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   }
 182
 183   /**
 184    * Gets whether there is an active text selection.
 185    */
 186   public get hasSelection(): boolean {
 187     return !!this._model.finalSelectionStart && !!this._model.finalSelectionEnd;
 188   }
 189
 190   /**
 191    * Gets the text currently selected.
 192    */
 193   public get selectionText(): string {
 194     const start = this._model.finalSelectionStart;
 195     const end = this._model.finalSelectionEnd;
 196     if (!start || !end) {
 197       return '';
 198     }
 199
 200     // Get first row
 201     const startRowEndCol = start[1] === end[1] ? end[0] : null;
 202     let result: string[] = [];
 203     result.push(this._translateBufferLineToString(this._buffer.get(start[1]), true, start[0], startRowEndCol));
 204
 205     // Get middle rows
 206     for (let i = start[1] + 1; i <= end[1] - 1; i++) {
 207       const bufferLine = this._buffer.get(i);
 208       const lineText = this._translateBufferLineToString(bufferLine, true);
 209       if (bufferLine.isWrapped) {
 210         result[result.length - 1] += lineText;
 211       } else {
 212         result.push(lineText);
 213       }
 214     }
 215
 216     // Get final row
 217     if (start[1] !== end[1]) {
 218       const bufferLine = this._buffer.get(end[1]);
 219       const lineText = this._translateBufferLineToString(bufferLine, true, 0, end[0]);
 220       if (bufferLine.isWrapped) {
 221         result[result.length - 1] += lineText;
 222       } else {
 223         result.push(lineText);
 224       }
 225     }
 226
 227     // Format string by replacing non-breaking space chars with regular spaces
 228     // and joining the array into a multi-line string.
 229     const formattedResult = result.map(line => {
 230       return line.replace(ALL_NON_BREAKING_SPACE_REGEX, ' ');
 231     }).join('\n');
 232
 233     return formattedResult;
 234   }
 235
 236   /**
 237    * Clears the current terminal selection.
 238    */
 239   public clearSelection(): void {
 240     this._model.clearSelection();
 241     this._removeMouseDownListeners();
 242     this.refresh();
 243   }
 244
 245   /**
 246    * Translates a buffer line to a string, with optional start and end columns.
 247    * Wide characters will count as two columns in the resulting string. This
 248    * function is useful for getting the actual text underneath the raw selection
 249    * position.
 250    * @param line The line being translated.
 251    * @param trimRight Whether to trim whitespace to the right.
 252    * @param startCol The column to start at.
 253    * @param endCol The column to end at.
 254    */
 255   private _translateBufferLineToString(line: any, trimRight: boolean, startCol: number = 0, endCol: number = null): string {
 256     // TODO: This function should live in a buffer or buffer line class
 257
 258     // Get full line
 259     let lineString = '';
 260     let widthAdjustedStartCol = startCol;
 261     let widthAdjustedEndCol = endCol;
 262     for (let i = 0; i < line.length; i++) {
 263       const char = line[i];
 264       lineString += char[LINE_DATA_CHAR_INDEX];
 265       // Adjust start and end cols for wide characters if they affect their
 266       // column indexes
 267       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 268         if (startCol >= i) {
 269           widthAdjustedStartCol--;
 270         }
 271         if (endCol >= i) {
 272           widthAdjustedEndCol--;
 273         }
 274       }
 275     }
 276
 277     // Calculate the final end col by trimming whitespace on the right of the
 278     // line if needed.
 279     let finalEndCol = widthAdjustedEndCol || line.length;
 280     if (trimRight) {
 281       const rightWhitespaceIndex = lineString.search(/\s+$/);
 282       if (rightWhitespaceIndex !== -1) {
 283         finalEndCol = Math.min(finalEndCol, rightWhitespaceIndex);
 284       }
 285       // Return the empty string if only trimmed whitespace is selected
 286       if (finalEndCol <= widthAdjustedStartCol) {
 287         return '';
 288       }
 289     }
 290
 291     return lineString.substring(widthAdjustedStartCol, finalEndCol);
 292   }
 293
 294   /**
 295    * Queues a refresh, redrawing the selection on the next opportunity.
 296    * @param isNewSelection Whether the selection should be registered as a new
 297    * selection on Linux.
 298    */
 299   public refresh(isNewSelection?: boolean): void {
 300     // Queue the refresh for the renderer
 301     if (!this._refreshAnimationFrame) {
 302       this._refreshAnimationFrame = window.requestAnimationFrame(() => this._refresh());
 303     }
 304
 305     // If the platform is Linux and the refresh call comes from a mouse event,
 306     // we need to update the selection for middle click to paste selection.
 307     if (Browser.isLinux && isNewSelection) {
 308       const selectionText = this.selectionText;
 309       if (selectionText.length) {
 310         this.emit('newselection', this.selectionText);
 311       }
 312     }
 313   }
 314
 315   /**
 316    * Fires the refresh event, causing consumers to pick it up and redraw the
 317    * selection state.
 318    */
 319   private _refresh(): void {
 320     this._refreshAnimationFrame = null;
 321     this.emit('refresh', { start: this._model.finalSelectionStart, end: this._model.finalSelectionEnd });
 322   }
 323
 324   /**
 325    * Selects all text within the terminal.
 326    */
 327   public selectAll(): void {
 328     this._model.isSelectAllActive = true;
 329     this.refresh();
 330   }
 331
 332   /**
 333    * Handle the buffer being trimmed, adjust the selection position.
 334    * @param amount The amount the buffer is being trimmed.
 335    */
 336   private _onTrim(amount: number) {
 337     const needsRefresh = this._model.onTrim(amount);
 338     if (needsRefresh) {
 339       this.refresh();
 340     }
 341   }
 342
 343   /**
 344    * Gets the 0-based [x, y] buffer coordinates of the current mouse event.
 345    * @param event The mouse event.
 346    */
 347   private _getMouseBufferCoords(event: MouseEvent): [number, number] {
 348     const coords = Mouse.getCoords(event, this._rowContainer, this._charMeasure, this._terminal.cols, this._terminal.rows, true);
 349     // Convert to 0-based
 350     coords[0]--;
 351     coords[1]--;
 352     // Convert viewport coords to buffer coords
 353     coords[1] += this._terminal.ydisp;
 354     return coords;
 355   }
 356
 357   /**
 358    * Gets the amount the viewport should be scrolled based on how far out of the
 359    * terminal the mouse is.
 360    * @param event The mouse event.
 361    */
 362   private _getMouseEventScrollAmount(event: MouseEvent): number {
 363     let offset = Mouse.getCoordsRelativeToElement(event, this._rowContainer)[1];
 364     const terminalHeight = this._terminal.rows * this._charMeasure.height;
 365     if (offset >= 0 && offset <= terminalHeight) {
 366       return 0;
 367     }
 368     if (offset > terminalHeight) {
 369       offset -= terminalHeight;
 370     }
 371
 372     offset = Math.min(Math.max(offset, -DRAG_SCROLL_MAX_THRESHOLD), DRAG_SCROLL_MAX_THRESHOLD);
 373     offset /= DRAG_SCROLL_MAX_THRESHOLD;
 374     return (offset / Math.abs(offset)) + Math.round(offset * (DRAG_SCROLL_MAX_SPEED - 1));
 375   }
 376
 377   /**
 378    * Handles te mousedown event, setting up for a new selection.
 379    * @param event The mousedown event.
 380    */
 381   private _onMouseDown(event: MouseEvent) {
 382     // Only action the primary button
 383     if (event.button !== 0) {
 384       return;
 385     }
 386
 387     // Tell the browser not to start a regular selection
 388     event.preventDefault();
 389
 390     // Reset drag scroll state
 391     this._dragScrollAmount = 0;
 392
 393     this._setMouseClickCount(event);
 394
 395     if (event.shiftKey) {
 396       this._onShiftClick(event);
 397     } else {
 398       if (this._clickCount === 1) {
 399           this._onSingleClick(event);
 400       } else if (this._clickCount === 2) {
 401           this._onDoubleClick(event);
 402       } else if (this._clickCount === 3) {
 403           this._onTripleClick(event);
 404       }
 405     }
 406
 407     this._addMouseDownListeners();
 408     this.refresh(true);
 409   }
 410
 411   /**
 412    * Adds listeners when mousedown is triggered.
 413    */
 414   private _addMouseDownListeners(): void {
 415     // Listen on the document so that dragging outside of viewport works
 416     this._rowContainer.ownerDocument.addEventListener('mousemove', this._mouseMoveListener);
 417     this._rowContainer.ownerDocument.addEventListener('mouseup', this._mouseUpListener);
 418     this._dragScrollIntervalTimer = setInterval(() => this._dragScroll(), DRAG_SCROLL_INTERVAL);
 419   }
 420
 421   /**
 422    * Removes the listeners that are registered when mousedown is triggered.
 423    */
 424   private _removeMouseDownListeners(): void {
 425     this._rowContainer.ownerDocument.removeEventListener('mousemove', this._mouseMoveListener);
 426     this._rowContainer.ownerDocument.removeEventListener('mouseup', this._mouseUpListener);
 427     clearInterval(this._dragScrollIntervalTimer);
 428     this._dragScrollIntervalTimer = null;
 429   }
 430
 431   /**
 432    * Performs a shift click, setting the selection end position to the mouse
 433    * position.
 434    * @param event The mouse event.
 435    */
 436   private _onShiftClick(event: MouseEvent): void {
 437     if (this._model.selectionStart) {
 438       this._model.selectionEnd = this._getMouseBufferCoords(event);
 439     }
 440   }
 441
 442   /**
 443    * Performs a single click, resetting relevant state and setting the selection
 444    * start position.
 445    * @param event The mouse event.
 446    */
 447   private _onSingleClick(event: MouseEvent): void {
 448     this._model.selectionStartLength = 0;
 449     this._model.isSelectAllActive = false;
 450     this._activeSelectionMode = SelectionMode.NORMAL;
 451     this._model.selectionStart = this._getMouseBufferCoords(event);
 452     if (this._model.selectionStart) {
 453       this._model.selectionEnd = null;
 454       // If the mouse is over the second half of a wide character, adjust the
 455       // selection to cover the whole character
 456       const char = this._buffer.get(this._model.selectionStart[1])[this._model.selectionStart[0]];
 457       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 458         this._model.selectionStart[0]++;
 459       }
 460     }
 461   }
 462
 463   /**
 464    * Performs a double click, selecting the current work.
 465    * @param event The mouse event.
 466    */
 467   private _onDoubleClick(event: MouseEvent): void {
 468     const coords = this._getMouseBufferCoords(event);
 469     if (coords) {
 470       this._activeSelectionMode = SelectionMode.WORD;
 471       this._selectWordAt(coords);
 472     }
 473   }
 474
 475   /**
 476    * Performs a triple click, selecting the current line and activating line
 477    * select mode.
 478    * @param event The mouse event.
 479    */
 480   private _onTripleClick(event: MouseEvent): void {
 481     const coords = this._getMouseBufferCoords(event);
 482     if (coords) {
 483       this._activeSelectionMode = SelectionMode.LINE;
 484       this._selectLineAt(coords[1]);
 485     }
 486   }
 487
 488   /**
 489    * Sets the number of clicks for the current mousedown event based on the time
 490    * and position of the last mousedown event.
 491    * @param event The mouse event.
 492    */
 493   private _setMouseClickCount(event: MouseEvent): void {
 494     let currentTime = (new Date()).getTime();
 495     if (currentTime - this._lastMouseDownTime > CLEAR_MOUSE_DOWN_TIME || this._distanceFromLastMousePosition(event) > CLEAR_MOUSE_DISTANCE) {
 496       this._clickCount = 0;
 497     }
 498     this._lastMouseDownTime = currentTime;
 499     this._lastMousePosition = [event.pageX, event.pageY];
 500     this._clickCount++;
 501   }
 502
 503   /**
 504    * Gets the maximum number of pixels in each direction the mouse has moved.
 505    * @param event The mouse event.
 506    */
 507   private _distanceFromLastMousePosition(event: MouseEvent): number {
 508     const result = Math.max(
 509         Math.abs(this._lastMousePosition[0] - event.pageX),
 510         Math.abs(this._lastMousePosition[1] - event.pageY));
 511     return result;
 512   }
 513
 514   /**
 515    * Handles the mousemove event when the mouse button is down, recording the
 516    * end of the selection and refreshing the selection.
 517    * @param event The mousemove event.
 518    */
 519   private _onMouseMove(event: MouseEvent) {
 520     // Record the previous position so we know whether to redraw the selection
 521     // at the end.
 522     const previousSelectionEnd = this._model.selectionEnd ? [this._model.selectionEnd[0], this._model.selectionEnd[1]] : null;
 523
 524     // Set the initial selection end based on the mouse coordinates
 525     this._model.selectionEnd = this._getMouseBufferCoords(event);
 526
 527     // Select the entire line if line select mode is active.
 528     if (this._activeSelectionMode === SelectionMode.LINE) {
 529       if (this._model.selectionEnd[1] < this._model.selectionStart[1]) {
 530         this._model.selectionEnd[0] = 0;
 531       } else {
 532         this._model.selectionEnd[0] = this._terminal.cols;
 533       }
 534     } else if (this._activeSelectionMode === SelectionMode.WORD) {
 535       this._selectToWordAt(this._model.selectionEnd);
 536     }
 537
 538     // Determine the amount of scrolling that will happen.
 539     this._dragScrollAmount = this._getMouseEventScrollAmount(event);
 540
 541     // If the cursor was above or below the viewport, make sure it's at the
 542     // start or end of the viewport respectively.
 543     if (this._dragScrollAmount > 0) {
 544       this._model.selectionEnd[0] = this._terminal.cols - 1;
 545     } else if (this._dragScrollAmount < 0) {
 546       this._model.selectionEnd[0] = 0;
 547     }
 548
 549     // If the character is a wide character include the cell to the right in the
 550     // selection. Note that selections at the very end of the line will never
 551     // have a character.
 552     if (this._model.selectionEnd[1] < this._buffer.length) {
 553       const char = this._buffer.get(this._model.selectionEnd[1])[this._model.selectionEnd[0]];
 554       if (char && char[2] === 0) {
 555         this._model.selectionEnd[0]++;
 556       }
 557     }
 558
 559     // Only draw here if the selection changes.
 560     if (!previousSelectionEnd ||
 561         previousSelectionEnd[0] !== this._model.selectionEnd[0] ||
 562         previousSelectionEnd[1] !== this._model.selectionEnd[1]) {
 563       this.refresh(true);
 564     }
 565   }
 566
 567   /**
 568    * The callback that occurs every DRAG_SCROLL_INTERVAL ms that does the
 569    * scrolling of the viewport.
 570    */
 571   private _dragScroll() {
 572     if (this._dragScrollAmount) {
 573       this._terminal.scrollDisp(this._dragScrollAmount, false);
 574       // Re-evaluate selection
 575       if (this._dragScrollAmount > 0) {
 576         this._model.selectionEnd = [this._terminal.cols - 1, this._terminal.ydisp + this._terminal.rows];
 577       } else {
 578         this._model.selectionEnd = [0, this._terminal.ydisp];
 579       }
 580       this.refresh();
 581     }
 582   }
 583
 584   /**
 585    * Handles the mouseup event, removing the mousedown listeners.
 586    * @param event The mouseup event.
 587    */
 588   private _onMouseUp(event: MouseEvent) {
 589     this._removeMouseDownListeners();
 590   }
 591
 592   /**
 593    * Converts a viewport column to the character index on the buffer line, the
 594    * latter takes into account wide characters.
 595    * @param coords The coordinates to find the 2 index for.
 596    */
 597   private _convertViewportColToCharacterIndex(bufferLine: any, coords: [number, number]): number {
 598     let charIndex = coords[0];
 599     for (let i = 0; coords[0] >= i; i++) {
 600       const char = bufferLine[i];
 601       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 602         charIndex--;
 603       }
 604     }
 605     return charIndex;
 606   }
 607
 608   /**
 609    * Gets positional information for the word at the coordinated specified.
 610    * @param coords The coordinates to get the word at.
 611    */
 612   private _getWordAt(coords: [number, number]): IWordPosition {
 613     const bufferLine = this._buffer.get(coords[1]);
 614     const line = this._translateBufferLineToString(bufferLine, false);
 615
 616     // Get actual index, taking into consideration wide characters
 617     let endIndex = this._convertViewportColToCharacterIndex(bufferLine, coords);
 618     let startIndex = endIndex;
 619
 620     // Record offset to be used later
 621     const charOffset = coords[0] - startIndex;
 622     let leftWideCharCount = 0;
 623     let rightWideCharCount = 0;
 624
 625     if (line.charAt(startIndex) === ' ') {
 626       // Expand until non-whitespace is hit
 627       while (startIndex > 0 && line.charAt(startIndex - 1) === ' ') {
 628         startIndex--;
 629       }
 630       while (endIndex < line.length && line.charAt(endIndex + 1) === ' ') {
 631         endIndex++;
 632       }
 633     } else {
 634       // Expand until whitespace is hit. This algorithm works by scanning left
 635       // and right from the starting position, keeping both the index format
 636       // (line) and the column format (bufferLine) in sync. When a wide
 637       // character is hit, it is recorded and the column index is adjusted.
 638       let startCol = coords[0];
 639       let endCol = coords[0];
 640       // Consider the initial position, skip it and increment the wide char
 641       // variable
 642       if (bufferLine[startCol][LINE_DATA_WIDTH_INDEX] === 0) {
 643         leftWideCharCount++;
 644         startCol--;
 645       }
 646       if (bufferLine[endCol][LINE_DATA_WIDTH_INDEX] === 2) {
 647         rightWideCharCount++;
 648         endCol++;
 649       }
 650       // Expand the string in both directions until a space is hit
 651       while (startIndex > 0 && !this._isCharWordSeparator(line.charAt(startIndex - 1))) {
 652         if (bufferLine[startCol - 1][LINE_DATA_WIDTH_INDEX] === 0) {
 653           // If the next character is a wide char, record it and skip the column
 654           leftWideCharCount++;
 655           startCol--;
 656         }
 657         startIndex--;
 658         startCol--;
 659       }
 660       while (endIndex + 1 < line.length && !this._isCharWordSeparator(line.charAt(endIndex + 1))) {
 661         if (bufferLine[endCol + 1][LINE_DATA_WIDTH_INDEX] === 2) {
 662           // If the next character is a wide char, record it and skip the column
 663           rightWideCharCount++;
 664           endCol++;
 665         }
 666         endIndex++;
 667         endCol++;
 668       }
 669     }
 670
 671     const start = startIndex + charOffset - leftWideCharCount;
 672     const length = Math.min(endIndex - startIndex + leftWideCharCount + rightWideCharCount + 1/*include endIndex char*/, this._terminal.cols);
 673     return {start, length};
 674   }
 675
 676   /**
 677    * Selects the word at the coordinates specified.
 678    * @param coords The coordinates to get the word at.
 679    */
 680   protected _selectWordAt(coords: [number, number]): void {
 681     const wordPosition = this._getWordAt(coords);
 682     this._model.selectionStart = [wordPosition.start, coords[1]];
 683     this._model.selectionStartLength = wordPosition.length;
 684   }
 685
 686   /**
 687    * Sets the selection end to the word at the coordinated specified.
 688    * @param coords The coordinates to get the word at.
 689    */
 690   private _selectToWordAt(coords: [number, number]): void {
 691     const wordPosition = this._getWordAt(coords);
 692     this._model.selectionEnd = [this._model.areSelectionValuesReversed() ? wordPosition.start : (wordPosition.start + wordPosition.length), coords[1]];
 693   }
 694
 695   /**
 696    * Gets whether the character is considered a word separator by the select
 697    * word logic.
 698    * @param char The character to check.
 699    */
 700   private _isCharWordSeparator(char: string): boolean {
 701     return WORD_SEPARATORS.indexOf(char) >= 0;
 702   }
 703
 704   /**
 705    * Selects the line specified.
 706    * @param line The line index.
 707    */
 708   protected _selectLineAt(line: number): void {
 709     this._model.selectionStart = [0, line];
 710     this._model.selectionStartLength = this._terminal.cols;
 711   }
 712 }