Properly setup and maintain tab stops for the alt buffer

src/Buffer.ts

@@ -82,10 +82,10 @@ export class Buffer implements IBuffer {
  this.ybase = 0;
  this.y = 0;
  this.x = 0;
- this.tabs = {};
  this._lines = new CircularList<LineData>(this._getCorrectBufferLength(this._terminal.rows));
  this.scrollTop = 0;
  this.scrollBottom = this._terminal.rows - 1;
+ this.setupTabStops();
  }
 
  /**
@@ -233,4 +233,47 @@ export class Buffer implements IBuffer {
 
  return lineString.substring(widthAdjustedStartCol, finalEndCol);
  }
+
+ /**
+ * Setup the tab stops.
+ * @param i The index to start setting up tab stops from.
+ */
+ public setupTabStops(i?: number): void {
+ if (i != null) {
+ if (!this.tabs[i]) {
+ i = this.prevStop(i);
+ }
+ } else {
+ this.tabs = {};
+ i = 0;
+ }
+
+ for (; i < this._terminal.cols; i += this._terminal.options.tabStopWidth) {
+ this.tabs[i] = true;
+ }
+ }
+
+ /**
+ * Move the cursor to the previous tab stop from the given position (default is current).
+ * @param x The position to move the cursor to the previous tab stop.
+ */
+ public prevStop(x?: number): number {
+ if (x == null) {
+ x = this.x;
+ }
+ while (!this.tabs[--x] && x > 0);
+ return x >= this._terminal.cols ? this._terminal.cols - 1 : x < 0 ? 0 : x;
+ }
+
+ /**
+ * Move the cursor one tab stop forward from the given position (default is current).
+ * @param x The position to move the cursor one tab stop forward.
+ */
+ public nextStop(x?: number): number {
+ if (x == null) {
+ x = this.x;
+ }
+ while (!this.tabs[++x] && x < this._terminal.cols);
+ return x >= this._terminal.cols ? this._terminal.cols - 1 : x < 0 ? 0 : x;
+ }
 }

src/BufferSet.ts

@@ -28,6 +28,8 @@ export class BufferSet extends EventEmitter implements IBufferSet {
  // See http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-The-Alternate-Screen-Buffer
  this._alt = new Buffer(this._terminal, false);
  this._activeBuffer = this._normal;
+
+ this.setupTabStops();
  }
 
  /**
@@ -87,4 +89,13 @@ export class BufferSet extends EventEmitter implements IBufferSet {
  this._normal.resize(newCols, newRows);
  this._alt.resize(newCols, newRows);
  }
+
+ /**
+ * Setup the tab stops.
+ * @param i The index to start setting up tab stops from.
+ */
+ public setupTabStops(i?: number): void {
+ this._normal.setupTabStops(i);
+ this._alt.setupTabStops(i);
+ }
 }

src/InputHandler.ts

@@ -157,7 +157,7 @@ export class InputHandler implements IInputHandler {
  * Horizontal Tab (HT) (Ctrl-I).
  */
  public tab(): void {
- this._terminal.buffer.x = this._terminal.nextStop();
+ this._terminal.buffer.x = this._terminal.buffer.nextStop();
  }
 
  /**
@@ -349,7 +349,7 @@ export class InputHandler implements IInputHandler {
  public cursorForwardTab(params: number[]): void {
  let param = params[0] || 1;
  while (param--) {
- this._terminal.buffer.x = this._terminal.nextStop();
+ this._terminal.buffer.x = this._terminal.buffer.nextStop();
  }
  }
 
@@ -548,7 +548,7 @@ export class InputHandler implements IInputHandler {
  public cursorBackwardTab(params: number[]): void {
  let param = params[0] || 1;
  while (param--) {
- this._terminal.buffer.x = this._terminal.prevStop();
+ this._terminal.buffer.x = this._terminal.buffer.prevStop();
  }
  }
 

src/Interfaces.ts

@@ -92,14 +92,12 @@ export interface IInputHandlingTerminal extends IEventEmitter {
  convertEol: boolean;
  updateRange(y: number): void;
  scroll(isWrapped?: boolean): void;
- nextStop(x?: number): number;
  setgLevel(g: number): void;
  eraseAttr(): number;
  eraseRight(x: number, y: number): void;
  eraseLine(y: number): void;
  eraseLeft(x: number, y: number): void;
  blankLine(cur?: boolean, isWrapped?: boolean): LineData;
- prevStop(x?: number): number;
  is(term: string): boolean;
  send(data: string): void;
  setgCharset(g: number, charset: Charset): void;
@@ -146,6 +144,8 @@ export interface IBuffer {
  savedY: number;
  savedX: number;
  translateBufferLineToString(lineIndex: number, trimRight: boolean, startCol?: number, endCol?: number): string;
+ nextStop(x?: number): number;
+ prevStop(x?: number): number;
 }
 
 export interface IBufferSet {

src/Terminal.ts

@@ -392,8 +392,6 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
  if (this.selectionManager) {
  this.selectionManager.setBuffer(this.buffer);
  }
-
- this.setupStops();
  }
 
  /**
@@ -486,7 +484,7 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
  this.buffers.resize(this.cols, this.rows);
  this.viewport.syncScrollArea();
  break;
- case 'tabStopWidth': this.setupStops(); break;
+ case 'tabStopWidth': this.buffers.setupTabStops(); break;
  case 'bellSound':
  case 'bellStyle': this.syncBellSound(); break;
  }
@@ -1938,7 +1936,7 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
 
  this.cols = x;
  this.rows = y;
- this.setupStops(this.cols);
+ this.buffers.setupTabStops(this.cols);
 
  this.charMeasure.measure();
 
@@ -1971,45 +1969,6 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
  this.refreshEnd = this.rows - 1;
  }
 
- /**
- * Setup the tab stops.
- * @param {number} i
- */
- public setupStops(i?: number): void {
- if (i != null) {
- if (!this.buffer.tabs[i]) {
- i = this.prevStop(i);
- }
- } else {
- this.buffer.tabs = {};
- i = 0;
- }
-
- for (; i < this.cols; i += this.getOption('tabStopWidth')) {
- this.buffer.tabs[i] = true;
- }
- }
-
- /**
- * Move the cursor to the previous tab stop from the given position (default is current).
- * @param {number} x The position to move the cursor to the previous tab stop.
- */
- public prevStop(x?: number): number {
- if (x == null) x = this.buffer.x;
- while (!this.buffer.tabs[--x] && x > 0);
- return x >= this.cols ? this.cols - 1 : x < 0 ? 0 : x;
- }
-
- /**
- * Move the cursor one tab stop forward from the given position (default is current).
- * @param {number} x The position to move the cursor one tab stop forward.
- */
- public nextStop(x?: number): number {
- if (x == null) x = this.buffer.x;
- while (!this.buffer.tabs[++x] && x < this.cols);
- return x >= this.cols ? this.cols - 1 : x < 0 ? 0 : x;
- }
-
  /**
  * Erase in the identified line everything from "x" to the end of the line (right).
  * @param {number} x The column from which to start erasing to the end of the line.

src/utils/TestUtils.test.ts

@@ -189,6 +189,12 @@ export class MockBuffer implements IBuffer {
  translateBufferLineToString(lineIndex: number, trimRight: boolean, startCol?: number, endCol?: number): string {
  throw new Error('Method not implemented.');
  }
+ nextStop(x?: number): number {
+ throw new Error('Method not implemented.');
+ }
+ prevStop(x?: number): number {
+ throw new Error('Method not implemented.');
+ }
 }
 
 export class MockViewport implements IViewport {