std::string DrawViewSpreadsheet::getSheetImage(void)
{
    std::stringstream result;

    App::DocumentObject* link = Source.getValue();
    std::string scellstart = CellStart.getValue();
    std::string scellend = CellEnd.getValue();

    std::vector<std::string> availcolumns = getAvailColumns();

    // build rows range and columns range
    std::vector<std::string> columns;
    std::vector<int> rows;
    try {
        for (unsigned int i=0; i<scellstart.length(); ++i) {
            if (isdigit(scellstart[i])) {
                columns.push_back(scellstart.substr(0,i));
                rows.push_back(std::atoi(scellstart.substr(i,scellstart.length()-1).c_str()));
            }
        }
        for (unsigned int i=0; i<scellend.length(); ++i) {
            if (isdigit(scellend[i])) {
                std::string startcol = columns.back();
                std::string endcol = scellend.substr(0,i);
                bool valid = false;
                for (std::vector<std::string>::const_iterator j = availcolumns.begin(); j != availcolumns.end(); ++j) {
                    if ( (*j) == startcol) {
                        if ( (*j) != endcol) {
                            valid = true;
                        }
                    } else {
                        if (valid) {
                            if ( (*j) == endcol) {
                                columns.push_back((*j));
                                valid = false;
                            } else {
                                columns.push_back((*j));
                            }
                        }
                    }
                }
                int endrow = std::atoi(scellend.substr(i,scellend.length()-1).c_str());
                for (int j=rows.back()+1; j<=endrow; ++j) {
                    rows.push_back(j);
                }
            }
        }
    } catch (std::exception) {
        Base::Console().Error("Invalid cell range for %s\n",getNameInDocument());
        return result.str();
    }

    // create the containing group
    std::string ViewName = Label.getValue();

    result << getSVGHead();

    App::Color c = TextColor.getValue();
    result  << "<g id=\"" << ViewName << "\">" << endl;

    // fill the cells
    float rowoffset = 0.0;
    float coloffset = 0.0;
    float cellheight = 100;
    float cellwidth = 100;
    std::string celltext;
    Spreadsheet::Sheet* sheet = static_cast<Spreadsheet::Sheet*>(link);
    std::vector<std::string> skiplist;
    for (std::vector<std::string>::const_iterator col = columns.begin(); col != columns.end(); ++col) {
        // create a group for each column
        result << "  <g id=\"" << ViewName << "_col" << (*col) << "\">" << endl;
        for (std::vector<int>::const_iterator row = rows.begin(); row != rows.end(); ++row) {
            // get cell size
            std::stringstream srow;
            srow << (*row);
            App::CellAddress address((*col) + srow.str());
            cellwidth = sheet->getColumnWidth(address.col());
            cellheight = sheet->getRowHeight(address.row());
            celltext = "";
            // get the text
            App::Property* prop = sheet->getPropertyByName(address.toString().c_str());
            std::stringstream field;
            if (prop != 0) {
                if (prop->isDerivedFrom((App::PropertyQuantity::getClassTypeId())))
                    field << static_cast<App::PropertyQuantity*>(prop)->getValue();
                else if (prop->isDerivedFrom((App::PropertyFloat::getClassTypeId())))
                    field << static_cast<App::PropertyFloat*>(prop)->getValue();
                else if (prop->isDerivedFrom((App::PropertyString::getClassTypeId())))
                    field << static_cast<App::PropertyString*>(prop)->getValue();
                else
                    assert(0);
                celltext = field.str();
            }
            // get colors, style, alignment and span
            int alignment;
            std::string bcolor = "none";
            std::string fcolor = c.asCSSString();
            std::string textstyle = "";
            Spreadsheet::Cell* cell = sheet->getCell(address);
            if (cell) {
                App::Color f,b;
                std::set<std::string> st;
                int colspan, rowspan;
                if (cell->getBackground(b)) {
                    bcolor = b.asCSSString();
                }
                if (cell->getForeground(f)) {
                    fcolor = f.asCSSString();
                }
                if (cell->getStyle(st)) {
                    for (std::set<std::string>::const_iterator i = st.begin(); i != st.end(); ++i) {
                         if ((*i) == "bold")
                            textstyle = textstyle + "font-weight: bold; ";
                        else if ((*i) == "italic")
                            textstyle = textstyle + "font-style: italic; ";
                        else if ((*i) == "underline")
                            textstyle = textstyle + "text-decoration: underline; ";
                    }
                }
                if (cell->getSpans(rowspan,colspan)) {
                    for (int i=0; i<colspan; ++i) {
                        for (int j=0; j<rowspan; ++j) {
                            App::CellAddress nextcell(address.row()+j,address.col()+i);
                            if (i > 0)
                                cellwidth = cellwidth + sheet->getColumnWidth(nextcell.col());
                            if (j > 0)
                                cellheight = cellheight + sheet->getRowHeight(nextcell.row());
                            if ( (i > 0) || (j > 0) )
                                skiplist.push_back(nextcell.toString());
                        }
                    }
                }
                cell->getAlignment(alignment);
            }
            // skip cell if found in skiplist
            if (std::find(skiplist.begin(), skiplist.end(), address.toString()) == skiplist.end()) {
                result << "    <rect x=\"" << coloffset << "\" y=\"" << rowoffset << "\" width=\"" << cellwidth
                       << "\" height=\"" << cellheight << "\" style=\"fill:" << bcolor << ";stroke-width:"
                       << LineWidth.getValue()/Scale.getValue() << ";stroke:" << c.asCSSString() << ";\" />" << endl;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_LEFT)
                    result << "    <text style=\"" << textstyle << "\" x=\"" << coloffset + TextSize.getValue()/2 << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_HCENTER)
                    result << "    <text text-anchor=\"middle\" style=\"" << textstyle << "\" x=\"" << coloffset + cellwidth/2 << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_RIGHT)
                    result << "    <text text-anchor=\"end\" style=\"" << textstyle << "\" x=\"" << coloffset + (cellwidth - TextSize.getValue()/2) << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                result << Font.getValue() << "\"" << " font-size=\"" << TextSize.getValue() << "\""
                       << " fill=\"" << fcolor << "\">" << celltext << "</text>" << endl;
            }
            rowoffset = rowoffset + cellheight;
        }
        result << "  </g>" << endl;
        rowoffset = 0.0;
        coloffset = coloffset + cellwidth;
    }

    // close the containing group
    result << "</g>" << endl;

    result << getSVGTail();

    return result.str();
}
App::DocumentObjectExecReturn *FeatureViewSpreadsheet::execute(void)
{
    // quick tests
    App::DocumentObject* link = Source.getValue();
    std::string scellstart = CellStart.getValue();
    std::string scellend = CellEnd.getValue();
    if (!link)
        return new App::DocumentObjectExecReturn("No spreadsheet linked");
    if (!link->getTypeId().isDerivedFrom(Spreadsheet::Sheet::getClassTypeId()))
        return new App::DocumentObjectExecReturn("The linked object is not a spreadsheet");
    if ( (scellstart.empty()) || (scellend.empty()) )
        return new App::DocumentObjectExecReturn("Empty cell value");
    
    // build a list of available colums: A, B, C, ... AA, AB, ... ZY, ZZ.
    std::string alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    std::vector<std::string> availcolumns;
    for (int i=0; i<26; ++i) {
        std::stringstream s;
        s << alphabet[i];
        availcolumns.push_back(s.str());
    }
    for (int i=0; i<26; ++i) {
        for (int j=0; i<26; ++i) {
            std::stringstream s;
            s << alphabet[i] << alphabet[j];
            availcolumns.push_back(s.str());
        }
    }
    
    // build rows range and columns range
    std::vector<std::string> columns;
    std::vector<int> rows;
    try {
        for (unsigned int i=0; i<scellstart.length(); ++i) {
            if (isdigit(scellstart[i])) {
                columns.push_back(scellstart.substr(0,i));
                rows.push_back(std::atoi(scellstart.substr(i,scellstart.length()-1).c_str()));
            }
        }
        for (unsigned int i=0; i<scellend.length(); ++i) {
            if (isdigit(scellend[i])) {
                std::string startcol = columns.back();
                std::string endcol = scellend.substr(0,i);
                bool valid = false;
                for (std::vector<std::string>::const_iterator j = availcolumns.begin(); j != availcolumns.end(); ++j) {
                    if ( (*j) == startcol) {
                        if ( (*j) != endcol) {
                            valid = true;
                        }
                    } else {
                        if (valid) {
                            if ( (*j) == endcol) {
                                columns.push_back((*j));
                                valid = false;
                            } else {
                                columns.push_back((*j));
                            }
                        }
                    }
                }
                int endrow = std::atoi(scellend.substr(i,scellend.length()-1).c_str());
                for (int j=rows.back()+1; j<=endrow; ++j) {
                    rows.push_back(j);
                }
            }
        }
    } catch (std::exception) {
        return new App::DocumentObjectExecReturn("Invalid cell range");
    }
    
    // create the containing group
    std::string ViewName = Label.getValue();
    std::stringstream result,hr,hg,hb;
    const App::Color& c = Color.getValue();
    hr << hex << setfill('0') << setw(2) << (int)(255.0*c.r);
    hg << hex << setfill('0') << setw(2) << (int)(255.0*c.g);
    hb << hex << setfill('0') << setw(2) << (int)(255.0*c.b);
    result  << "<g id=\"" << ViewName << "\" transform=\"translate(" << X.getValue() << "," << Y.getValue() << ")"
            << " rotate(" << Rotation.getValue() << ")"
            << " scale(" << Scale.getValue() << ")\">" << endl;

    // fill the cells
    float rowoffset = 0.0;
    float coloffset = 0.0;
    float cellheight = 100;
    float cellwidth = 100;
    std::string celltext;
    Spreadsheet::Sheet* sheet = static_cast<Spreadsheet::Sheet*>(link); 
    std::vector<std::string> skiplist;   
    for (std::vector<std::string>::const_iterator col = columns.begin(); col != columns.end(); ++col) {
        // create a group for each column
        result << "  <g id=\"" << ViewName << "_col" << (*col) << "\">" << endl;
        for (std::vector<int>::const_iterator row = rows.begin(); row != rows.end(); ++row) {
            // get cell size
            std::stringstream srow;
            srow << (*row);
            App::CellAddress address((*col) + srow.str());
            cellwidth = sheet->getColumnWidth(address.col());
            cellheight = sheet->getRowHeight(address.row());
            celltext = "";
            // get the text
            App::Property* prop = sheet->getPropertyByName(address.toString().c_str());
            std::stringstream field;
            if (prop != 0) {
                if (prop->isDerivedFrom((App::PropertyQuantity::getClassTypeId())))
                    field << static_cast<App::PropertyQuantity*>(prop)->getValue();
                else if (prop->isDerivedFrom((App::PropertyFloat::getClassTypeId())))
                    field << static_cast<App::PropertyFloat*>(prop)->getValue();
                else if (prop->isDerivedFrom((App::PropertyString::getClassTypeId())))
                    field << static_cast<App::PropertyString*>(prop)->getValue();
                else
                    assert(0);
                celltext = field.str();
            }
            // get colors, style, alignment and span
            int alignment;
            std::string bcolor = "none";
            std::string fcolor = "#" + hr.str() + hg.str() + hb.str();
            std::string textstyle = "";
            Spreadsheet::Cell* cell = sheet->getCell(address);
            if (cell) {
                App::Color f,b;
                std::set<std::string> st;
                int colspan, rowspan;
                if (cell->getBackground(b)) {
                    std::stringstream br,bg,bb;
                    br << hex << setfill('0') << setw(2) << (int)(255.0*b.r);
                    bg << hex << setfill('0') << setw(2) << (int)(255.0*b.g);
                    bb << hex << setfill('0') << setw(2) << (int)(255.0*b.b);
                    bcolor = "#" + br.str() + bg.str() + bb.str();
                }
                if (cell->getForeground(f)) {
                    std::stringstream fr,fg,fb;
                    fr << hex << setfill('0') << setw(2) << (int)(255.0*f.r);
                    fg << hex << setfill('0') << setw(2) << (int)(255.0*f.g);
                    fb << hex << setfill('0') << setw(2) << (int)(255.0*f.b);
                    fcolor = "#" + fr.str() + fg.str() + fb.str();
                }
                if (cell->getStyle(st)) {
                    for (std::set<std::string>::const_iterator i = st.begin(); i != st.end(); ++i) {
                         if ((*i) == "bold")
                            textstyle = textstyle + "font-weight: bold; ";
                        else if ((*i) == "italic")
                            textstyle = textstyle + "font-style: italic; ";
                        else if ((*i) == "underline")
                            textstyle = textstyle + "text-decoration: underline; ";
                    }
                }
                if (cell->getSpans(rowspan,colspan)) {
                    for (int i=0; i<colspan; ++i) {
                        for (int j=0; j<rowspan; ++j) {
                            App::CellAddress nextcell(address.row()+j,address.col()+i);
                            if (i > 0)
                                cellwidth = cellwidth + sheet->getColumnWidth(nextcell.col());
                            if (j > 0)
                                cellheight = cellheight + sheet->getRowHeight(nextcell.row());
                            if ( (i > 0) || (j > 0) )
                                skiplist.push_back(nextcell.toString());
                        }
                    }
                }
                cell->getAlignment(alignment);
            }
            // skip cell if found in skiplist
            if (std::find(skiplist.begin(), skiplist.end(), address.toString()) == skiplist.end()) {
                result << "    <rect x=\"" << coloffset << "\" y=\"" << rowoffset << "\" width=\"" << cellwidth 
                       << "\" height=\"" << cellheight << "\" style=\"fill:" << bcolor << ";stroke-width:"
                       << LineWidth.getValue()/Scale.getValue() << ";stroke:#" << hr.str() << hg.str() << hb.str() << ";\" />" << endl;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_LEFT)
                    result << "    <text style=\"" << textstyle << "\" x=\"" << coloffset + FontSize.getValue()/2 << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_HCENTER)
                    result << "    <text text-anchor=\"middle\" style=\"" << textstyle << "\" x=\"" << coloffset + cellwidth/2 << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                if (alignment & Spreadsheet::Cell::ALIGNMENT_RIGHT)
                    result << "    <text text-anchor=\"end\" style=\"" << textstyle << "\" x=\"" << coloffset + (cellwidth - FontSize.getValue()/2) << "\" y=\"" << rowoffset + 0.75 * cellheight << "\" font-family=\"" ;
                result << Font.getValue() << "\"" << " font-size=\"" << FontSize.getValue() << "\""
                       << " fill=\"" << fcolor << "\">" << celltext << "</text>" << endl;
            }
            rowoffset = rowoffset + cellheight;
        }
        result << "  </g>" << endl;
        rowoffset = 0.0;
        coloffset = coloffset + cellwidth;
    }

    // close the containing group
    result << "</g>" << endl;

    // Apply the resulting fragment
    ViewResult.setValue(result.str().c_str());

    return App::DocumentObject::StdReturn;
}