devextreme/dist/transpiled/viz/vector_map/gesture_handler.js

HTML5 JavaScript Component Suite for Responsive Web Development

"use strict";

var _ln = Math.log,
    _LN2 = Math.LN2;

function GestureHandler(params) {
    var that = this;
    that._projection = params.projection;
    that._renderer = params.renderer;
    that._x = that._y = 0;
    that._subscribeToTracker(params.tracker);
}

GestureHandler.prototype = {
    constructor: GestureHandler,

    dispose: function dispose() {
        this._offTracker();
        this._offTracker = null;
    },

    _subscribeToTracker: function _subscribeToTracker(tracker) {
        var that = this,
            isActive = false;
        that._offTracker = tracker.on({
            "start": function start(arg) {
                // TODO: This is an implicit dependency on the ControlBar which must be removed
                isActive = arg.data.name !== "control-bar";
                if (isActive) {
                    that._processStart(arg);
                }
            },
            "move": function move(arg) {
                if (isActive) {
                    that._processMove(arg);
                }
            },
            "end": function end() {
                if (isActive) {
                    that._processEnd();
                }
            },
            "zoom": function zoom(arg) {
                that._processZoom(arg);
            }

        });
    },

    setInteraction: function setInteraction(options) {
        this._processEnd();
        this._centeringEnabled = options.centeringEnabled;
        this._zoomingEnabled = options.zoomingEnabled;
    },

    _processStart: function _processStart(arg) {
        if (this._centeringEnabled) {
            this._x = arg.x;
            this._y = arg.y;
            this._projection.beginMoveCenter();
        }
    },

    _processMove: function _processMove(arg) {
        var that = this;
        if (that._centeringEnabled) {
            that._renderer.root.attr({ cursor: "move" });
            that._projection.moveCenter([that._x - arg.x, that._y - arg.y]);
            that._x = arg.x;
            that._y = arg.y;
        }
    },

    _processEnd: function _processEnd() {
        if (this._centeringEnabled) {
            this._renderer.root.attr({ cursor: "default" });
            this._projection.endMoveCenter();
        }
    },

    _processZoom: function _processZoom(arg) {
        var that = this,
            delta,
            screenPosition,
            coords;
        if (that._zoomingEnabled) {
            if (arg.delta) {
                delta = arg.delta;
            } else if (arg.ratio) {
                delta = _ln(arg.ratio) / _LN2;
            }
            if (that._centeringEnabled) {
                screenPosition = that._renderer.getRootOffset();
                screenPosition = [arg.x - screenPosition.left, arg.y - screenPosition.top];
                coords = that._projection.fromScreenPoint(screenPosition);
            }
            that._projection.changeScaledZoom(delta);
            if (that._centeringEnabled) {
                that._projection.setCenterByPoint(coords, screenPosition);
            }
        }
    }
};

exports.GestureHandler = GestureHandler;