forked from xtermjs/xterm.js
/
BufferSet.ts
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/
BufferSet.ts
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/**
* Copyright (c) 2017 The xterm.js authors. All rights reserved.
* @license MIT
*/
import { ITerminal, IBufferSet } from './Types';
import { Buffer } from './Buffer';
import { EventEmitter } from './common/EventEmitter';
/**
* 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 extends EventEmitter implements IBufferSet {
private _normal: Buffer;
private _alt: Buffer;
private _activeBuffer: Buffer;
/**
* Create a new BufferSet for the given terminal.
* @param _terminal - The terminal the BufferSet will belong to
*/
constructor(private _terminal: ITerminal) {
super();
this._normal = new Buffer(this._terminal, true);
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(this._terminal, false);
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;
}
// 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.emit('activate', {
activeBuffer: this._normal,
inactiveBuffer: this._alt
});
}
/**
* Sets the alt Buffer of the BufferSet as its currently active Buffer
*/
public activateAltBuffer(): 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();
this._activeBuffer = this._alt;
this.emit('activate', {
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);
}
}