sequenceaddlink(linkname, nodename)

function sequenceaddlink(linkname, nodename)
% SEQUENCEADDLINK(LINKNAME, NODENAME) Add a link with LINKNAME from
% the current node to NODENAME.  If NODENAME doesn't exist yet,
% create it.

% Author: Eric Ludlam
% Copyright (c) 2006 The MathWorks Inc.
    
    
    SD = getappdata(gcf,'SD');
    
    % Previous node
    
    if isempty(SD.links)
        lastlinkidx = 0;
        lastnodeidx = 0;
    else
        lastlinkidx = length(SD.links);
        lastnodeidx = SD.links(lastlinkidx).nodeidx;
    end
    linkidx = lastlinkidx+1;
    
    loop = false;

    if lastnodeidx > 0
        createnode(SD.nodes(lastnodeidx).name, linkidx);
        if strcmp(SD.nodes(lastnodeidx).name, nodename)
            loop = true;
        end
    end
    
    if ~isempty(nodename)
        node = createnode(nodename, linkidx, loop);

        SD = getappdata(gcf,'SD');
    
        nodeidx = node.nodeidx;
    else
        nodeidx = 0;
    end

    % Check for repeating Ctor/Dtor issues.
    if 0 && lastlinkidx > 0 && ...
            SD.links(lastlinkidx).lastnodeidx == nodeidx && ...
            SD.links(lastlinkidx).nodeidx ~= nodeidx && ...
            any(regexp(linkname, '^[CD]tor ')) && ...
            strcmp(SD.links(lastlinkidx).name, 'return')

        % If the last link is a return from this very object, and
        % We are issuing a CTor/DTor, then remove the return
        % and replace it with this new link.
        delete(SD.links(lastlinkidx).line);
        delete(SD.links(lastlinkidx).text);
        
        linkidx = lastlinkidx;
        lastnodeidx = nodeidx;
        
    end
    
    % Create the new link.
    
    link = makelink(linkname, linkidx, lastnodeidx, nodeidx);
    
    if isempty(SD.links)
        SD.links = link;
    else
        SD.links(linkidx) = link;
    end
    
    %SAVE
    
    setappdata(SD.fig,'SD',SD);