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Nevron Diagram for .NET Features

Diagram Document Object Model

Regardless of whether you are creating a WinForm or an ASP.NET diagramming application, with Nevron Diagram for .NET, you use the same API to create your diagram documents.
The set of objects you can use to construct a document is called the document object model (DOM). The DOM of Nevron Diagram for .NET is very consistent and designed to be further extended.

It all starts with the type of document you want to construct. In the diagram, you basically have two types of documents:
  • Drawing Document - represents a diagram drawing. A drawing basically consists of shapes residing in layers. Shapes can be linked to form complex graph relationships. Drawings can be automatically laid-out, visually edited, and exported to various raster and vector formats (for example, BMP, PNG, and SVG, to name a few). Drawings can be printed.

  • Library Document - represents a collection of reusable drawing clippings (masters), which you can drag and drop into the drawing document. Masters can contain one or more shapes and the connections between them.
Both types of documents are constructed from a consistent set of elements, the most notable ones being shapes. Documents are displayed inside different views in the context of WinForm and ASP.NET environments.

Shapes and Groups

When constructing diagrams, you basically work with shapes. In Nevron Diagram for .NET, there are two types of shapes:
  • 2D shapes
    2D shapes represent boxes containing vector or raster primitives and text. 2D shapes are usually simply called shapes.

  • 1D shapes
    1D shapes represent lines with different geometry and behavior, which interconnect other shapes. 1D shapes are often called connectors.
Nevron Diagram for .NET provides an extensive set of predefined shapes (see Predefined Shapes) but also lets you create custom ones by simply composing drawing primitives (lines, polylines, curves, rectangles, ellipses, text blocks, etc.).

All types of shapes can be grouped to create groups. Groups can also be by preference 1D or 2D. They act as a single shape but are, in fact, composed of several others. Groups can be used for the creation of custom shapes.

All 1D shapes have plugs, while both 1D and 2D shapes can have an arbitrary number of ports. A diagram with connections is thus primarily constructed by connecting plugs to ports. Nevron Diagram for .NET also supports an extended type of connection, which is performed by inward and outward ports - e.g., shapes can be connected by ports too.

In Nevron Diagram, you can convert a 1D shape to a 2D shape and vice versa via a single property.

All types of shapes can have control points. Control points are used to visually change the appearance of a shape by simply dragging them.

All types of shapes can have an arbitrary number of labels. Labels can be anchored to specific aspects of the shape.

Styles and Styling

The visual appearance of all diagram elements is controlled via styles. Styles can be locally specified (per each element individually) or reused through the inheritance or style sheets.

The usage of inheritance and style sheets greatly minimizes the effort needed to apply a consistent outlook to your diagram and then have the ability to easily change it. It also minimizes the memory footprint of your diagrams.

Behavior Customizations

Nevron Diagram for .NET provides you with built-in options to consistently customize the behavior of different diagram elements. Following is a brief overview of the most important behavior customization features:
  • Protection
    Protection helps you protect certain diagram element aspects from being changed or viewed by the user. For example, you can protect shapes from being moved, resized, printed, exported to an image, deleted, etc.

  • Interaction style
    The interaction style defines the aspects of a shape, for which a view must create trackers (visual editors with handles) when the shape is selected. For example: when a 2D shape is selected, the view will create trackers for its bounds, rotation angle, and pinpoint. If you want to remove the rotation angle and pinpoint trackers, you just have to apply the desired interaction style to the shape.

  • Translation slaves
    Translation slaves let you specify the shapes, which are automatically translated when a certain shape is translated. This helps you build rigid structures.

Visual Effects and Decorations

Nevron Diagram for .NET gives you full control over advanced visual effects. Raster graphics effects include image filters, which can be applied to any element, displaying vector and/or raster content. Image filter effects can be combined with classical fill styles (solid color, gradient, hatch, image, and advanced gradients).

The component has industry-leading support for shadows - it provides several types of shadows and lets you choose the Z-order in which they are dropped (behind the document, behind the layer, etc.).

Diagram-specific decorations are also not left behind. Nevron Diagram for .NET can automatically display bridges (hops) on connector intersections and self-intersections. The bridge's appearance is controlled via styling.

In diagramming, arrowheads are usually used to distinguish between the different types of relations (one to many, one to one, etc.). Nevron Diagram has numerous built-in arrowheads, provides the ability to define custom ones, and lets you customize their appearance via styling.

Graphs and Trees

Nevron Diagram for .NET has a built-in support for graph and tree data structures and the core operations with them:
For example, performing different traversals - depth-first, breadth-first, etc., checking whether the graph is acyclic, whether it is a tree, and so forth.

Graph and tree data structures can be generated from the shapes of a drawing document. This gives you the needed flexibility to operate with a visually constructed diagram as if it is a simple graph or tree.

Measurement Units

You won't find many diagram components which work transparently with different measurement units. In Nevron Diagram for .NET, you can use Metric, English, and pixel units to define your drawing content measurements. The component also provides support for drawing scale, which lets you work with either too small or too large drawings (for example, diagrams measured in nanometers or kilometers).

Automatic Layouts

The automatic arrangement of diagrams is an indispensable feature, especially when diagrams are either too large or are automatically generated. Nevron Diagram for .NET comes equipped with a sophisticated set of automatic layouts. Following is a brief overview:

Obstacle Avoidance Routing

The obstacle avoidance routing of routable connectors addresses user-laid-out diagrams in which certain connectors must be automatically rerouted not to cross any obstacles (shapes) in their path. Nevron Diagram for .NET provides support for both Mesh and Grid connectors routing, which is automatically performed. Addressed are issues like minimal bendings, port headings, etc.

Tree Layouts

Nevron Diagram for .NET provides an extended set of automatic layouts, which deal with the shape placement and connector routing in the case of diagrams representing trees. Implemented is the following set of tree layouts:
  • Layered Tree Layout
    Layouts the tree vertices in layers. Supports breadth compaction. Produces both straight line and orthogonal tree drawings. Supports layout direction (top-to-bottom, left-to-right etc.).

  • Compact Depth Tree Layout
    The depth arrangement of the vertices is as compact as possible. This layout supports breadth compaction. Produces both straight line and orthogonal tree drawings. Supports layout direction (top-to-bottom, left-to-right etc.).

  • Tip Over Tree Layout
    Layouts the children vertices of a vertex in either a single row or a single column. The children's placement can be specified on a per-vertex basis. Produces orthogonal tree drawings.

  • Balloon Tree Layout
    Layouts the children vertices in a single circle around its parent vertex. The children's angular range can be the controller. Produces straight line tree drawings.

Graph Layouts

Nevron Diagram for .NET provides an extended set of automatic layouts, which deal with the shape placement and connector routing in the case of diagrams representing graphs. Implemented is the following set of graph layouts:
  • Layered Graph Layout (Hierarchical Graph Layout)
    This layout distributes vertices to layers. It tries to minimize the number of edge crossings and edge bends. Supports layout direction (top-to-bottom, left-to-right etc.). Produces polyline graph drawings.

  • Orthogonal Graph Layout
    This layout tries to display the graph only with orthogonal edges and tries to minimize the drawing area, edge crossings, and edge bends.

  • Symmetrical Graph Layout
    This is a force-directed layout, which aims to produce a straight line graph drawing with uniform edge lengths. It couples attractive and repulsive forces, which balance each other at the user-specified desired edge length. Because of that, the produced drawings tend to be symmetrical.

  • Spring Graph Layout
    This is a force-directed layout, which aims to produce a straight line graph drawing that reflects the nature of the graph. It couples an electrical force (repels the vertices, which are close to each other) and a spring force (tries to enforce a certain distance between connected vertices). The parameters of the spring force can be specified on a per edge basis (e.g., some edges can be longer and/or stiffer than others).

  • Barycenter Graph Layout
    This is a force-directed layout, which splits the graph into fixed and free vertices. It places the fixed vertices at a strictly convex polygon and then places the free vertices at their barycenter (center of mass). This layout produces straight-line graph drawings.

  • Radial Graph Layout
    This is a circular graph layout, which layouts the graph in concentric circles. Produces straight-line graph drawings.

Cells Layouts

Sometimes it is needed to arrange only the vertices of the graph. In these cases, each vertex can be treated as a cell. Nevron Diagram for .NET implements the following cells layouts:
  • Stack Layout
    The stack layout represents a directed, constrained cell layout, which stacks the cells in horizontal or vertical order. Depending on the layout direction, the layout is constrained by either width or height.

  • Flow Layout
    The flow layout represents a directed constrained cells layout, which arranges the cells in horizontal or vertical lanes. The flow layout does not preserve tabular metrics.

  • Table Layout
    The table layout represents a directed constrained cells layout, which arranges cells in a tabular manner (e.g., preserves tabular metrics).

  • Dock Layout
    The dock layout represents a space-eating cells layout, which places vertices at per-vertex specified docking areas of the currently available layout area.

Visio Stencil Importer

The Nevron Diagram Visio Stencil Importer will allow you to import and reuse the standard or custom-designed MS Visio shapes inside your projects which use Nevron Diagramming controls. It takes as an input an XML serialized Visio stencil (VSX format) and imports its shapes in a Nevron library document which you can use with Nevron diagrams.

Review the Nevron Diagram Gallery for some examples of imported Visio Shapes inside Nevron Diagram.

We are providing support for additional customization of the shapes and full integration for desktop or web applications. Now, you can build more complex and stylish diagrams by combining the Visio shapes with the power of Nevron Diagramming components. Developers can exploit all the functionality of the Nevron Diagram to further customize and fine-tune your projects, well beyond the capabilities of any other diagramming solution available.

Maps (part of Nevron Diagram for .NET Enterprise edition)

Nevron Diagram for .NET has built-in support for the display of maps. ESRI shapefiles (the industry-leading standard for storing map data) can be easily imported into any diagram with just a few lines of code.

Maps and diagrams fit perfectly together – in many cases, the simple vector data provided by the ESRI shapefiles needs additional decorations and interactivity extensions. For example, you may want to display predefined shapes on certain points of interest, use different color coding rules depending on the data associated with the shape, provide the user with the ability to drag and drop objects on maps, etc., provide free-hand drawing, etc. – in all these scenarios you will soon discover that you do not need a simple map component – you need a diagram with map support.

Following is a brief overview of the most important mapping features:
  • Supports ESRI shapefile format - the industry leading standard
  • Supports 22 projection types
  • Intelligent layer properties- show/hide layers based on zoom level
  • Automatic naming and labeling of map elements through data field association
  • Full programmatic access to map elements, including shapes and paths

Thick client (WinForms) and Visual Editing

Nevron Diagram for .NET provides the leading built-in support for developing thick client diagramming applications.

Ready to use Controls

Nevron Diagram for .NET comes equipped with several ready-to-use controls, which can help you create a standalone diagramming application in minutes. In fact, the Diagram Designer application, which is included in the package, is built only by assembling the following controls:
  • Drawing View
    The drawing view helps you display and edit drawing documents. Drawing views are feature-rich and help you zoom, pan, stretch and fit documents. Drawing views can edit numerous shape features via interactive editors (trackers).

  • Library View
    The library view helps you display and edit library documents. You can drag and drop shapes from the library view to the drawing view and vice versa.

  • Pan and Zoom Control
    The pan and zoom control helps you display a bird's eye view of the document, which is being edited in its master drawing view. It also lets you interactively pan and zoom the master drawing view.

  • Diagram Command Bars Manager
    The diagram command bars manager help you visualize and execute the set of predefined commands, which can be performed on drawing and library views.

  • Diagram Properties Browser
    The diagram properties browser helps you instantly edit the properties of the document, the active layer, the selected element, or the view.

  • Diagram Status Bar
    The diagram status bar displays important information about the current state of a drawing view (size of the selected element, keyboard state, measurement unit, etc.).


Nevron Diagram for .NET has support for Undo/Redo that works for everything the user does. The support for Undo/Redo is deeply integrated into the product and provides you with a transaction-based programming model - this means that not only the user actions but also the programmable actions can be undone and redone.


Nevron Diagram for .NET takes a radical approach to processing the user gestures in both drawing and library views. All UI events are processed via tools, which are maintained by a controller assigned to each view. This helps you easily configure the way in which the user interacts with your diagram, which is achieved by simply enabling/disabling certain tools. If the myriad of predefined tools does not fit your particular integration case, you can enrich your application by implementing custom tools.

Advanced Visual Aids

Nevron Diagram for .NET has industry-leading support for visual aids. Following is a brief overview:
  • Previews
    All operations, which the user performs with shapes, are previewed. For example: if you move shapes, drag and drop shapes, or rotate or resize shapes, the diagram will automatically generate previews for the shapes upon which the operation is performed. This helps the user see the effect of the action before it is actually committed. All previewed actions can be canceled by pressing the Esc key.

  • Snapping
    Previews are smartly snapped. Snapping is context-sensitive. For example, if you move a connector plug, it tries to snap to inward ports first. If you move a shape, it tries to snap its outward ports to inward ports first. If you rotate a shape, the diagram tries to snap the rotation angle and so forth. Snapping can be tuned in numerous ways.

  • Grid and Rulers
    All previews can be snapped to grid lines and ruler ticks. The grid and ruler components are built-in in each drawing view. Both the grid and rulers have smart scales - for example, if you zoom in/out the diagram, they try to adjust their tick steps automatically in order to fill the viewport area in the best way (e.g., automatically increase or decrease the step). They can, of course, have a fixed step too if you prefer. Both grid and rulers can operate in different measurement units.

  • Auto scrolling
    Auto-scrolling helps the user to scroll the view while moving shapes by just moving the mouse to close the view rims.

  • Attention to detail
    Nevron Diagram for .NET pays great attention to visual aids details.
    For example, The cursors, which appear on resize handles, are properly oriented. Many operations accept Ctrl/Shift modifications (Ctrl + Move, for example, duplicates a shape). Tooltips appear on handles, control points, rulers, etc. Connection ports are highlighted to indicate a connection. Selection target shapes are highlighted. Moved region bounds are projected on the rulers. The mouse cursor position is projected on rulers. Multiple moving shapes and bounds are displayed. And many more.

Thin client (ASP.NET) and AJAX

Nevron Diagram for .NET provides built-in support for developing interactive thin client diagramming applications. It can operate either in Postback or in AJAX mode. Following is a brief description of the thin client modes:


Nevron Diagram for .NET comes with a powerful yet easy-to-use built-in set of AJAX interactivity styles. It is based on the Nevron AJAX Framework, which is a reliable, fault-tolerant, and cross-browser compatible JavaScript library, that converts the simple diagram images inside your web page into an interactive client-side application with flicker-free asynchronous image updates. Following is a brief overview of the AJAX features of Nevron Diagram for .NET:
  • Refresh and Auto Refresh
    The diagram inside your web page can be configured to refresh itself within a specified update interval by simply enabling auto-refresh and implementing the server-side logic that will modify the diagram on refresh. The diagram can also be updated on demand through the client-side JavaScript API, exposed by the Nevron AJAX Framework.

  • Client Side AJAX Tools
    Most of the Nevron Diagram for .NET AJAX functionality is based on the controller/tools architecture. Pure client-side tools that work with an updateable diagram image are the Tooltip tool, the Dynamic cursor tool, and the Browser redirect tool.
    In addition, a set of tools is available that intercept the user input and route it via AJAX calls to the server for processing. All mouse events can be enabled for AJAX routing, helping you create drill-down functionality and add hover effects. The controller/tools architecture allows you to easily extend the AJAX functionality by creating new custom tools.

  • Reliability and Fault Tolerance
    You should think of an AJAX web page as a classical client-server application. The client is implemented with JavaScript classes, running within the browser's DOM. The server is your ASP.NET AJAX-enabled web form. Client and server communicate asynchronously, and once initialized, the client runs independently from the server and is operational even if the server is unavailable. The Nevron AJAX Framework implements all the necessary logic required to adequately notify the user of server unavailability and to resume operation when the connection to the server is restored.

ASP.NET Postback Mode

Nevron Diagram for .NET provides a set of useful features that help you add interactivity to your web application while sticking to the more traditional and simple postback technology:
  • Interactive Image Maps
    Nevron Diagram for .NET can send an HTML image map to the client browser, which allows you to build web applications with drill-down capabilities. The interactive image map helps you add the following interactivity to your diagram:
    - client-side browser redirect, with configurable target URL for every diagram element;
    - dynamic cursor, that changes when the user hovers over diagram elements
    - client-side tooltips.
    It also provides a way to inject client-side script blocks to be executed on user input on a per-diagram element basis.

  • SVG Image Response
    The SVG image response sends the client a rich vector graphics image. This helps you have the diagram image rescaled in the web browser without loss of quality, which would be the case if rescaling raster format images. The SVG format also allows client-side interactivity, such as mouse hover effects.

Customer Quotes:

QUOTE We use Nevron Diagram for .NET in our client server software that allows Enel’s operational compartments to plan the electrical net; the software enable electrical engineers to find less expensive, but still efficient, solutions for the electrical net. The software works in disconnected mode, as a smart client, and allows the personnel to simulate various configuration of the electrical net; using the client program it is possible to add, remove or substitute pieces of the MT electrical net representation as well as change connection points.

The simulator, then, allows to emulate every single point of failure of the net and for each of them reconfigures the net for the best off-line time (breakers take several maneuvers and counter-maneuvers to operate correctly). At the end of the simulation an animation is recorded for the best solution found (time/price). The animation is then displayed , using Nevron Graph controls, allowing the electrical engineer to check the correctness of the result and the various “moves” that the simulator toke to get to the best solution. When the personnel is then satisfied with the solution it uses the client application to update the remote DB with a request to acquire the needed resources to build this new configuration on the real net.

Gian Piero Anselmi
NIT - New Information Technology S.r.l.