PR1-Spreadsheet/Axel/src/de/hs_mannheim/informatik/spreadsheet/Spreadsheet.java

234 lines
6.5 KiB
Java

package de.hs_mannheim.informatik.spreadsheet;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* A simplified spreadsheet class for the PR1 programming lab at Hochschule Mannheim.
* One aspect worth mentioning is that it only supports long numbers, not doubles.
*
* @author Oliver Hummel
*/
public class Spreadsheet {
Cell[][] cells;
/**
* Constructor that creates a Spreadsheet of size rows * cols.
* @param rows number of rows
* @param cols number of columns
*/
public Spreadsheet(int rows, int cols) {
// TODO limit the maximum size on 99 (1..99) rows and 26 (A..Z) columns
if (rows>99){
rows=99;
}
if (cols>26) {
cols=26;
}
cells = new Cell[rows][cols];
for (int r = 0; r < rows; r++)
for (int c = 0; c < cols; c++)
cells[r][c] = new Cell();
}
// -----
// retrieve or change values of cells
private String get(int row, int col) {
return cells[row][col].getValue();
}
public String get(String cellName) {
cellName = cellName.toUpperCase();
return get(getRow(cellName), getCol(cellName));
}
private void put(int row, int col, String value) {
if (!value.startsWith("="))
cells[row][col].setValue(value);
else {
cells[row][col].setFormula(value);
evaluateCell(row, col);
}
}
public void put(String cellName, String value) {
cellName = cellName.toUpperCase();
put(getRow(cellName), getCol(cellName), value);
}
private int getCol(String cellName) {
return cellName.charAt(0) - 'A';
}
private int getRow(String cellName) {
if(cellName.length()==3)
return Integer.parseInt((cellName.charAt(1)+"")+(cellName.charAt(2)+""))-1;
else
return cellName.charAt(1) - '1';
}
// -----
// business logic
/**
* A method for reading in data from a CSV file.
* @param path The file to read.
* @param separator The char used to split up the input, e.g. a comma or a semicolon.
* @param starCellName The upper left cell where data from the CSV file should be inserted.
* @return Nothing.
* @exception IOException If path does not exist.
*/
public void readCsv(String path, char separator, String startCellName) throws FileNotFoundException {
// TODO: implement this
}
/**
* A method for saving data to a CSV file.
* @param path The file to write.
* @return Nothing.
* @exception IOException If path does not exist.
*/
public void saveCsv(String path) throws FileNotFoundException {
PrintWriter out = new PrintWriter(path);
for (Cell[] row : cells) {
for (Cell cell : row) {
if (!cell.getFormula().isEmpty())
out.print("=" + cell.getFormula());
else
out.print(cell.getValue());
if (cell != row[cells.length-1])
out.print(",");
}
out.println();
}
out.close();
}
/**
* This method does the actual evaluation/calcluation of a specific cell
* @param cellName the name of the cell to be evaluated
* @return Nothing.
*/
private void evaluateCell(int row, int col) {
String formula = cells[row][col].getFormula();
String result = "";
if (formula.startsWith("SUMME(")) // e.g. SUMME(A3:A8)
if(formula.length()==14)
result = "" + sum(formula.substring(6, 9), formula.substring(10, 13));
else if(formula.length()==13)
result = "" + sum(formula.substring(6, 8), formula.substring(9, 12));
else
result = "" + sum(formula.substring(6, 8), formula.substring(9, 11));
else if (formula.startsWith("PRODUKT(")) // e.g. PRODUKT(A3:B9)
result = "TODO"; // TODO
else if (formula.startsWith("MITTELWERT(")) // e.g. MITTELWERT(A3:A5)
result = "TODO"; // TODO
else if (formula.startsWith("STABW(")) // e.g. STABW(C6:D8) -> Standardabweichung
result = "TODO"; // TODO
else if (formula.startsWith("MIN(")) // e.g. MIN(C13:H13) -> größter Wert
result = "TODO"; // TODO
else if (formula.startsWith("MAX(")) // e.g. MAX(A1:A10) -> Standardabweichung
result = "TODO"; // TODO
else if (!formula.isEmpty()) {
try {
result = "" + calculate(formula);
} catch(ArithmeticException ae) {
result = "exc.";
}
}
cells[row][col].setValue("" + result);
}
/**
* Method for calculating the sum of a rectangular block of cells, such as from A1 to B3.
* @param startCellName The name of the cell in the upper left corner of the rectangle.
* @param endCellName The name of the cell in the lower right corner of the rectangle.
* @return The sum calculated.
*/
private long sum(String startCellName, String endCellName) {
int sum=0;
int startCellRow;
int endCellRow;
if(startCellName.length()==3)
startCellRow=Integer.parseInt((startCellName.charAt(1)+"")+(startCellName.charAt(2)+""))-1;
else
startCellRow=startCellName.charAt(1)-'1';
if(endCellName.length()==3)
endCellRow=Integer.parseInt((endCellName.charAt(1)+"")+(endCellName.charAt(2)+""))-1;
else
endCellRow=endCellName.charAt(1)-'1';
for(int i=startCellName.charAt(0)-'A'; i<=endCellName.charAt(0)-'A'; i++) {
for(int j=startCellRow; j<=endCellRow; j++) {
if(cells[j][i].isEmpty()) {
continue;
}
sum+=Integer.parseInt(cells[j][i].getValue());
}
}
return sum;
}
/**
* This method calculates the result of a "normal" algebraic expression. It only needs to support
* expressions like =B4 or =2+A3-B2, i.e. only with int numbers and other cells and with plus,
* minus, times, split only. An expression always starts with either a number or a cell name. If it
* continues, it is guaranteed that this is followed by an operator and either a number or a
* cell name again. It is NOT required to implement dot before dash or parentheses in formulas.
* @param formula The expression to be evaluated.
* @return The result calculated.
*/
private long calculate(String formula) throws ArithmeticException {
Matcher m = Pattern.compile("([A-Z][0-9]*)|[-\\+\\*/]|[0-9]*").matcher(formula);
long res = 0;
// TODO implement
// uncomment the following to see an example how the elements of a formula can be accessed
while (m.find()) { // m.find() must always be used before m.group()
String s = m.group();
if (!s.isEmpty()) {
System.out.println(s);
}
}
return res;
}
// -----
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(" ");
for (int i = 0; i < cells[0].length; i++) {
sb.append(" " + (char)('A'+ i) + " | ");
}
int rc = 1;
for (Cell[] r : cells) {
sb.append(System.lineSeparator());
sb.append(String.format("%2s", rc++) + ": ");
for (Cell c : r) {
sb.append(c + " | ");
}
}
return sb.toString();
}
}