Files
openlayers/src/ol/source/mapguidesource.js

157 lines
4.1 KiB
JavaScript

goog.provide('ol.source.MapGuide');
goog.require('goog.object');
goog.require('goog.uri.utils');
goog.require('ol.ImageUrlFunction');
goog.require('ol.extent');
goog.require('ol.source.Image');
/**
* @constructor
* @extends {ol.source.Image}
* @param {olx.source.MapGuideOptions} options Options.
*/
ol.source.MapGuide = function(options) {
var imageUrlFunction;
if (goog.isDef(options.url)) {
var params = goog.isDef(options.params) ? options.params : {};
imageUrlFunction = ol.ImageUrlFunction.createFromParamsFunction(
options.url, params, goog.bind(this.getUrl, this));
} else {
imageUrlFunction = ol.ImageUrlFunction.nullImageUrlFunction;
}
goog.base(this, {
extent: options.extent,
projection: options.projection,
resolutions: options.resolutions,
imageUrlFunction: imageUrlFunction
});
/**
* @private
* @type {boolean}
*/
this.hidpi_ = goog.isDef(options.hidpi) ? options.hidpi : true;
/**
* @private
* @type {number}
*/
this.displayDpi_ = goog.isDef(options.displayDpi) ?
options.displayDpi : 96;
/**
* @private
* @type {number}
*/
this.metersPerUnit_ = goog.isDef(options.metersPerUnit) ?
options.metersPerUnit : 1;
/**
* @private
* @type {number}
*/
this.ratio_ = goog.isDef(options.ratio) ? options.ratio : 1;
/**
* @private
* @type {boolean}
*/
this.useOverlay_ = goog.isDef(options.useOverlay) ?
options.useOverlay : false;
/**
* @private
* @type {ol.Image}
*/
this.image_ = null;
};
goog.inherits(ol.source.MapGuide, ol.source.Image);
/**
* @inheritDoc
*/
ol.source.MapGuide.prototype.getImage =
function(extent, resolution, pixelRatio, projection) {
resolution = this.findNearestResolution(resolution);
pixelRatio = this.hidpi_ ? pixelRatio : 1;
var image = this.image_;
if (!goog.isNull(image) &&
image.getResolution() == resolution &&
image.getPixelRatio() == pixelRatio &&
ol.extent.containsExtent(image.getExtent(), extent)) {
return image;
}
if (this.ratio_ != 1) {
extent = extent.slice();
ol.extent.scaleFromCenter(extent, this.ratio_);
}
var width = (extent[2] - extent[0]) / resolution;
var height = (extent[3] - extent[1]) / resolution;
var size = [width * pixelRatio, height * pixelRatio];
this.image_ = this.createImage(
extent, resolution, pixelRatio, size, projection);
return this.image_;
};
/**
* @param {ol.Extent} extent The map extents.
* @param {ol.Size} size the viewport size.
* @param {number} metersPerUnit The meters-per-unit value.
* @param {number} dpi The display resolution.
* @return {number} The computed map scale.
*/
ol.source.MapGuide.getScale = function(extent, size, metersPerUnit, dpi) {
var mcsW = ol.extent.getWidth(extent);
var mcsH = ol.extent.getHeight(extent);
var devW = size[0];
var devH = size[1];
var mpp = 0.0254 / dpi;
if (devH * mcsW > devW * mcsH) {
return mcsW * metersPerUnit / (devW * mpp); // width limited
} else {
return mcsH * metersPerUnit / (devH * mpp); // height limited
}
};
/**
* @param {string} baseUrl The mapagent url.
* @param {Object.<string, string|number>} params Request parameters.
* @param {ol.Extent} extent Extent.
* @param {ol.Size} size Size.
* @param {ol.proj.Projection} projection Projection.
* @return {string} The mapagent map image request URL.
*/
ol.source.MapGuide.prototype.getUrl =
function(baseUrl, params, extent, size, projection) {
var scale = ol.source.MapGuide.getScale(extent, size,
this.metersPerUnit_, this.displayDpi_);
var center = ol.extent.getCenter(extent);
var baseParams = {
'OPERATION': this.useOverlay_ ? 'GETDYNAMICMAPOVERLAYIMAGE' : 'GETMAPIMAGE',
'VERSION': '2.0.0',
'LOCALE': 'en',
'CLIENTAGENT': 'ol.source.MapGuide source',
'CLIP': '1',
'SETDISPLAYDPI': this.displayDpi_,
'SETDISPLAYWIDTH': Math.round(size[0]),
'SETDISPLAYHEIGHT': Math.round(size[1]),
'SETVIEWSCALE': scale,
'SETVIEWCENTERX': center[0],
'SETVIEWCENTERY': center[1]
};
goog.object.extend(baseParams, params);
return goog.uri.utils.appendParamsFromMap(baseUrl, baseParams);
};