Improve scaling of speed graphs

Make Y axis scale to fix on predetermined nice looking positions

src/base/utils/misc.cpp

@@ -84,6 +84,27 @@ namespace
         QT_TRANSLATE_NOOP3("misc", "PiB", "pebibytes (1024 tebibytes)"),
         QT_TRANSLATE_NOOP3("misc", "EiB", "exbibytes (1024 pebibytes)")
     };
+
+    // return best userfriendly storage unit (B, KiB, MiB, GiB, TiB, ...)
+    // use Binary prefix standards from IEC 60027-2
+    // see http://en.wikipedia.org/wiki/Kilobyte
+    // value must be given in bytes
+    // to send numbers instead of strings with suffixes
+    bool splitToFriendlyUnit(const qint64 sizeInBytes, qreal &val, Utils::Misc::SizeUnit &unit)
+    {
+        if (sizeInBytes < 0) return false;
+
+        int i = 0;
+        qreal rawVal = static_cast<qreal>(sizeInBytes);
+
+        while ((rawVal >= 1024.) && (i <= static_cast<int>(Utils::Misc::SizeUnit::ExbiByte))) {
+            rawVal /= 1024.;
+            ++i;
+        }
+        val = rawVal;
+        unit = static_cast<Utils::Misc::SizeUnit>(i);
+        return true;
+    }
 }
 
 void Utils::Misc::shutdownComputer(const ShutdownDialogAction &action)
@@ -237,52 +258,30 @@ QPoint Utils::Misc::screenCenter(const QWidget *w)
 }
 #endif
 
-QString Utils::Misc::unitString(Utils::Misc::SizeUnit unit)
-{
-    return QCoreApplication::translate("misc",
-                                       units[static_cast<int>(unit)].source, units[static_cast<int>(unit)].comment);
-}
-
-// return best userfriendly storage unit (B, KiB, MiB, GiB, TiB, ...)
-// use Binary prefix standards from IEC 60027-2
-// see http://en.wikipedia.org/wiki/Kilobyte
-// value must be given in bytes
-// to send numbers instead of strings with suffixes
-bool Utils::Misc::friendlyUnit(qint64 sizeInBytes, qreal &val, Utils::Misc::SizeUnit &unit)
+QString Utils::Misc::unitString(const SizeUnit unit, const bool isSpeed)
 {
-    if (sizeInBytes < 0) return false;
-
-    int i = 0;
-    qreal rawVal = static_cast<qreal>(sizeInBytes);
-
-    while ((rawVal >= 1024.) && (i <= static_cast<int>(SizeUnit::ExbiByte))) {
-        rawVal /= 1024.;
-        ++i;
-    }
-    val = rawVal;
-    unit = static_cast<SizeUnit>(i);
-    return true;
+    const auto &unitString = units[static_cast<int>(unit)];
+    QString ret = QCoreApplication::translate("misc", unitString.source, unitString.comment);
+    if (isSpeed)
+        ret += QCoreApplication::translate("misc", "/s", "per second");
+    return ret;
 }
 
 QString Utils::Misc::friendlyUnit(qint64 bytesValue, bool isSpeed)
 {
     SizeUnit unit;
     qreal friendlyVal;
-    if (!friendlyUnit(bytesValue, friendlyVal, unit))
+    if (!splitToFriendlyUnit(bytesValue, friendlyVal, unit))
         return QCoreApplication::translate("misc", "Unknown", "Unknown (size)");
-    QString ret;
-    if (unit == SizeUnit::Byte)
-        ret = QString::number(bytesValue) + QString::fromUtf8(C_NON_BREAKING_SPACE) + unitString(unit);
-    else
-        ret = Utils::String::fromDouble(friendlyVal, friendlyUnitPrecision(unit)) + QString::fromUtf8(C_NON_BREAKING_SPACE) + unitString(unit);
-    if (isSpeed)
-        ret += QCoreApplication::translate("misc", "/s", "per second");
-    return ret;
+    return Utils::String::fromDouble(friendlyVal, friendlyUnitPrecision(unit))
+           + QString::fromUtf8(C_NON_BREAKING_SPACE)
+           + unitString(unit, isSpeed);
 }
 
 int Utils::Misc::friendlyUnitPrecision(SizeUnit unit)
 {
     // friendlyUnit's number of digits after the decimal point
+    if (unit == SizeUnit::Byte) return 0;
     if (unit <= SizeUnit::MebiByte) return 1;
     else if (unit == SizeUnit::GibiByte) return 2;
     else return 3;

src/base/utils/misc.h

@@ -79,11 +79,10 @@ namespace Utils
         QString boostVersionString();
         QString libtorrentVersionString();
 
-        QString unitString(SizeUnit unit);
+        QString unitString(SizeUnit unit, bool isSpeed = false);
 
         // return the best user friendly storage unit (B, KiB, MiB, GiB, TiB)
         // value must be given in bytes
-        bool friendlyUnit(qint64 sizeInBytes, qreal &val, SizeUnit &unit);
         QString friendlyUnit(qint64 bytesValue, bool isSpeed = false);
         int friendlyUnitPrecision(SizeUnit unit);
         qint64 sizeInBytes(qreal size, SizeUnit unit);

src/gui/properties/speedplotview.cpp

@@ -28,9 +28,11 @@
 
 #include "speedplotview.h"
 
+#include <QLocale>
 #include <QPainter>
 #include <QPen>
 #include "base/global.h"
+#include "base/unicodestrings.h"
 #include "base/utils/misc.h"
 
 namespace
@@ -48,6 +50,63 @@ namespace
     const int HOUR6_BUF_SIZE = 5 * 60;
     const int DIVIDER_30MIN = MIN30_SEC / MIN30_BUF_SIZE;
     const int DIVIDER_6HOUR = HOUR6_SEC / HOUR6_BUF_SIZE;
+
+
+    // table of supposed nice steps for grid marks to get nice looking quarters of scale
+    const double roundingTable[] = {1.2, 1.6, 2, 2.4, 2.8, 3.2, 4, 6, 8};
+
+    struct SplittedValue
+    {
+        double arg;
+        Utils::Misc::SizeUnit unit;
+        qint64 sizeInBytes() const
+        {
+            return Utils::Misc::sizeInBytes(arg, unit);
+        }
+    };
+
+    SplittedValue getRoundedYScale(double value)
+    {
+        using Utils::Misc::SizeUnit;
+
+        if (value == 0.0) return {0, SizeUnit::Byte};
+        if (value <= 12.0) return {12, SizeUnit::Byte};
+
+        SizeUnit calculatedUnit = SizeUnit::Byte;
+        while (value > 1024) {
+            value /= 1024;
+            calculatedUnit = static_cast<SizeUnit>(static_cast<int>(calculatedUnit) + 1);
+        }
+
+        if (value > 100.0) {
+            int roundedValue = static_cast<int>(value / 40) * 40;
+            while (roundedValue < value)
+                roundedValue += 40;
+            return {static_cast<double>(roundedValue), calculatedUnit};
+        }
+
+        if (value > 10.0) {
+            int roundedValue = static_cast<int>(value / 4) * 4;
+            while (roundedValue < value)
+                roundedValue += 4;
+            return {static_cast<double>(roundedValue), calculatedUnit};
+        }
+
+        for (const auto &roundedValue : roundingTable) {
+            if (value <= roundedValue)
+                return {roundedValue, calculatedUnit};
+        }
+        return {10.0, calculatedUnit};
+    }
+
+    QString formatLabel(const double argValue, const Utils::Misc::SizeUnit unit)
+    {
+        // check is there need for digits after decimal separator
+        const int precision = (argValue < 10) ? friendlyUnitPrecision(unit) : 0;
+        return QLocale::system().toString(argValue, 'f', precision)
+               + QString::fromUtf8(C_NON_BREAKING_SPACE)
+               + unitString(unit, true);
+    }
 }
 
 SpeedPlotView::Averager::Averager(int divider, boost::circular_buffer<PointData> &sink)
@@ -211,18 +270,16 @@ void SpeedPlotView::paintEvent(QPaintEvent *)
     QFontMetrics fontMetrics = painter.fontMetrics();
 
     rect.adjust(4, 4, 0, -4); // Add padding
-
-    quint64 maxY = maxYValue();
-
+    const SplittedValue niceScale = getRoundedYScale(maxYValue());
     rect.adjust(0, fontMetrics.height(), 0, 0); // Add top padding for top speed text
 
     // draw Y axis speed labels
     QVector<QString> speedLabels = {
-        Utils::Misc::friendlyUnit(maxY, true),
-        Utils::Misc::friendlyUnit(0.75 * maxY, true),
-        Utils::Misc::friendlyUnit(0.5 * maxY, true),
-        Utils::Misc::friendlyUnit(0.25 * maxY, true),
-        Utils::Misc::friendlyUnit(0, true)
+        formatLabel(niceScale.arg, niceScale.unit),
+        formatLabel((0.75 * niceScale.arg), niceScale.unit),
+        formatLabel((0.50 * niceScale.arg), niceScale.unit),
+        formatLabel((0.25 * niceScale.arg), niceScale.unit),
+        formatLabel(0.0, niceScale.unit),
     };
 
     int yAxisWidth = 0;
@@ -264,8 +321,8 @@ void SpeedPlotView::paintEvent(QPaintEvent *)
     // draw graphs
     rect.adjust(3, 0, 0, 0); // Need, else graphs cross left gridline
 
-    double yMultiplier = (maxY == 0) ? 0.0 : static_cast<double>(rect.height()) / maxY;
-    double xTickSize = static_cast<double>(rect.width()) / m_viewablePointsCount;
+    const double yMultiplier = (niceScale.arg == 0.0) ? 0.0 : (rect.height() / niceScale.sizeInBytes());
+    const double xTickSize = static_cast<double>(rect.width()) / m_viewablePointsCount;
 
     boost::circular_buffer<PointData> &queue = getCurrentData();
 

src/gui/search/searchjobwidget.cpp

@@ -315,6 +315,8 @@ void SearchJobWidget::updateFilter()
 void SearchJobWidget::fillFilterComboBoxes()
 {
     using Utils::Misc::SizeUnit;
+    using Utils::Misc::unitString;
+
     QStringList unitStrings;
     unitStrings.append(unitString(SizeUnit::Byte));
     unitStrings.append(unitString(SizeUnit::KibiByte));