TableCalculator.java

/*
 * TableCalculator.java
 *
 * Created on April 25, 2007, 7:35 PM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
package ngmf.ui.calc;

import gnu.jel.CompilationException;
import gnu.jel.CompiledExpression;
import gnu.jel.Evaluator;
import java.io.IOException;
import java.io.InputStream;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;

/**
 */
public class TableCalculator {

    String usage() {
        try {
            InputStream is = this.getClass().getResourceAsStream("/ngmf/ui/calc/Functions.txt");
            if (is == null) {
                return "";
            }
            int c;
            StringBuffer b = new StringBuffer();
            while ((c = is.read()) != -1) {
                b.append((char) c);
            }
            is.close();
            return b.toString();
        } catch (IOException ex) {
            return ex.getMessage();
        }
    }

    public String apply(JelLibrarySupport jel, JTable table, String expr) {

        AbstractTableModel model = (AbstractTableModel) table.getModel();

        String lhs = null;
        String rhs = expr;

        if (expr.equals("help")) {
            return usage();
        }

        int idx = expr.indexOf('=');
        if ((idx > 0) &&
                (expr.charAt(idx + 1) != '=') &&
                (expr.charAt(idx - 1) != '!') &&
                (expr.charAt(idx - 1) != '<') &&
                (expr.charAt(idx - 1) != '>')) {
            lhs = expr.substring(0, expr.indexOf('=')).trim();
            rhs = expr.substring(expr.indexOf('=') + 1).trim();
        }


        expr = expr.trim();
        if (expr.startsWith("=")) {
            if (table.getSelectedColumns().length > 0 && table.getSelectedRows().length > 0) {
                int[] cols = table.getSelectedColumns();
                int[] rows = table.getSelectedRows();
                for (int r = 0; r < rows.length; r++) {
                    for (int c = 0; c < cols.length; c++) {
                        model.setValueAt(expr.substring(1), rows[r], cols[c]);
                        model.fireTableCellUpdated(rows[r], cols[c]);
                    }
                }
            }
        } else {
            if (expr.startsWith("*") || expr.startsWith("/") || expr.startsWith("+") || expr.startsWith("-")) {
                if (table.getSelectedColumns().length > 0 && table.getSelectedRows().length > 0) {
                    int[] cols = table.getSelectedColumns();
                    int[] rows = table.getSelectedRows();
                    for (int r = 0; r < rows.length; r++) {
                        for (int c = 0; c < cols.length; c++) {
                            try {
                                String val = table.getValueAt(rows[r], cols[c]).toString() + expr;
                                CompiledExpression expr_c = Evaluator.compile(val, jel.getLibrary());
                                Object result = expr_c.evaluate(jel.getContext());
                                model.setValueAt(result, rows[r], cols[c]);
                                model.fireTableCellUpdated(rows[r], cols[c]);
                            } catch (Throwable ex) {
                                return "Error " + ex.getMessage();
                            }
                        }
                    }
                    return "";
                } else {
                    return "Error : nothing selected in table";
                }
            }
            try {
                // test if implicite looping
                if (expr.indexOf('$') == -1) {
                    CompiledExpression expr_c = Evaluator.compile(rhs, jel.getLibrary());
                    // single expression
                    if (lhs == null) {
                        try {
                            Object result = expr_c.evaluate(jel.getContext());
                            if (result != null) {
                                return " Result of '" + rhs + "': " + result + "\n";
                            }
                        } catch (Throwable ex) {
                            return "Error " + ex.getMessage();
                        }
                    }
                } else if (lhs != null) {
                    CompiledExpression expr_c = Evaluator.compile(rhs, jel.getLibrary());
                    if (lhs.startsWith("$")) {
                        lhs = lhs.substring(1);
                        int col = Util.findColumn(model, lhs);
                        if (col == -1) {
                            return "No such column " + lhs + "\n";
                        }
                        for (int row = 0; row < model.getRowCount(); row++) {
                            try {
                                jel.getResolver().setRow(row);
                                Object result = expr_c.evaluate(jel.getContext());
                                if (result != null) {
                                    model.setValueAt(result, row, col);
                                    model.fireTableCellUpdated(row, col);
                                }
                            } catch (Throwable ex) {
                                return "Error " + ex.getMessage();
                            }
                        }
                    } else {
                        return "lhs array not supported yet. \n";
                    }
                } else {
                    // row selection
                    CompiledExpression expr_c = Evaluator.compile(rhs, jel.getLibrary());
                    table.clearSelection();
                    table.setColumnSelectionAllowed(false);
                    StringBuffer b = new StringBuffer();
                    for (int row = 0; row < model.getRowCount(); row++) {
                        try {
                            jel.getResolver().setRow(row);
                            Object result = expr_c.evaluate(jel.getContext());
                            if (result != null) {
                                if (result.getClass() == Boolean.class) {
                                    boolean r = (Boolean) result;
                                    if (r) {
                                        table.addRowSelectionInterval(row, row);
                                    }
                                } else {
                                    b.append(result);
                                }
                            }
                        } catch (Throwable ex) {
                            return "Error " + ex.getMessage();
                        }
                    }
                    return b.toString();
                }
            } catch (CompilationException ce) {
                StringBuffer b = new StringBuffer();
                b.append("  ERROR: ");
                b.append(ce.getMessage() + "\n");
                b.append("                       ");
                b.append(rhs + "\n");
                int column = ce.getColumn(); // Column, where error was found
                for (int i = 0; i <
                        column + 23 - 1; i++) {
                    b.append(' ');
                }

                b.append("^\n");
                return b.toString();
            }
        }
        return "";
    }
}