/// <summary>
/// Find a FeatureLayer in the map which uses the
/// specified table, and return it.
/// </summary>
/// <param name="map">The Map object to search</param>
/// <param name="sourceTable">
/// A table which may or may not be displayed in a FeatureLayer</param>
/// <param name="currentFeatureLayer">
/// If null is passed, we will return the first FeatureLayer we find
/// that uses the specified table; if currentFeatureLayer is not
/// null, we will search for the next FeatureLayer that uses
/// the same table.
/// </param>
/// <param name="wrapAround">true if you want a "find next" search
/// to wrap around to the beginning of the layer tree, if necessary,
/// to find the next layer; false if you do not want the search to wrap.
/// </param>
/// <returns>A FeatureLayer object (which may be identical to
/// the currentFeatureLayer param, e.g. if the currentFeatureLayer
/// param represents the only FeatureLayer in the map); or null if
/// the map does not contain any FeatureLayer based on the specified table.
/// </returns>
private FeatureLayer LocateNextFeatureLayer(
Map map, Table sourceTable, FeatureLayer currentFeatureLayer, bool wrapAround)
{
FilterByLayerType featureLayerFilter =
new FilterByLayerType(
LayerType.Normal, LayerType.Grid,
LayerType.Raster, LayerType.Wms);
MapLayerEnumerator mapLayerEnum =
map.Layers.GetMapLayerEnumerator(
featureLayerFilter, MapLayerEnumeratorOptions.Recurse);
FeatureLayer matchingFeatureLayer = null;
FeatureLayer firstMatchingFeatureLayer = null;
bool bPassedCurrentFeatureLayer = false;
foreach (FeatureLayer featLyr in mapLayerEnum)
{
if (featLyr.Table == sourceTable)
{
// This FeatureLayer uses the correct table
if (firstMatchingFeatureLayer == null)
{
// We found our first match, so make a note of it,
// even though it may not be ideal (i.e. it may not
// be the "next" FeatureLayer that was requested).
firstMatchingFeatureLayer = featLyr;
}
// Now determine whether this match is an ideal match.
// We may have been passed a FeatureLayer, and asked
// to find the "next" FeatureLayer. So we may need
// to skip over the current FeatureLayer if it's
// the same as the FeatureLayer that was passed in.
if (currentFeatureLayer != null &&
!bPassedCurrentFeatureLayer)
{
// We WERE asked to find the "next" FeatureLayer,
// which means that our first task is to find
// the FeatureLayer that the user right-clicked.
// But according to the flag, we have not yet
// looped past the currently-selected FeatureLayer.
// So we will continue the loop instead of
// assigning matchingFeatureLayer.
if (featLyr == currentFeatureLayer)
{
bPassedCurrentFeatureLayer = true;
}
continue;
}
matchingFeatureLayer = featLyr;
break;
}
}
if (matchingFeatureLayer == null)
{
// We did not find an ideal match (i.e. we may have been
// asked to find the Next FeatureLayer, and there may not
// have been a Next FeatureLayer).
// At this point, since we did not find a perfect match,
// we will consider a less-than-perfect match.
if (wrapAround)
{
// wrapAround is true, meaning that when we search for
// the next layer, we should wrap around to the top of
// the layer list, if necessary
matchingFeatureLayer = firstMatchingFeatureLayer;
}
else
{
// wrapAround is false, meaning that when we cannot find
// a next layer, we should return the layer that was
// originally specified, which will tell the caller,
// "there is no Next layer."
matchingFeatureLayer = currentFeatureLayer;
}
}
return(matchingFeatureLayer);
}
/// <summary>
/// Find a LabelSource in the map which uses the
/// specified table, and return it, or return null
/// if no suitable LabelSource exists.
/// </summary>
/// <param name="map">The Map object to search</param>
/// <param name="sourceTable">
/// A table which may or may not be labeled currently</param>
/// <param name="currentLabelSource">
/// If null is passed, we will return the first LabelSource we find
/// that uses the specified table; if currentLabelSource is not
/// null, we will search for the next LabelSource that uses
/// the same table.
/// </param>
/// <param name="wrapAround">true if you want a "find next" search
/// to wrap around to the beginning of the layer tree, if necessary,
/// to find the next LabelSource; false if you do not the search to wrap.
/// </param>
/// <returns>A LabelSource object (which may be identical to
/// the currentLabelSource param, e.g. if the currentLabelSource
/// param represents the only LabelSource in the map); or null if
/// the map does not contain any LabelSource based on the specified table.
/// </returns>
private LabelSource LocateNextLabelSource(
Map map, Table sourceTable, LabelSource currentLabelSource, bool wrapAround)
{
// Get a collection of all LabelLayers in the map
FilterByLayerType labelLayerFilter =
new FilterByLayerType(LayerType.Label);
MapLayerEnumerator mapLayerEnum =
map.Layers.GetMapLayerEnumerator(
labelLayerFilter, MapLayerEnumeratorOptions.Recurse);
_firstLabelLayer = null;
LabelSource matchingLabelSource = null;
LabelSource firstMatchingLabelSource = null;
bool bPassedCurrentLabelSource = false;
// Given the set of all LabelLayers in the layer tree,
// search each LabelLayer to try to find a LabelSource
// child node that is based on the specified table
// (the sourceTable param).
// OR: If a non-null currentLabelSource param
// was passed in, then it represents an existing
// LabelSource, and our job is to find the NEXT
// LabelSource that uses the same table.
foreach (LabelLayer ll in mapLayerEnum)
{
if (_firstLabelLayer == null)
{
// Make a note of the first LabelLayer we find;
// later, if we decide to create a new LabelSource,
// it will go into this first LabelLayer.
_firstLabelLayer = ll;
}
// Look through this LabelLayer's collection of LabelSources
foreach (LabelSource lblSource in ll.Sources)
{
if (lblSource.Table == sourceTable)
{
// This LabelSource uses the correct table
if (firstMatchingLabelSource == null)
{
// We found our first match, so make a note of it,
// even though it may not be ideal (i.e. it may not
// be the "next" LabelSource that was requested).
firstMatchingLabelSource = lblSource;
}
// Now determine whether this match is an ideal match.
// We may have been passed a LabelSource, and asked
// to find the "next" LabelSource. So we may need
// to skip over the current LabelSource if it's
// the same as the LabelSource that was passed in.
if (currentLabelSource != null &&
!bPassedCurrentLabelSource)
{
// We WERE asked to find the "next" LabelSource,
// which means that our first task is to find
// the LabelSource that the user right-clicked.
// But according to the flag, we have not yet
// looped past the currently-selected LabelSource.
// So we will continue the loop instead of
// assigning matchingLabelSource.
if (lblSource == currentLabelSource)
{
// We were asked to find the next LabelSource,
// and this LabelSource is the same one that
// was passed in. In this case, just set the
// flag, so that the next match will be used.
bPassedCurrentLabelSource = true;
}
continue;
}
// We found a LabelSource that is a perfect match.
matchingLabelSource = lblSource;
break;
}
} // This ends the "for each LabelSource in this LabelLayer" loop
if (matchingLabelSource != null)
{
// We found an ideal match, so we can skip searching
// the other LabelLayers. Break the outer foreach loop:
break;
}
} // This ends the "for each LabelLayer" loop
if (matchingLabelSource == null)
{
// We end up here if we did not find an ideal match; for
// example, if we were asked to find the "next" node, and
// we did not find a next matching node, but we did find a
// previous matching node, we end up here.
// At this point, since we did not find a perfect match,
// we will consider a less-than-perfect match.
if (wrapAround)
{
// Wrapping is On, meaning that when we search for
// the next LabelSource, we should wrap around to the top of
// the layer list, if necessary
matchingLabelSource = firstMatchingLabelSource;
}
else
{
// Wrap is Off, meaning: if we did not find a Next LabelSource,
// return the LabelSource that was originally specified,
// which will tell the caller, "there IS no Next LabelSource."
matchingLabelSource = currentLabelSource;
}
}
return(matchingLabelSource);
}
