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openlayers

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Build tools and sources for developing OpenLayers based mapping applications

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goog.provide('ol.interaction.PinchZoom'); goog.require('ol'); goog.require('ol.View'); goog.require('ol.functions'); goog.require('ol.interaction.Interaction'); goog.require('ol.interaction.Pointer'); /** * @classdesc * Allows the user to zoom the map by pinching with two fingers * on a touch screen. * * @constructor * @extends {ol.interaction.Pointer} * @param {olx.interaction.PinchZoomOptions=} opt_options Options. * @api stable */ ol.interaction.PinchZoom = function(opt_options) { ol.interaction.Pointer.call(this, { handleDownEvent: ol.interaction.PinchZoom.handleDownEvent_, handleDragEvent: ol.interaction.PinchZoom.handleDragEvent_, handleUpEvent: ol.interaction.PinchZoom.handleUpEvent_ }); var options = opt_options ? opt_options : {}; /** * @private * @type {boolean} */ this.constrainResolution_ = options.constrainResolution || false; /** * @private * @type {ol.Coordinate} */ this.anchor_ = null; /** * @private * @type {number} */ this.duration_ = options.duration !== undefined ? options.duration : 400; /** * @private * @type {number|undefined} */ this.lastDistance_ = undefined; /** * @private * @type {number} */ this.lastScaleDelta_ = 1; }; ol.inherits(ol.interaction.PinchZoom, ol.interaction.Pointer); /** * @param {ol.MapBrowserPointerEvent} mapBrowserEvent Event. * @this {ol.interaction.PinchZoom} * @private */ ol.interaction.PinchZoom.handleDragEvent_ = function(mapBrowserEvent) { ol.DEBUG && console.assert(this.targetPointers.length >= 2, 'length of this.targetPointers should be 2 or more'); var scaleDelta = 1.0; var touch0 = this.targetPointers[0]; var touch1 = this.targetPointers[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 (this.lastDistance_ !== undefined) { scaleDelta = this.lastDistance_ / distance; } this.lastDistance_ = distance; if (scaleDelta != 1.0) { this.lastScaleDelta_ = scaleDelta; } var map = mapBrowserEvent.map; var view = map.getView(); var resolution = view.getResolution(); // scale anchor point. var viewportPosition = map.getViewport().getBoundingClientRect(); var centroid = ol.interaction.Pointer.centroid(this.targetPointers); centroid[0] -= viewportPosition.left; centroid[1] -= viewportPosition.top; this.anchor_ = map.getCoordinateFromPixel(centroid); // scale, bypass the resolution constraint map.render(); ol.interaction.Interaction.zoomWithoutConstraints( map, view, resolution * scaleDelta, this.anchor_); }; /** * @param {ol.MapBrowserPointerEvent} mapBrowserEvent Event. * @return {boolean} Stop drag sequence? * @this {ol.interaction.PinchZoom} * @private */ ol.interaction.PinchZoom.handleUpEvent_ = function(mapBrowserEvent) { if (this.targetPointers.length < 2) { var map = mapBrowserEvent.map; var view = map.getView(); view.setHint(ol.View.Hint.INTERACTING, -1); if (this.constrainResolution_) { var resolution = view.getResolution(); // Zoom to final resolution, with an animation, and provide a // direction not to zoom out/in if user was pinching in/out. // Direction is > 0 if pinching out, and < 0 if pinching in. var direction = this.lastScaleDelta_ - 1; ol.interaction.Interaction.zoom(map, view, resolution, this.anchor_, this.duration_, direction); } return false; } else { return true; } }; /** * @param {ol.MapBrowserPointerEvent} mapBrowserEvent Event. * @return {boolean} Start drag sequence? * @this {ol.interaction.PinchZoom} * @private */ ol.interaction.PinchZoom.handleDownEvent_ = function(mapBrowserEvent) { if (this.targetPointers.length >= 2) { var map = mapBrowserEvent.map; this.anchor_ = null; this.lastDistance_ = undefined; this.lastScaleDelta_ = 1; if (!this.handlingDownUpSequence) { map.getView().setHint(ol.View.Hint.INTERACTING, 1); } return true; } else { return false; } }; /** * @inheritDoc */ ol.interaction.PinchZoom.prototype.shouldStopEvent = ol.functions.FALSE;