Can you send me a simple example of how to implement and expand collapse on a tree diagram?

thanks.

Hello Yoav,

You can take a look at the Help Documentation: Diagram for .NET > User's Guide > Document Object Model > Models > Shapes > Decorators

The following code example will generate a tree diagram with show-hide subtree decorator for each shape that has children:

using Nevron.Diagram;

using Nevron.Diagram.Shapes;

using Nevron.Diagram.WinForm;

using Nevron.Diagram.Templates;

using Nevron.Diagram.Filters;

using Nevron.Diagram.Layout;

using Nevron.Diagram.DataStructures;

…

NDrawingView view = new NDrawingView();

NDrawingDocument document = new NDrawingDocument();

this.Controls.Add(view);

view.Document = document;

view.BeginInit();

view.Dock = DockStyle.Fill;

view.ViewLayout = ViewLayout.Fit;

view.Grid.Visible = false;

view.GlobalVisibility.ShowPorts = false;

document.BeginInit();

// create a random tree

NGenericTreeTemplate treeTemplate = new NGenericTreeTemplate();

treeTemplate.BranchNodes = 3;

treeTemplate.VerticesSize = new NSizeF(50, 50);

treeTemplate.Balanced = false;

treeTemplate.Levels = 5;

treeTemplate.Create(document);

// add show-hide subtree decorator for each shape that has children

foreach (NShape shape in document.ActiveLayer.Children(NFilters.Shape2D))

{

    if (shape.GetOutgoingShapes().Count == 0)

        continue;

    // create the decorators collection

    shape.CreateShapeElements(ShapeElementsMask.Decorators);

    NShowHideSubtreeDecorator decorator = new NShowHideSubtreeDecorator();

    decorator.Offset = new NSizeF(-11, 11);

    decorator.Size = new NSizeF(15, 15);

    decorator.Alignment = new NContentAlignment(ContentAlignment.TopLeft);

    shape.Decorators.AddChild(decorator);

}

document.AutoBoundsMinSize = new NSizeF(400, 400);

// layout with a layered tree layout

NLayoutContext context = new NLayoutContext();

context.GraphAdapter = new NShapeGraphAdapter(true);

context.BodyAdapter = new NShapeBodyAdapter(document);

context.BodyContainerAdapter = new NDrawingBodyContainerAdapter(document);

NLayeredTreeLayout layout = new NLayeredTreeLayout();

layout.VertexSpacing = 50;

layout.LayerSpacing = 50;

layout.Layout(document.ActiveLayer.Children(null), context);

// size to visible shapes

document.SizeToContent(document.AutoBoundsMinSize, document.AutoBoundsPadding, NFilters.Visible);

document.EndInit();

view.EndInit();

Related examples:

Windows Forms: Document Object Model - Shapes - Decorators folder

Best Regards,
Nevron Support Team