80 lines
2.2 KiB
JavaScript
80 lines
2.2 KiB
JavaScript
/**
|
|
* @fileoverview Mouse Wheel Handler.
|
|
*
|
|
* Provides a class for listening to mousewheel events on a DOM element
|
|
* and dispatching mousewheel events to a map instance.
|
|
*
|
|
* The default behavior for the mousewheel event is zooming the map.
|
|
*/
|
|
|
|
goog.provide('ol.handler.MouseWheel');
|
|
|
|
goog.require('ol.handler.MapHandler');
|
|
goog.require('ol.events.MapEvent');
|
|
goog.require('ol.events.MapEventType');
|
|
|
|
goog.require('goog.asserts');
|
|
goog.require('goog.events');
|
|
goog.require('goog.style');
|
|
goog.require('goog.events.MouseWheelHandler');
|
|
goog.require('goog.events.MouseWheelHandler.EventType');
|
|
|
|
|
|
/**
|
|
* @constructor
|
|
* @extends {ol.handler.MapHandler}
|
|
* @param {ol.Map} map The map instance.
|
|
* @param {ol.handler.states} states An object for the handlers to share
|
|
* states.
|
|
*/
|
|
ol.handler.MouseWheel = function(map, states) {
|
|
goog.base(this, map, states);
|
|
|
|
/**
|
|
* @type {goog.events.MouseWheelHandler}
|
|
*/
|
|
this.handler_ = new goog.events.MouseWheelHandler(this.element_);
|
|
|
|
var handler = this.handler_;
|
|
this.registerDisposable(handler);
|
|
|
|
goog.events.listen(handler,
|
|
goog.events.MouseWheelHandler.EventType.MOUSEWHEEL,
|
|
this.handleMouseWheel, false, this);
|
|
|
|
};
|
|
goog.inherits(ol.handler.MouseWheel, ol.handler.MapHandler);
|
|
|
|
/**
|
|
* @param {goog.events.MouseWheelEvent} e
|
|
*/
|
|
ol.handler.MouseWheel.prototype.handleMouseWheel = function(e) {
|
|
var newE = new ol.events.MapEvent(ol.events.MapEventType.MOUSEWHEEL, e);
|
|
var rt = goog.events.dispatchEvent(this.map_, newE);
|
|
if (rt) {
|
|
this.defaultMouseWheel(e);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* @param {goog.events.MouseWheelEvent} e
|
|
*/
|
|
ol.handler.MouseWheel.prototype.defaultMouseWheel = function(e) {
|
|
var me = this;
|
|
if (e.deltaY === 0 || me.zoomBlocked_) {
|
|
return;
|
|
}
|
|
me.zoomBlocked_ = window.setTimeout(function() {
|
|
me.zoomBlocked_ = null;
|
|
}, 200);
|
|
|
|
var map = me.map_,
|
|
step = e.deltaY / Math.abs(e.deltaY);
|
|
map.setZoom(map.getZoom() - step,
|
|
goog.style.getRelativePosition(e, this.element_));
|
|
|
|
// We don't want the page to scroll.
|
|
// (MouseWheelEvent is a BrowserEvent)
|
|
e.preventDefault();
|
|
};
|