--- /dev/null
+/**
+ * Copyright (c) 2017 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { IBuffer, IBufferSet } from 'common/buffer/Types';
+import { IAttributeData } from 'common/Types';
+import { Buffer } from 'common/buffer/Buffer';
+import { EventEmitter, IEvent } from 'common/EventEmitter';
+import { IOptionsService, IBufferService } from 'common/services/Services';
+
+/**
+ * The BufferSet represents the set of two buffers used by xterm terminals (normal and alt) and
+ * provides also utilities for working with them.
+ */
+export class BufferSet implements IBufferSet {
+ private _normal: Buffer;
+ private _alt: Buffer;
+ private _activeBuffer: Buffer;
+
+
+ private _onBufferActivate = new EventEmitter<{activeBuffer: IBuffer, inactiveBuffer: IBuffer}>();
+ public get onBufferActivate(): IEvent<{activeBuffer: IBuffer, inactiveBuffer: IBuffer}> { return this._onBufferActivate.event; }
+
+ /**
+ * Create a new BufferSet for the given terminal.
+ * @param _terminal - The terminal the BufferSet will belong to
+ */
+ constructor(
+ readonly optionsService: IOptionsService,
+ readonly bufferService: IBufferService
+ ) {
+ this._normal = new Buffer(true, optionsService, bufferService);
+ this._normal.fillViewportRows();
+
+ // The alt buffer should never have scrollback.
+ // See http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-The-Alternate-Screen-Buffer
+ this._alt = new Buffer(false, optionsService, bufferService);
+ this._activeBuffer = this._normal;
+
+ this.setupTabStops();
+ }
+
+ /**
+ * Returns the alt Buffer of the BufferSet
+ */
+ public get alt(): Buffer {
+ return this._alt;
+ }
+
+ /**
+ * Returns the normal Buffer of the BufferSet
+ */
+ public get active(): Buffer {
+ return this._activeBuffer;
+ }
+
+ /**
+ * Returns the currently active Buffer of the BufferSet
+ */
+ public get normal(): Buffer {
+ return this._normal;
+ }
+
+ /**
+ * Sets the normal Buffer of the BufferSet as its currently active Buffer
+ */
+ public activateNormalBuffer(): void {
+ if (this._activeBuffer === this._normal) {
+ return;
+ }
+ this._normal.x = this._alt.x;
+ this._normal.y = this._alt.y;
+ // The alt buffer should always be cleared when we switch to the normal
+ // buffer. This frees up memory since the alt buffer should always be new
+ // when activated.
+ this._alt.clear();
+ this._activeBuffer = this._normal;
+ this._onBufferActivate.fire({
+ activeBuffer: this._normal,
+ inactiveBuffer: this._alt
+ });
+ }
+
+ /**
+ * Sets the alt Buffer of the BufferSet as its currently active Buffer
+ */
+ public activateAltBuffer(fillAttr?: IAttributeData): void {
+ if (this._activeBuffer === this._alt) {
+ return;
+ }
+ // Since the alt buffer is always cleared when the normal buffer is
+ // activated, we want to fill it when switching to it.
+ this._alt.fillViewportRows(fillAttr);
+ this._alt.x = this._normal.x;
+ this._alt.y = this._normal.y;
+ this._activeBuffer = this._alt;
+ this._onBufferActivate.fire({
+ activeBuffer: this._alt,
+ inactiveBuffer: this._normal
+ });
+ }
+
+ /**
+ * Resizes both normal and alt buffers, adjusting their data accordingly.
+ * @param newCols The new number of columns.
+ * @param newRows The new number of rows.
+ */
+ public resize(newCols: number, newRows: number): void {
+ 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);
+ }
+}