Controlling Color, Line Style, and other Shape Properties

Applies to: Visual Studio Visual Studio for Mac

Note

This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

Some shape properties such as color can be 'exposed'. That is, the properties can be linked to a domain property of the shape. Others have to be controlled directly.

Exposing a property

Some shape properties such as color can be linked to the value of a domain property.

In the DSL Definition, select a shape, connector or diagram class. On its right-click menu, choose Add Exposed, and then choose the property you want, such as Fill Color.

The shape now has a domain property that you can set in program code or as a user.

Dynamically updating an exposed property

Typically you want to make the exposed property dependent on another property. For example, you might want a shape to turn red whenever a particular domain property is less than zero. To make this dependency, create a rule. For example:

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.VisualStudio.Modeling;
using Microsoft.VisualStudio.Modeling.Diagrams;
namespace ExampleNamespace
{
 // Attribute associates the rule with class:
 [RuleOn(typeof(CarShape), FireTime = TimeToFire.TopLevelCommit)]
 // The rule is a class derived from one of the abstract rules:
 class CarShapeAddRule : AddRule
 {
 // Override the abstract method:
 public override void ElementAdded(ElementAddedEventArgs e)
 {
 base.ElementAdded(e);
 CarShape shape = e.ModelElement as CarShape;
 Store store = shape.Store;
 // Ignore this call if we're currently loading a model:
 if (store.TransactionManager.CurrentTransaction.IsSerializing)
  return;
 Car car = shape.ModelElement as Car;
 // Code here propagates change as required - for example:
 shape.FillColor = car.Somebool ? System.Drawing.Color.Red : System.Drawing.Color.Green;
 }
}
 // The rule must be registered:
 public partial class ExampleDomainModel
 {
 protected override Type[] GetCustomDomainModelTypes()
 {
  List<Type> types = new List<Type>(base.GetCustomDomainModelTypes());
  types.Add(typeof(CarShapeAddRule));
  // If you add more rules, list them here.
  return types.ToArray();
 }
 }
}