Util: Introduce DD:HH:MM:SS.mmm nnn ppp fff format

This also fixes bug #371.

diff --git a/pv/util.cpp b/pv/util.cpp
index e3619829d1eab230cd0bda0b1b160fe5e7e404e5..cf42eb16f25b78a11c5fbef9db610c8f58d9cda0 100644 (file)
--- a/pv/util.cpp
+++ b/pv/util.cpp
@@ -24,6 +24,8 @@
 
 #include <assert.h>
 
+#include <algorithm>
+
 #include <QTextStream>
 #include <QDebug>
 
@@ -35,7 +37,8 @@ namespace util {
 static const QString SIPrefixes[17] =
        {"y", "z", "a", "f", "p", "n", QChar(0x03BC), "m", "", "k", "M", "G",
        "T", "P", "E", "Z", "Y"};
-const int FirstSIPrefixPower = -24;
+const int FirstSIPrefix = 8;
+const int FirstSIPrefixPower = -(FirstSIPrefix * 3);
 
 QString format_si_value(double v, QString unit, int prefix,
        unsigned int precision, bool sign)
@@ -67,13 +70,116 @@ QString format_si_value(double v, QString unit, int prefix,
        return s;
 }
 
+static QString pad_number(unsigned int number, int length)
+{
+       return QString("%1").arg(number, length, 10, QChar('0'));
+}
+
+static QString format_time_in_full(double t, signed precision, bool force_sign)
+{
+       const unsigned int whole_seconds = abs((int) t);
+       const unsigned int days = whole_seconds / (60 * 60 * 24);
+       const unsigned int hours = (whole_seconds / (60 * 60)) % 24;
+       const unsigned int minutes = (whole_seconds / 60) % 60;
+       const unsigned int seconds = whole_seconds % 60;
+
+       QString s;
+       QTextStream ts(&s);
+
+       if (force_sign && (t >= 0))
+               ts << "+";
+       if (t < 0)
+               ts << "-";
+
+       bool use_padding = false;
+
+       if (days) {
+               ts << days << ":";
+               use_padding = true;
+       }
+
+       if (hours || days) {
+               ts << pad_number(hours, use_padding ? 2 : 0) << ":";
+               use_padding = true;
+       }
+
+       if (minutes || hours || days) {
+               ts << pad_number(minutes, use_padding ? 2 : 0);
+               use_padding = true;
+
+               // We're not showing any seconds with a negative precision
+               if (precision >= 0)
+                        ts << ":";
+       }
+
+       // precision < 0: Use DD:HH:MM format
+       // precision = 0: Use DD:HH:MM:SS format
+       // precision > 0: Use DD:HH:MM:SS.mmm nnn ppp fff format
+       if (precision >= 0) {
+               ts << pad_number(seconds, use_padding ? 2 : 0);
+
+               const double fraction = fabs(t - whole_seconds);
+
+               if (precision > 0 && precision < 1000) {
+                       QString fs = QString("%1").arg(fraction, -(2 + precision), 'f',
+                               precision, QChar('0'));
+
+                       ts << ".";
+
+                       // Copy all digits, inserting spaces as unit separators
+                       for (int i = 1; i <= precision; i++) {
+                               // Start at index 2 to skip the "0." at the beginning
+                               ts << fs[1 + i];
+
+                               if ((i > 0) && (i % 3 == 0))
+                                       ts << " ";
+                       }
+               }
+       }
+
+       return s;
+}
+
 QString format_time(double t, int prefix, TimeUnit unit,
-       unsigned int precision, bool sign)
+       unsigned int precision, double step_size, bool sign)
 {
-       if (unit == TimeUnit::Time)
-               return format_si_value(t, "s", prefix, precision, sign);
-       else
-               return format_si_value(t, "sa", prefix, precision, sign);
+       // If we have to use samples then we have no alternative formats
+       if (unit == Samples) {
+               // The precision is always given without taking the prefix into account
+               // so we need to deduct the number of decimals the prefix might imply
+               const int prefix_order =
+                       -(prefix * 3 + pv::util::FirstSIPrefixPower);
+
+               const unsigned int relative_prec =
+                       (prefix >= pv::util::FirstSIPrefix) ? precision :
+                       std::max((int)(precision - prefix_order), 0);
+
+               return format_si_value(t, "sa", prefix, relative_prec, sign);
+       }
+
+       // View zoomed way out -> low precision (0), high step size (>60s)
+       // -> DD:HH:MM
+       if ((precision == 0) && (step_size >= 60)) {
+               return format_time_in_full(t, -1, sign);
+       }
+
+       // View in "normal" range -> medium precision, medium step size
+       // -> HH:MM:SS.mmm... or xxxx (si unit) if less than 60 seconds
+       // View zoomed way in -> high precision (>3), low step size (<1s)
+       // -> HH:MM:SS.mmm... or xxxx (si unit) if less than 60 seconds
+       if (abs(t) < 60) {
+               // The precision is always given without taking the prefix into account
+               // so we need to deduct the number of decimals the prefix might imply
+               const int prefix_order =
+                       -(prefix * 3 + pv::util::FirstSIPrefixPower);
+
+               const unsigned int relative_prec =
+                       (prefix >= pv::util::FirstSIPrefix) ? precision :
+                       std::max((int)(precision - prefix_order), 0);
+
+               return format_si_value(t, "s", prefix, relative_prec, sign);
+       } else
+               return format_time_in_full(t, precision, sign);
 }
 
 QString format_second(double second)

diff --git a/pv/util.hpp b/pv/util.hpp
index f13516508aa45da7050a1aef0b9dd14f803e98af..ba6702f79f175f345ddfd814ae6fc1ae2ceeda78 100644 (file)
--- a/pv/util.hpp
+++ b/pv/util.hpp
@@ -56,14 +56,15 @@ QString format_si_value(
  * @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 unit The unit of quantity.
- * @param precision The number of digits after the decimal separator.
+ * @param precision The number of digits after the decimal separator or period (.).
+ * @param step_size The delta between two consecutive time markers (if applicable).
  * @param sign Whether or not to add a sign also for positive numbers.
  *
  * @return The formated value.
  */
 QString format_time(
        double t, int prefix = -1, TimeUnit unit = Time, unsigned precision = 0,
-       bool sign = true);
+       double step_size = 0, bool sign = true);
 
 /**
  * Formats a given time value with a SI prefix so that the