src/SelectionModel.ts

   1 /**
   2  * @license MIT
   3  */
   4
   5 import { ITerminal } from './Interfaces';
   6
   7 export class SelectionModel {
   8   /**
   9    * Whether select all is currently active.
  10    */
  11   public isSelectAllActive: boolean;
  12
  13   /**
  14    * The [x, y] position the selection starts at.
  15    */
  16   public selectionStart: [number, number];
  17
  18   /**
  19    * The minimal length of the selection from the start position. When double
  20    * clicking on a word, the word will be selected which makes the selection
  21    * start at the start of the word and makes this variable the length.
  22    */
  23   public selectionStartLength: number;
  24
  25   /**
  26    * The [x, y] position the selection ends at.
  27    */
  28   public selectionEnd: [number, number];
  29
  30   constructor(
  31     private _terminal: ITerminal
  32   ) {
  33   }
  34
  35   /**
  36    * The final selection start, taking into consideration select all.
  37    */
  38   public get finalSelectionStart(): [number, number] {
  39     if (this.isSelectAllActive) {
  40       return [0, 0];
  41     }
  42
  43     if (!this.selectionEnd) {
  44       return this.selectionStart;
  45     }
  46
  47     return this._areSelectionValuesReversed() ? this.selectionEnd : this.selectionStart;
  48   }
  49
  50   /**
  51    * The final selection end, taking into consideration select all, double click
  52    * word selection and triple click line selection.
  53    */
  54   public get finalSelectionEnd(): [number, number] {
  55     if (this.isSelectAllActive) {
  56       return [this._terminal.cols - 1, this._terminal.ybase + this._terminal.rows - 1];
  57     }
  58
  59     if (!this.selectionStart) {
  60       return null;
  61     }
  62
  63     // Use the selection start if the end doesn't exist or they're reversed
  64     if (!this.selectionEnd || this._areSelectionValuesReversed()) {
  65       return [this.selectionStart[0] + this.selectionStartLength, this.selectionStart[1]];
  66     }
  67
  68     // Ensure the the word/line is selected after a double/triple click
  69     if (this.selectionStartLength) {
  70       // Select the larger of the two when start and end are on the same line
  71       if (this.selectionEnd[1] === this.selectionStart[1]) {
  72         return [Math.max(this.selectionStart[0] + this.selectionStartLength, this.selectionEnd[0]), this.selectionEnd[1]];
  73       }
  74     }
  75     return this.selectionEnd;
  76   }
  77
  78   /**
  79    * Returns whether the selection start and end are reversed.
  80    */
  81   private _areSelectionValuesReversed(): boolean {
  82     const start = this.selectionStart;
  83     const end = this.selectionEnd;
  84     return start[1] > end[1] || (start[1] === end[1] && start[0] > end[0]);
  85   }
  86
  87   /**
  88    * Handle the buffer being trimmed, adjust the selection position.
  89    * @param amount The amount the buffer is being trimmed.
  90    * @return Whether a refresh is necessary.
  91    */
  92   public onTrim(amount: number): boolean {
  93     // Adjust the selection position based on the trimmed amount.
  94     if (this.selectionStart) {
  95       this.selectionStart[0] -= amount;
  96     }
  97     if (this.selectionEnd) {
  98       this.selectionEnd[0] -= amount;
  99     }
 100
 101     // The selection has moved off the buffer, clear it.
 102     if (this.selectionEnd && this.selectionEnd[0] < 0) {
 103       this.selectionStart = null;
 104       this.selectionEnd = null;
 105       return true;
 106     }
 107
 108     // If the selection start is trimmed, ensure the start column is 0.
 109     if (this.selectionStart && this.selectionStart[0] < 0) {
 110       this.selectionStart[1] = 0;
 111     }
 112     return false;
 113   }
 114 }