spreadsheet.java

实用的spreadsheet功能

		int width,
		int height) {
	this.app = app;
	this.bgColor = bgColor;
	this.fgColor = fgColor;
	this.highlightColor = highlightColor;
	this.width = width;
	this.height = height;
	needRedisplay = true;
    }
		
    public void setRawValue(float f) {
	valueString = Float.toString(f);
	value = f;
    }
    public void setValue(float f) {
	setRawValue(f);
	printString = "v" + valueString;
	type = Cell.VALUE;
	paused = false;
	app.recalculate();
	needRedisplay = true;
    }

    public void setTransientValue(float f) {
	transientValue = true;
	value = f;
	needRedisplay = true;
	app.recalculate();
    }

    public void setUnparsedValue(String s) {
	switch (s.charAt(0)) {
	  case 'v':
	    setValue(Cell.VALUE, s.substring(1));
	    break;
	  case 'f':
	    setValue(Cell.FORMULA, s.substring(1));
	    break;
	  case 'l':
	    setValue(Cell.LABEL, s.substring(1));
	    break;
	  case 'u':
	    setValue(Cell.URL, s.substring(1));
	    break;
	}
    }

    /**
     * Parse a spreadsheet formula. The syntax is defined as:
     *
     * formula -> value
     * formula -> value op value
     * value -> '(' formula ')'
     * value -> cell
     * value -> <number>
     * op -> '+' | '*' | '/' | '-'
     * cell -> <letter><number>
     */
    public String parseFormula(String formula, Node node) {
	String subformula;
	String restFormula;
	float value;
	int length = formula.length();
	Node left;
	Node right;
	char op;

	if (formula == null) {
	    return null;
	}
	subformula = parseValue(formula, node);
	//System.out.println("subformula = " + subformula);
	if (subformula == null || subformula.length() == 0) {
	    //System.out.println("Parse succeeded");
	    return null;
	}
	if (subformula == formula) {
	    //System.out.println("Parse failed");
	    return formula;
	}

	// parse an operator and then another value
	switch (op = subformula.charAt(0)) {
	  case 0:
	    //System.out.println("Parse succeeded");
	    return null;
	  case ')':
	    //System.out.println("Returning subformula=" + subformula);
	    return subformula;
	  case '+':
	  case '*':
	  case '-':
	  case '/':
	    restFormula = subformula.substring(1);
	    subformula = parseValue(restFormula, right=new Node());
	    //System.out.println("subformula(2) = " + subformula);
	    if (subformula != restFormula) {
		//System.out.println("Parse succeeded");
		left = new Node(node);
		node.left = left;
		node.right = right;
		node.op = op;
		node.type = Node.OP;
		//node.print(3);
		return subformula;
	    } else {
		//System.out.println("Parse failed");
		return formula;
	    }
	  default:
	    //System.out.println("Parse failed (bad operator): " + subformula);
	    return formula;
	}
    }

    public String parseValue(String formula, Node node) {
	char	c = formula.charAt(0);
	String	subformula;
	String	restFormula;
	float	value;
	int	row;
	int	column;

	//System.out.println("parseValue: " + formula);
	restFormula = formula;
	if (c == '(') {
	    //System.out.println("parseValue(" + formula + ")");
	    restFormula = formula.substring(1);
	    subformula = parseFormula(restFormula, node);
	    //System.out.println("rest=(" + subformula + ")");
	    if (subformula == null ||
		subformula.length() == restFormula.length()) {
		//System.out.println("Failed");
		return formula;
	    } else if (! (subformula.charAt(0) == ')')) {
	        //System.out.println("Failed (missing parentheses)");
		return formula;
	    }
	    restFormula = subformula;
	} else if (c >= '0' && c <= '9') {
	    int i;

	    //System.out.println("formula=" + formula);
	    for (i=0; i < formula.length(); i++) {
		c = formula.charAt(i);
		if ((c < '0' || c > '9') && c != '.') {
		    break;
		}
	    }
	    try {
		value = Float.valueOf(formula.substring(0, i)).floatValue();
	    } catch (NumberFormatException e) {
		//System.out.println("Failed (number format error)");
		return formula;
	    }
	    node.type = Node.VALUE;
	    node.value = value;
	    //node.print(3);
	    restFormula = formula.substring(i);
	    //System.out.println("value= " + value + " i=" + i +
		//		       " rest = " + restFormula);
	    return restFormula;
	} else if (c >= 'A' && c <= 'Z') {
	    int i;

	    column = c - 'A';
	    restFormula = formula.substring(1);
	    for (i=0; i < restFormula.length(); i++) {
		c = restFormula.charAt(i);
		if (c < '0' || c > '9') {
		    break;
		}
	    }
	    row = Float.valueOf(restFormula.substring(0, i)).intValue();
	    //System.out.println("row = " + row + " column = " + column);
	    node.row = row - 1;
	    node.column = column;
	    node.type = Node.CELL;
	    //node.print(3);
	    if (i == restFormula.length()) {
		restFormula = null;
	    } else {
		restFormula = restFormula.substring(i);
		if (restFormula.charAt(0) == 0) {
		    return null;
		}
	    }	    
	}

	return restFormula;
    }


    public void setValue(int type, String s) {
	paused = false;
	if (this.type == Cell.URL) {
	    updaterThread.stop();
	    updaterThread = null;
	}

	valueString = new String(s);
	this.type = type;
	needRedisplay = true;
	switch (type) {
	  case Cell.VALUE:
	    setValue(Float.valueOf(s).floatValue());
	    break;
	  case Cell.LABEL:
	    printString = "l" + valueString;
	    break;
	  case Cell.URL:
	    printString = "u" + valueString;
	    updaterThread = new CellUpdater(this);
	    updaterThread.start();
	    break;
	  case Cell.FORMULA:
	    parseFormula(valueString, parseRoot = new Node());
	    printString = "f" + valueString;
	    break;
	}
	app.recalculate();
    }

    public String getValueString() {
	return valueString;
    }

    public String getPrintString() {
	return printString;
    }

    public void select() {
	selected = true;
	paused = true;
    }
    public void deselect() {
	selected = false;
	paused = false;
	needRedisplay = true;
	app.repaint();
    }
    public void paint(Graphics g, int x, int y) {
	if (selected) {
	    g.setColor(highlightColor);
	} else {
	    g.setColor(bgColor);
	}
	g.fillRect(x, y, width - 1, height);
	if (valueString != null) {
	    switch (type) {
	      case Cell.VALUE:
	      case Cell.LABEL:
		g.setColor(fgColor);
		break;
	      case Cell.FORMULA:
		g.setColor(Color.red);
		break;
	      case Cell.URL:
		g.setColor(Color.blue);
		break;
	    }
	    if (transientValue){
		g.drawString("" + value, x, y + (height / 2) + 5);
	    } else {
		if (valueString.length() > 14) {
		    g.drawString(valueString.substring(0, 14),
				 x, y + (height / 2) + 5);
		} else {
		    g.drawString(valueString, x, y + (height / 2) + 5);
		}
	    }
	}
	needRedisplay = false;
    }
}

class Node {
    public static final int OP = 0;
    public static final	int VALUE = 1;
    public static final int CELL = 2;

    int		type;
    Node 	left;
    Node 	right;
    int  	row;
    int  	column;
    float	value;
    char	op;

    public Node() {
	left = null;
	right = null;
	value = 0;
	row = -1;
	column = -1;
	op = 0;
	type = Node.VALUE;
    }
    public Node(Node n) {
	left = n.left;
	right = n.right;
	value = n.value;
	row = n.row;
	column = n.column;
	op = n.op;
	type = n.type;
    }
    public void indent(int ind) {
	for (int i = 0; i < ind; i++) {
	    System.out.print(" ");
	}
    }
    public void print(int indentLevel) {
	char l[] = new char[1];
	indent(indentLevel);
	System.out.println("NODE type=" + type);
	indent(indentLevel);
	switch (type) {
	  case Node.VALUE:
	    System.out.println(" value=" + value);
	    break;
	  case Node.CELL:
	    l[0] = (char)((int)'A' + column);
	    System.out.println(" cell=" + new String(l) + (row+1));
	    break;
	  case Node.OP:
	    System.out.println(" op=" + op);
	    left.print(indentLevel + 3);
	    right.print(indentLevel + 3);
	    break;
	}
    }
}

class InputField {
    int		maxchars = 50;
    int		cursorPos = 0;
    Applet	app;
    String	sval;
    char	buffer[];
    int		nChars;
    int		width;
    int		height;
    Color	bgColor;
    Color	fgColor;

    public InputField(String initValue, Applet app, int width, int height,
		      Color bgColor, Color fgColor) {
	this.width = width;
	this.height = height;
	this.bgColor = bgColor;
	this.fgColor = fgColor;
	this.app = app;
	buffer = new char[maxchars];
	nChars = 0;
	if (initValue != null) {
	    initValue.getChars(0, initValue.length(), this.buffer, 0);
	    nChars = initValue.length();
	}
	sval = initValue;
    }

    public void setText(String val) {
	int i;

	for (i=0; i < maxchars; i++) {
	    buffer[i] = 0;
	}
	if (val == null) {
	    sval = "";
	} else {
	    sval = val;
	}
	nChars = sval.length();
	sval.getChars(0, sval.length(), buffer, 0);
    }

    public String getValue() {
	return sval;
    }

    public void paint(Graphics g, int x, int y) {
	g.setColor(bgColor);
	g.fillRect(x, y, width, height);
	if (sval != null) {
	    g.setColor(fgColor);
	    g.drawString(sval, x, y + (height / 2) + 3);
	}
    }

    public void processKey(KeyEvent e) {
        char ch = e.getKeyChar();
        switch (ch) {
            case '\b': // delete
                if (nChars > 0) {
                    nChars--;
                    sval = new String(buffer, 0, nChars);
                }
                break;
            case '\n': // return
	        selected();
	        break;
            default:
	        if (nChars < maxchars && ch >= '0') {
	            buffer[nChars++] = ch;
	            sval = new String(buffer, 0, nChars);
	        }
        }
        app.repaint();    
    }
  
    public void keyReleased(KeyEvent e) {
    }      
  
    public void selected() {
    }
}

class SpreadSheetInput 
    extends InputField {
    
  public SpreadSheetInput(String initValue,
			  SpreadSheet app,
			  int width,
			  int height,
			  Color bgColor,
			  Color fgColor) {
    super(initValue, app, width, height, bgColor, fgColor);
  }
      
    public void selected() {
	float f;

	switch (sval.charAt(0)) {
	  case 'v':
	      String s= sval.substring(1);
	    try {
		int i;
		for (i = 0; i < s.length(); i++) {
		    char c = s.charAt(i);
		    if (c < '0' || c > '9')
			break;
		}
		s = s.substring(0, i);
		f = Float.valueOf(s).floatValue();
		((SpreadSheet)app).setCurrentValue(f);
	    } catch (NumberFormatException e) {
		System.out.println("Not a float: '" + s + "'");
	    }
	    break;
	  case 'l':
	    ((SpreadSheet)app).setCurrentValue(Cell.LABEL, sval.substring(1));
	    break;
	  case 'u':
	    ((SpreadSheet)app).setCurrentValue(Cell.URL, sval.substring(1));
	    break;
	  case 'f':
	    ((SpreadSheet)app).setCurrentValue(Cell.FORMULA, sval.substring(1));
	    break;
	}
    }
}