How to position node’s port

1 Nov 202113 minutes to read

Diagram allows you to customize the position and appearance of the port efficiently. Port can be aligned relative to the node boundaries. It has Margin, Offset, Horizontal, and Vertical alignment settings. It is quite tricky when all four alignments are used together but gives more control over alignments properties of the PointPort class. Ports of a node can be positioned using the following properties of PointPort.

  • Offset
  • HorizontalAlignment
  • VerticalAlignment
  • Margin

Offset

The Offset property is used to align the Ports based on fractions. 0 represents top/left corner, 1 represents bottom/right corner, and 0.5 represents half of width/height.

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent Height="600px" Nodes="@nodes"/>

@code
{
    DiagramObjectCollection<Node> nodes;

    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>();
        // A node is created and stored in nodes collection.
        Node node = new Node()
        {
            // Position of the node
            OffsetX = 250,
            OffsetY = 250,
            // Size of the node
            Width = 100,
            Height = 100,
            Style = new ShapeStyle() { Fill = "#6495ED", StrokeColor = "white" },
            // Initialize port collection
            Ports = new DiagramObjectCollection<PointPort>()
            {
                new PointPort() 
                {
                    ID = "port1",
                    // Sets the offset for the port
                    Offset = new DiagramPoint() { X = 0, Y = 0.5 },
                    Visibility = PortVisibility.Visible,
                    //Set the style for the port
                    Style= new ShapeStyle() { Fill = "gray", StrokeColor = "black" },
                    Width = 12,
                    Height = 12,
                    // Sets the shape of the port as Square 
                    Shape = PortShapes.Square
                }
            }
        };
        nodes.Add(node);
    }
}

Blazor Diagram with Port based on Offset

The following table shows the relationship between the shape port position and path port offset (fraction values).

Offset values Output
(0,0) Blazor Diagram Port in Left Top Offset Values
(0,0.5) Blazor Diagram Port in Left Center Offset Values
(0,1) Blazor Diagram Port in Left Bottom Offset Values
(0.5,0) Blazor Diagram Port in Center Top Offset Values
(0.5,0.5) Blazor Diagram Port in Center Offset Values
(0.5,1) Blazor Diagram Port in Center Bottom Offset Values
(1,0) Blazor Diagram Port in Right Top Offset Values
(1,0.5) Blazor Diagram Port in Right Center Offset Values
(1,1) Blazor Diagram Port in Right Bottom Offset Values

Horizontal and Vertical alignment

The HorizontalAlignment property of the port is used to set how the port is horizontally aligned at the port position determined from the fraction values. The VerticalAlignment property is used to set how the port is vertically aligned at the port position.

The following table shows all the possible alignments visually with offset (0, 0).

Horizontal Alignment Vertical Alignment Output with Offset(0,0)
Left Top Blazor Diagram Port in Left Top Position
Center Top Blazor Diagram Port in Center Top Position
Right Top Blazor Diagram Port in Right Top Position
Left Center Blazor Diagram Port in Left Center Position
Center Center Blazor Diagram Port in Center Center Position
Right Center Blazor Diagram Port in Right Center Position
Left Bottom Blazor Diagram Port in Left Bottom Position
Center Bottom Blazor Diagram Port in Center Bottom Position
Right Bottom Blazor Diagram Port in Right Bottom Position

The following code explains how to align ports.

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent Height="600px" Nodes="@nodes"/>

@code
{
    DiagramObjectCollection<Node> nodes;

    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>();
        // A node is created and stored in nodes array.
        Node node = new Node()
        {
            // Position of the node
            OffsetX = 250,
            OffsetY = 250,
            // Size of the node
            Width = 100,
            Height = 100,
            Style = new ShapeStyle() { Fill = "#6495ED", StrokeColor = "white" },
            // Initialize port collection
            Ports = new DiagramObjectCollection<PointPort>() 
            {
                new PointPort() 
                {
                    ID = "port1",
                    Offset = new DiagramPoint() { X = 0, Y = 0 },
                    Visibility = PortVisibility.Visible,
                    //Set the style for the port
                    Style = new ShapeStyle(){ Fill="gray", StrokeColor="black"},
                    Width = 12, 
                    Height = 12, 
                    // Sets the shape of the port as Square                    
                    Shape = PortShapes.Square,
                    HorizontalAlignment = HorizontalAlignment.Center,
                    VerticalAlignment = VerticalAlignment.Center
                }
            }
        };
        nodes.Add(node);
    }
}

Changin Port Position in Blazor Diagram

The value of the HorizontalAlignment is Center by default. The value of the VerticalAlignment is Center by default. Alignment positioned based on the offset value.

Margin

Margin is an absolute value used to add some blank space to any one of its four sides. The ports can be displaced with the margin property. The following code example explains how to align a port based on its Offset, HorizontalAlignment, VerticalAlignment, and Margin values.

@using Syncfusion.Blazor.Diagram

<SfDiagramComponent Height="600px" Nodes="@nodes"/>

@code
{
    DiagramObjectCollection<Node> nodes;

    protected override void OnInitialized()
    {
        nodes = new DiagramObjectCollection<Node>();
        // A node is created and stored in nodes array.
        Node node = new Node()
        {
            // Position of the node
            OffsetX = 250,
            OffsetY = 250,
            // Size of the node
            Width = 100,
            Height = 100,
            Style = new ShapeStyle() { Fill = "#6495ED", StrokeColor = "white" },
            // Initialize port collection
            Ports = new DiagramObjectCollection<PointPort>() 
            {
                new PointPort() 
                {
                    ID = "port1",
                    Offset = new DiagramPoint() { X = 0.5, Y = 1 },
                    Visibility = PortVisibility.Visible,
                    //Set the style for the port
                    Style= new ShapeStyle() { Fill = "gray", StrokeColor = "black" },
                    Width = 12,
                    Height = 12, 
                    // Sets the shape of the port as Square
                    Shape = PortShapes.Square,
                    HorizontalAlignment = HorizontalAlignment.Left,
                    VerticalAlignment = VerticalAlignment.Top,
                    Margin = new Margin() { Top = 10 }
                }
            }
        };
        nodes.Add(node);
    }
}

Blazor Diagram Port with Margin

See also