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/*
* noVNC: HTML5 VNC client
* Copyright (C) 2018 The noVNC Authors
* Licensed under MPL 2.0 or any later version (see LICENSE.txt)
*/
import { supportsCursorURIs, isTouchDevice } from './browser.js';
const useFallback = !supportsCursorURIs() || isTouchDevice;
export default class Cursor {
constructor(container) {
this._target = null;
this._canvas = document.createElement('canvas');
if (useFallback) {
this._canvas.style.position = 'fixed';
this._canvas.style.zIndex = '65535';
this._canvas.style.pointerEvents = 'none';
// Can't use "display" because of Firefox bug #1445997
this._canvas.style.visibility = 'hidden';
document.body.appendChild(this._canvas);
}
this._position = { x: 0, y: 0 };
this._hotSpot = { x: 0, y: 0 };
this._eventHandlers = {
'mouseover': this._handleMouseOver.bind(this),
'mouseleave': this._handleMouseLeave.bind(this),
'mousemove': this._handleMouseMove.bind(this),
'mouseup': this._handleMouseUp.bind(this),
'touchstart': this._handleTouchStart.bind(this),
'touchmove': this._handleTouchMove.bind(this),
'touchend': this._handleTouchEnd.bind(this),
};
}
attach(target) {
if (this._target) {
this.detach();
}
this._target = target;
if (useFallback) {
// FIXME: These don't fire properly except for mouse
/// movement in IE. We want to also capture element
// movement, size changes, visibility, etc.
const options = { capture: true, passive: true };
this._target.addEventListener('mouseover', this._eventHandlers.mouseover, options);
this._target.addEventListener('mouseleave', this._eventHandlers.mouseleave, options);
this._target.addEventListener('mousemove', this._eventHandlers.mousemove, options);
this._target.addEventListener('mouseup', this._eventHandlers.mouseup, options);
// There is no "touchleave" so we monitor touchstart globally
window.addEventListener('touchstart', this._eventHandlers.touchstart, options);
this._target.addEventListener('touchmove', this._eventHandlers.touchmove, options);
this._target.addEventListener('touchend', this._eventHandlers.touchend, options);
}
this.clear();
}
detach() {
if (useFallback) {
const options = { capture: true, passive: true };
this._target.removeEventListener('mouseover', this._eventHandlers.mouseover, options);
this._target.removeEventListener('mouseleave', this._eventHandlers.mouseleave, options);
this._target.removeEventListener('mousemove', this._eventHandlers.mousemove, options);
this._target.removeEventListener('mouseup', this._eventHandlers.mouseup, options);
window.removeEventListener('touchstart', this._eventHandlers.touchstart, options);
this._target.removeEventListener('touchmove', this._eventHandlers.touchmove, options);
this._target.removeEventListener('touchend', this._eventHandlers.touchend, options);
}
this._target = null;
}
change(rgba, hotx, hoty, w, h) {
if ((w === 0) || (h === 0)) {
this.clear();
return;
}
this._position.x = this._position.x + this._hotSpot.x - hotx;
this._position.y = this._position.y + this._hotSpot.y - hoty;
this._hotSpot.x = hotx;
this._hotSpot.y = hoty;
let ctx = this._canvas.getContext('2d');
this._canvas.width = w;
this._canvas.height = h;
let img;
try {
// IE doesn't support this
img = new ImageData(new Uint8ClampedArray(rgba), w, h);
} catch (ex) {
img = ctx.createImageData(w, h);
img.data.set(new Uint8ClampedArray(rgba));
}
ctx.clearRect(0, 0, w, h);
ctx.putImageData(img, 0, 0);
if (useFallback) {
this._updatePosition();
} else {
let url = this._canvas.toDataURL();
this._target.style.cursor = 'url(' + url + ')' + hotx + ' ' + hoty + ', default';
}
}
clear() {
this._target.style.cursor = 'none';
this._canvas.width = 0;
this._canvas.height = 0;
this._position.x = this._position.x + this._hotSpot.x;
this._position.y = this._position.y + this._hotSpot.y;
this._hotSpot.x = 0;
this._hotSpot.y = 0;
}
_handleMouseOver(event) {
// This event could be because we're entering the target, or
// moving around amongst its sub elements. Let the move handler
// sort things out.
this._handleMouseMove(event);
}
_handleMouseLeave(event) {
this._hideCursor();
}
_handleMouseMove(event) {
this._updateVisibility(event.target);
this._position.x = event.clientX - this._hotSpot.x;
this._position.y = event.clientY - this._hotSpot.y;
this._updatePosition();
}
_handleMouseUp(event) {
// We might get this event because of a drag operation that
// moved outside of the target. Check what's under the cursor
// now and adjust visibility based on that.
let target = document.elementFromPoint(event.clientX, event.clientY);
this._updateVisibility(target);
}
_handleTouchStart(event) {
// Just as for mouseover, we let the move handler deal with it
this._handleTouchMove(event);
}
_handleTouchMove(event) {
this._updateVisibility(event.target);
this._position.x = event.changedTouches[0].clientX - this._hotSpot.x;
this._position.y = event.changedTouches[0].clientY - this._hotSpot.y;
this._updatePosition();
}
_handleTouchEnd(event) {
// Same principle as for mouseup
let target = document.elementFromPoint(event.changedTouches[0].clientX,
event.changedTouches[0].clientY);
this._updateVisibility(target);
}
_showCursor() {
if (this._canvas.style.visibility === 'hidden') {
this._canvas.style.visibility = '';
}
}
_hideCursor() {
if (this._canvas.style.visibility !== 'hidden') {
this._canvas.style.visibility = 'hidden';
}
}
// Should we currently display the cursor?
// (i.e. are we over the target, or a child of the target without a
// different cursor set)
_shouldShowCursor(target) {
// Easy case
if (target === this._target) {
return true;
}
// Other part of the DOM?
if (!this._target.contains(target)) {
return false;
}
// Has the child its own cursor?
// FIXME: How can we tell that a sub element has an
// explicit "cursor: none;"?
if (window.getComputedStyle(target).cursor !== 'none') {
return false;
}
return true;
}
_updateVisibility(target) {
if (this._shouldShowCursor(target)) {
this._showCursor();
} else {
this._hideCursor();
}
}
_updatePosition() {
this._canvas.style.left = this._position.x + "px";
this._canvas.style.top = this._position.y + "px";
}
}
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