core/input/mouse.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2019 The noVNC Authors
   4  * Licensed under MPL 2.0 or any later version (see LICENSE.txt)
   5  */
   6
   7 import * as Log from '../util/logging.js';
   8 import { setCapture, stopEvent, getPointerEvent } from '../util/events.js';
   9
  10 export default class Mouse {
  11     constructor(target) {
  12         this._target = target || document;
  13
  14         this._pos = null;
  15
  16         this._eventHandlers = {
  17             'mousedown': this._handleMouseDown.bind(this),
  18             'mouseup': this._handleMouseUp.bind(this),
  19             'mousemove': this._handleMouseMove.bind(this),
  20             'mousedisable': this._handleMouseDisable.bind(this)
  21         };
  22
  23         // ===== EVENT HANDLERS =====
  24
  25         this.onmousebutton = () => {}; // Handler for mouse button press/release
  26         this.onmousemove = () => {}; // Handler for mouse movement
  27     }
  28
  29     // ===== PRIVATE METHODS =====
  30
  31     _resetDoubleClickTimer() {
  32         this._doubleClickTimer = null;
  33     }
  34
  35     _handleMouseButton(e, down) {
  36         this._updateMousePosition(e);
  37         let pos = this._pos;
  38
  39         let bmask = 1 << e.button;
  40
  41         Log.Debug("onmousebutton " + (down ? "down" : "up") +
  42                   ", x: " + pos.x + ", y: " + pos.y + ", bmask: " + bmask);
  43         this.onmousebutton(pos.x, pos.y, down, bmask);
  44
  45         stopEvent(e);
  46     }
  47
  48     _handleMouseDown(e) {
  49         setCapture(this._target);
  50
  51         this._handleMouseButton(e, 1);
  52     }
  53
  54     _handleMouseUp(e) {
  55         this._handleMouseButton(e, 0);
  56     }
  57
  58     _handleMouseMove(e) {
  59         this._updateMousePosition(e);
  60         this.onmousemove(this._pos.x, this._pos.y);
  61         stopEvent(e);
  62     }
  63
  64     _handleMouseDisable(e) {
  65         /*
  66          * Stop propagation if inside canvas area
  67          * Note: This is only needed for the 'click' event as it fails
  68          *       to fire properly for the target element so we have
  69          *       to listen on the document element instead.
  70          */
  71         if (e.target == this._target) {
  72             stopEvent(e);
  73         }
  74     }
  75
  76     // Update coordinates relative to target
  77     _updateMousePosition(e) {
  78         e = getPointerEvent(e);
  79         const bounds = this._target.getBoundingClientRect();
  80         let x;
  81         let y;
  82         // Clip to target bounds
  83         if (e.clientX < bounds.left) {
  84             x = 0;
  85         } else if (e.clientX >= bounds.right) {
  86             x = bounds.width - 1;
  87         } else {
  88             x = e.clientX - bounds.left;
  89         }
  90         if (e.clientY < bounds.top) {
  91             y = 0;
  92         } else if (e.clientY >= bounds.bottom) {
  93             y = bounds.height - 1;
  94         } else {
  95             y = e.clientY - bounds.top;
  96         }
  97         this._pos = {x: x, y: y};
  98     }
  99
 100     // ===== PUBLIC METHODS =====
 101
 102     grab() {
 103         const t = this._target;
 104         t.addEventListener('mousedown', this._eventHandlers.mousedown);
 105         t.addEventListener('mouseup', this._eventHandlers.mouseup);
 106         t.addEventListener('mousemove', this._eventHandlers.mousemove);
 107
 108         // Prevent middle-click pasting (see above for why we bind to document)
 109         document.addEventListener('click', this._eventHandlers.mousedisable);
 110
 111         // preventDefault() on mousedown doesn't stop this event for some
 112         // reason so we have to explicitly block it
 113         t.addEventListener('contextmenu', this._eventHandlers.mousedisable);
 114     }
 115
 116     ungrab() {
 117         const t = this._target;
 118
 119         t.removeEventListener('mousedown', this._eventHandlers.mousedown);
 120         t.removeEventListener('mouseup', this._eventHandlers.mouseup);
 121         t.removeEventListener('mousemove', this._eventHandlers.mousemove);
 122
 123         document.removeEventListener('click', this._eventHandlers.mousedisable);
 124
 125         t.removeEventListener('contextmenu', this._eventHandlers.mousedisable);
 126     }
 127 }