call calculate()

src/com/bytezone/diskbrowser/visicalc/Cell.java

@@ -18,6 +18,7 @@ class Cell implements Comparable<Cell>, Value
 
   private String expressionText;
   private Value value;
+  private ValueType valueType;
 
   enum CellType
   {
@@ -181,6 +182,12 @@ class Cell implements Comparable<Cell>, Value
     return value.getValue ();
   }
 
+  @Override
+  public ValueType getValueType ()
+  {
+    return valueType;
+  }
+
   @Override
   public String getText ()
   {
@@ -210,12 +217,15 @@ class Cell implements Comparable<Cell>, Value
     {
       System.out.printf ("%s null expression text %n", address);
       value = Function.getInstance (parent, "@ERROR");
+      valueType = ValueType.ERROR;
     }
     else
+    {
       // should use Number or Cell for simple Values
       value = new Expression (parent, expressionText);
-
-    value.calculate ();
+      value.calculate ();
+      valueType = value.getValueType ();
+    }
   }
 
   @Override

src/com/bytezone/diskbrowser/visicalc/Condition.java

@@ -49,8 +49,14 @@ class Condition
     {
       conditionExpression = new Expression (parent, conditionText);
       valueExpression = new Expression (parent, valueText);
+
+      conditionExpression.calculate ();
+      valueExpression.calculate ();
     }
 
+    if (conditionExpression.isError () || valueExpression.isError ())
+      return false;
+
     double conditionResult = conditionExpression.getValue ();
     double valueResult = valueExpression.getValue ();
 

src/com/bytezone/diskbrowser/visicalc/Count.java

@@ -19,7 +19,7 @@ class Count extends Function
       Cell cell = parent.getCell (address);
       if (cell == null || cell.isError () || cell.isNaN ())
       {
-        isError = true;
+        valueType = ValueType.ERROR;
         break;
       }
 

src/com/bytezone/diskbrowser/visicalc/Expression.java

@@ -32,7 +32,8 @@ class Expression implements Value
   private final List<String> operators = new ArrayList<String> ();
   private final List<String> signs = new ArrayList<String> ();
 
-  protected boolean isError;
+  //  protected boolean isError;
+  private ValueType valueType;
   private double value;
 
   public Expression (Sheet parent, String text)
@@ -118,34 +119,60 @@ class Expression implements Value
   @Override
   public void calculate ()
   {
-    Value thisValue = values.get (0);
-    value = thisValue == null ? 0 : values.get (0).getValue ();
-
-    String sign = signs.get (0);
-    if (sign.equals ("(-)"))
-      value *= -1;
-
-    for (int i = 1; i < values.size (); i++)
+    try
     {
-      thisValue = values.get (i);
-      double nextValue = thisValue == null ? 0 : thisValue.getValue ();
+      Value thisValue = values.get (0);
+      thisValue.calculate ();
+      if (thisValue.isError ())
+      {
+        valueType = ValueType.ERROR;
+        return;
+      }
+      value = thisValue.getValue ();
 
-      sign = signs.get (i);
+      String sign = signs.get (0);
       if (sign.equals ("(-)"))
-        nextValue *= -1;
+        value *= -1;
 
-      String operator = operators.get (i - 1);
-      if (operator.equals ("+"))
-        value += nextValue;
-      else if (operator.equals ("-"))
-        value -= nextValue;
-      else if (operator.equals ("*"))
-        value *= nextValue;
-      else if (operator.equals ("/"))
-        value /= nextValue;
-      else if (operator.equals ("^"))
-        value = Math.pow (value, nextValue);
+      for (int i = 1; i < values.size (); i++)
+      {
+        thisValue = values.get (i);
+        thisValue.calculate ();
+        if (thisValue.isError ())
+        {
+          valueType = ValueType.ERROR;
+          return;
+        }
+        double nextValue = thisValue.getValue ();
+
+        sign = signs.get (i);
+        if (sign.equals ("(-)"))
+          nextValue *= -1;
+
+        String operator = operators.get (i - 1);
+        if (operator.equals ("+"))
+          value += nextValue;
+        else if (operator.equals ("-"))
+          value -= nextValue;
+        else if (operator.equals ("*"))
+          value *= nextValue;
+        else if (operator.equals ("/"))
+          value /= nextValue;
+        else if (operator.equals ("^"))
+          value = Math.pow (value, nextValue);
+      }
+      valueType = ValueType.VALUE;
     }
+    catch (Exception e)
+    {
+      valueType = ValueType.ERROR;
+    }
+  }
+
+  @Override
+  public ValueType getValueType ()
+  {
+    return valueType;
   }
 
   @Override
@@ -157,22 +184,19 @@ class Expression implements Value
   @Override
   public String getText ()
   {
-    if (isNaN ())
-      return "NaN";
-    if (isError ())
-      return "Error";
-    return "";
+    return isNaN () ? "NaN" : isError () ? "Error" : "";
   }
 
   @Override
   public boolean isError ()
   {
-    return isError;
+    return valueType == ValueType.ERROR;
   }
 
   @Override
   public double getValue ()
   {
+    assert valueType == ValueType.VALUE : "Expression ValueType = " + valueType;
     return value;
   }
 

src/com/bytezone/diskbrowser/visicalc/Function.java

@@ -33,7 +33,7 @@ abstract class Function implements Value
   protected final Sheet parent;
   protected String functionText;
 
-  protected boolean isError;
+  protected ValueType valueType;
   protected double value;
 
   static Function getInstance (Sheet parent, String text)
@@ -102,10 +102,16 @@ abstract class Function implements Value
       functionText = "";
   }
 
+  @Override
+  public ValueType getValueType ()
+  {
+    return valueType;
+  }
+
   @Override
   public boolean isError ()
   {
-    return isError;
+    return valueType == ValueType.ERROR;
   }
 
   @Override
@@ -117,17 +123,14 @@ abstract class Function implements Value
   @Override
   public double getValue ()
   {
+    assert valueType == ValueType.VALUE : "Function ValueType = " + valueType;
     return value;
   }
 
   @Override
   public String getText ()
   {
-    if (isNaN ())
-      return "NaN";
-    if (isError ())
-      return "Error";
-    return "";
+    return isNaN () ? "NaN" : isError () ? "Error" : "";
   }
 
   protected Range getRange (String text)

src/com/bytezone/diskbrowser/visicalc/If.java

@@ -25,17 +25,31 @@ class If extends Function
   @Override
   public void calculate ()
   {
+    valueType = ValueType.VALUE;
+
     if (condition.getResult ())
     {
       if (expTrue == null)
+      {
         expTrue = new Expression (parent, textTrue);
-      value = expTrue.getValue ();
+        expTrue.calculate ();
+      }
+      if (expTrue.isError () || expTrue.isNaN ())
+        valueType = expTrue.getValueType ();
+      else
+        value = expTrue.getValue ();
     }
     else
     {
       if (expFalse == null)
+      {
         expFalse = new Expression (parent, textFalse);
-      value = expFalse.getValue ();
+        expFalse.calculate ();
+      }
+      if (expFalse.isError () || expFalse.isNaN ())
+        valueType = expFalse.getValueType ();
+      else
+        value = expFalse.getValue ();
     }
   }
 

src/com/bytezone/diskbrowser/visicalc/IsError.java

@@ -13,7 +13,9 @@ class IsError extends Function
   @Override
   public void calculate ()
   {
-    value = expression.getValue ();
-    isError = expression.isError ();
+    expression.calculate ();
+    //    value = expression.getValue ();
+    valueType = expression.getValueType ();
+    value = isError () ? 1 : 0;
   }
 }

src/com/bytezone/diskbrowser/visicalc/IsNa.java

@@ -14,6 +14,6 @@ public class IsNa extends Function
   public void calculate ()
   {
     value = expression.getValue ();
-    isError = expression.isError ();
+    valueType = expression.getValueType ();
   }
 }

src/com/bytezone/diskbrowser/visicalc/Lookup.java

@@ -3,7 +3,6 @@ package com.bytezone.diskbrowser.visicalc;
 class Lookup extends Function
 {
   Range range;
-  //  boolean hasValue;
   String sourceText;
   String rangeText;
   Expression source;
@@ -20,15 +19,15 @@ class Lookup extends Function
     range = getRange (rangeText);
   }
 
-  // need a mechanism to return NA and ERROR
-  //  @Override
-  //  public boolean hasValue ()
-  //  {
-  //    return hasValue;
-  //  }
-
+  @Override
   public void calculate ()
   {
+    source.calculate ();
+    if (source.isError () || source.isNaN ())
+    {
+      valueType = source.getValueType ();
+      return;
+    }
     double sourceValue = source.getValue ();
 
     Address target = null;
@@ -45,7 +44,5 @@ class Lookup extends Function
         value = parent.getCell (target.nextColumn ()).getValue ();
       else
         value = parent.getCell (target.nextRow ()).getValue ();
-
-    //    return 0;
   }
 }

src/com/bytezone/diskbrowser/visicalc/Max.java

@@ -14,7 +14,6 @@ class Max extends Function
   public void calculate ()
   {
     value = Double.MIN_VALUE;
-    isError = false;
     int totalChecked = 0;
 
     for (Address address : range)
@@ -25,8 +24,8 @@ class Max extends Function
 
       if (cell.isError () || cell.isNaN ())
       {
-        isError = true;
-        break;
+        valueType = ValueType.ERROR;
+        return;
       }
 
       double temp = cell.getValue ();
@@ -36,6 +35,8 @@ class Max extends Function
     }
 
     if (totalChecked == 0)
-      isError = true;
+      valueType = ValueType.ERROR;
+    else
+      valueType = ValueType.VALUE;
   }
 }

src/com/bytezone/diskbrowser/visicalc/Min.java

@@ -14,7 +14,6 @@ class Min extends Function
   public void calculate ()
   {
     value = Double.MAX_VALUE;
-    isError = false;
     int totalChecked = 0;
 
     for (Address address : range)
@@ -25,8 +24,8 @@ class Min extends Function
 
       if (cell.isError () || cell.isNaN ())
       {
-        isError = true;
-        break;
+        valueType = ValueType.ERROR;
+        return;
       }
 
       double temp = cell.getValue ();
@@ -36,6 +35,8 @@ class Min extends Function
     }
 
     if (totalChecked == 0)
-      isError = true;
+      valueType = ValueType.ERROR;
+    else
+      valueType = ValueType.VALUE;
   }
 }

src/com/bytezone/diskbrowser/visicalc/Npv.java

@@ -24,6 +24,7 @@ public class Npv extends Function
   public void calculate ()
   {
     value = 0;
+    valueType = ValueType.VALUE;
 
     for (Address address : range)
     {
@@ -33,8 +34,8 @@ public class Npv extends Function
 
       if (cell.isError () || cell.isNaN ())
       {
-        isError = true;
-        break;
+        valueType = ValueType.VALUE;
+        return;
       }
 
       double temp = cell.getValue ();

src/com/bytezone/diskbrowser/visicalc/Number.java

@@ -2,8 +2,8 @@ package com.bytezone.diskbrowser.visicalc;
 
 class Number implements Value
 {
-  double value;
-  boolean isError;
+  private double value;
+  private ValueType valueType;
 
   public Number (String text)
   {
@@ -13,14 +13,14 @@ class Number implements Value
     }
     catch (NumberFormatException e)
     {
-      isError = true;
+      valueType = ValueType.ERROR;
     }
   }
 
   @Override
   public boolean isError ()
   {
-    return isError;
+    return valueType == ValueType.ERROR;
   }
 
   @Override
@@ -51,4 +51,10 @@ class Number implements Value
   public void calculate ()
   {
   }
+
+  @Override
+  public ValueType getValueType ()
+  {
+    return null;
+  }
 }

src/com/bytezone/diskbrowser/visicalc/Sum.java

@@ -14,6 +14,8 @@ class Sum extends Function
   public void calculate ()
   {
     value = 0;
+    valueType = ValueType.VALUE;
+
     for (Address address : range)
     {
       Cell cell = parent.getCell (address);
@@ -22,8 +24,8 @@ class Sum extends Function
 
       if (cell.isError () || cell.isNaN ())
       {
-        isError = true;
-        break;
+        valueType = ValueType.ERROR;
+        return;
       }
       value += cell.getValue ();
     }

src/com/bytezone/diskbrowser/visicalc/Value.java

@@ -2,7 +2,12 @@ package com.bytezone.diskbrowser.visicalc;
 
 interface Value
 {
-  //  public boolean hasValue ();
+  enum ValueType
+  {
+    VALUE, ERROR, NA
+  }
+
+  public ValueType getValueType ();
 
   public double getValue ();