Getting Started - miroiu/nodify Wiki

It is important to understand how components are named and what's their role in the visual tree of the editor in order to understand the code and the documentation.

Hierarchy and terminology

The root component is an editor which holds nodes and connections together with a few additional UI elements such as a selection rectangle and a pending connection in order to make the editor interactive.

Nodes are containers for connectors or the node itself can be a connector (e.g. State Node).

Connectors can create pending connections that can become real connections when completed.

A picture is worth a thousand words

nodes-hierarchy

Content Layers

You may wonder how a node can be a connector itself and still behave like a normal node. The editor contains three big layers which help solve this problem:

  1. The items layer (NodifyEditor.ItemsSource) - here, each control is wrapped inside an Item Container making it selectable, draggable, etc and it is possible to have any control rendered (e.g a connector, a text block).
  2. The connections layer (NodifyEditor.Connections) - this is where all the connections coexist and are rendered behind the items layer by default
  3. The decorators layer (NodifyEditor.Decorators) - here, each control is given a location inside the graph

Having those layers separated enables the possibility of asynchronously loading each one of them.

Creating an editor

Import the nodify namespace: xmlns:nodify="https://miroiu.github.io/nodify" or xmlns:nodify="clr-namespace:Nodify;assembly=Nodify" in your file and create an instance of the editor <nodify:NodifyEditor />. If you start the application, you will see an empty space where you can create a selection rectangle.

Tip: Drag the selection rectangle near the edge of the editor area and the screen will automatically move in that direction.

Using an existing theme

Merge one of the following themes into your resource dictionary in App.xaml:

  • Dark theme (default theme if not specified):
<ResourceDictionary Source="pack://application:,,,/Nodify;component/Themes/Dark.xaml" />
  • Light theme:
<ResourceDictionary Source="pack://application:,,,/Nodify;component/Themes/Light.xaml" />
  • Nodify theme:
<ResourceDictionary Source="pack://application:,,,/Nodify;component/Themes/Nodify.xaml" />

Drawing a grid

Drawing a simple grid is just a matter of creating a grid brush, applying the editor transform to it, and using the brush as the Background of the editor.

Because the grid we are drawing is made of lines and is not filled, the Background of the editor will have some transparency, meaning that we'll see the background color of the control below. To solve this, wrap the editor in a Grid and set its Background or set the Background of the Window.

Use the ViewportTransform dependency property to have the grid move with the view.

Note: The example uses static resources which are provided by the selected theme in App.xaml.

<Window x:Class="MyProject.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:nodify="https://miroiu.github.io/nodify"
        mc:Ignorable="d">

    <Window.Resources>
        <GeometryDrawing x:Key="SmallGridGeometry"
                        Geometry="M0,0 L0,1 0.03,1 0.03,0.03 1,0.03 1,0 Z"
                        Brush="{StaticResource NodifyEditor.SelectionRectangleBackgroundBrush}" />

        <GeometryDrawing x:Key="LargeGridGeometry"
                        Geometry="M0,0 L0,1 0.015,1 0.015,0.015 1,0.015 1,0 Z"
                        Brush="{StaticResource NodifyEditor.SelectionRectangleBackgroundBrush}" />

        <DrawingBrush x:Key="SmallGridLinesDrawingBrush"
                    TileMode="Tile"
                    ViewportUnits="Absolute"
                    Viewport="0 0 20 20"
                    Transform="{Binding ViewportTransform, ElementName=Editor}"
                    Drawing="{StaticResource SmallGridGeometry}" />

        <DrawingBrush x:Key="LargeGridLinesDrawingBrush"
                    TileMode="Tile"
                    ViewportUnits="Absolute"
                    Opacity="0.5"
                    Viewport="0 0 100 100"
                    Transform="{Binding ViewportTransform, ElementName=Editor}"
                    Drawing="{StaticResource LargeGridGeometry}" />
    </Window.Resources>

    <Grid Background="{StaticResource NodifyEditor.BackgroundBrush}">
        <nodify:NodifyEditor x:Name="Editor" Background="{StaticResource SmallGridLinesDrawingBrush}" />

        <Grid Background="{StaticResource LargeGridLinesDrawingBrush}"
              Panel.ZIndex="-2" />
    </Grid>
</Window>

Tip: Right-click and drag the screen around to move the view and use the mouse wheel to zoom in and out.

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