New Post: Offset line feature

I saw this code in Mapwindow5 and was thinking if there was a way to convert it to dotspatial to offset line feature.

It would be great if the code can be converted and incorporated into the dotspatial editor in the future.

In the interim, I want to get it to work for offsetting selected line feature.
Any suggestions would be welcomed.


namespace MW5.Plugins.ShapeEditor.Operations
{

internal class CopyOperation
{
    private readonly IMuteMap _map;
    private readonly IGeoprocessingService _geoService;
    private const double SCREEN_OFFSET = 50.0;
    private IFeatureSet _buffer;

    public CopyOperation(IMuteMap map, IGeoprocessingService geoService)
    {
        if (map == null) throw new ArgumentNullException("map");
        if (geoService == null) throw new ArgumentNullException("geoService");
        _map = map;
        _geoService = geoService;
    }

    public bool IsEmpty
    {
        get { return _buffer == null; }
    }

    public IFeatureSet Buffer
    {
        get { return _buffer; }
    }

    public void Clear()
    {
        if (_buffer != null)
        {
            _buffer.Close();
            _buffer = null;
        }
    }

    public void Copy(int layerHandle, IFeatureSet fs)
    {
        if (fs == null || fs.NumSelected == 0) return;
        PopulateBuffer(fs);
        OffsetShapes();
    }

    public bool Cut(int layerHandle, IFeatureSet fs)
    {
        if (fs == null || fs.NumSelected == 0)
        {
            return false;
        }

        PopulateBuffer(fs);

        _geoService.RemoveSelectedShapes(layerHandle, false);
        return true;
    }

    public PasteResult Paste(int layerHandle, IFeatureSet fs)
    {
        if (fs == null || IsEmpty || !fs.InteractiveEditing)
        {
            return PasteResult.NoInput;
        }

        if (_buffer.GeometryType != fs.GeometryType)
        {
            return PasteResult.ShapeTypeMismatch;
        }

        var fieldMap = _buffer.Table.BuildFieldMap(fs.Table);

        var history = _map.History;
        history.BeginBatch();

        fs.ClearSelection();

        for (int i = 0; i < _buffer.Features.Count; i++)
        {
            // don't create a copy, buffer won't be used any more
            int shapeIndex = fs.Features.EditAdd(_buffer.Features[i].Geometry.Clone());    

            _buffer.Table.CopyAttributes(i, fs.Table, shapeIndex, fieldMap);   // TODO: don't use field map for the same FeatureSet
            history.Add(UndoOperation.AddShape, layerHandle, shapeIndex);
            fs.Features[shapeIndex].Selected = true;
        }

        history.EndBatch();

        Clear();
        return PasteResult.Ok;
    }

    private void FeatureSetToSystemClipboard(IFeatureSet fs)
    {
        string s = fs.SerializeForClipboard();
        ClipboardHelper.SetText(s);
    }

    private void PopulateBuffer(IFeatureSet sf)
    {
        var buffer = sf.ExportSelection();
        Clear();
        _buffer = buffer;
        FeatureSetToSystemClipboard(buffer);
    }

    private void OffsetShapes()
    {
        if (IsEmpty) return;
        OffsetShapes(_buffer, SCREEN_OFFSET, SCREEN_OFFSET);
    }

    public void OffsetShapes(IFeatureSet fs, double screenOffsetX, double screenOffsetY)
    {
        double x1, x2, y1, y2;
        _map.PixelToProj(0.0, 0.0, out x1, out y1);
        _map.PixelToProj(screenOffsetX, screenOffsetY, out x2, out y2);
        foreach(var ft in fs.Features)
        {
            ft.Geometry.Move(x2 - x1, y2 - y1);
        }
    }
}

}