preparations for multiple unit (uBTC, mBTC, BTC) support, fix amount entry issue

1 files changed, 96 insertions, 0 deletions

diff --git a/src/qt/bitcoinunits.cpp b/src/qt/bitcoinunits.cpp
new file mode 100644
index 0000000000..ff30563f97
--- /dev/null
+++ b/src/qt/bitcoinunits.cpp
@@ -0,0 +1,96 @@
+#include "bitcoinunits.h"
+
+#include <QStringList>
+
+QString BitcoinUnits::name(BitcoinUnits::Unit unit)
+{
+    switch(unit)
+    {
+    case BTC: return "BTC";
+    case mBTC: return "mBTC";
+    case uBTC: return "uBTC";
+    default: return "???";
+    }
+}
+
+QString BitcoinUnits::description(BitcoinUnits::Unit unit)
+{
+    switch(unit)
+    {
+    case BTC: return "Bitcoin";
+    case mBTC: return "Milli-bitcoin";
+    case uBTC: return "Micro-bitcoin";
+    default: return "???";
+    }
+}
+
+qint64 BitcoinUnits::factor(BitcoinUnits::Unit unit)
+{
+    switch(unit)
+    {
+    case BTC:  return 100000000;
+    case mBTC: return 100000;
+    case uBTC: return 100;
+    default:   return 100000000;
+    }
+}
+
+int BitcoinUnits::decimals(BitcoinUnits::Unit unit)
+{
+    switch(unit)
+    {
+    case BTC: return 8;
+    case mBTC: return 5;
+    case uBTC: return 2;
+    default: return 0;
+    }
+}
+
+QString BitcoinUnits::format(BitcoinUnits::Unit unit, qint64 n, bool fPlus)
+{
+    // Note: not using straight sprintf here because we do NOT want
+    // localized number formatting.
+    qint64 coin = factor(unit);
+    int num_decimals = decimals(unit);
+    qint64 n_abs = (n > 0 ? n : -n);
+    qint64 quotient = n_abs / coin;
+    qint64 remainder = n_abs % coin;
+    QString quotient_str = QString::number(quotient);
+    QString remainder_str = QString::number(remainder).rightJustified(num_decimals, '0');
+
+    // Right-trim excess 0's after the decimal point
+    int nTrim = 0;
+    for (int i = remainder_str.size()-1; i>=2 && (remainder_str.at(i) == '0'); --i)
+        ++nTrim;
+    remainder_str.chop(nTrim);
+
+    if (n < 0)
+        quotient_str.insert(0, '-');
+    else if (fPlus && n > 0)
+        quotient_str.insert(0, '+');
+    return quotient_str + QString(".") + remainder_str;
+}
+
+QString BitcoinUnits::formatWithUnit(BitcoinUnits::Unit unit, qint64 amount, bool plussign)
+{
+    return format(unit, amount, plussign) + QString(" ") + name(unit);
+}
+
+bool BitcoinUnits::parse(BitcoinUnits::Unit unit, const QString &value, qint64 *val_out)
+{
+    int num_decimals = decimals(unit);
+    QStringList parts = value.split(".");
+    if(parts.size() != 2 || parts.at(1).size() > num_decimals)
+        return false; // Max num decimals
+    bool ok = false;
+    QString str = parts[0] + parts[1].leftJustified(num_decimals, '0');
+    if(str.size()>18)
+        return false; // Bounds check
+
+    qint64 retvalue = str.toLongLong(&ok);
+    if(val_out)
+    {
+        *val_out = retvalue;
+    }
+    return ok;
+}