devextreme/dist/transpiled/events/pointer/observer.js

HTML5 JavaScript Component Suite for Responsive Web Development

"use strict";

var each = require("../../core/utils/iterator").each,
    readyCallbacks = require("../../core/utils/ready_callbacks"),
    domAdapter = require("../../core/dom_adapter");

var addEventsListener = function addEventsListener(events, handler) {
    readyCallbacks.add(function () {
        events.split(" ").forEach(function (event) {
            domAdapter.listen(domAdapter.getDocument(), event, handler, true);
        });
    });
};

var Observer = function Observer(eventMap, pointerEquals, onPointerAdding) {

    onPointerAdding = onPointerAdding || function () {};

    var pointers = [];

    var getPointerIndex = function getPointerIndex(e) {
        var index = -1;

        each(pointers, function (i, pointer) {
            if (!pointerEquals(e, pointer)) {
                return true;
            }

            index = i;
            return false;
        });

        return index;
    };

    var addPointer = function addPointer(e) {
        if (getPointerIndex(e) === -1) {
            onPointerAdding(e);
            pointers.push(e);
        }
    };

    var removePointer = function removePointer(e) {
        var index = getPointerIndex(e);
        if (index > -1) {
            pointers.splice(index, 1);
        }
    };

    var updatePointer = function updatePointer(e) {
        pointers[getPointerIndex(e)] = e;
    };

    addEventsListener(eventMap["dxpointerdown"], addPointer);
    addEventsListener(eventMap["dxpointermove"], updatePointer);
    addEventsListener(eventMap["dxpointerup"], removePointer);
    addEventsListener(eventMap["dxpointercancel"], removePointer);

    this.pointers = function () {
        return pointers;
    };

    this.reset = function () {
        pointers = [];
    };
};

module.exports = Observer;