cabana: show signal values with consistent number of digits (#27556)

tools/cabana/dbc.cc

@@ -1,4 +1,5 @@
 #include "tools/cabana/dbc.h"
+#include "tools/cabana/util.h"
 
 uint qHash(const MessageId &item) {
   return qHash(item.source) ^ qHash(item.address);
@@ -12,6 +13,10 @@ std::vector<const cabana::Signal*> cabana::Msg::getSignals() const {
   return ret;
 }
 
+void cabana::Signal::updatePrecision() {
+  precision = std::max(num_decimals(factor), num_decimals(offset));
+}
+
 // helper functions
 
 static QVector<int> BIG_ENDIAN_START_BITS = []() {

tools/cabana/dbc.h

@@ -51,6 +51,8 @@ namespace cabana {
     QString min, max, unit;
     QString comment;
     ValueDescription val_desc;
+    int precision = 0;
+    void updatePrecision();
   };
 
   struct Msg {

tools/cabana/dbcmanager.cc

@@ -38,6 +38,7 @@ bool DBCManager::open(const QString &name, const QString &content, QString *erro
         sig.factor = s.factor;
         sig.offset = s.offset;
         sig.is_little_endian = s.is_little_endian;
+        sig.updatePrecision();
       }
     }
     parseExtraInfo(content);

tools/cabana/historylog.cc

@@ -14,11 +14,14 @@ QVariant HistoryLogModel::data(const QModelIndex &index, int role) const {
     if (index.column() == 0) {
       return QString::number((m.mono_time / (double)1e9) - can->routeStartTime(), 'f', 2);
     }
-    return show_signals ? QString::number(m.sig_values[index.column() - 1]) : toHex(m.data);
+    int i = index.column() - 1;
+    return show_signals ? QString::number(m.sig_values[i], 'f', sigs[i]->precision) : toHex(m.data);
   } else if (role == ColorsRole) {
     return QVariant::fromValue(m.colors);
   } else if (role == BytesRole) {
     return m.data;
+  } else if (role == Qt::TextAlignmentRole) {
+    return Qt::AlignRight;
   }
   return {};
 }
@@ -235,7 +238,7 @@ LogsWidget::LogsWidget(QWidget *parent) : QFrame(parent) {
   delegate = new MessageBytesDelegate(this);
   logs->setItemDelegateForColumn(1, new MessageBytesDelegate(this));
   logs->setHorizontalHeader(new HeaderView(Qt::Horizontal, this));
-  logs->horizontalHeader()->setDefaultAlignment(Qt::AlignLeft | (Qt::Alignment)Qt::TextWordWrap);
+  logs->horizontalHeader()->setDefaultAlignment(Qt::AlignRight | (Qt::Alignment)Qt::TextWordWrap);
   logs->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents);
   logs->verticalHeader()->setVisible(false);
   logs->setFrameShape(QFrame::NoFrame);

tools/cabana/signaledit.cc

@@ -62,7 +62,7 @@ void SignalModel::updateState(const QHash<MessageId, CanData> *msgs) {
     auto &dat = can->lastMessage(msg_id).dat;
     int row = 0;
     for (auto item : root->children) {
-      QString value = QString::number(get_raw_value((uint8_t *)dat.begin(), dat.size(), *item->sig));
+      QString value = QString::number(get_raw_value((uint8_t *)dat.begin(), dat.size(), *item->sig), 'f', item->sig->precision);
       if (!item->sig->unit.isEmpty()){
         value += " " + item->sig->unit;
       }
@@ -184,6 +184,7 @@ bool SignalModel::setData(const QModelIndex &index, const QVariant &value, int r
     case Item::Desc: s.val_desc = value.value<ValueDescription>(); break;
     default: return false;
   }
+  s.updatePrecision();
   bool ret = saveSignal(item->sig, s);
   emit dataChanged(index, index, {Qt::DisplayRole, Qt::EditRole, Qt::CheckStateRole});
   return ret;

tools/cabana/util.cc

@@ -184,3 +184,13 @@ QString toHex(uint8_t byte) {
   }();
   return hex[byte];
 }
+
+int num_decimals(double num) {
+   const QString string = QString::number(num);
+   const QStringList split = string.split('.');
+   if (split.size() == 1) {
+     return 0;
+   } else {
+     return split[1].size();
+   }
+ }

tools/cabana/util.h

@@ -91,3 +91,4 @@ QPixmap icon(const QString &id);
 }
 
 QToolButton *toolButton(const QString &icon, const QString &tooltip);
+int num_decimals(double num);