Spreadsheet: Refactored alias checking code, so GUI and Python error messages are aligned.

src/Mod/Spreadsheet/App/PropertySheet.cpp

@@ -176,6 +176,33 @@ const Cell * PropertySheet::getValueFromAlias(const std::string &alias) const
         return getValue(it->second);
     else
         return 0;
+
+}
+
+bool PropertySheet::isValidAlias(const std::string &candidate)
+{
+    static const boost::regex gen("^[A-Za-z][_A-Za-z0-9]*$");
+    boost::cmatch cm;
+
+    /* Check if it is used before */
+    if (getValueFromAlias(candidate) != 0)
+        return false;
+
+    if (boost::regex_match(candidate.c_str(), cm, gen)) {
+        static const boost::regex e("\\${0,1}([A-Z]{1,2})\\${0,1}([0-9]{1,5})");
+
+        if (boost::regex_match(candidate.c_str(), cm, e)) {
+            const boost::sub_match<const char *> colstr = cm[1];
+            const boost::sub_match<const char *> rowstr = cm[2];
+
+            // A valid cell address?
+            if (Spreadsheet::validRow(rowstr.str()) >= 0 && Spreadsheet::validColumn(colstr.str()) >= 0)
+                return false;
+        }
+        return true;
+    }
+    else
+        return false;
 }
 
 std::set<CellAddress> PropertySheet::getUsedCells() const
@@ -452,7 +479,15 @@ void PropertySheet::setDisplayUnit(CellAddress address, const std::string &unit)
 
 void PropertySheet::setAlias(CellAddress address, const std::string &alias)
 {
+    if (alias.size() > 0 && !isValidAlias(alias))
+        throw Base::Exception("Invalid alias");
+
+    const Cell * aliasedCell = getValueFromAlias(alias);
     Cell * cell = nonNullCellAt(address);
+
+    if (aliasedCell != 0 && cell != aliasedCell)
+        throw Base::Exception("Alias already defined.");
+
     assert(cell != 0);
 
     /* Mark cells depending on this cell dirty; they need to be resolved when an alias changes or disappears */

src/Mod/Spreadsheet/App/PropertySheet.h

@@ -85,6 +85,8 @@ public:
 
     const Cell * getValueFromAlias(const std::string &alias) const;
 
+    bool isValidAlias(const std::string &candidate);
+
     std::set<CellAddress> getUsedCells() const;
 
     Sheet * sheet() const { return owner; }

src/Mod/Spreadsheet/App/Sheet.cpp

@@ -1123,19 +1123,28 @@ void Sheet::setComputedUnit(CellAddress address, const Base::Unit &unit)
 }
 
 /**
- * @brief Set alias for cell at address \a address to \a alias.
+ * @brief Set alias for cell at address \a address to \a alias. If the alias
+ * is an empty string, the existing alias is removed.
  * @param address Address of cell
  * @param alias New alias.
  */
 
 void Sheet::setAlias(CellAddress address, const std::string &alias)
 {
-    const Cell * cell = cells.getValueFromAlias(alias);
+    std::string existingAlias = getAddressFromAlias(alias);
 
-    if (cell != 0)
-        throw Base::Exception("Alias already defined.");
+    if (existingAlias.size() > 0) {
+        if (existingAlias == address.toString()) // Same as old?
+            return;
         else
+            throw Base::Exception("Alias already defined");
+    }
+    else if (alias.size() == 0) // Empty?
+        cells.setAlias(address, "");
+    else if (isValidAlias(alias)) // Valid?
         cells.setAlias(address, alias);
+    else
+        throw Base::Exception("Invalid alias");
 }
 
 /**
@@ -1155,6 +1164,31 @@ std::string Sheet::getAddressFromAlias(const std::string &alias) const
         return std::string();
 }
 
+/**
+ * @brief Determine whether a given alias candiate is valid or not.
+ *
+ * A candidate is valid is the string is syntactically correct,
+ * and the alias does not conflict with an existing property.
+ *
+ */
+
+bool Sheet::isValidAlias(const std::string & candidate)
+{
+    // Valid syntactically?
+    if (!cells.isValidAlias(candidate))
+        return false;
+
+    // Existing alias? Then it's ok
+    if (getAddressFromAlias(candidate).size() > 0 )
+        return true;
+
+    // Check to see that is does not crash with any other property in the Sheet object.
+    if (getPropertyByName(candidate.c_str()))
+        return false;
+    else
+        return true;
+}
+
 /**
  * @brief Set row and column span for the cell at address \a address to \a rows and \a columns.
  * @param address Address to upper right corner of cell

src/Mod/Spreadsheet/App/Sheet.h

@@ -142,6 +142,8 @@ public:
 
     std::string getAddressFromAlias(const std::string & alias) const;
 
+    bool isValidAlias(const std::string &candidate);
+
     void setSpans(CellAddress address, int rows, int columns);
 
     std::set<std::string> dependsOn(CellAddress address) const;

src/Mod/Spreadsheet/App/Utils.cpp

@@ -84,13 +84,12 @@ std::string Spreadsheet::rowName(int row)
 
 int Spreadsheet::decodeRow(const std::string &rowstr)
 {
-    char * end;
-    int i = strtol(rowstr.c_str(), &end, 10);
+    int row = validRow(rowstr);
 
-    if (i <0 || i >= CellAddress::MAX_ROWS || *end)
+    if (row >= 0)
+        return row;
+    else
         throw Base::Exception("Invalid row specification.");
-
-    return i - 1;
 }
 
 /**
@@ -103,6 +102,44 @@ int Spreadsheet::decodeRow(const std::string &rowstr)
   */
 
 int Spreadsheet::decodeColumn(const std::string &colstr)
+{
+    int col = validColumn(colstr);
+
+    if (col >= 0)
+        return col;
+    else
+        throw Base::Exception("Invalid column specification");
+}
+
+/**
+  * Determine wheter a row specification is valid or not.
+  *
+  * @param rowstr Row specified as a string, with "1" being the first row.
+  *
+  * @returns 0 or positive on success, -1 on error.
+  */
+
+int Spreadsheet::validRow(const std::string &rowstr)
+{
+    char * end;
+    int i = strtol(rowstr.c_str(), &end, 10);
+
+    if (i <0 || i >= CellAddress::MAX_ROWS || *end)
+        return -1;
+
+    return i - 1;
+}
+
+/**
+  * Determine whether a column specification is valid or not.
+  *
+  * @param colstr Column specified as a string, with "A" begin the first column.
+  *
+  * @returns 0 or positive on success, -1 on error.
+  *
+  */
+
+int Spreadsheet::validColumn(const std::string &colstr)
 {
     int col = 0;
 
@@ -110,7 +147,7 @@ int Spreadsheet::decodeColumn(const std::string &colstr)
         if ((colstr[0] >= 'A' && colstr[0] <= 'Z'))
             col = colstr[0] - 'A';
         else
-            throw Base::Exception("Invalid column specification");
+            return -1;
     }
     else {
         col = 0;
@@ -120,7 +157,7 @@ int Spreadsheet::decodeColumn(const std::string &colstr)
             if ((*i >= 'A' && *i <= 'Z'))
                 v = *i - 'A';
             else
-                throw Base::Exception("Invalid column specification");
+                return -1;
 
             col = col * 26 + v;
         }

src/Mod/Spreadsheet/App/Utils.h

@@ -37,6 +37,9 @@ SpreadsheetExport std::string columnName(int col);
 SpreadsheetExport std::string rowName(int row);
 int decodeColumn(const std::string &colstr);
 int decodeRow(const std::string &rowstr);
+int validColumn(const std::string &colstr);
+int validRow(const std::string &rowstr);
+
 SpreadsheetExport CellAddress stringToAddress(const char *strAddress);
 SpreadsheetExport void createRectangles(std::set<std::pair<int, int> > & cells, std::map<std::pair<int, int>, std::pair<int, int> > & rectangles);
 SpreadsheetExport std::string quote(const std::string &input);

src/Mod/Spreadsheet/Gui/PropertiesDialog.cpp

@@ -204,22 +204,7 @@ void PropertiesDialog::aliasChanged(const QString & text)
 {
     QPalette palette = ui->alias->palette();
 
-    aliasOk = true;
-
-    if (sheet->getAddressFromAlias(Base::Tools::toStdString(text)).size() > 0)
-        aliasOk = false;
-
-    if (text.indexOf(QRegExp(QString::fromLatin1("^[A-Za-z][_A-Za-z0-9]*$"))) >= 0) {
-        try {
-            CellAddress address(text.toUtf8().constData());
-            aliasOk = false;
-        }
-        catch (...) { }
-    }
-    else {
-        if (!text.isEmpty())
-            aliasOk = false;
-    }
+    aliasOk = text.isEmpty() || sheet->isValidAlias(Base::Tools::toStdString(text));
 
     alias = aliasOk ? Base::Tools::toStdString(text) : "";
     palette.setColor(QPalette::Text, aliasOk ? Qt::black : Qt::red);