截获对形状或修饰器的单击

项目
01/15/2024

以下过程演示了如何截获对形状或图标修饰器的单击。可以截获单击、双击、拖动及其他笔势，让元素做出响应。

截获对形状的单击

在 Dsl 项目中，在与生成的代码文件分离的代码文件中，为形状类编写分部类定义。替代 OnDoubleClick() 或名称以 On... 开头的其他方法之一。例如：

public partial class MyShape // change
{
  public override void OnDoubleClick(DiagramPointEventArgs e)
  {
    base.OnDoubleClick(e);
    System.Windows.Forms.MessageBox.Show("Click");
    e.Handled = true;
  }
}

注意

除非想要将事件传递到包含的形状或图表，否则请将 e.Handled 设置为 true。

截获对修饰器的单击

具有 OnDoubleClick 方法的 ImageField 类的实例上承载了图像修饰器。如果编写了 ImageField 子类，则可以截获单击。字段在 InitializeShapeFields 方法中设置。因此，必须更改该方法以实例化子类（而不是常规的 ImageField）。 InitializeShapeFields 方法位于 shape 类的生成代码中。如果按照以下过程中的说明设置 shape 类的 Generates Double Derived 属性，则可以替代该类。

虽然 InitializeShapeFields 是实例方法，但每个类仅调用一次该方法。因此，每个类中的每个字段只有一个 ClickableImageField 实例，而并非图表中每个形状都有一个实例。当用户双击某个实例时，必须确定要单击的实例，如示例中的代码所示。

若要截获对图标修饰器的单击，请执行以下步骤：

打开或创建 DSL 解决方案。
选择或创建具有图标修饰器的形状，并将其映射到域类。

在与 GeneratedCode 文件夹中的文件分开的代码文件中，创建 ImageField 的新子类：

using Microsoft.VisualStudio.Modeling;
using Microsoft.VisualStudio.Modeling.Design;
using Microsoft.VisualStudio.Modeling.Diagrams;
using System.Collections.Generic;
using System.Linq;

namespace Fabrikam.MyDsl { // Change to your namespace
internal class ClickableImageField : ImageField
{
  // You can also override OnClick and so on.
  public override void OnDoubleClick(DiagramPointEventArgs e)
  {
    base.OnDoubleClick(e);
    // Work out which instance was hit.
    MyShape shapeHit = e.HitDiagramItem.Shape as MyShape;
    if (shapeHit != null)
    {
      MyDomainClass element =
          shapeHit.ModelElement as MyDomainClass;
      System.Windows.Forms.MessageBox.Show(
         "Double click on shape for " + element.Name);
      // If we do not set Handled, the event will
      // be passed to the containing shape:
      e.Handled = true;
    }
  }

   public ClickableImageField(string fieldName)
     : base(fieldName)
   { }
}

如果不希望将事件传递到包含的形状，则应将 Handled 设置为 true。

通过添加以下分部类定义来替代 shape 类中的 InitializeShapeFields 方法。

public partial class MyShape // change
{
 protected override void InitializeShapeFields
      (IList<ShapeField> shapeFields)
 {
  base.InitializeShapeFields(shapeFields);
  // You can see the above method in MyShapeBase
  // in the generated Shapes.cs
  // It has already added fields for the Icons.
  // So you will have to retrieve them and replace with your own.
  ShapeField unwantedField = shapeFields.First
      (field => field.Name == "IconDecorator1");
  shapeFields.Remove(unwantedField);

  // Now replicate the generated code from the base class
  // in Shape.cs, but with your own image constructor.
  ImageField field2 = new ClickableImageField("IconDecorator1");
  field2.DefaultImage = ImageHelper.GetImage(
    MyDslDomainModel.SingletonResourceManager
    .GetObject("MyShapeIconDecorator1DefaultImage"));
      shapeFields.Add(field2);
}

生成并运行解决方案。
双击形状实例上的图标。测试消息应会出现。

截获对 CompartmentShape 列表的单击和拖动

以下示例允许用户通过拖移隔离舱形状中的项对其进行重新排序。

使用“类图”解决方案模板创建新的 DSL 解决方案。

也可使用自己的包含隔离舱形状的解决方案。此代码假定由形状表示的模型元素与隔离舱列表项中表示的元素之间存在嵌入关系。
设置隔离舱形状的“生成双重派生”属性。
将此代码添加到 Dsl 项目的文件中。
调整此代码中的域类和形状名称以匹配你自己的 DSL。

代码的工作原理如下。在此示例中，ClassShape 是隔离舱形状的名称。

一组鼠标事件处理程序在创建时被附加到每个隔离舱实例。
ClassShape.MouseDown 事件存储当前项。
当鼠标移出当前项时，会创建一个 MouseAction 实例，该实例将设置光标并捕获鼠标，直到释放鼠标为止。

为避免干扰其他鼠标操作（例如选择项的文本），在鼠标离开原始项之前不会创建 MouseAction。

创建 MouseAction 的另一种方法是只需侦听 MouseUp。但是，如果用户在将鼠标拖到隔离舱外后释放鼠标，此方法将不起作用。无论鼠标在哪里释放，MouseAction 都能够执行相应的操作。
释放鼠标后，MouseAction.MouseUp 将重新排列模型元素之间的链接顺序。
角色顺序的更改将触发用于更新显示的规则。此行为已定义，无需额外的代码。

以下是示例代码：

using Microsoft.VisualStudio.Modeling;
using Microsoft.VisualStudio.Modeling.Design;
using Microsoft.VisualStudio.Modeling.Diagrams;
using System.Collections.Generic;
using System.Linq;

// This sample allows users to re-order items in a compartment shape by dragging.

// This example is built on the "Class Diagrams" solution template of VMSDK (DSL Tools).
// You will need to change the following domain class names to your own:
// ClassShape = a compartment shape
// ClassModelElement = the domain class displayed using a ClassShape
// This code assumes that the embedding relationships
// displayed in the compartments don't use inheritance
// (don't have base or derived domain relationships).

namespace Company.CompartmentDrag
{
 /// <summary>
 /// Manage the mouse while dragging a compartment item.
 /// </summary>
 public class CompartmentDragMouseAction : MouseAction
 {
  private ModelElement sourceChild;
  private ClassShape sourceShape;
  private RectangleD sourceCompartmentBounds;

  public CompartmentDragMouseAction(ModelElement sourceChildElement, ClassShape sourceParentShape, RectangleD bounds)
   : base (sourceParentShape.Diagram)
  {
   sourceChild = sourceChildElement;
   sourceShape = sourceParentShape;
   sourceCompartmentBounds = bounds; // For cursor.
  }

  /// <summary>
  /// Call back to the source shape to drop the dragged item.
  /// </summary>
  /// <param name="e"></param>
  protected override void OnMouseUp(DiagramMouseEventArgs e)
  {
   base.OnMouseUp(e);
   sourceShape.DoMouseUp(sourceChild, e);
   this.Cancel(e.DiagramClientView);
   e.Handled = true;
  }

  /// <summary>
  /// Ideally, this shouldn't happen. This action should only be active
  /// while the mouse is still pressed. However, it can happen if you
  /// move the mouse rapidly out of the source shape, let go, and then
  /// click somewhere else in the source shape.
  /// </summary>
  /// <param name="e"></param>
  protected override void OnMouseDown(DiagramMouseEventArgs e)
  {
   base.OnMouseDown(e);
   this.Cancel(e.DiagramClientView);
   e.Handled = false;
  }

  /// <summary>
  /// Display an appropriate cursor while the drag is in progress:
  /// Up-down arrow if we are inside the original compartment.
  /// No entry if we are elsewhere.
  /// </summary>
  /// <param name="currentCursor"></param>
  /// <param name="diagramClientView"></param>
  /// <param name="mousePosition"></param>
  /// <returns></returns>
  public override System.Windows.Forms.Cursor GetCursor(System.Windows.Forms.Cursor currentCursor, DiagramClientView diagramClientView, PointD mousePosition)
  {
   // If the cursor is inside the original compartment, show up-down cursor.
   return sourceCompartmentBounds.Contains(mousePosition)
    ? System.Windows.Forms.Cursors.SizeNS // Up-down arrow.
    : System.Windows.Forms.Cursors.No;
  }
 }

 /// <summary>
 /// Override some methods of the compartment shape.
 /// *** GenerateDoubleDerived must be set for this shape in DslDefinition.dsl. ****
 /// </summary>
 public partial class ClassShape
 {
  /// <summary>
  /// Model element that is being dragged.
  /// </summary>
  private static ClassModelElement dragStartElement = null;
  /// <summary>
  /// Absolute bounds of the compartment, used to set the cursor.
  /// </summary>
  private static RectangleD compartmentBounds;

  /// <summary>
  /// Attach mouse listeners to the compartments for the shape.
  /// This is called once per compartment shape.
  /// The base method creates the compartments for this shape.
  /// </summary>
  public override void EnsureCompartments()
  {
   base.EnsureCompartments();
   foreach (Compartment compartment in this.NestedChildShapes.OfType<Compartment>())
   {
    compartment.MouseDown += new DiagramMouseEventHandler(compartment_MouseDown);
    compartment.MouseUp += new DiagramMouseEventHandler(compartment_MouseUp);
    compartment.MouseMove += new DiagramMouseEventHandler(compartment_MouseMove);
   }
  }

  /// <summary>
  /// Remember which item the mouse was dragged from.
  /// We don't create an Action immediately, as this would inhibit the
  /// inline text editing feature. Instead, we just remember the details
  /// and will create an Action when/if the mouse moves off this list item.
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  void compartment_MouseDown(object sender, DiagramMouseEventArgs e)
  {
   dragStartElement = e.HitDiagramItem.RepresentedElements
     .OfType<ClassModelElement>().FirstOrDefault();
   compartmentBounds = e.HitDiagramItem.Shape.AbsoluteBoundingBox;
  }

  /// <summary>
  /// When the mouse moves away from the initial list item,
  /// but still inside the compartment, create an Action
  /// to supervise the cursor and handle subsequent mouse events.
  /// Transfer the details of the initial mouse position to the Action.
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  void compartment_MouseMove(object sender, DiagramMouseEventArgs e)
  {
   if (dragStartElement != null)
   {
    if (dragStartElement != e.HitDiagramItem.RepresentedElements.OfType<ClassModelElement>().FirstOrDefault())
    {
     e.DiagramClientView.ActiveMouseAction = new CompartmentDragMouseAction(dragStartElement, this, compartmentBounds);
     dragStartElement = null;
    }
   }
  }

  /// <summary>
  /// User has released the mouse button.
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  void compartment_MouseUp(object sender, DiagramMouseEventArgs e)
  {
   dragStartElement = null;
  }

  /// <summary>
  /// Forget the source item if mouse up occurs outside the
  /// compartment.
  /// </summary>
  /// <param name="e"></param>
  public override void OnMouseUp(DiagramMouseEventArgs e)
  {
   base.OnMouseUp(e);
   dragStartElement = null;
  }

  /// <summary>
  /// Called by the Action when the user releases the mouse.
  /// If we are still on the same compartment but in a different list item,
  /// move the starting item to the position of the current one.
  /// </summary>
  /// <param name="dragFrom"></param>
  /// <param name="e"></param>
  public void DoMouseUp(ModelElement dragFrom, DiagramMouseEventArgs e)
  {
   // Original or "from" item:
   ClassModelElement dragFromElement = dragFrom as ClassModelElement;
   // Current or "to" item:
   ClassModelElement dragToElement = e.HitDiagramItem.RepresentedElements.OfType<ClassModelElement>().FirstOrDefault();
   if (dragFromElement != null && dragToElement != null)
   {
    // Find the common parent model element, and the relationship links:
    ElementLink parentToLink = GetEmbeddingLink(dragToElement);
    ElementLink parentFromLink = GetEmbeddingLink(dragFromElement);
    if (parentToLink != parentFromLink && parentFromLink != null && parentToLink != null)
    {
     // Get the static relationship and role (= end of relationship):
     DomainRelationshipInfo relationshipFrom = parentFromLink.GetDomainRelationship();
     DomainRoleInfo parentFromRole = relationshipFrom.DomainRoles[0];
     // Get the node in which the element is embedded, usually the element displayed in the shape:
     ModelElement parentFrom = parentFromLink.LinkedElements[0];

     // Same again for the target:
     DomainRelationshipInfo relationshipTo = parentToLink.GetDomainRelationship();
     DomainRoleInfo parentToRole = relationshipTo.DomainRoles[0];
     ModelElement parentTo = parentToLink.LinkedElements[0];

     // Mouse went down and up in same parent and same compartment:
     if (parentTo == parentFrom && relationshipTo == relationshipFrom)
     {
      // Find index of target position:
      int newIndex = 0;
      var elementLinks = parentToRole.GetElementLinks(parentTo);
      foreach (ElementLink link in elementLinks)
      {
       if (link == parentToLink) { break; }
       newIndex++;
      }

      if (newIndex < elementLinks.Count)
      {
       using (Transaction t = parentFrom.Store.TransactionManager.BeginTransaction("Move list item"))
       {
        parentFromLink.MoveToIndex(parentFromRole, newIndex);
        t.Commit();
       }
      }
     }
    }
   }
  }

  /// <summary>
  /// Get the embedding link to this element.
  /// Assumes there is no inheritance between embedding relationships.
  /// (If there is, you need to make sure you've got the relationship
  /// that is represented in the shape compartment.)
  /// </summary>
  /// <param name="child"></param>
  /// <returns></returns>
  ElementLink GetEmbeddingLink(ClassModelElement child)
  {
   foreach (DomainRoleInfo role in child.GetDomainClass().AllEmbeddedByDomainRoles)
   {
    foreach (ElementLink link in role.OppositeDomainRole.GetElementLinks(child))
    {
     // Just the assume the first embedding link is the only one.
     // Not a valid assumption if one relationship is derived from another.
     return link;
    }
   }
   return null;
  }
 }
}

通过

截获对形状或修饰器的单击

截获对形状的单击

截获对修饰器的单击

截获对 CompartmentShape 列表的单击和拖动

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其他资源

通过

截获对形状或修饰器的单击

截获对形状的单击

截获对修饰器的单击

截获对 CompartmentShape 列表的单击和拖动

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