Serializing to / from a text file


To serialize the tree view control override the Serialize() function. The Serialize() function is a virtual function defined in Cobject.

In the code below we save the outline to a text file and can read it back from a text file. When saving the outline to the archive, tabs are used to indent the item text. Again, when reading back, tabs are used to determine the level that the newly read item should be placed at.
 

void CTreeCtrlX::Serialize(CArchive& ar) 
{
	if (ar.IsStoring())
	{	
		// storing code
		HTREEITEM hti = GetRootItem();
		while( hti )
		{
			int indent = GetIndentLevel( hti );
			while( indent-- )
				ar.WriteString( "\t" );
			ar.WriteString( GetItemText( hti ) + "\r\n");
			hti = GetNextItem( hti );
		}
		
	}
	else
	{	
		// loading code
		CString sLine;
		if( !ar.ReadString( sLine ) )
			return;

		HTREEITEM hti = NULL;
		int indent, baseindent = 0;
		while( sLine[baseindent] == '\t' )
			baseindent++;
		do
		{
			if( sLine.GetLength() == 0 )
				continue;
			for( indent = 0; sLine[indent] == '\t'; indent++ )
				;		// We don't need a body
			sLine = sLine.Right( sLine.GetLength() - indent );
			indent -= baseindent;

			HTREEITEM parent;
			int previndent = GetIndentLevel( hti );
			if( indent ==  previndent)
				parent = GetParentItem( hti );
			else if( indent > previndent )
				parent = hti;
			else
			{
				int nLevelsUp = previndent - indent;
				parent = GetParentItem( hti );
				while( nLevelsUp-- )
					parent = GetParentItem( parent );
			}
			hti = InsertItem( sLine, parent ? parent : TVI_ROOT, TVI_LAST );
		}while( ar.ReadString( sLine ) );

	}
}



int CTreeCtrlX::GetIndentLevel( HTREEITEM hItem )
{
	int iIndent = 0;

	while( (hItem = GetParentItem( hItem )) != NULL )
		iIndent++;
	return iIndent;
}


// GetNextItem	- Get next item as if outline was completely expanded
// Returns		- The item immediately below the reference item
// hItem		- The reference item
HTREEITEM CTreeCtrlX::GetNextItem( HTREEITEM hItem )
{
	HTREEITEM	hti;

	if( ItemHasChildren( hItem ) )
		return GetChildItem( hItem );		// return first child
	else{
		// return next sibling item
		// Go up the tree to find a parent's sibling if needed.
		while( (hti = GetNextSiblingItem( hItem )) == NULL ){
			if( (hItem = GetParentItem( hItem ) ) == NULL )
				return NULL;
		}
	}
	return hti;
}

 



Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • IBM Worklight is a mobile application development platform that lets you extend your business to mobile devices. It is designed to provide an open, comprehensive platform to build, run and manage HTML5, hybrid and native mobile apps.

  • Discover how to quickly remediate aggressive security threats. Read this report from Forrester Research and get the facts about new automated compliance processes and how they will reduce your organization's vulnerability and risk. Learn to: Adopt a set of cyber "Rules of Engagement" Define the appropriate response through the "Response Index" Create actionable response metrics Ensure multiple levels of audit and reinforcement Plus, find out how to better align security and operations teams and put the …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date