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