source: trunk/gsdl3/src/java/org/greenstone/gsdl3/gs3build/util/HTMLContext.java@ 7306

package org.greenstone.gsdl3.gs3build.util;

public class HTMLContext
{ boolean valid;
    StringBuffer    text;
    
    public static   HTMLTagVector breakTags = new HTMLTagVector("a,h1,h2,h3,h4,h5,h6,table,hr,p,ul,ol,dl,dt,dd,li,tr,td,th,map");

    private int offset (String string, int direction)
    {   int offset;

        if (direction > 0)
        {   offset = string.indexOf('.');
        }
        else
        {   offset = string.lastIndexOf('.');
        }
        return offset;
    }

    public HTMLContext(HTMLBlock parent, HTMLBlock child, int scope)
    { int pos;
        int start, startoffset;
        int end, endoffset;
        int length;
        String  string;
        HTMLTag tag;

        this.text   = null;

        // if we can't match it, give up!
        pos = parent.find(child);
        if (pos < 0)
        { this.valid    = false;
            return;
        }

        // get start!
        if (pos > 0)
        { start = pos - 1;
        }
        else
        {   start   = 0;
        }   
        startoffset = -1;
        length  = 0;
        while ( start > 0)
        {   
          /*
          if (parent.elementAt(start) instanceof String)
            {   string = (String) parent.elementAt(start);

                startoffset = offset(string, -1);
                if (startoffset > 0)
                {   break;
                }

                length += string.length();
                
                if (length >= scope)
                {   break;
                }
                }
                else 
          */
            if (parent.elementAt(start) instanceof HTMLCText)
            {   string = ((HTMLCText) parent.elementAt(start)).toString();

                startoffset = offset(string, -1);
                if (startoffset > 0)
                {   break;
                }

                length += string.length();

                if (length >= scope)
                {   break;
                }
            }
            else if (parent.elementAt(start) instanceof HTMLTag)
            {   // do some checks
                tag = (HTMLTag) parent.elementAt(start);

                if (breakTags.matches(tag, false))
                {   startoffset = -1;
                    break;
                }
            }
            start --;
        }

        // get end!
        pos = pos + child.size();
        if (pos < parent.size())
        { end   = pos + 1;
        }
        else
        {   end = parent.size();
        }   
        endoffset   = -1;
        length  = 0;
        string  = null;
        while (end < parent.size())
        {   if (parent.content.elementAt(start) instanceof String)
            {   string = (String) parent.content.elementAt(start);

                endoffset   = offset(string, +1);
                if (endoffset >= 0)
                {   break;
                }

                length += string.length();

                if (length >= scope)
                {   break;
                }
            }
            else if (parent.content.elementAt(start) instanceof HTMLCText)
            {   string = ((HTMLCText) parent.content.elementAt(start)).toString();

                endoffset   = offset(string, +1);
                if (endoffset >= 0)
                {   break;
                }

                length += string.length();

                if (length >= scope)
                {   break;
                }
            }
            else if (parent.content.elementAt(start) instanceof HTMLTag)
            {   tag = (HTMLTag) parent.elementAt(start);

                if (breakTags.matches(tag, false))
                {   endoffset   = -1;
                    end = end - 1;
                    break;
                }
            }
            System.out.println("String:"+string);
            end ++;
        }

        this.text   = new StringBuffer();
        if (startoffset >= 0)
        {   string  = null;

            if (parent.content.elementAt(start) instanceof String)
            {   string = (String) parent.content.elementAt(start);
            }
            else if (parent.content.elementAt(start) instanceof HTMLCText)
            {   string = ((HTMLCText) parent.content.elementAt(start)).toString();
            }
            
            if (string != null)
            { this.text.append(string.substring(startoffset+1));
            }
            start ++;
        }

        for (pos = start; pos <= end; pos ++)
        { if (pos == end && endoffset >= 0)
            {   break;
            }

            if (parent.content.elementAt(pos) instanceof String)
            {   this.text.append((String) parent.content.elementAt(pos));
            }
            else if (parent.content.elementAt(pos) instanceof HTMLCText)
            {   this.text.append(((HTMLCText) parent.content.elementAt(pos)).toString());
            }
            else if (parent.content.elementAt(pos) instanceof HTMLTag)
            { // don't add it!
            }
        }

        if (pos == end && endoffset > 0)    // this deliberately ignore endoffset == 0
                                                                            // 'cos nothing should happen anyhow!
        {   string  = null;

            if (parent.content.elementAt(pos) instanceof String)
            {   string = (String) parent.content.elementAt(pos);
            }
            else if (parent.content.elementAt(pos) instanceof HTMLCText)
            {   string = ((HTMLCText) parent.content.elementAt(pos)).toString();
            }
        
            if (string != null)
            {   this.text.append(string.substring(0, endoffset));
            }
        }
    }

    public String toString()
    {   if (this.text == null)
        { return "";
        }
        return this.text.toString();
    }
}