https://redbase.app/_content/Microsoft.FluentUI.AspNetCore.Compone…/FluentPullToRefresh.awzanx0pu8.razor.js

1let emulatorInitialized = false;
2export function getScrollDistToTop() {
3    const scrollTop = document.documentElement.scrollTop || document.body.scrollTop || 0;
4    return Math.round(scrollTop);
5}
6
7export function getScrollDistToBottom() {
8    const dist = document.documentElement.scrollHeight -
9        document.documentElement.scrollTop -
10        document.documentElement.clientHeight;
11    return Math.round(dist);
12}
13
14export function initTouchEmulator() {
15    loadTouchEmulator();
16
17}
18
19// Based on https://github.com/youzan/vant/blob/main/packages/vant-touch-emulator/src/index.js
20window.loadTouchEmulator = function () {
21    if (typeof window === 'undefined' || emulatorInitialized)  {
22        return;
23    }
24    var eventTarget;
25    var supportTouch = 'ontouchstart' in window;
26
27    // polyfills
28    if (!document.createTouch) {
29        document.createTouch = function (
30            view,
31            target,
32            identifier,
33            pageX,
34            pageY,
35            screenX,
36            screenY
37        ) {
38            // auto set
39            return new Touch(
40                target,
41                identifier,
42                {
43                    pageX: pageX,
44                    pageY: pageY,
45                    screenX: screenX,
46                    screenY: screenY,
47                    clientX: pageX - window.scrollX,
48                    clientY: pageY - window.scrollY,
49                },
50                0,
51                0
52            );
53        };
54    }
55
56    if (!document.createTouchList) {
57        document.createTouchList = function () {
58            var touchList = TouchList();
59            for (var i = 0; i < arguments.length; i++) {
60                touchList[i] = arguments[i];
61            }
62            touchList.length = arguments.length;
63            return touchList;
64        };
65    }
66
67    if (!Element.prototype.matches) {
68        Element.prototype.matches =
69            Element.prototype.msMatchesSelector ||
70            Element.prototype.matches;
71    }
72
73    if (!Element.prototype.closest) {
74        Element.prototype.closest = function (s) {
75            var el = this;
76
77            do {
78                if (el.matches(s)) return el;
79                el = el.parentElement || el.parentNode;
80            } while (el !== null && el.nodeType === 1);
81
82            return null;
83        };
84    }
85
86    /**
87     * create an touch point
88     * @constructor
89     * @param target
90     * @param identifier
91     * @param pos
92     * @param deltaX
93     * @param deltaY
94     * @returns {Object} touchPoint
95     */
96
97    var Touch = function Touch(target, identifier, pos, deltaX, deltaY) {
98        deltaX = deltaX || 0;
99        deltaY = deltaY || 0;
100
101        this.identifier = identifier;
102        this.target = target;
103        this.clientX = pos.clientX + deltaX;
104        this.clientY = pos.clientY + deltaY;
105        this.screenX = pos.screenX + deltaX;
106        this.screenY = pos.screenY + deltaY;
107        this.pageX = pos.pageX + deltaX;
108        this.pageY = pos.pageY + deltaY;
109    };
110
111    /**
112     * create empty touchlist with the methods
113     * @constructor
114     * @returns touchList
115     */
116    function TouchList() {
117        var touchList = [];
118
119        touchList['item'] = function (index) {
120            return this[index] || null;
121        };
122
123        // specified by Mozilla
124        touchList['identifiedTouch'] = function (id) {
125            return this[id + 1] || null;
126        };
127
128        return touchList;
129    }
130
131    /**
132     * only trigger touches when the left mousebutton has been pressed
133     * @param touchType
134     * @returns {Function}
135     */
136
137    var initiated = false;
138    function onMouse(touchType) {
139        return function (ev) {
140            // prevent mouse events
141
142            if (ev.type === 'mousedown') {
143                initiated = true;
144            }
145
146            if (ev.type === 'mouseup') {
147                initiated = false;
148            }
149
150            if (ev.type === 'mousemove' && !initiated) {
151                return;
152            }
153
154            // The EventTarget on which the touch point started when it was first placed on the surface,
155            // even if the touch point has since moved outside the interactive area of that element.
156            // also, when the target doesnt exist anymore, we update it
157            if (
158                ev.type === 'mousedown' ||
159                !eventTarget ||
160                (eventTarget && !eventTarget.dispatchEvent)
161            ) {
162                eventTarget = ev.target;
163            }
164
165            if (eventTarget.closest('[data-no-touch-simulate]') == null) {
166                triggerTouch(touchType, ev);
167            }
168
169            // reset
170            if (ev.type === 'mouseup') {
171                eventTarget = null;
172            }
173        };
174    }
175
176    /**
177     * trigger a touch event
178     * @param eventName
179     * @param mouseEv
180     */
181    function triggerTouch(eventName, mouseEv) {
182        var touchEvent = new Event(eventName, { bubbles: true, cancelable: true });

183        //document.createEvent('Event');
184        //touchEvent.initEvent(eventName, true, true);
185
186        touchEvent.altKey = mouseEv.altKey;
187        touchEvent.ctrlKey = mouseEv.ctrlKey;
188        touchEvent.metaKey = mouseEv.metaKey;
189        touchEvent.shiftKey = mouseEv.shiftKey;
190
191        touchEvent.touches = getActiveTouches(mouseEv);
192        touchEvent.targetTouches = getActiveTouches(mouseEv);
193        touchEvent.changedTouches = createTouchList(mouseEv);
194
195        eventTarget.dispatchEvent(touchEvent);
196    }
197
198    /**
199     * create a touchList based on the mouse event
200     * @param mouseEv
201     * @returns {TouchList}
202     */
203    function createTouchList(mouseEv) {
204        var touchList = TouchList();
205        touchList.push(new Touch(eventTarget, 1, mouseEv, 0, 0));
206        return touchList;
207    }
208
209    /**
210     * receive all active touches
211     * @param mouseEv
212     * @returns {TouchList}
213     */
214    function getActiveTouches(mouseEv) {
215        // empty list
216        if (mouseEv.type === 'mouseup') {
217            return TouchList();
218        }
219        return createTouchList(mouseEv);
220    }
221
222    /**
223     * TouchEmulator initializer
224     */
225    function TouchEmulator() {
226        window.addEventListener('mousedown', onMouse('touchstart'), true);
227        window.addEventListener('mousemove', onMouse('touchmove'), true);
228        window.addEventListener('mouseup', onMouse('touchend'), true);
229    }
230
231    // start distance when entering the multitouch mode
232    TouchEmulator['multiTouchOffset'] = 75;
233
234    if (!supportTouch) {
235        new TouchEmulator();
236    }
237
238    emulatorInitialized = true;
239};