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  • Your email address will not be published.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

  • Thanks to wide spread cloud hosting and innovations small businesses can meet and exceed the legacy systems of goliath corporations. Explore the freedom to work how you want, with a phone system that will adapt to your evolving needs and actually save you lots of expense—read Get an Enterprise Phone System without High Cost and Complexity. The article clearly illustrates: The only hardware you'll need is phone equipment for advanced voice and fax. How to join all your employees, mobile devices, …

  • By now you've likely heard of Agile development and building products in small incremental pieces, so you can get real feedback along the way. In fact, you may even be considering using Agile on your next project. But where do you start? Agile can take a lot of forms, such as Scrum or Kanban. Each form has advantages and disadvantages, but both will help your team get the right feedback they need to build great products. Read this white paper to find out which one is right for you.

Most Popular Programming Stories

More for Developers

RSS Feeds

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