util: Added format_si_value

diff --git a/pv/util.cpp b/pv/util.cpp
index 62f0ee1f67002b33ef2816bef15ccd3679dc4a00..2a04aaec7d99e68fb7ef9295c6ec4e40f5476425 100644 (file)
--- a/pv/util.cpp
+++ b/pv/util.cpp
@@ -36,9 +36,21 @@ static const QString SIPrefixes[9] =
        {"f", "p", "n", QChar(0x03BC), "m", "", "k", "M", "G"};
 const int FirstSIPrefixPower = -15;
 
-QString format_time(double t, unsigned int prefix,
+QString format_si_value(double v, QString unit, int prefix,
        unsigned int precision, bool sign)
 {
+       if (prefix < 0) {
+               int exp = -FirstSIPrefixPower;
+
+               prefix = 0;
+               while ((fabs(v) * pow(10.0, exp)) > 999.0 &&
+                       prefix < (int)(countof(SIPrefixes) - 1)) {
+                       prefix++;
+                       exp -= 3;
+               }
+       }
+
+       assert(prefix >= 0);
        assert(prefix < countof(SIPrefixes));
 
        const double multiplier = pow(10.0,
@@ -46,26 +58,23 @@ QString format_time(double t, unsigned int prefix,
 
        QString s;
        QTextStream ts(&s);
-       if (sign) {
+       if (sign)
                ts << forcesign;
-       }
        ts << fixed << qSetRealNumberPrecision(precision)
-               << (t  * multiplier) << SIPrefixes[prefix] << "s";
+               << (v  * multiplier) << SIPrefixes[prefix] << unit;
 
        return s;
 }
 
-QString format_second(double second)
+QString format_time(double t, int prefix,
+       unsigned int precision, bool sign)
 {
-       unsigned int i = 0;
-       int exp = - FirstSIPrefixPower;
-
-       while ((second * pow(10.0, exp)) > 999.0 && i < countof(SIPrefixes) - 1) {
-               i++;
-               exp -= 3;
-       }
+       return format_si_value(t, "s", prefix, precision, sign);
+}
 
-       return format_time(second, i, 0, false);
+QString format_second(double second)
+{
+       return format_si_value(second, "s", -1, 0, false);
 }
 
 } // namespace util

diff --git a/pv/util.hpp b/pv/util.hpp
index 572bed31814e6bba0baa670027e1762f04b261c9..5d65694054ab2c0b2e6a9f652fc736abfc5da8cd 100644 (file)
--- a/pv/util.hpp
+++ b/pv/util.hpp
@@ -31,18 +31,33 @@ namespace util {
 extern const int FirstSIPrefixPower;
 
 /**
- * Formats a given time value with the specified SI prefix.
+ * Formats a given value with the specified SI prefix.
+ * @param v The value to format.
+ * @param unit The unit of quantity.
+ * @param prefix The number of the prefix, from 0 for 'femto' up to
+ *   8 for 'giga'. If prefix is set to -1, the prefix will be calculated.
+ * @param precision The number of digits after the decimal separator.
+ * @param sign Whether or not to add a sign also for positive numbers.
+ *
+ * @return The formated value.
+ */
+QString format_si_value(
+       double v, QString unit, int prefix = -1,
+       unsigned precision = 0, bool sign = true);
+
+/**
+ * Formats a given time with the specified SI prefix.
  * @param t The time value in seconds to format.
  * @param prefix The number of the prefix, from 0 for 'femto' up to
- *               8 for 'giga'.
- * @parma precision The number of digits after the decimal separator.
+ *   8 for 'giga'. If prefix is set to -1, the prefix will be calculated.
+ * @param unit The unit of quantity.
+ * @param precision The number of digits after the decimal separator.
  * @param sign Whether or not to add a sign also for positive numbers.
  *
  * @return The formated value.
  */
 QString format_time(
-       double t, unsigned int prefix,
-       unsigned precision = 0, bool sign = true);
+       double t, int prefix = -1, unsigned precision = 0, bool sign = true);
 
 /**
  * Formats a given time value with a SI prefix so that the