goog.provide('ol.interaction.MouseWheelZoom');
goog.require('goog.asserts');
goog.require('ol');
goog.require('ol.Coordinate');
goog.require('ol.events.EventType');
goog.require('ol.interaction.Interaction');
goog.require('ol.math');
/**
* @classdesc
* Allows the user to zoom the map by scrolling the mouse wheel.
*
* @constructor
* @extends {ol.interaction.Interaction}
* @param {olx.interaction.MouseWheelZoomOptions=} opt_options Options.
* @api stable
*/
ol.interaction.MouseWheelZoom = function(opt_options) {
goog.base(this, {
handleEvent: ol.interaction.MouseWheelZoom.handleEvent
});
var options = opt_options || {};
/**
* @private
* @type {number}
*/
this.delta_ = 0;
/**
* @private
* @type {number}
*/
this.duration_ = options.duration !== undefined ? options.duration : 250;
/**
* @private
* @type {boolean}
*/
this.useAnchor_ = options.useAnchor !== undefined ? options.useAnchor : true;
/**
* @private
* @type {?ol.Coordinate}
*/
this.lastAnchor_ = null;
/**
* @private
* @type {number|undefined}
*/
this.startTime_ = undefined;
/**
* @private
* @type {number|undefined}
*/
this.timeoutId_ = undefined;
};
goog.inherits(ol.interaction.MouseWheelZoom, ol.interaction.Interaction);
/**
* Handles the {@link ol.MapBrowserEvent map browser event} (if it was a
* mousewheel-event) and eventually zooms the map.
* @param {ol.MapBrowserEvent} mapBrowserEvent Map browser event.
* @return {boolean} `false` to stop event propagation.
* @this {ol.interaction.MouseWheelZoom}
* @api
*/
ol.interaction.MouseWheelZoom.handleEvent = function(mapBrowserEvent) {
var stopEvent = false;
if (mapBrowserEvent.type == ol.events.EventType.WHEEL ||
mapBrowserEvent.type == ol.events.EventType.MOUSEWHEEL) {
var map = mapBrowserEvent.map;
var wheelEvent = /** @type {WheelEvent} */ (mapBrowserEvent.originalEvent);
Eif (this.useAnchor_) {
this.lastAnchor_ = mapBrowserEvent.coordinate;
}
// Delta normalisation inspired by
// https://github.com/mapbox/mapbox-gl-js/blob/001c7b9/js/ui/handler/scroll_zoom.js
//TODO There's more good stuff in there for inspiration to improve this interaction.
var delta;
if (mapBrowserEvent.type == ol.events.EventType.WHEEL) {
delta = wheelEvent.deltaY;
if (ol.has.FIREFOX &&
wheelEvent.deltaMode === goog.global.WheelEvent.DOM_DELTA_PIXEL) {
delta /= ol.has.DEVICE_PIXEL_RATIO;
}
if (wheelEvent.deltaMode === goog.global.WheelEvent.DOM_DELTA_LINE) {
delta *= 40;
}
} else Eif (mapBrowserEvent.type == ol.events.EventType.MOUSEWHEEL) {
delta = -wheelEvent.wheelDeltaY;
if (ol.has.SAFARI) {
delta /= 3;
}
}
this.delta_ += delta;
Eif (this.startTime_ === undefined) {
this.startTime_ = Date.now();
}
var duration = ol.MOUSEWHEELZOOM_TIMEOUT_DURATION;
var timeLeft = Math.max(duration - (Date.now() - this.startTime_), 0);
goog.global.clearTimeout(this.timeoutId_);
this.timeoutId_ = goog.global.setTimeout(
this.doZoom_.bind(this, map), timeLeft);
mapBrowserEvent.preventDefault();
stopEvent = true;
}
return !stopEvent;
};
/**
* @private
* @param {ol.Map} map Map.
*/
ol.interaction.MouseWheelZoom.prototype.doZoom_ = function(map) {
var maxDelta = ol.MOUSEWHEELZOOM_MAXDELTA;
var delta = ol.math.clamp(this.delta_, -maxDelta, maxDelta);
var view = map.getView();
goog.asserts.assert(view, 'map must have view');
map.render();
ol.interaction.Interaction.zoomByDelta(map, view, -delta, this.lastAnchor_,
this.duration_);
this.delta_ = 0;
this.lastAnchor_ = null;
this.startTime_ = undefined;
this.timeoutId_ = undefined;
};
/**
* Enable or disable using the mouse's location as an anchor when zooming
* @param {boolean} useAnchor true to zoom to the mouse's location, false
* to zoom to the center of the map
* @api
*/
ol.interaction.MouseWheelZoom.prototype.setMouseAnchor = function(useAnchor) {
this.useAnchor_ = useAnchor;
Eif (!useAnchor) {
this.lastAnchor_ = null;
}
};
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