// Determine the format that will be used when interpreting a value to write,
// or when presenting a value for which default formatting has been requested.
void QEStringFormatting::determineDbFormat( const QVariant &value )
{
// Assume default formatting, and only a single value
dbFormat = FORMAT_DEFAULT;
dbFormatArray = false;
// Get the value type
QVariant::Type t = value.type();
// If the value is a list, get the type of the first element in the list
if( t == QVariant::List )
{
// Note that whatever the format, we have an array of them
dbFormatArray = true;
// Get the list
const QVariantList valueArray = value.toList();
// If the list has anything in it, get the type of the first
if( valueArray.count() )
{
t = valueArray[0].type();
}
else
{
formatFailure( QString( "Bug in QEStringFormatting::determineDefaultFormatting(). Empty array" ) );
return;
}
}
// Determine the formatting type from the variant type
switch( t )
{
case QVariant::Double:
dbFormat = FORMAT_FLOATING;
break;
case QVariant::LongLong:
case QVariant::Int:
dbFormat = FORMAT_INTEGER;
break;
case QVariant::ULongLong:
case QVariant::UInt:
dbFormat = FORMAT_UNSIGNEDINTEGER;
break;
case QVariant::String:
dbFormat = FORMAT_STRING;
break;
default:
formatFailure( QString( "Bug in QEStringFormatting::determineDbFormatting(). The QVariant type was not expected" ) );
break;
}
}
/*!
Generate an integer given a value, using formatting defined within this class.
*/
long QCaIntegerFormatting::formatInteger( const QVariant &value ) {
// Determine the format from the variant type.
// Only the types used to store ca data are used. any other type is considered a failure.
switch( value.type() ) {
case QVariant::Double :
{
return formatFromFloating( value );
}
case QVariant::LongLong :
{
return value.toLongLong(); // No conversion requried. Stored in variant as required type
}
case QVariant::ULongLong :
{
return formatFromUnsignedInteger( value );
}
case QVariant::String :
{
return formatFromString( value );
}
default :
{
return formatFailure( QString( "Bug in QCaIntegerFormatting::formatInteger(). The QVariant type was not expected" ) );
}
}
}
/*
Format a variant value as an integer representation of a string.
This method was written to convert a QVariant of type String, but should cope with a variant of any type.
Convert the variant value to an unsigned long. It may or may not be a ulonglong type variant. If it is - good,
there will be no conversion problems.
*/
long QEIntegerFormatting::formatFromString( const QVariant &value ) {
// Extract the value as a long using whatever conversion the QVariant uses.
// If that fails, try extracting the value as a double using whatever conversion the QVariant uses, then cast it as a long.
//
// Note, this will not pick up if the QVariant type is not one of the types used to represent CA data.
// This is OK as it is not absolutely nessesary to do this sort of check at this point. Also the code is more robust as it will
// work if the range of QVariant types used expands.
// Note, this does not give us the freedom to specify what conversions should fail or succeed. For example, does QVariant::toLongLong()
// work if the value it holds is the string 1.0001 and should it?
// If QVariant::toLongLong() does not do exactly what is required, a switch statement for each of the types used to hold CA data
// will need to be added and the conversions done manually or using QVariant::toLongLong() as required.
bool convertOk;
long lValue = value.toLongLong( &convertOk );
if( convertOk )
return lValue;
double dValue = value.toDouble( &convertOk );
if( convertOk )
{
lValue = (long)dValue;
return lValue;
}
return formatFailure( QString( "Warning from QEIntegerFormatting::formatFromString(). A variant could not be converted to a string." ) );
}
/*
Format a variant value as a string representation of an unsigned integer.
This method was written to convert a QVariant of type ULongLong, but should cope with a variant of any type.
First convert the variant value to an unsigned long. It may or may not be a ulonglong type variant. If it is - good,
there will be no conversion problems.
Then format it as a string using the formatting information stored in this class.
*/
void QEStringFormatting::formatFromUnsignedInteger( const QVariant &value ) {
// Extract the value as an unsigned long using whatever conversion the QVariant uses.
//
// Note, this will not pick up if the QVariant type is not one of the types used to represent CA data.
// This is OK as it is not absolutely nessesary to do this sort of check at this point. Also the code is more robust as it will
// work if the range of QVariant types used expands.
// Note, this does not give us the freedom to specify what conversions should fail or succeed. For example, does QVariant::toULongLong()
// work if the value it holds is the string 1.000 and should it?
// If QVariant::toULongLong() does not do exactly what is required, a switch statement for each of the types used to hold CA data
// will need to be added and the conversions done manually or using QVariant::toULongLong() as required.
// Use QString conversions is variant is a string.
// (QVariant toLongLong can't convert strings like "2.000"!)
bool convertOk;
unsigned long ulValue;
if( value.type() == QVariant::String )
{
QString str = value.toString();
double dd = str.toDouble( &convertOk );
ulValue = dd;
}
// Use QVariant conversions otherwise
else
{
ulValue = value.toULongLong( &convertOk );
}
if( !convertOk )
{
formatFailure( QString( "Warning from QEStringFormatting::formatFromUnsignedInteger(). A variant could not be converted to an unsigned long." ) );
return;
}
// Generate the text
stream << ulValue;
// Add sperators if needs be
outStr = insertSeparators( outStr );
}
/*
Format a variant value as a string representation of a floating point
number.
First convert the variant value to a double. It may or may not be a
floating point type variant. If it is - good,
there will be no conversion problems.
Then format it as a string using the formatting information stored in this
class.
*/
void QEStringFormatting::formatFromFloating( const QVariant &value ) {
// Extract the value as a double using whatever conversion the QVariant uses.
//
// Note, this will not pick up if the QVariant type is not one of the types used to represent CA data.
// This is OK as it is not absolutely nessesary to do this sort of check at this point. Also the code is more robust as it will
// work if the range of QVariant types used expands.
// Note, this does not give us the freedom to specify what conversions should fail or succeed. For example, does QVariant::toDouble()
// work if the value it holds is the string 1.234 10^6, or does it work for both - 1.234 and -1.234, and should it?
// If QVariant::toDouble() does not do exactly what is required, a switch statement for each of the types used to hold CA data
// will need to be added and the conversions done manually or using QVariant::toDouble() as required.
bool convertOk;
double dValue = value.toDouble( &convertOk );
if( !convertOk ) {
formatFailure( QString( "Warning from QEStringFormatting::formatFromFloating(). A variant could not be converted to a long." ) );
return;
}
// NOTE: Smart notation (NOTATION_AUTOMATIC) does not honor real number precision.
// So select FixedNotation or ScientificNotation as appropriate.
//
QTextStream::RealNumberNotation rnn = stream.realNumberNotation();
if( rnn == QTextStream::SmartNotation ){
int prec;
double low_fixed_limit;
double high_fixed_limit;
double absDbValue;
// Extact precision being used.
prec = stream.realNumberPrecision ();
prec = LIMIT( prec, 0, 15 );
// Example, if prec = 3, when low limit is 0.01
low_fixed_limit = EXP10( 1 - prec );
high_fixed_limit = 1.0E+05;
// Work with absoloute value
absDbValue = ABS( dValue );
if( absDbValue == 0.0 || ( absDbValue >= low_fixed_limit && absDbValue < high_fixed_limit )){
stream.setRealNumberNotation( QTextStream::FixedNotation );
} else {
stream.setRealNumberNotation( QTextStream::ScientificNotation );
}
}
// Generate the text
stream << dValue;
stream.setRealNumberNotation( rnn ); // reset
// Remove leading zero if required
if( !leadingZero ) {
if( outStr.left(2) == "0." )
outStr = outStr.right( outStr.length()-1);
}
// Remove trailing zeros if required, but don't leave a naked decimal point, i.e. 4.0000 becomes 4.0 (as opposed to 4.)
// Also need to be careful to ensure 1.23000e+100 becomes 1.23e+100 (as opposed to 1.23000e+1)
if( !trailingZeros ) {
int dp = outStr.indexOf( ".", 0 );
if( dp >= 0 ){
int ep = outStr.indexOf( "e", dp ); // find exponent if it exists
if( ep < 0 ) ep = outStr.indexOf( "E", dp ); // allow for either case
if( ep < 0 ) ep = outStr.length (); // otherwise start at end of string
int sp = ep;
while( ( sp > dp + 2 ) && ( outStr[sp - 1] == '0' ) ){
sp--;
}
if( sp < ep ){
outStr.replace( sp, ep - sp, "" );
}
}
}
// Add sperators if needs be
outStr = insertSeparators( outStr );
}
/*
Generate a string given an element value, using formatting defined within this class.
*/
QString QEStringFormatting::formatElementString( const QVariant& value ) {
// Examine the value and note the matching format
determineDbFormat( value );
// Initialise
bool errorMessage = false; // Set if an error message is the result
outStr.clear();
// Set the precision
if( useDbPrecision )
stream.setRealNumberPrecision( dbPrecision );
else
stream.setRealNumberPrecision( precision );
// Format the value as requested
switch( format )
{
// Determine the format from the variant type.
// Only the types used to store ca data are used. any other type is
// considered a failure.
case FORMAT_DEFAULT :
{
bool haveEnumeratedString = false; // Successfully converted the value to an enumerated string
// If a list of enumerated strings is available, attempt to get an enumerated string
if( dbEnumerations.size() )
{
// Ensure the input value can be used as an index into the list of enumerated strings
bool convertOk;
long lValue = value.toLongLong( &convertOk );
if( convertOk && lValue >= 0 )
{
// Get the appropriate enumerated string
if( lValue < dbEnumerations.size() )
{
outStr = dbEnumerations[lValue];
haveEnumeratedString = true;
}
// NOTE: STAT field hard-coded values now set up in QCaObject.cpp - extra values appended to dbEnumerations.
}
}
// If no list of enumerated strings was available, or a string could not be selected,
// convert the value based on it's type.
if( !haveEnumeratedString )
{
switch( dbFormat )
{
case FORMAT_FLOATING:
formatFromFloating( value );
break;
case FORMAT_INTEGER:
formatFromInteger( value );
break;
case FORMAT_UNSIGNEDINTEGER:
formatFromUnsignedInteger( value );
break;
case FORMAT_STRING:
formatFromString( value );
break;
default:
formatFailure( QString( "Bug in QEStringFormatting::formatString(). The QVariant type was not expected" ) );
errorMessage = true;
break;
}
}
break;
}
// Format as requested, ignoring the database type
case FORMAT_FLOATING:
formatFromFloating( value );
break;
case FORMAT_INTEGER:
formatFromInteger( value );
break;
case FORMAT_UNSIGNEDINTEGER:
formatFromUnsignedInteger( value );
break;
case FORMAT_LOCAL_ENUMERATE:
formatFromEnumeration( value );
break;
case FORMAT_TIME:
formatFromTime( value );
break;
case FORMAT_STRING:
formatFromString( value );
break;
// Don't know how to format.
// This is a code error. All cases in QEStringFormatting::formats should be catered for
default:
formatFailure( QString( "Bug in QEStringFormatting::format(). The format type was not expected" ) );
errorMessage = true;
break;
}
return outStr;
}