openlayers
Version:
Build tools and sources for developing OpenLayers based mapping applications
271 lines (229 loc) • 6.77 kB
JavaScript
goog.provide('ol.interaction.MouseWheelZoom');
goog.require('ol');
goog.require('ol.View');
goog.require('ol.easing');
goog.require('ol.events.EventType');
goog.require('ol.has');
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) {
ol.interaction.Interaction.call(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 {number}
*/
this.timeout_ = options.timeout !== undefined ? options.timeout : 80;
/**
* @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;
/**
* @private
* @type {ol.interaction.MouseWheelZoom.Mode|undefined}
*/
this.mode_ = undefined;
/**
* Trackpad events separated by this delay will be considered separate
* interactions.
* @type {number}
*/
this.trackpadEventGap_ = 400;
/**
* @type {number|undefined}
*/
this.trackpadTimeoutId_ = undefined;
/**
* The number of delta values per zoom level
* @private
* @type {number}
*/
this.trackpadDeltaPerZoom_ = 300;
/**
* The zoom factor by which scroll zooming is allowed to exceed the limits.
* @private
* @type {number}
*/
this.trackpadZoomBuffer_ = 1.5;
};
ol.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} Allow event propagation.
* @this {ol.interaction.MouseWheelZoom}
* @api
*/
ol.interaction.MouseWheelZoom.handleEvent = function(mapBrowserEvent) {
var type = mapBrowserEvent.type;
if (type !== ol.events.EventType.WHEEL && type !== ol.events.EventType.MOUSEWHEEL) {
return true;
}
mapBrowserEvent.preventDefault();
var map = mapBrowserEvent.map;
var wheelEvent = /** @type {WheelEvent} */ (mapBrowserEvent.originalEvent);
if (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
var delta;
if (mapBrowserEvent.type == ol.events.EventType.WHEEL) {
delta = wheelEvent.deltaY;
if (ol.has.FIREFOX &&
wheelEvent.deltaMode === WheelEvent.DOM_DELTA_PIXEL) {
delta /= ol.has.DEVICE_PIXEL_RATIO;
}
if (wheelEvent.deltaMode === WheelEvent.DOM_DELTA_LINE) {
delta *= 40;
}
} else if (mapBrowserEvent.type == ol.events.EventType.MOUSEWHEEL) {
delta = -wheelEvent.wheelDeltaY;
if (ol.has.SAFARI) {
delta /= 3;
}
}
if (delta === 0) {
return false;
}
var now = Date.now();
if (this.startTime_ === undefined) {
this.startTime_ = now;
}
if (!this.mode_ || now - this.startTime_ > this.trackpadEventGap_) {
this.mode_ = Math.abs(delta) < 4 ?
ol.interaction.MouseWheelZoom.Mode.TRACKPAD :
ol.interaction.MouseWheelZoom.Mode.WHEEL;
}
if (this.mode_ === ol.interaction.MouseWheelZoom.Mode.TRACKPAD) {
var view = map.getView();
if (this.trackpadTimeoutId_) {
clearTimeout(this.trackpadTimeoutId_);
} else {
view.setHint(ol.View.Hint.INTERACTING, 1);
}
this.trackpadTimeoutId_ = setTimeout(this.decrementInteractingHint_.bind(this), this.trackpadEventGap_);
var resolution = view.getResolution() * Math.pow(2, delta / this.trackpadDeltaPerZoom_);
var minResolution = view.getMinResolution();
var maxResolution = view.getMaxResolution();
var rebound = 0;
if (resolution < minResolution) {
resolution = Math.max(resolution, minResolution / this.trackpadZoomBuffer_);
rebound = 1;
} else if (resolution > maxResolution) {
resolution = Math.min(resolution, maxResolution * this.trackpadZoomBuffer_);
rebound = -1;
}
if (this.lastAnchor_) {
var center = view.calculateCenterZoom(resolution, this.lastAnchor_);
view.setCenter(center);
}
view.setResolution(resolution);
if (rebound > 0) {
view.animate({
resolution: minResolution,
easing: ol.easing.easeOut,
anchor: this.lastAnchor_,
duration: 500
});
} else if (rebound < 0) {
view.animate({
resolution: maxResolution,
easing: ol.easing.easeOut,
anchor: this.lastAnchor_,
duration: 500
});
}
this.startTime_ = now;
return false;
}
this.delta_ += delta;
var timeLeft = Math.max(this.timeout_ - (now - this.startTime_), 0);
clearTimeout(this.timeoutId_);
this.timeoutId_ = setTimeout(this.handleWheelZoom_.bind(this, map), timeLeft);
return false;
};
/**
* @private
*/
ol.interaction.MouseWheelZoom.prototype.decrementInteractingHint_ = function() {
this.trackpadTimeoutId_ = undefined;
var view = this.getMap().getView();
view.setHint(ol.View.Hint.INTERACTING, -1);
};
/**
* @private
* @param {ol.Map} map Map.
*/
ol.interaction.MouseWheelZoom.prototype.handleWheelZoom_ = function(map) {
var view = map.getView();
if (view.getAnimating()) {
view.cancelAnimations();
}
var maxDelta = ol.MOUSEWHEELZOOM_MAXDELTA;
var delta = ol.math.clamp(this.delta_, -maxDelta, maxDelta);
ol.interaction.Interaction.zoomByDelta(map, view, -delta, this.lastAnchor_,
this.duration_);
this.mode_ = undefined;
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;
if (!useAnchor) {
this.lastAnchor_ = null;
}
};
/**
* @enum {string}
*/
ol.interaction.MouseWheelZoom.Mode = {
TRACKPAD: 'trackpad',
WHEEL: 'wheel'
};