Metacat

/*

Author:       Gertjan van Oosten gertjan at west dot nl

License:      LGPL as per: http://www.gnu.org/copyleft/lesser.html

$Id: OverviewMap.js 3887 2008-02-27 18:18:53Z ahocevar $

*/

// Ensure this object's dependancies are loaded.

mapbuilder.loadScript(baseDir+"/util/openlayers/OpenLayers.js");

mapbuilder.loadScript(baseDir+"/widget/WidgetBase.js");

/**

 * Widget to add an OL OverviewMap to a main map.

 * @constructor

 * @base WidgetBase

 * @param widgetNode  The widget's XML object node from the configuration document.

 * @param model       The model object that this widget belongs to.

 */

function OverviewMap(widgetNode, model) {

  WidgetBase.apply(this,new Array(widgetNode, model));

  var width = this.getProperty("mb:width");

  if (width) {

    this.width = new Number(width);

  }

  var height = this.getProperty("mb:height");

  if (height) {

    this.height = new Number(height);

  }

  var minRatio = this.getProperty("mb:minRatio");

  if (minRatio) {

    this.minRatio = new Number(minRatio);

  }

  var maxRatio = this.getProperty("mb:maxRatio");

  if (maxRatio) {

    this.maxRatio = new Number(maxRatio);

  }

  var layersNode = widgetNode.selectSingleNode("mb:layers");

  if (layersNode) {

    this.layerNames = new Array();

    var layers = layersNode.childNodes;

    for (var i = 0; i < layers.length; i++) {

      if (layers[i].firstChild) {

        this.layerNames.push(getNodeValue(layers[i]));

      }

    }

  }

  this.model.addListener("refresh", this.addOverviewMap, this);

}

/**

 * Add an overview map to the map in this widget's model.

 * If layers have been specified in the config, clone these layers for the

 * overview map, otherwise just use the base layer from the main map.

 * If any of the layers to use are WMS layers it uses an untiled version of them.

 * @param objRef Pointer to widget object.

 */

OverviewMap.prototype.addOverviewMap = function(objRef) {

  if (objRef.model && objRef.model.map) {

    var map = objRef.model.map;

    /** reference to the OpenLayers OverviewMap control */

    this.control = null

    // Specify div and layers for overview map.

    var options = {

      div: objRef.getNode(),

      objRef: this,

      destroy: function() {

        OpenLayers.Control.OverviewMap.prototype.destroy.apply(this, arguments);

        this.div = null;

        objRef.control = null;

        objRef = null;

      },

      layers: new Array()

    };

    if (objRef.minRatio) options.minRatio = objRef.minRatio;

    if (objRef.maxRatio) options.maxRatio = objRef.maxRatio;

    // Clone the base layer. This is not really the OpenLayers base layer, but

    // the lowest layer in the Mapbuilder layers stack.

    if (!objRef.layerNames) {

      for (var i in map.mbMapPane.oLlayers) {

        var oLlayer = map.mbMapPane.oLlayers[i];

        if (oLlayer) {

          var baseLayer = objRef.getClonedLayer(oLlayer, true);

          options.layers.push(baseLayer);

          break;

        } 

      }

    }

    // Check for specifically requested layers

    var isBaseLayer = true;

    if (objRef.layerNames) {

      for (var i = 0; i < objRef.layerNames.length; i++) {

        var oLlayer = map.mbMapPane.getLayer(map.mbMapPane, objRef.layerNames[i]);

        if (oLlayer) {

          options.layers.push(objRef.getClonedLayer(oLlayer, isBaseLayer));

          isBaseLayer = false;

        }

      }

    }

    // Determine size:

    // - if width and height are both set, use these as the size;

    // - if only width or height is set, take aspect ratio of main map into account;

    // - otherwise, OL defaults to (180,90).

    var extent = map.getExtent();

    if (objRef.width && objRef.height) {

      options.size = new OpenLayers.Size(objRef.width, objRef.height);

    }

    else if (objRef.width) {

      options.size = new OpenLayers.Size(

        objRef.width,

        objRef.width * extent.getHeight() / extent.getWidth());

    }

    else if (objRef.height) {

      options.size = new OpenLayers.Size(

        objRef.height * extent.getWidth() / extent.getHeight(),

        objRef.height);

    }

    // Add the overview to the main map

    if (!objRef.control) {

      objRef.control = new OpenLayers.Control.OverviewMap(options);

      objRef.control.mapOptions = {theme: null};

      map.addControl(objRef.control);

    }

    // make all layers visible

    for (var i=0; i<options.layers.length; i++) {

      options.layers[i].setVisibility(true);

    }

  }

}

/**

 * Clone a map layer (OpenLayers.Layer subclass).

 * If the layer is a WMS layer it returns an untiled version of it.

 * @param layer Pointer to layer object.

 * @param isBaseLayer {Boolean} optional parameter: should the layer become

 * baselayer on the overview map?

 */

OverviewMap.prototype.getClonedLayer = function(layer, isBaseLayer) {

  if (layer == null) {

    return null;

  }

  isBaseLayer = isBaseLayer ? true : false;

  if (layer instanceof OpenLayers.Layer.WMS) {

    // make an untiled wms layer, with ratio 1

    var layerOptions = {

      units: layer.units,

      projection: layer.projection,

      maxExtent: layer.maxExtent,

      maxResolution: "auto",

      ratio: 1,

      singleTile: true,

      isBaseLayer: isBaseLayer

    };

    return new OpenLayers.Layer.WMS(layer.name,

      layer.url, {

        layers: layer.params.LAYERS,

        format: layer.params.FORMAT,

        transparent: layer.params.TRANSPARENT,

        sld: layer.params.SLD,

        sld_body: layer.params.SLD_BODY,

        styles: layer.params.STYLES

      }, layerOptions);

  }

  else {

    // take the layer as-is and clone it

    var clonedLayer = layer.clone();

    clonedLayer.setVisibility(true);

    return clonedLayer;

  }

}