| /* |
| * noVNC: HTML5 VNC client |
| * Copyright (C) 2019 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() { |
| 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'; |
| } |
| |
| 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), |
| }; |
| } |
| |
| attach(target) { |
| if (this._target) { |
| this.detach(); |
| } |
| |
| this._target = target; |
| |
| if (useFallback) { |
| document.body.appendChild(this._canvas); |
| |
| // 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); |
| } |
| |
| this.clear(); |
| } |
| |
| detach() { |
| if (!this._target) { |
| return; |
| } |
| |
| 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); |
| |
| document.body.removeChild(this._canvas); |
| } |
| |
| 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; |
| } |
| |
| // Mouse events might be emulated, this allows |
| // moving the cursor in such cases |
| move(clientX, clientY) { |
| if (!useFallback) { |
| return; |
| } |
| // clientX/clientY are relative the _visual viewport_, |
| // but our position is relative the _layout viewport_, |
| // so try to compensate when we can |
| if (window.visualViewport) { |
| this._position.x = clientX + window.visualViewport.offsetLeft; |
| this._position.y = clientY + window.visualViewport.offsetTop; |
| } else { |
| this._position.x = clientX; |
| this._position.y = clientY; |
| } |
| this._updatePosition(); |
| let target = document.elementFromPoint(clientX, clientY); |
| this._updateVisibility(target); |
| } |
| |
| _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) { |
| // Check if we should show the cursor on the element we are leaving to |
| this._updateVisibility(event.relatedTarget); |
| } |
| |
| _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); |
| |
| // Captures end with a mouseup but we can't know the event order of |
| // mouseup vs releaseCapture. |
| // |
| // In the cases when releaseCapture comes first, the code above is |
| // enough. |
| // |
| // In the cases when the mouseup comes first, we need wait for the |
| // browser to flush all events and then check again if the cursor |
| // should be visible. |
| if (this._captureIsActive()) { |
| window.setTimeout(() => { |
| // We might have detached at this point |
| if (!this._target) { |
| return; |
| } |
| // Refresh the target from elementFromPoint since queued events |
| // might have altered the DOM |
| target = document.elementFromPoint(event.clientX, |
| event.clientY); |
| this._updateVisibility(target); |
| }, 0); |
| } |
| } |
| |
| _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) { |
| if (!target) { |
| return false; |
| } |
| // 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) { |
| // When the cursor target has capture we want to show the cursor. |
| // So, if a capture is active - look at the captured element instead. |
| if (this._captureIsActive()) { |
| target = document.captureElement; |
| } |
| 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"; |
| } |
| |
| _captureIsActive() { |
| return document.captureElement && |
| document.documentElement.contains(document.captureElement); |
| } |
| } |