/// <summary>
/// This calculates the extent for the category and caches it in the extents collection
/// </summary>
/// <param name="category"></param>
protected virtual Extent CalculateCategoryExtent(IFeatureCategory category)
{
Extent ext = new Extent(new[]{double.MaxValue, double.MaxValue, double.MinValue, double.MinValue});
if(_editMode)
{
IDictionary<IFeature, IDrawnState> features = _drawingFilter.DrawnStates;
foreach (IFeature f in DataSet.Features)
{
if (category == features[f].SchemeCategory)
{
ext.ExpandToInclude(new Extent(f.Envelope));
}
}
if (_categoryExtents.Keys.Contains(category))
{
_categoryExtents[category] = ext.Copy();
}
else
{
_categoryExtents.Add(category, ext.Copy());
}
}
else
{
FastDrawnState[] states = DrawnStates;
List<ShapeRange> ranges = DataSet.ShapeIndices;
for(int shp = 0; shp < DrawnStates.Length; shp++)
{
if(!_categoryExtents.ContainsKey(states[shp].Category))
{
_categoryExtents.Add(states[shp].Category, ranges[shp].Extent.Copy());
}
else
{
_categoryExtents[states[shp].Category].ExpandToInclude(ranges[shp].Extent);
}
}
}
return ext;
}
