IVsQueryUndoUnit::ActionWouldBeAborted Method (Int32)

Visual Studio 2015

Queries each member of a linked undo set to determine if an undo action would be aborted.

Namespace: Microsoft.VisualStudio.TextManager.Interop
Assembly: Microsoft.VisualStudio.TextManager.Interop.8.0 (in Microsoft.VisualStudio.TextManager.Interop.8.0.dll)

Syntax

C++

int ActionWouldBeAborted(
	[OutAttribute] int% pbWouldBeAborted
)

Parameters

pbWouldBeAborted: Type: System::Int32
[out] If 1 (TRUE), undo action would be aborted; if 0 (FALSE) undo action would not be aborted.

Return Value

Type: System::Int32

If the method succeeds, it returns S_OK. If it fails, it returns an error code.

Remarks

A linked undo set tracks the same undo action in multiple buffers.

This interface queries a linked undo set to allow each member of the set to determine if an undo action would be aborted.

Call this method before attempting a linked undo in order to avoid having to roll back linked undo actions.

Notes to Implementers:

Implement this method for the initial parent of a linked undo set. In the implementation, query each undo child and call ActionWouldBeAborted if the child supports IVsQueryUndoUnit.

Examples

In this C++ example, the parent stops querying if any child returns true:

C++

STDMETHODIMP
CParentUndoUnit::ActionWouldBeAborted
(
   BOOL *pbWouldBeAborted // [out] Would the action be aborted?
)
{
    HRESULT hr = S_OK;
    if ( pbWouldBeAborted == NULL )
    {
        hr = E_POINTER;
    }
    else
    {
        *pbWouldBeAborted = FALSE;
        // Loop over child units for edit actions
        CEditNode *pNode = m_pEditFirst;
        while (pNode && SUCCEEDED(hr))
        {
            if (pNode->m_pEditUnit)
            {
                CComQIPtr<IVsQueryUndoUnit, &IID_IVsQueryUndoUnit> srpQueryUndoUnitForUserAbort(pNode->m_pEditUnit);
                if ( srpQueryUndoUnitForUserAbort )
                {
                    hr = srpQueryUndoUnitForUserAbort->ActionWouldBeAborted(pbWouldBeAborted);
        // If any action would be aborted, stop looking
                    if ( SUCCEEDED(hr)  &&  *pbWouldBeAborted == TRUE )
                    {
                        break;
                    }
                }
            }
            pNode = pNode->m_pNext;
        }
    }
    return hr;
}