src/SelectionManager.ts

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