Files
openlayers/src/ol/interaction/touchzoominteraction.js
2013-03-06 02:20:10 +01:00

106 lines
2.4 KiB
JavaScript

// FIXME works for View2D only
goog.provide('ol.interaction.TouchZoom');
goog.require('goog.asserts');
goog.require('ol.View');
goog.require('ol.ViewHint');
goog.require('ol.interaction.Touch');
/**
* @define {number} Animation duration.
*/
ol.interaction.TOUCHZOOM_ANIMATION_DURATION = 250;
/**
* @constructor
* @extends {ol.interaction.Touch}
*/
ol.interaction.TouchZoom = function() {
goog.base(this);
/**
* @private
* @type {number|undefined}
*/
this.lastDistance_;
};
goog.inherits(ol.interaction.TouchZoom, ol.interaction.Touch);
/**
* @inheritDoc
*/
ol.interaction.TouchZoom.prototype.handleTouchMove =
function(mapBrowserEvent) {
goog.asserts.assert(this.targetTouches.length >= 2);
var scaleDelta = 1.0;
var touch0 = this.targetTouches[0];
var touch1 = this.targetTouches[1];
var dx = touch0.clientX - touch1.clientX;
var dy = touch0.clientY - touch1.clientY;
// distance between touches
var distance = Math.sqrt(dx * dx + dy * dy);
if (goog.isDef(this.lastDistance_)) {
scaleDelta = this.lastDistance_ / distance;
}
this.lastDistance_ = distance;
var map = mapBrowserEvent.map;
var view = map.getView();
// scale anchor point.
var viewportPosition = goog.style.getClientPosition(map.getViewport());
var centroid = ol.interaction.Touch.centroid(this.targetTouches);
centroid.x -= viewportPosition.x;
centroid.y -= viewportPosition.y;
var anchor = map.getCoordinateFromPixel(centroid);
// scale, bypass the resolution constraint
view.zoomWithoutConstraints(map, view.getResolution() * scaleDelta, anchor);
};
/**
* @inheritDoc
*/
ol.interaction.TouchZoom.prototype.handleTouchEnd =
function(mapBrowserEvent) {
if (this.targetTouches.length < 2) {
var map = mapBrowserEvent.map;
var view = map.getView();
// take the resolution constraint into account
view.zoom(map, view.getResolution(), undefined,
ol.interaction.TOUCHZOOM_ANIMATION_DURATION);
view.setHint(ol.ViewHint.INTERACTING, -1);
return false;
} else {
return true;
}
};
/**
* @inheritDoc
*/
ol.interaction.TouchZoom.prototype.handleTouchStart =
function(mapBrowserEvent) {
if (this.targetTouches.length >= 2) {
var view = mapBrowserEvent.map.getView();
this.lastDistance_ = undefined;
view.setHint(ol.ViewHint.INTERACTING, 1);
return true;
} else {
return false;
}
};