Mostly implemented buffer API

Part of #1994

src/public/Terminal.ts

@@ -3,8 +3,8 @@
  * @license MIT
  */
 
-import { Terminal as ITerminalApi, ITerminalOptions, IMarker, IDisposable, ILinkMatcherOptions, ITheme, ILocalizableStrings } from 'xterm';
-import { ITerminal } from '../Types';
+import { Terminal as ITerminalApi, ITerminalOptions, IMarker, IDisposable, ILinkMatcherOptions, ITheme, ILocalizableStrings, IBuffer as IBufferApi, IBufferLine as IBufferLineApi, IBufferCell as IBufferCellApi } from 'xterm';
+import { ITerminal, IBufferLine, IBuffer } from '../Types';
 import { Terminal as TerminalCore } from '../Terminal';
 import * as Strings from '../Strings';
 
@@ -19,6 +19,7 @@ export class Terminal implements ITerminalApi {
   public get textarea(): HTMLTextAreaElement { return this._core.textarea; }
   public get rows(): number { return this._core.rows; }
   public get cols(): number { return this._core.cols; }
+  public get buffer(): IBufferApi { return new BufferApiView(this._core.buffer); }
   public get markers(): IMarker[] { return this._core.markers; }
   public blur(): void {
     this._core.blur();
@@ -158,3 +159,30 @@ export class Terminal implements ITerminalApi {
     return Strings;
   }
 }
+
+class BufferApiView implements IBufferApi {
+  constructor(private _buffer: IBuffer) {}
+
+  public get cursorY(): number { return this._buffer.y; }
+  public get cursorX(): number { return this._buffer.x; }
+  public get viewportY(): number { return this._buffer.ydisp; }
+  public get baseY(): number { return this._buffer.ybase; }
+  public get length(): number { return this._buffer.lines.length; }
+  public getLine(y: number): IBufferLineApi { return new BufferLineApiView(this._buffer.lines.get(y)); }
+}
+
+class BufferLineApiView implements IBufferLineApi {
+  constructor(private _line: IBufferLine) {}
+
+  public get isWrapped(): boolean { return this._line.isWrapped; }
+  public getCell(x: number): IBufferCellApi { return new BufferCellApiView(this._line, x); }
+  public translateToString(trimRight: boolean, startColumn: number, endColumn: number): string {
+    return this._line.translateToString(trimRight, startColumn, endColumn);
+  }
+}
+
+class BufferCellApiView implements IBufferCellApi {
+  constructor(private _line: IBufferLine, private _x: number) {}
+  public get char(): string { return this._line.getString(this._x); }
+  public get width(): number { return this._line.getWidth(this._x); }
+}