Session: Fix issue #67 by improving error handling

[pulseview.git] / pv / util.cpp

diff --git a/pv/util.cpp b/pv/util.cpp
index 237ca7f059f1e589dac4dd9e6f6bc29120a6e3c5..dfb8c72b43504a95ad1f107c66a16e289858ba82 100644 (file)
--- a/pv/util.cpp
+++ b/pv/util.cpp
@@ -110,25 +110,31 @@ static QTextStream& operator<<(QTextStream& stream, const Timestamp& t)
        return stream << QString::fromStdString(str);
 }
 
-QString format_time_si(const Timestamp& v, SIPrefix prefix,
-       unsigned int precision, QString unit, bool sign)
+SIPrefix determine_value_prefix(double v)
 {
-       if (prefix == SIPrefix::unspecified) {
-               // No prefix given, calculate it
-
-               if (v.is_zero()) {
-                       prefix = SIPrefix::none;
-               } else {
-                       int exp = exponent(SIPrefix::yotta);
-                       prefix = SIPrefix::yocto;
-                       while ((fabs(v) * pow(Timestamp(10), exp)) > 999 &&
-                                       prefix < SIPrefix::yotta) {
-                               prefix = successor(prefix);
-                               exp -= 3;
-                       }
+       SIPrefix prefix;
+
+       if (v == 0) {
+               prefix = SIPrefix::none;
+       } else {
+               int exp = exponent(SIPrefix::yotta);
+               prefix = SIPrefix::yocto;
+               while ((fabs(v) * pow(10, exp)) > 999 &&
+                               prefix < SIPrefix::yotta) {
+                       prefix = successor(prefix);
+                       exp -= 3;
                }
        }
 
+       return prefix;
+}
+
+QString format_time_si(const Timestamp& v, SIPrefix prefix,
+       unsigned int precision, QString unit, bool sign)
+{
+       if (prefix == SIPrefix::unspecified)
+               prefix = determine_value_prefix(v.convert_to<double>());
+
        assert(prefix >= SIPrefix::yocto);
        assert(prefix <= SIPrefix::yotta);
 
@@ -137,10 +143,9 @@ QString format_time_si(const Timestamp& v, SIPrefix prefix,
        QString s;
        QTextStream ts(&s);
        if (sign && !v.is_zero())
-               ts << forcesign;
+               ts.setNumberFlags(ts.numberFlags() | QTextStream::ForceSign);
        ts << qSetRealNumberPrecision(precision) << (v * multiplier);
-       if (!unit.isNull())
-               ts << ' ' << prefix << unit;
+       ts << ' ' << prefix << unit;
 
        return s;
 }
@@ -149,19 +154,11 @@ QString format_value_si(double v, SIPrefix prefix, unsigned precision,
        QString unit, bool sign)
 {
        if (prefix == SIPrefix::unspecified) {
-               // No prefix given, calculate it
-
-               if (v == 0) {
-                       prefix = SIPrefix::none;
-               } else {
-                       int exp = exponent(SIPrefix::yotta);
-                       prefix = SIPrefix::yocto;
-                       while ((fabs(v) * pow(Timestamp(10), exp)) > 999 &&
-                                       prefix < SIPrefix::yotta) {
-                               prefix = successor(prefix);
-                               exp -= 3;
-                       }
-               }
+               prefix = determine_value_prefix(v);
+
+               const int prefix_order = -exponent(prefix);
+               precision = (prefix >= SIPrefix::none) ? max((int)(precision + prefix_order), 0) :
+                       max((int)(precision - prefix_order), 0);
        }
 
        assert(prefix >= SIPrefix::yocto);
@@ -172,7 +169,7 @@ QString format_value_si(double v, SIPrefix prefix, unsigned precision,
        QString s;
        QTextStream ts(&s);
        if (sign && (v != 0))
-               ts << forcesign;
+               ts.setNumberFlags(ts.numberFlags() | QTextStream::ForceSign);
        ts.setRealNumberNotation(QTextStream::FixedNotation);
        ts.setRealNumberPrecision(precision);
        ts << (v * multiplier) << ' ' << prefix << unit;
@@ -282,5 +279,22 @@ vector<string> split_string(string text, string separator)
        return result;
 }
 
+/**
+ * Return the width of a string in a given font.
+ *
+ * @param[in] metric metrics of the font
+ * @param[in] string the string whose width should be determined
+ *
+ * @return width of the string in pixels
+ */
+std::streamsize text_width(const QFontMetrics &metric, const QString &string)
+{
+#if QT_VERSION >= QT_VERSION_CHECK(5, 11, 0)
+       return metric.horizontalAdvance(string);
+#else
+       return metric.width(string);
+#endif
+}
+
 } // namespace util
 } // namespace pv