CompoundAction Class

Article
02/04/2013

Manages a group of edit operations that are treated as a single operation.

This API is not CLS-compliant. The CLS-compliant alternative is [None].

Inheritance Hierarchy

System.Object
Microsoft.VisualStudio.Package.CompoundActionBase
Microsoft.VisualStudio.Package.CompoundAction

Namespace: Microsoft.VisualStudio.Package
Assemblies:   Microsoft.VisualStudio.Package.LanguageService.10.0 (in Microsoft.VisualStudio.Package.LanguageService.10.0.dll)
  Microsoft.VisualStudio.Package.LanguageService.9.0 (in Microsoft.VisualStudio.Package.LanguageService.9.0.dll)
  Microsoft.VisualStudio.Package.LanguageService (in Microsoft.VisualStudio.Package.LanguageService.dll)

Syntax

'Declaration
<CLSCompliantAttribute(False)> _
Public Class CompoundAction _
    Inherits CompoundActionBase

[CLSCompliantAttribute(false)]
public class CompoundAction : CompoundActionBase

[CLSCompliantAttribute(false)]
public ref class CompoundAction : public CompoundActionBase

[<CLSCompliantAttribute(false)>]
type CompoundAction =  
    class
        inherit CompoundActionBase
    end

public class CompoundAction extends CompoundActionBase

The CompoundAction type exposes the following members.

Constructors

	Name	Description
	CompoundAction	Initializes a new instance of the CompoundAction class.

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Methods

	Name	Description
	Abort	Terminates the current compound action, throwing away all edits. (Overrides CompoundActionBase.Abort().)
	Close	Closes the compound action and commits all edits to the source file. (Overrides CompoundActionBase.Close().)
	Dispose()	Deallocates any resources just before the CompoundAction object is destroyed.
	Dispose()	Deallocates any resources just before the CompoundAction object is destroyed. (Inherited from CompoundActionBase.)
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	FlushEditActions	Flushes any pending edit actions from the current compound action. (Overrides CompoundActionBase.FlushEditActions().)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Fields

	Name	Description
	action	Interface for a CompoundAction action. (Inherited from CompoundActionBase.)
	opened	Specifies if a compound action has been opened. (Inherited from CompoundActionBase.)

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Remarks

This class is used to simplify wrapping a collection of edit operations into a single undoable event. This is achieved by calling the OpenCompoundAction method on the IVsCompoundAction interface that is obtained from the current IVsTextLines object stored in the Source object. When this class is disposed off, the IVsCompoundAction interface is closed and that commits all the edit events made to the IVsTextLines object as a single operation.

Notes to Implementers

This class contains everything necessary to open a compound action given a Source object and to close that action when this class is disposed off.

Notes to Callers

Instantiate a CompoundAction object with the Source object when you need to wrap one or more edit operations that can be undone in a single action. Then perform your edit operations as normal. When the new CompoundAction object is disposed of, the edit operations are stored as a single action.

If you have access to the IVsTextView object, use CompoundViewAction class instead as it allows the text view to optimize the edits so only the final result is seen by the user.

Examples

This example shows how to use the CompoundAction class. This example inserts a list of words at the current location in the source file. Without the CompoundAction object, each of these insertions is treated as a separate edit event and requires a separate undo operation. However, with the CompoundAction object, the entire list can be undone with a single undo operation.

using Microsoft.VisualStudio.Package

namespace MyLanguagePackage
{
    class CMyLanguageService : LanguageService
    {
        // Insert the list of words, one per line.
        void InsertWords(Source src,string[] wordList)
        {
            if (LastActiveTextView != null)
            {
                CompoundAction action = new CompoundAction(src,"Update source");
                using (action)
                {
                    int currentLine = 0;
                    int currentCol = 0;
                    LastActiveTextView.GetCaretPos(out currentLine, out currentCol);
                    // Insert list in reverse so the words appear in the proper
                    // order in the sourec file.
                    for (int i = wordList.Length - 1, i >= 0; i--)
                    {
                        string w = wordList[i] + "\n";
                        src.SetText(currentLine, currentCol, currentLine, currentCol, w);
                    }
                }
            }
        }
    }
}

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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