C++ TDocument::Commit方法代码示例

//
/// Saves the current data to storage. When a file is closed, the document manager
/// calls either Commit or Revert. If force is true, all data is written to storage.
/// Commit checks any child documents and commits their changes to storage also.
/// Before the current data is saved, all child documents must return true. If all
/// child documents return true, Commit flushes the views for operations that
/// occurred since the last time the view was checked. After all data for the
/// document is updated and saved, Commit returns true.
//
bool
TDocument::Commit(bool force)
{
  TDocument* pdoc = 0;
  while ((pdoc = ChildDoc.Next(pdoc)) != 0) {
    if (!pdoc->Commit(force))
      return false;
  }

  WARNX(OwlDocView, !DocPath, 0, _T("Commit(): 0 DocPath!"));
  return NotifyViews(vnCommit, force);
}

//
/// SelectAnySave() is called to get a template. Then the Commit() function is called
/// for the current document.
//
void
TDocManager::FileSaveAs()
{
  TDocument* doc = GetCurrentDoc();
  if (doc) {
    TDocTemplate* tpl = SelectAnySave(*doc, true);
    if (tpl) {
      if (tpl != doc->Template)
        doc->SetTemplate(tpl);       // replace existing template
      if (doc->Commit(true))         // force rewrite to new path
        PostEvent(dnRename, *doc); // WM_OWLDOCUMENT
    }
  }
}

//
/// Method invoked when specified document is about to be closed.
/// Updates the document with any changes and prompts the user for confirmation of
/// updates.
/// Returns 'true' if DocManager should proceed with the closing
/// stages of the document, or 'false' otherwise.
//
bool
TDocManager::FlushDoc(TDocument& doc)
{
  while (doc.IsDirty()) {
    int saveOrNot = doc.IsEmbedded() ?
                      IDYES :
                      PostDocError(doc, IDS_DOCCHANGED, MB_YESNOCANCEL);

    switch (saveOrNot) {
      case IDYES:
        // Prompt the user for filename in save-as situation
        //
        if (!doc.IsEmbedded() && doc.GetDocPath() == 0) {

        // !BB
        // !BB It does not make sense to invoke SelectAnySave
        // !BB with false here... This would allow the user
        // !BB to switch to any available template when saving the
        // !BB document. In other words, a user would be allowed to
        // !BB save a .TXT file as a .PTS file although they are
        // !BB not related whatsoever...
        // !BB
        // !BB I'm switching this to use true - let me know if you
        // !BB know of a reason for the prior behaviour.
        // !BB

#if defined(OLD_DOCVIEW)
          TDocTemplate* tpl = SelectAnySave(doc, false);
#else
          TDocTemplate* tpl = SelectAnySave(doc, true);
#endif
          if (!tpl)
            continue;

          // !BB
          // !BB The following is suspicious: Is there a reason
          // !BB to allow the user to switch the template in the first
          // !BB place?? OK, if everyone agrees that same TDocument-derived
          // !BB type implies compatible document, that would be OK.
          // !BB However, that's not what we've encouraged. Our own
          // !BB examples use the same TFileDocument for incompatible
          // !BB document types. Hence, if an app. has a
          // !BB TBitmapView/TFileDocument and a TTextView/TFileDocument pair,
          // !BB the following would allow the user to save a text file as a .BMP
          // !BB Ack!!
          // !BB If the following is really the intent, then DV users must be
          // !BB conscious that they will more often than not be using TFileDocument-
          // !BB derived documents as a method to specify compatible and incompatible
          // !BB document types.
          //
          if (tpl != doc.Template)
            doc.SetTemplate(tpl);
        }
        if (doc.Commit())
          return true;
        continue;

      case IDNO:
        if (doc.Revert(true))
          return true;
        return false;

      case IDCANCEL:
        return false;
    }
  }
  return true;
}