Change object color and shape via data import

Applies to: Nevron Diagram for .NET

How to change object color and shape via data import?

You can use the DataImport for generating a graph using data tables. You can add labels to the connectors, change the shape for certain objects and change from one color to another. The following source code makes a simple drawing which imports data from two tables. The vertices have different shape and color, and edges have labels.

using System;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using Nevron.Diagram;
using Nevron.Diagram.DataImport;
using Nevron.Diagram.Layout;
using Nevron.Diagram.WinForm;
using Nevron.GraphicsCore;
private void Form1_Load(object sender, EventArgs e)
    NDrawingView view = new NDrawingView();
    view.Dock = DockStyle.Fill;
    view.GlobalVisibility.ShowPorts = false;
    NDrawingDocument doc = new NDrawingDocument();
    view.Document = doc;
    DataTable vtable = new DataTable();
    vtable.Columns.Add("id", typeof(int));
    vtable.Columns.Add("text", typeof(string));
    vtable.Rows.Add(1, "root");
    vtable.Rows.Add(2, "c1");
    vtable.Rows.Add(3, "c2");
    DataTable etable = new DataTable();
    etable.Columns.Add("from", typeof(int));
    etable.Columns.Add("to", typeof(int));
    etable.Columns.Add("text", typeof(string));
    etable.Rows.Add(1, 2, "label1");
    etable.Rows.Add(1, 3, "label2");
    NGraphDataSourceImporter importer = new NGraphDataSourceImporter();
    importer.Document = doc;
    importer.VertexDataSource = vtable;
    importer.EdgeDataSource = etable;
    importer.VertexIdColumnName = "id";
    importer.FromVertexIdColumnName = "from";
    importer.ToVertexIdColumnName = "to";
    importer.Layout = new NLayeredGraphLayout();
    importer.VertexShapesFactory = new MyShapeFactory();
    importer.VertexImported += new ShapeImportedDelegate(importer_VertexImported);
    importer.EdgeImported += new ShapeImportedDelegate(importer_EdgeImported);
void importer_EdgeImported(NDataSourceImporter dataSourceImporter, NShape shape, INDataRecord record)
    shape.Text = record.GetColumnValue("text").ToString();
void importer_VertexImported(NDataSourceImporter dataSourceImporter, NShape shape, INDataRecord record)
    shape.Text = record.GetColumnValue("text").ToString();
    NCompositeShape cshape = shape as NCompositeShape;
    if (shape.Text == "root")
        cshape.Primitives.AddChild(new NRectanglePath(0, 0, 80, 80));
        cshape.Style.FillStyle = new NColorFillStyle(Color.CornflowerBlue);
        cshape.Primitives.AddChild(new NEllipsePath(0, 0, 80, 80));
        cshape.Style.FillStyle = new NColorFillStyle(Color.OrangeRed);
    cshape.Ports.AddChild(new NDynamicPort(new NContentAlignment(), DynamicPortGlueMode.GlueToContour));
public class MyShapeFactory : INShapesFactory
    #region INShapesFactory Members
    public bool CanCreateShape(string name)
        return true;
    public NShape CreateShape(string name)
        return new NCompositeShape();

Imports System
Imports System.Data
Imports System.Drawing
Imports System.Windows.Forms
Imports Nevron.Diagram
Imports Nevron.Diagram.DataImport
Imports Nevron.Diagram.Layout
Imports Nevron.Diagram.WinForm
Imports Nevron.GraphicsCore
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim view As New NDrawingView()
    view.Dock = DockStyle.Fill
    view.GlobalVisibility.ShowPorts = False
    Dim doc As New NDrawingDocument()
    view.Document = doc
    Dim vtable As New DataTable()
    vtable.Columns.Add("id", GetType(Integer))
    vtable.Columns.Add("text", GetType(String))
    vtable.Rows.Add(1, "root")
    vtable.Rows.Add(2, "c1")
    vtable.Rows.Add(3, "c2")
    Dim etable As New DataTable()
    etable.Columns.Add("from", GetType(Integer))
    etable.Columns.Add("to", GetType(Integer))
    etable.Columns.Add("text", GetType(String))
    etable.Rows.Add(1, 2, "label1")
    etable.Rows.Add(1, 3, "label2")
    Dim importer As New NGraphDataSourceImporter()
    importer.Document = doc
    importer.VertexDataSource = vtable
    importer.EdgeDataSource = etable
    importer.VertexIdColumnName = "id"
    importer.FromVertexIdColumnName = "from"
    importer.ToVertexIdColumnName = "to"
    importer.Layout = New NLayeredGraphLayout()
    importer.VertexShapesFactory = New MyShapeFactory()
    AddHandler importer.VertexImported, AddressOf importer_VertexImported
    AddHandler importer.EdgeImported, AddressOf importer_EdgeImported
End Sub
Private Sub importer_EdgeImported(ByVal dataSourceImporter As NDataSourceImporter, ByVal shape As NShape, ByVal record As INDataRecord)
    shape.Text = record.GetColumnValue("text").ToString()
End Sub
Private Sub importer_VertexImported(ByVal dataSourceImporter As NDataSourceImporter, ByVal shape As NShape, ByVal record As INDataRecord)
    shape.Text = record.GetColumnValue("text").ToString()
    Dim cshape As NCompositeShape = TryCast(shape, NCompositeShape)
    If shape.Text = "root" Then
        cshape.Primitives.AddChild(New NRectanglePath(0, 0, 80, 80))
        cshape.Style.FillStyle = New NColorFillStyle(Color.CornflowerBlue)
        cshape.Primitives.AddChild(New NEllipsePath(0, 0, 80, 80))
        cshape.Style.FillStyle = New NColorFillStyle(Color.OrangeRed)
    End If
    cshape.Ports.AddChild(New NDynamicPort(New NContentAlignment(), DynamicPortGlueMode.GlueToContour))
End Sub
Public Class MyShapeFactory
        Implements INShapesFactory
#Region "INShapesFactory Members"
        Public Function CanCreateShape(ByVal name As String) As Boolean Implements Nevron.Diagram.INShapesFactory.CanCreateShape
            Return True
        End Function
        Public Function CreateShape(ByVal name As String) As NShape Implements Nevron.Diagram.INShapesFactory.CreateShape
            Return New NCompositeShape()
        End Function
#End Region
End Class

A simple shape factory is implemented, which always returns a composite shape. In the VertexImported handler the composite shape geometry primitives are initialized depending on the data record for which the vertex is created. By default if an edge factory is not assigned the data importer will create NRoutableConnector instances. These connectors have a single label of type NLogicalLineLabel which is anchored to 50% of the connector length. Setting the Text property of the connector will actually set this label text value.

Article ID: 82, Created On: 10/8/2010, Modified: 12/1/2010