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  • Your email address will not be published.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

  • Live Event Date: October 29, 2014 @ 11:00 a.m. ET / 8:00 a.m. PT Are you interested in building a cognitive application using the power of IBM Watson? Need a platform that provides speed and ease for rapidly deploying this application? Join Chris Madison, Watson Solution Architect, as he walks through the process of building a Watson powered application on IBM Bluemix. Chris will talk about the new Watson Services just released on IBM bluemix, but more importantly he will do a step by step cognitive …

  • In support of their business continuity and disaster recovery plans, many midsized companies endeavor to avoid putting all their eggs in one basket. Understanding the critical role of last-mile connectivity and always available Internet access for their enterprises, savvy firms utilize redundant connections from multiple service providers. Despite the good intentions, their Internet connectivity risk may still be in a single basket. That is because internet service providers (ISPs) and competitive local …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds