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       result.push(translateBufferLineToString(this._buffer.get(i), true));
 188     }
 189
 190     // Get final row
 191     if (start[1] !== end[1]) {
 192       result.push(translateBufferLineToString(this._buffer.get(end[1]), true, 0, end[0]));
 193     }
 194
 195     // Format string by replacing non-breaking space chars with regular spaces
 196     // and joining the array into a multi-line string.
 197     const formattedResult = result.map(line => {
 198       return line.replace(ALL_NON_BREAKING_SPACE_REGEX, ' ');
 199     }).join('\n');
 200
 201     return formattedResult;
 202   }
 203
 204   /**
 205    * Clears the current terminal selection.
 206    */
 207   public clearSelection(): void {
 208     this._model.clearSelection();
 209     this._removeMouseDownListeners();
 210     this.refresh();
 211   }
 212
 213   /**
 214    * Queues a refresh, redrawing the selection on the next opportunity.
 215    */
 216   public refresh(): void {
 217     if (!this._refreshAnimationFrame) {
 218       this._refreshAnimationFrame = window.requestAnimationFrame(() => this._refresh());
 219     }
 220   }
 221
 222   /**
 223    * Fires the refresh event, causing consumers to pick it up and redraw the
 224    * selection state.
 225    */
 226   private _refresh(): void {
 227     this._refreshAnimationFrame = null;
 228     this.emit('refresh', { start: this._model.finalSelectionStart, end: this._model.finalSelectionEnd });
 229   }
 230
 231   /**
 232    * Selects all text within the terminal.
 233    */
 234   public selectAll(): void {
 235     this._model.isSelectAllActive = true;
 236     this.refresh();
 237   }
 238
 239   /**
 240    * Handle the buffer being trimmed, adjust the selection position.
 241    * @param amount The amount the buffer is being trimmed.
 242    */
 243   private _onTrim(amount: number) {
 244     const needsRefresh = this._model.onTrim(amount);
 245     if (needsRefresh) {
 246       this.refresh();
 247     }
 248   }
 249
 250   /**
 251    * Gets the 0-based [x, y] buffer coordinates of the current mouse event.
 252    * @param event The mouse event.
 253    */
 254   private _getMouseBufferCoords(event: MouseEvent): [number, number] {
 255     const coords = Mouse.getCoords(event, this._rowContainer, this._charMeasure, this._terminal.cols, this._terminal.rows);
 256     // Convert to 0-based
 257     coords[0]--;
 258     coords[1]--;
 259     // Convert viewport coords to buffer coords
 260     coords[1] += this._terminal.ydisp;
 261     return coords;
 262   }
 263
 264   /**
 265    * Gets the amount the viewport should be scrolled based on how far out of the
 266    * terminal the mouse is.
 267    * @param event The mouse event.
 268    */
 269   private _getMouseEventScrollAmount(event: MouseEvent): number {
 270     let offset = Mouse.getCoordsRelativeToElement(event, this._rowContainer)[1];
 271     const terminalHeight = this._terminal.rows * this._charMeasure.height;
 272     if (offset >= 0 && offset <= terminalHeight) {
 273       return 0;
 274     }
 275     if (offset > terminalHeight) {
 276       offset -= terminalHeight;
 277     }
 278
 279     offset = Math.min(Math.max(offset, -DRAG_SCROLL_MAX_THRESHOLD), DRAG_SCROLL_MAX_THRESHOLD);
 280     offset /= DRAG_SCROLL_MAX_THRESHOLD;
 281     return (offset / Math.abs(offset)) + Math.round(offset * (DRAG_SCROLL_MAX_SPEED - 1));
 282   }
 283
 284   /**
 285    * Handles te mousedown event, setting up for a new selection.
 286    * @param event The mousedown event.
 287    */
 288   private _onMouseDown(event: MouseEvent) {
 289     // Only action the primary button
 290     if (event.button !== 0) {
 291       return;
 292     }
 293
 294     // Reset drag scroll state
 295     this._dragScrollAmount = 0;
 296
 297     this._setMouseClickCount(event);
 298
 299     if (event.shiftKey) {
 300       this._onShiftClick(event);
 301     } else {
 302       if (this._clickCount === 1) {
 303           this._onSingleClick(event);
 304       } else if (this._clickCount === 2) {
 305           this._onDoubleClick(event);
 306       } else if (this._clickCount === 3) {
 307           this._onTripleClick(event);
 308       }
 309     }
 310
 311     this._addMouseDownListeners();
 312     this.refresh();
 313   }
 314
 315   /**
 316    * Adds listeners when mousedown is triggered.
 317    */
 318   private _addMouseDownListeners(): void {
 319     // Listen on the document so that dragging outside of viewport works
 320     this._rowContainer.ownerDocument.addEventListener('mousemove', this._mouseMoveListener);
 321     this._rowContainer.ownerDocument.addEventListener('mouseup', this._mouseUpListener);
 322     this._dragScrollIntervalTimer = setInterval(() => this._dragScroll(), DRAG_SCROLL_INTERVAL);
 323   }
 324
 325   /**
 326    * Removes the listeners that are registered when mousedown is triggered.
 327    */
 328   private _removeMouseDownListeners(): void {
 329     this._rowContainer.ownerDocument.removeEventListener('mousemove', this._mouseMoveListener);
 330     this._rowContainer.ownerDocument.removeEventListener('mouseup', this._mouseUpListener);
 331     clearInterval(this._dragScrollIntervalTimer);
 332     this._dragScrollIntervalTimer = null;
 333   }
 334
 335   /**
 336    * Performs a shift click, setting the selection end position to the mouse
 337    * position.
 338    * @param event The mouse event.
 339    */
 340   private _onShiftClick(event: MouseEvent): void {
 341     if (this._model.selectionStart) {
 342       this._model.selectionEnd = this._getMouseBufferCoords(event);
 343     }
 344   }
 345
 346   /**
 347    * Performs a single click, resetting relevant state and setting the selection
 348    * start position.
 349    * @param event The mouse event.
 350    */
 351   private _onSingleClick(event: MouseEvent): void {
 352     this._model.selectionStartLength = 0;
 353     this._model.isSelectAllActive = false;
 354     this._isLineSelectModeActive = false;
 355     this._model.selectionStart = this._getMouseBufferCoords(event);
 356     if (this._model.selectionStart) {
 357       this._model.selectionEnd = null;
 358       // If the mouse is over the second half of a wide character, adjust the
 359       // selection to cover the whole character
 360       const char = this._buffer.get(this._model.selectionStart[1])[this._model.selectionStart[0]];
 361       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 362         this._model.selectionStart[0]++;
 363       }
 364     }
 365   }
 366
 367   /**
 368    * Performs a double click, selecting the current work.
 369    * @param event The mouse event.
 370    */
 371   private _onDoubleClick(event: MouseEvent): void {
 372     const coords = this._getMouseBufferCoords(event);
 373     if (coords) {
 374       this._selectWordAt(coords);
 375     }
 376   }
 377
 378   /**
 379    * Performs a triple click, selecting the current line and activating line
 380    * select mode.
 381    * @param event The mouse event.
 382    */
 383   private _onTripleClick(event: MouseEvent): void {
 384     const coords = this._getMouseBufferCoords(event);
 385     if (coords) {
 386       this._isLineSelectModeActive = true;
 387       this._selectLineAt(coords[1]);
 388     }
 389   }
 390
 391   /**
 392    * Sets the number of clicks for the current mousedown event based on the time
 393    * and position of the last mousedown event.
 394    * @param event The mouse event.
 395    */
 396   private _setMouseClickCount(event: MouseEvent): void {
 397     let currentTime = (new Date()).getTime();
 398     if (currentTime - this._lastMouseDownTime > CLEAR_MOUSE_DOWN_TIME || this._distanceFromLastMousePosition(event) > CLEAR_MOUSE_DISTANCE) {
 399       this._clickCount = 0;
 400     }
 401     this._lastMouseDownTime = currentTime;
 402     this._lastMousePosition = [event.pageX, event.pageY];
 403     this._clickCount++;
 404   }
 405
 406   /**
 407    * Gets the maximum number of pixels in each direction the mouse has moved.
 408    * @param event The mouse event.
 409    */
 410   private _distanceFromLastMousePosition(event: MouseEvent): number {
 411     const result = Math.max(
 412         Math.abs(this._lastMousePosition[0] - event.pageX),
 413         Math.abs(this._lastMousePosition[1] - event.pageY));
 414     return result;
 415   }
 416
 417   /**
 418    * Handles the mousemove event when the mouse button is down, recording the
 419    * end of the selection and refreshing the selection.
 420    * @param event The mousemove event.
 421    */
 422   private _onMouseMove(event: MouseEvent) {
 423     // Record the previous position so we know whether to redraw the selection
 424     // at the end.
 425     const previousSelectionEnd = this._model.selectionEnd ? [this._model.selectionEnd[0], this._model.selectionEnd[1]] : null;
 426
 427     // Set the initial selection end based on the mouse coordinates
 428     this._model.selectionEnd = this._getMouseBufferCoords(event);
 429
 430     // Select the entire line if line select mode is active.
 431     if (this._isLineSelectModeActive) {
 432       if (this._model.selectionEnd[1] < this._model.selectionStart[1]) {
 433         this._model.selectionEnd[0] = 0;
 434       } else {
 435         this._model.selectionEnd[0] = this._terminal.cols;
 436       }
 437     }
 438
 439     // Determine the amount of scrolling that will happen.
 440     this._dragScrollAmount = this._getMouseEventScrollAmount(event);
 441
 442     // If the cursor was above or below the viewport, make sure it's at the
 443     // start or end of the viewport respectively.
 444     if (this._dragScrollAmount > 0) {
 445       this._model.selectionEnd[0] = this._terminal.cols - 1;
 446     } else if (this._dragScrollAmount < 0) {
 447       this._model.selectionEnd[0] = 0;
 448     }
 449
 450     // If the character is a wide character include the cell to the right in the
 451     // selection. Note that selections at the very end of the line will never
 452     // have a character.
 453     if (this._model.selectionEnd[1] < this._buffer.length) {
 454       const char = this._buffer.get(this._model.selectionEnd[1])[this._model.selectionEnd[0]];
 455       if (char && char[2] === 0) {
 456         this._model.selectionEnd[0]++;
 457       }
 458     }
 459
 460     // Only draw here if the selection changes.
 461     if (!previousSelectionEnd ||
 462         previousSelectionEnd[0] !== this._model.selectionEnd[0] ||
 463         previousSelectionEnd[1] !== this._model.selectionEnd[1]) {
 464       this.refresh();
 465     }
 466   }
 467
 468   /**
 469    * The callback that occurs every DRAG_SCROLL_INTERVAL ms that does the
 470    * scrolling of the viewport.
 471    */
 472   private _dragScroll() {
 473     if (this._dragScrollAmount) {
 474       this._terminal.scrollDisp(this._dragScrollAmount, false);
 475       // Re-evaluate selection
 476       if (this._dragScrollAmount > 0) {
 477         this._model.selectionEnd = [this._terminal.cols - 1, this._terminal.ydisp + this._terminal.rows];
 478       } else {
 479         this._model.selectionEnd = [0, this._terminal.ydisp];
 480       }
 481       this.refresh();
 482     }
 483   }
 484
 485   /**
 486    * Handles the mouseup event, removing the mousedown listeners.
 487    * @param event The mouseup event.
 488    */
 489   private _onMouseUp(event: MouseEvent) {
 490     this._removeMouseDownListeners();
 491   }
 492
 493   /**
 494    * Converts a viewport column to the character index on the buffer line, the
 495    * latter takes into account wide characters.
 496    * @param coords The coordinates to find the 2 index for.
 497    */
 498   private _convertViewportColToCharacterIndex(bufferLine: any, coords: [number, number]): number {
 499     let charIndex = coords[0];
 500     for (let i = 0; coords[0] >= i; i++) {
 501       const char = bufferLine[i];
 502       if (char[LINE_DATA_WIDTH_INDEX] === 0) {
 503         charIndex--;
 504       }
 505     }
 506     return charIndex;
 507   }
 508
 509   public setSelection(col: number, row: number, length: number): void {
 510     this._model.clearSelection();
 511     this._removeMouseDownListeners();
 512     console.log('setSelection', arguments);
 513     this._model.selectionStart = [col, row];
 514     this._model.selectionStartLength = length;
 515     this.refresh();
 516   }
 517
 518   /**
 519    * Selects the word at the coordinates specified. Words are defined as all
 520    * non-whitespace characters.
 521    * @param coords The coordinates to get the word at.
 522    */
 523   protected _selectWordAt(coords: [number, number]): void {
 524     const bufferLine = this._buffer.get(coords[1]);
 525     const line = translateBufferLineToString(bufferLine, false);
 526
 527     // Get actual index, taking into consideration wide characters
 528     let endIndex = this._convertViewportColToCharacterIndex(bufferLine, coords);
 529     let startIndex = endIndex;
 530
 531     // Record offset to be used later
 532     const charOffset = coords[0] - startIndex;
 533     let leftWideCharCount = 0;
 534     let rightWideCharCount = 0;
 535
 536     if (line.charAt(startIndex) === ' ') {
 537       // Expand until non-whitespace is hit
 538       while (startIndex > 0 && line.charAt(startIndex - 1) === ' ') {
 539         startIndex--;
 540       }
 541       while (endIndex < line.length && line.charAt(endIndex + 1) === ' ') {
 542         endIndex++;
 543       }
 544     } else {
 545       // Expand until whitespace is hit. This algorithm works by scanning left
 546       // and right from the starting position, keeping both the index format
 547       // (line) and the column format (bufferLine) in sync. When a wide
 548       // character is hit, it is recorded and the column index is adjusted.
 549       let startCol = coords[0];
 550       let endCol = coords[0];
 551       // Consider the initial position, skip it and increment the wide char
 552       // variable
 553       if (bufferLine[startCol][LINE_DATA_WIDTH_INDEX] === 0) {
 554         leftWideCharCount++;
 555         startCol--;
 556       }
 557       if (bufferLine[endCol][LINE_DATA_WIDTH_INDEX] === 2) {
 558         rightWideCharCount++;
 559         endCol++;
 560       }
 561       // Expand the string in both directions until a space is hit
 562       while (startIndex > 0 && line.charAt(startIndex - 1) !== ' ') {
 563         if (bufferLine[startCol - 1][LINE_DATA_WIDTH_INDEX] === 0) {
 564           // If the next character is a wide char, record it and skip the column
 565           leftWideCharCount++;
 566           startCol--;
 567         }
 568         startIndex--;
 569         startCol--;
 570       }
 571       while (endIndex + 1 < line.length && line.charAt(endIndex + 1) !== ' ') {
 572         if (bufferLine[endCol + 1][LINE_DATA_WIDTH_INDEX] === 2) {
 573           // If the next character is a wide char, record it and skip the column
 574           rightWideCharCount++;
 575           endCol++;
 576         }
 577         endIndex++;
 578         endCol++;
 579       }
 580     }
 581
 582     // Record the resulting selection
 583     this._model.selectionStart = [startIndex + charOffset - leftWideCharCount, coords[1]];
 584     this._model.selectionStartLength = Math.min(endIndex - startIndex + leftWideCharCount + rightWideCharCount + 1/*include endIndex char*/, this._terminal.cols);
 585   }
 586
 587   /**
 588    * Selects the line specified.
 589    * @param line The line index.
 590    */
 591   protected _selectLineAt(line: number): void {
 592     this._model.selectionStart = [0, line];
 593     this._model.selectionStartLength = this._terminal.cols;
 594   }
 595 }