src/SelectionManager.ts

   1 /**
   2  * @license MIT
   3  */
   4
   5 import * as Mouse from './utils/Mouse';
   6 import * as Browser from './utils/Browser';
   7 import { CharMeasure } from './utils/CharMeasure';
   8 import { CircularList } from './utils/CircularList';
   9 import { EventEmitter } from './EventEmitter';
  10 import { ITerminal } from './Interfaces';
  11 import { SelectionModel } from './SelectionModel';
  12
  13 /**
  14  * The number of pixels the mouse needs to be above or below the viewport in
  15  * order to scroll at the maximum speed.
  16  */
  17 const DRAG_SCROLL_MAX_THRESHOLD = 50;
  18
  19 /**
  20  * The maximum scrolling speed
  21  */
  22 const DRAG_SCROLL_MAX_SPEED = 15;
  23
  24 /**
  25  * The number of milliseconds between drag scroll updates.
  26  */
  27 const DRAG_SCROLL_INTERVAL = 50;
  28
  29 /**
  30  * The amount of time before mousedown events are no longer stacked to create
  31  * double/triple click events.
  32  */
  33 const CLEAR_MOUSE_DOWN_TIME = 400;
  34
  35 /**
  36  * The number of pixels in each direction that the mouse must move before
  37  * mousedown events are no longer stacked to create double/triple click events.
  38  */
  39 const CLEAR_MOUSE_DISTANCE = 10;
  40
  41 /**
  42  * A string containing all characters that are considered word separated by the
  43  * double click to select work logic.
  44  */
  45 const WORD_SEPARATORS = ' ()[]{}:\'"';
  46
  47 // TODO: Move these constants elsewhere, they belong in a buffer or buffer
  48 //       data/line class.
  49 const LINE_DATA_CHAR_INDEX = 1;
  50 const LINE_DATA_WIDTH_INDEX = 2;
  51
  52 const NON_BREAKING_SPACE_CHAR = String.fromCharCode(160);
  53 const ALL_NON_BREAKING_SPACE_REGEX = new RegExp(NON_BREAKING_SPACE_CHAR, 'g');
  54
  55 /**
  56  * Represents a position of a word on a line.
  57  */
  58 interface IWordPosition {
  59   start: number;
  60   length: number;
  61 }
  62
  63 /**
  64  * A selection mode, this drives how the selection behaves on mouse move.
  65  */
  66 enum SelectionMode {
  67   NORMAL,
  68   WORD,
  69   LINE
  70 }
  71
  72 /**
  73  * A class that manages the selection of the terminal. With help from
  74  * SelectionModel, SelectionManager handles with all logic associated with
  75  * dealing with the selection, including handling mouse interaction, wide
  76  * characters and fetching the actual text within the selection. Rendering is
  77  * not handled by the SelectionManager but a 'refresh' event is fired when the
  78  * selection is ready to be redrawn.
  79  */
  80 export class SelectionManager extends EventEmitter {
  81   protected _model: SelectionModel;
  82
  83   /**
  84    * The amount to scroll every drag scroll update (depends on how far the mouse
  85    * drag is above or below the terminal).
  86    */
  87   private _dragScrollAmount: number;
  88
  89   /**
  90    * The last time the mousedown event fired, this is used to track double and
  91    * triple clicks.
  92    */
  93   private _lastMouseDownTime: number;
  94
  95   /**
  96    * The last position the mouse was clicked [x, y].
  97    */
  98   private _lastMousePosition: [number, number];
  99
 100   /**
 101    * The number of clicks of the mousedown event. This is used to keep track of
 102    * double and triple clicks.
 103    */
 104   private _clickCount: number;
 105
 106   /**
 107    * The current selection mode.
 108    */
 109   private _activeSelectionMode: SelectionMode;
 110
 111   /**
 112    * A setInterval timer that is active while the mouse is down whose callback
 113    * scrolls the viewport when necessary.
 114    */
 115   private _dragScrollIntervalTimer: NodeJS.Timer;
 116
 117   /**
 118    * The animation frame ID used for refreshing the selection.
 119    */
 120   private _refreshAnimationFrame: number;
 121
 122   private _bufferTrimListener: any;
 123   private _mouseMoveListener: EventListener;
 124   private _mouseDownListener: EventListener;
 125   private _mouseUpListener: EventListener;
 126
 127   constructor(
 128     private _terminal: ITerminal,
 129     private _buffer: CircularList<any>,
 130     private _rowContainer: HTMLElement,
 131     private _charMeasure: CharMeasure
 132   ) {
 133     super();
 134     this._initListeners();
 135     this.enable();
 136
 137     this._model = new SelectionModel(_terminal);
 138     this._lastMouseDownTime = 0;
 139     this._activeSelectionMode = SelectionMode.NORMAL;
 140   }
 141
 142   /**
 143    * Initializes listener variables.
 144    */
 145   private _initListeners() {
 146     this._bufferTrimListener = (amount: number) => this._onTrim(amount);
 147     this._mouseMoveListener = event => this._onMouseMove(<MouseEvent>event);
 148     this._mouseDownListener = event => this._onMouseDown(<MouseEvent>event);
 149     this._mouseUpListener = event => this._onMouseUp(<MouseEvent>event);
 150   }
 151
 152   /**
 153    * Disables the selection manager. This is useful for when terminal mouse
 154    * are enabled.
 155    */
 156   public disable() {
 157     this.clearSelection();
 158     this._buffer.off('trim', this._bufferTrimListener);
 159     this._rowContainer.removeEventListener('mousedown', this._mouseDownListener);
 160   }
 161
 162   /**
 163    * Enable the selection manager.
 164    */
 165   public enable() {
 166     // Only adjust the selection on trim, shiftElements is rarely used (only in
 167     // reverseIndex) and delete in a splice is only ever used when the same
 168     // number of elements was just added. Given this is could actually be
 169     // beneficial to leave the selection as is for these cases.
 170     this._buffer.on('trim', this._bufferTrimListener);
 171     this._rowContainer.addEventListener('mousedown', this._mouseDownListener);
 172   }
 173
 174   /**
 175    * Sets the active buffer, this should be called when the alt buffer is
 176    * switched in or out.
 177    * @param buffer The active buffer.
 178    */
 179   public setBuffer(buffer: CircularList<any>): void {
 180     this._buffer = buffer;
 181     this.clearSelection();
 182   }
 183
 184   /**
 185    * Gets whether there is an active text selection.
 186    */
 187   public get hasSelection(): boolean {
 188     const start = this._model.finalSelectionStart;
 189     const end = this._model.finalSelectionEnd;
 190     if (!start || !end) {
 191       return false;
 192     }
 193     return start[0] !== end[0] || start[1] !== end[1];
 194   }
 195
 196   /**
 197    * Gets the text currently selected.
 198    */
 199   public get selectionText(): string {
 200     const start = this._model.finalSelectionStart;
 201     const end = this._model.finalSelectionEnd;
 202     if (!start || !end) {
 203       return '';
 204     }
 205
 206     // Get first row
 207     const startRowEndCol = start[1] === end[1] ? end[0] : null;
 208     let result: string[] = [];
 209     result.push(this._translateBufferLineToString(this._buffer.get(start[1]), true, start[0], startRowEndCol));
 210
 211     // Get middle rows
 212     for (let i = start[1] + 1; i <= end[1] - 1; i++) {
 213       const bufferLine = this._buffer.get(i);
 214       const lineText = this._translateBufferLineToString(bufferLine, true);
 215       if (bufferLine.isWrapped) {
 216         result[result.length - 1] += lineText;
 217       } else {
 218         result.push(lineText);
 219       }
 220     }
 221
 222     // Get final row
 223     if (start[1] !== end[1]) {
 224       const bufferLine = this._buffer.get(end[1]);
 225       const lineText = this._translateBufferLineToString(bufferLine, true, 0, end[0]);
 226       if (bufferLine.isWrapped) {
 227         result[result.length - 1] += lineText;
 228       } else {
 229         result.push(lineText);
 230       }
 231     }
 232
 233     // Format string by replacing non-breaking space chars with regular spaces
 234     // and joining the array into a multi-line string.
 235     const formattedResult = result.map(line => {
 236       return line.replace(ALL_NON_BREAKING_SPACE_REGEX, ' ');
 237     }).join(Browser.isMSWindows ? '\r\n' : '\n');
 238
 239     return formattedResult;
 240   }
 241
 242   /**
 243    * Clears the current terminal selection.
 244    */
 245   public clearSelection(): void {
 246     this._model.clearSelection();
 247     this._removeMouseDownListeners();
 248     this.refresh();
 249   }
 250
 251   /**
 252    * Translates a buffer line to a string, with optional start and end columns.
 253    * Wide characters will count as two columns in the resulting string. This
 254    * function is useful for getting the actual text underneath the raw selection
 255    * position.
 256    * @param line The line being translated.
 257    * @param trimRight Whether to trim whitespace to the right.
 258    * @param startCol The column to start at.
 259    * @param endCol The column to end at.
 260    */
 261   private _translateBufferLineToString(line: any, trimRight: boolean, startCol: number = 0, endCol: number = null): string {
 262     // TODO: This function should live in a buffer or buffer line class
 263
 264     // Get full line
 265     let lineString = '';
 266     let widthAdjustedStartCol = startCol;
 267     let widthAdjustedEndCol = endCol;
 268     for (let i = 0; i < line.length; i++) {
 269       const char = line[i];
 270       lineString += char[LINE_DATA_CHAR_INDEX];
 271       // Adjust start and end cols for wide characters if they affect their
 272       // column indexes
 273       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 274         if (startCol >= i) {
 275           widthAdjustedStartCol--;
 276         }
 277         if (endCol >= i) {
 278           widthAdjustedEndCol--;
 279         }
 280       }
 281     }
 282
 283     // Calculate the final end col by trimming whitespace on the right of the
 284     // line if needed.
 285     let finalEndCol = widthAdjustedEndCol || line.length;
 286     if (trimRight) {
 287       const rightWhitespaceIndex = lineString.search(/\s+$/);
 288       if (rightWhitespaceIndex !== -1) {
 289         finalEndCol = Math.min(finalEndCol, rightWhitespaceIndex);
 290       }
 291       // Return the empty string if only trimmed whitespace is selected
 292       if (finalEndCol <= widthAdjustedStartCol) {
 293         return '';
 294       }
 295     }
 296
 297     return lineString.substring(widthAdjustedStartCol, finalEndCol);
 298   }
 299
 300   /**
 301    * Queues a refresh, redrawing the selection on the next opportunity.
 302    * @param isNewSelection Whether the selection should be registered as a new
 303    * selection on Linux.
 304    */
 305   public refresh(isNewSelection?: boolean): void {
 306     // Queue the refresh for the renderer
 307     if (!this._refreshAnimationFrame) {
 308       this._refreshAnimationFrame = window.requestAnimationFrame(() => this._refresh());
 309     }
 310
 311     // If the platform is Linux and the refresh call comes from a mouse event,
 312     // we need to update the selection for middle click to paste selection.
 313     if (Browser.isLinux && isNewSelection) {
 314       const selectionText = this.selectionText;
 315       if (selectionText.length) {
 316         this.emit('newselection', this.selectionText);
 317       }
 318     }
 319   }
 320
 321   /**
 322    * Fires the refresh event, causing consumers to pick it up and redraw the
 323    * selection state.
 324    */
 325   private _refresh(): void {
 326     this._refreshAnimationFrame = null;
 327     this.emit('refresh', { start: this._model.finalSelectionStart, end: this._model.finalSelectionEnd });
 328   }
 329
 330   /**
 331    * Selects all text within the terminal.
 332    */
 333   public selectAll(): void {
 334     this._model.isSelectAllActive = true;
 335     this.refresh();
 336   }
 337
 338   /**
 339    * Handle the buffer being trimmed, adjust the selection position.
 340    * @param amount The amount the buffer is being trimmed.
 341    */
 342   private _onTrim(amount: number) {
 343     const needsRefresh = this._model.onTrim(amount);
 344     if (needsRefresh) {
 345       this.refresh();
 346     }
 347   }
 348
 349   /**
 350    * Gets the 0-based [x, y] buffer coordinates of the current mouse event.
 351    * @param event The mouse event.
 352    */
 353   private _getMouseBufferCoords(event: MouseEvent): [number, number] {
 354     const coords = Mouse.getCoords(event, this._rowContainer, this._charMeasure, this._terminal.cols, this._terminal.rows, true);
 355     // Convert to 0-based
 356     coords[0]--;
 357     coords[1]--;
 358     // Convert viewport coords to buffer coords
 359     coords[1] += this._terminal.ydisp;
 360     return coords;
 361   }
 362
 363   /**
 364    * Gets the amount the viewport should be scrolled based on how far out of the
 365    * terminal the mouse is.
 366    * @param event The mouse event.
 367    */
 368   private _getMouseEventScrollAmount(event: MouseEvent): number {
 369     let offset = Mouse.getCoordsRelativeToElement(event, this._rowContainer)[1];
 370     const terminalHeight = this._terminal.rows * this._charMeasure.height;
 371     if (offset >= 0 && offset <= terminalHeight) {
 372       return 0;
 373     }
 374     if (offset > terminalHeight) {
 375       offset -= terminalHeight;
 376     }
 377
 378     offset = Math.min(Math.max(offset, -DRAG_SCROLL_MAX_THRESHOLD), DRAG_SCROLL_MAX_THRESHOLD);
 379     offset /= DRAG_SCROLL_MAX_THRESHOLD;
 380     return (offset / Math.abs(offset)) + Math.round(offset * (DRAG_SCROLL_MAX_SPEED - 1));
 381   }
 382
 383   /**
 384    * Handles te mousedown event, setting up for a new selection.
 385    * @param event The mousedown event.
 386    */
 387   private _onMouseDown(event: MouseEvent) {
 388     // Only action the primary button
 389     if (event.button !== 0) {
 390       return;
 391     }
 392
 393     // Tell the browser not to start a regular selection
 394     event.preventDefault();
 395
 396     // Reset drag scroll state
 397     this._dragScrollAmount = 0;
 398
 399     this._setMouseClickCount(event);
 400
 401     if (event.shiftKey) {
 402       this._onShiftClick(event);
 403     } else {
 404       if (this._clickCount === 1) {
 405           this._onSingleClick(event);
 406       } else if (this._clickCount === 2) {
 407           this._onDoubleClick(event);
 408       } else if (this._clickCount === 3) {
 409           this._onTripleClick(event);
 410       }
 411     }
 412
 413     this._addMouseDownListeners();
 414     this.refresh(true);
 415   }
 416
 417   /**
 418    * Adds listeners when mousedown is triggered.
 419    */
 420   private _addMouseDownListeners(): void {
 421     // Listen on the document so that dragging outside of viewport works
 422     this._rowContainer.ownerDocument.addEventListener('mousemove', this._mouseMoveListener);
 423     this._rowContainer.ownerDocument.addEventListener('mouseup', this._mouseUpListener);
 424     this._dragScrollIntervalTimer = setInterval(() => this._dragScroll(), DRAG_SCROLL_INTERVAL);
 425   }
 426
 427   /**
 428    * Removes the listeners that are registered when mousedown is triggered.
 429    */
 430   private _removeMouseDownListeners(): void {
 431     this._rowContainer.ownerDocument.removeEventListener('mousemove', this._mouseMoveListener);
 432     this._rowContainer.ownerDocument.removeEventListener('mouseup', this._mouseUpListener);
 433     clearInterval(this._dragScrollIntervalTimer);
 434     this._dragScrollIntervalTimer = null;
 435   }
 436
 437   /**
 438    * Performs a shift click, setting the selection end position to the mouse
 439    * position.
 440    * @param event The mouse event.
 441    */
 442   private _onShiftClick(event: MouseEvent): void {
 443     if (this._model.selectionStart) {
 444       this._model.selectionEnd = this._getMouseBufferCoords(event);
 445     }
 446   }
 447
 448   /**
 449    * Performs a single click, resetting relevant state and setting the selection
 450    * start position.
 451    * @param event The mouse event.
 452    */
 453   private _onSingleClick(event: MouseEvent): void {
 454     this._model.selectionStartLength = 0;
 455     this._model.isSelectAllActive = false;
 456     this._activeSelectionMode = SelectionMode.NORMAL;
 457     this._model.selectionStart = this._getMouseBufferCoords(event);
 458     if (this._model.selectionStart) {
 459       this._model.selectionEnd = null;
 460       // If the mouse is over the second half of a wide character, adjust the
 461       // selection to cover the whole character
 462       const char = this._buffer.get(this._model.selectionStart[1])[this._model.selectionStart[0]];
 463       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 464         this._model.selectionStart[0]++;
 465       }
 466     }
 467   }
 468
 469   /**
 470    * Performs a double click, selecting the current work.
 471    * @param event The mouse event.
 472    */
 473   private _onDoubleClick(event: MouseEvent): void {
 474     const coords = this._getMouseBufferCoords(event);
 475     if (coords) {
 476       this._activeSelectionMode = SelectionMode.WORD;
 477       this._selectWordAt(coords);
 478     }
 479   }
 480
 481   /**
 482    * Performs a triple click, selecting the current line and activating line
 483    * select mode.
 484    * @param event The mouse event.
 485    */
 486   private _onTripleClick(event: MouseEvent): void {
 487     const coords = this._getMouseBufferCoords(event);
 488     if (coords) {
 489       this._activeSelectionMode = SelectionMode.LINE;
 490       this._selectLineAt(coords[1]);
 491     }
 492   }
 493
 494   /**
 495    * Sets the number of clicks for the current mousedown event based on the time
 496    * and position of the last mousedown event.
 497    * @param event The mouse event.
 498    */
 499   private _setMouseClickCount(event: MouseEvent): void {
 500     let currentTime = (new Date()).getTime();
 501     if (currentTime - this._lastMouseDownTime > CLEAR_MOUSE_DOWN_TIME || this._distanceFromLastMousePosition(event) > CLEAR_MOUSE_DISTANCE) {
 502       this._clickCount = 0;
 503     }
 504     this._lastMouseDownTime = currentTime;
 505     this._lastMousePosition = [event.pageX, event.pageY];
 506     this._clickCount++;
 507   }
 508
 509   /**
 510    * Gets the maximum number of pixels in each direction the mouse has moved.
 511    * @param event The mouse event.
 512    */
 513   private _distanceFromLastMousePosition(event: MouseEvent): number {
 514     const result = Math.max(
 515         Math.abs(this._lastMousePosition[0] - event.pageX),
 516         Math.abs(this._lastMousePosition[1] - event.pageY));
 517     return result;
 518   }
 519
 520   /**
 521    * Handles the mousemove event when the mouse button is down, recording the
 522    * end of the selection and refreshing the selection.
 523    * @param event The mousemove event.
 524    */
 525   private _onMouseMove(event: MouseEvent) {
 526     // Record the previous position so we know whether to redraw the selection
 527     // at the end.
 528     const previousSelectionEnd = this._model.selectionEnd ? [this._model.selectionEnd[0], this._model.selectionEnd[1]] : null;
 529
 530     // Set the initial selection end based on the mouse coordinates
 531     this._model.selectionEnd = this._getMouseBufferCoords(event);
 532
 533     // Select the entire line if line select mode is active.
 534     if (this._activeSelectionMode === SelectionMode.LINE) {
 535       if (this._model.selectionEnd[1] < this._model.selectionStart[1]) {
 536         this._model.selectionEnd[0] = 0;
 537       } else {
 538         this._model.selectionEnd[0] = this._terminal.cols;
 539       }
 540     } else if (this._activeSelectionMode === SelectionMode.WORD) {
 541       this._selectToWordAt(this._model.selectionEnd);
 542     }
 543
 544     // Determine the amount of scrolling that will happen.
 545     this._dragScrollAmount = this._getMouseEventScrollAmount(event);
 546
 547     // If the cursor was above or below the viewport, make sure it's at the
 548     // start or end of the viewport respectively.
 549     if (this._dragScrollAmount > 0) {
 550       this._model.selectionEnd[0] = this._terminal.cols - 1;
 551     } else if (this._dragScrollAmount < 0) {
 552       this._model.selectionEnd[0] = 0;
 553     }
 554
 555     // If the character is a wide character include the cell to the right in the
 556     // selection. Note that selections at the very end of the line will never
 557     // have a character.
 558     if (this._model.selectionEnd[1] < this._buffer.length) {
 559       const char = this._buffer.get(this._model.selectionEnd[1])[this._model.selectionEnd[0]];
 560       if (char && char[2] === 0) {
 561         this._model.selectionEnd[0]++;
 562       }
 563     }
 564
 565     // Only draw here if the selection changes.
 566     if (!previousSelectionEnd ||
 567         previousSelectionEnd[0] !== this._model.selectionEnd[0] ||
 568         previousSelectionEnd[1] !== this._model.selectionEnd[1]) {
 569       this.refresh(true);
 570     }
 571   }
 572
 573   /**
 574    * The callback that occurs every DRAG_SCROLL_INTERVAL ms that does the
 575    * scrolling of the viewport.
 576    */
 577   private _dragScroll() {
 578     if (this._dragScrollAmount) {
 579       this._terminal.scrollDisp(this._dragScrollAmount, false);
 580       // Re-evaluate selection
 581       if (this._dragScrollAmount > 0) {
 582         this._model.selectionEnd = [this._terminal.cols - 1, this._terminal.ydisp + this._terminal.rows];
 583       } else {
 584         this._model.selectionEnd = [0, this._terminal.ydisp];
 585       }
 586       this.refresh();
 587     }
 588   }
 589
 590   /**
 591    * Handles the mouseup event, removing the mousedown listeners.
 592    * @param event The mouseup event.
 593    */
 594   private _onMouseUp(event: MouseEvent) {
 595     this._removeMouseDownListeners();
 596   }
 597
 598   /**
 599    * Converts a viewport column to the character index on the buffer line, the
 600    * latter takes into account wide characters.
 601    * @param coords The coordinates to find the 2 index for.
 602    */
 603   private _convertViewportColToCharacterIndex(bufferLine: any, coords: [number, number]): number {
 604     let charIndex = coords[0];
 605     for (let i = 0; coords[0] >= i; i++) {
 606       const char = bufferLine[i];
 607       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 608         charIndex--;
 609       }
 610     }
 611     return charIndex;
 612   }
 613
 614   /**
 615    * Gets positional information for the word at the coordinated specified.
 616    * @param coords The coordinates to get the word at.
 617    */
 618   private _getWordAt(coords: [number, number]): IWordPosition {
 619     const bufferLine = this._buffer.get(coords[1]);
 620     const line = this._translateBufferLineToString(bufferLine, false);
 621
 622     // Get actual index, taking into consideration wide characters
 623     let endIndex = this._convertViewportColToCharacterIndex(bufferLine, coords);
 624     let startIndex = endIndex;
 625
 626     // Record offset to be used later
 627     const charOffset = coords[0] - startIndex;
 628     let leftWideCharCount = 0;
 629     let rightWideCharCount = 0;
 630
 631     if (line.charAt(startIndex) === ' ') {
 632       // Expand until non-whitespace is hit
 633       while (startIndex > 0 && line.charAt(startIndex - 1) === ' ') {
 634         startIndex--;
 635       }
 636       while (endIndex < line.length && line.charAt(endIndex + 1) === ' ') {
 637         endIndex++;
 638       }
 639     } else {
 640       // Expand until whitespace is hit. This algorithm works by scanning left
 641       // and right from the starting position, keeping both the index format
 642       // (line) and the column format (bufferLine) in sync. When a wide
 643       // character is hit, it is recorded and the column index is adjusted.
 644       let startCol = coords[0];
 645       let endCol = coords[0];
 646       // Consider the initial position, skip it and increment the wide char
 647       // variable
 648       if (bufferLine[startCol][LINE_DATA_WIDTH_INDEX] === 0) {
 649         leftWideCharCount++;
 650         startCol--;
 651       }
 652       if (bufferLine[endCol][LINE_DATA_WIDTH_INDEX] === 2) {
 653         rightWideCharCount++;
 654         endCol++;
 655       }
 656       // Expand the string in both directions until a space is hit
 657       while (startIndex > 0 && !this._isCharWordSeparator(line.charAt(startIndex - 1))) {
 658         if (bufferLine[startCol - 1][LINE_DATA_WIDTH_INDEX] === 0) {
 659           // If the next character is a wide char, record it and skip the column
 660           leftWideCharCount++;
 661           startCol--;
 662         }
 663         startIndex--;
 664         startCol--;
 665       }
 666       while (endIndex + 1 < line.length && !this._isCharWordSeparator(line.charAt(endIndex + 1))) {
 667         if (bufferLine[endCol + 1][LINE_DATA_WIDTH_INDEX] === 2) {
 668           // If the next character is a wide char, record it and skip the column
 669           rightWideCharCount++;
 670           endCol++;
 671         }
 672         endIndex++;
 673         endCol++;
 674       }
 675     }
 676
 677     const start = startIndex + charOffset - leftWideCharCount;
 678     const length = Math.min(endIndex - startIndex + leftWideCharCount + rightWideCharCount + 1/*include endIndex char*/, this._terminal.cols);
 679     return {start, length};
 680   }
 681
 682   /**
 683    * Selects the word at the coordinates specified.
 684    * @param coords The coordinates to get the word at.
 685    */
 686   protected _selectWordAt(coords: [number, number]): void {
 687     const wordPosition = this._getWordAt(coords);
 688     this._model.selectionStart = [wordPosition.start, coords[1]];
 689     this._model.selectionStartLength = wordPosition.length;
 690   }
 691
 692   /**
 693    * Sets the selection end to the word at the coordinated specified.
 694    * @param coords The coordinates to get the word at.
 695    */
 696   private _selectToWordAt(coords: [number, number]): void {
 697     const wordPosition = this._getWordAt(coords);
 698     this._model.selectionEnd = [this._model.areSelectionValuesReversed() ? wordPosition.start : (wordPosition.start + wordPosition.length), coords[1]];
 699   }
 700
 701   /**
 702    * Gets whether the character is considered a word separator by the select
 703    * word logic.
 704    * @param char The character to check.
 705    */
 706   private _isCharWordSeparator(char: string): boolean {
 707     return WORD_SEPARATORS.indexOf(char) >= 0;
 708   }
 709
 710   /**
 711    * Selects the line specified.
 712    * @param line The line index.
 713    */
 714   protected _selectLineAt(line: number): void {
 715     this._model.selectionStart = [0, line];
 716     this._model.selectionStartLength = this._terminal.cols;
 717   }
 718 }