this._allRows[this._rowIndex++] = this._currentRow;
     this._currentRow = '';
+    this._nullCellCount = 0;
   }
 
   protected _cellFlagsChanged(cell: IBufferCell, oldCell: IBufferCell, row: number, col: number): void {
@@ -133,6 +135,15 @@ class StringSerializeHandler extends BaseSerializeHandler {
   }
 
   protected _nextCell(cell: IBufferCell, oldCell: IBufferCell, row: number, col: number): void {
+    // Count number of null cells encountered after the last non-null cell and move the cursor
+    // if a non-null cell is found (eg. \t or cursor move)
+    if (cell.char === '') {
+      this._nullCellCount++;
+    } else if (this._nullCellCount > 0) {
+      this._currentRow += `\x1b[${this._nullCellCount}C`;
+      this._nullCellCount = 0;
+    }
+
     const fgChanged = !cell.equalFg(oldCell);
     const bgChanged = !cell.equalBg(oldCell);
     const flagsChanged = !cell.equalFlags(oldCell);