openlayers
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Build tools and sources for developing OpenLayers based mapping applications
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JavaScript
goog.provide('ol.source.ImageArcGISRest');
goog.require('ol');
goog.require('ol.Image');
goog.require('ol.asserts');
goog.require('ol.events');
goog.require('ol.events.EventType');
goog.require('ol.extent');
goog.require('ol.obj');
goog.require('ol.source.Image');
goog.require('ol.uri');
/**
* @classdesc
* Source for data from ArcGIS Rest services providing single, untiled images.
* Useful when underlying map service has labels.
*
* If underlying map service is not using labels,
* take advantage of ol image caching and use
* {@link ol.source.TileArcGISRest} data source.
*
* @constructor
* @fires ol.source.Image.Event
* @extends {ol.source.Image}
* @param {olx.source.ImageArcGISRestOptions=} opt_options Image ArcGIS Rest Options.
* @api
*/
ol.source.ImageArcGISRest = function(opt_options) {
var options = opt_options || {};
ol.source.Image.call(this, {
attributions: options.attributions,
logo: options.logo,
projection: options.projection,
resolutions: options.resolutions
});
/**
* @private
* @type {?string}
*/
this.crossOrigin_ =
options.crossOrigin !== undefined ? options.crossOrigin : null;
/**
* @private
* @type {string|undefined}
*/
this.url_ = options.url;
/**
* @private
* @type {ol.ImageLoadFunctionType}
*/
this.imageLoadFunction_ = options.imageLoadFunction !== undefined ?
options.imageLoadFunction : ol.source.Image.defaultImageLoadFunction;
/**
* @private
* @type {!Object}
*/
this.params_ = options.params || {};
/**
* @private
* @type {ol.Image}
*/
this.image_ = null;
/**
* @private
* @type {ol.Size}
*/
this.imageSize_ = [0, 0];
/**
* @private
* @type {number}
*/
this.renderedRevision_ = 0;
/**
* @private
* @type {number}
*/
this.ratio_ = options.ratio !== undefined ? options.ratio : 1.5;
};
ol.inherits(ol.source.ImageArcGISRest, ol.source.Image);
/**
* Get the user-provided params, i.e. those passed to the constructor through
* the "params" option, and possibly updated using the updateParams method.
* @return {Object} Params.
* @api stable
*/
ol.source.ImageArcGISRest.prototype.getParams = function() {
return this.params_;
};
/**
* @inheritDoc
*/
ol.source.ImageArcGISRest.prototype.getImageInternal = function(extent, resolution, pixelRatio, projection) {
if (this.url_ === undefined) {
return null;
}
resolution = this.findNearestResolution(resolution);
var image = this.image_;
if (image &&
this.renderedRevision_ == this.getRevision() &&
image.getResolution() == resolution &&
image.getPixelRatio() == pixelRatio &&
ol.extent.containsExtent(image.getExtent(), extent)) {
return image;
}
var params = {
'F': 'image',
'FORMAT': 'PNG32',
'TRANSPARENT': true
};
ol.obj.assign(params, this.params_);
extent = extent.slice();
var centerX = (extent[0] + extent[2]) / 2;
var centerY = (extent[1] + extent[3]) / 2;
if (this.ratio_ != 1) {
var halfWidth = this.ratio_ * ol.extent.getWidth(extent) / 2;
var halfHeight = this.ratio_ * ol.extent.getHeight(extent) / 2;
extent[0] = centerX - halfWidth;
extent[1] = centerY - halfHeight;
extent[2] = centerX + halfWidth;
extent[3] = centerY + halfHeight;
}
var imageResolution = resolution / pixelRatio;
// Compute an integer width and height.
var width = Math.ceil(ol.extent.getWidth(extent) / imageResolution);
var height = Math.ceil(ol.extent.getHeight(extent) / imageResolution);
// Modify the extent to match the integer width and height.
extent[0] = centerX - imageResolution * width / 2;
extent[2] = centerX + imageResolution * width / 2;
extent[1] = centerY - imageResolution * height / 2;
extent[3] = centerY + imageResolution * height / 2;
this.imageSize_[0] = width;
this.imageSize_[1] = height;
var url = this.getRequestUrl_(extent, this.imageSize_, pixelRatio,
projection, params);
this.image_ = new ol.Image(extent, resolution, pixelRatio,
this.getAttributions(), url, this.crossOrigin_, this.imageLoadFunction_);
this.renderedRevision_ = this.getRevision();
ol.events.listen(this.image_, ol.events.EventType.CHANGE,
this.handleImageChange, this);
return this.image_;
};
/**
* Return the image load function of the source.
* @return {ol.ImageLoadFunctionType} The image load function.
* @api
*/
ol.source.ImageArcGISRest.prototype.getImageLoadFunction = function() {
return this.imageLoadFunction_;
};
/**
* @param {ol.Extent} extent Extent.
* @param {ol.Size} size Size.
* @param {number} pixelRatio Pixel ratio.
* @param {ol.proj.Projection} projection Projection.
* @param {Object} params Params.
* @return {string} Request URL.
* @private
*/
ol.source.ImageArcGISRest.prototype.getRequestUrl_ = function(extent, size, pixelRatio, projection, params) {
ol.DEBUG && console.assert(this.url_ !== undefined, 'url is defined');
// ArcGIS Server only wants the numeric portion of the projection ID.
var srid = projection.getCode().split(':').pop();
params['SIZE'] = size[0] + ',' + size[1];
params['BBOX'] = extent.join(',');
params['BBOXSR'] = srid;
params['IMAGESR'] = srid;
params['DPI'] = 90 * pixelRatio;
var url = this.url_;
var modifiedUrl = url
.replace(/MapServer\/?$/, 'MapServer/export')
.replace(/ImageServer\/?$/, 'ImageServer/exportImage');
if (modifiedUrl == url) {
ol.asserts.assert(false, 50); // `options.featureTypes` should be an Array
}
return ol.uri.appendParams(modifiedUrl, params);
};
/**
* Return the URL used for this ArcGIS source.
* @return {string|undefined} URL.
* @api stable
*/
ol.source.ImageArcGISRest.prototype.getUrl = function() {
return this.url_;
};
/**
* Set the image load function of the source.
* @param {ol.ImageLoadFunctionType} imageLoadFunction Image load function.
* @api
*/
ol.source.ImageArcGISRest.prototype.setImageLoadFunction = function(imageLoadFunction) {
this.image_ = null;
this.imageLoadFunction_ = imageLoadFunction;
this.changed();
};
/**
* Set the URL to use for requests.
* @param {string|undefined} url URL.
* @api stable
*/
ol.source.ImageArcGISRest.prototype.setUrl = function(url) {
if (url != this.url_) {
this.url_ = url;
this.image_ = null;
this.changed();
}
};
/**
* Update the user-provided params.
* @param {Object} params Params.
* @api stable
*/
ol.source.ImageArcGISRest.prototype.updateParams = function(params) {
ol.obj.assign(this.params_, params);
this.image_ = null;
this.changed();
};