HSLayers.Control.LayerSwitcher
==============================
`HSLayers.Control.LayerSwitcher
<http://www.bnhelp.cz/wwwlibs/hslayers/3.0/doc/symbols/HSLayers.Control.LayerSwitcher.html>`_
is advanced layerswitcher for OpenLayers. Basic features are following:

    **Layers are organized into tree structure**
        You can create nest the layers simply adding ``/`` in the layer
        name, example::
            
            new OpenLayers.Layer.WMS("Parent/child/Layer name",http://foo/bar);

    **Nodes do represent groups**
        Nodes in the tree structure are usually not single layers, but they are
        to be understand as `groups of layers <http://www.bnhelp.cz/wwwlibs/hslayers/3.0/doc/symbols/HSLayers.Control.LayerSwitcher.LayerGroup.html>`_, covered under one hood --
        one tree node. In this manner, you can easily turn one layer off
        for specified scales, and switch other on for other scales - for
        user, they are represented as one single layer (but they are
        more). HSLayers introduces new :attr:`OpenLayers.Layer.group`
        attribute, where the name can be defined. If the attribute is not
        set, layer's name is taken. 

        .. code-block:: javascript

            var smallMap = new OpenLayers.Layer.WMS("Small scales map",
                                                    "http://foo/bar",
                                                    {layers:"layer"},
                                                    {
                                                        maxScale: 100000,
                                                        group: "Some map"
                                                    });

            var bigMap = new OpenLayers.Layer.WMS("Big scales map",
                                                    "http://bar/foo",
                                                    {layers:"other_layer"},
                                                    {
                                                        minScale: 100000,
                                                        group: "Some map"
                                                    });
                                                    
            map.addLayers([smallMap, bigMap]);

        Both layers will be rendered as one node in the layerswitcher with
        name `Some map`.

    **LayerSwitcher indicates if the layer is visible within current scale**
        Groups of layers, which is not possible to see, are gray

    **Opacity settings**
        You can set opacity

    **legendURL, source, metadataURL**
        HSLayers addes new attributes to :class:`OpenLayers.Layer`, namely 
            
            :attr:`OpenLayers.Layer.legendURL` -- displays legend in the switcher

            :attr:`OpenLayers.Layer.source` -- creates download link to original data source
            
            :attr:`OpenLayers.Layer.metadataURL` -- creates link to layer metadata in the switcher

    **User can change layer order**
        Using drag&drop

HSLayers.Control.LayerSwitcher.MultiLayer
-----------------------------------------
`HSLayers.Control.LayerSwitcher.MultiLayer
<http://www.bnhelp.cz/wwwlibs/hslayers/3.0/doc/symbols/HSLayers.Control.LayerSwitcher.MultiLayer.html>`_
is special case of LayerSwitcher, used for rendering special
`HSLayers.Layer.MapServer <>`_.