qt: Skip displayUnitChanged signal if unit is not actually changed

Co-authored-by: João Barbosa <[email protected]>

Author: hebasto

src/qt/optionsmodel.cpp

@@ -519,15 +519,13 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
     return successful;
 }
 
-/** Updates current unit in memory, settings and emits displayUnitChanged(newUnit) signal */
-void OptionsModel::setDisplayUnit(const QVariant &value)
+void OptionsModel::setDisplayUnit(const QVariant& new_unit)
 {
-    if (!value.isNull()) {
-        QSettings settings;
-        m_display_bitcoin_unit = value.value<BitcoinUnit>();
-        settings.setValue("DisplayBitcoinUnit", QVariant::fromValue(m_display_bitcoin_unit));
-        Q_EMIT displayUnitChanged(m_display_bitcoin_unit);
-    }
+    if (new_unit.isNull() || new_unit.value<BitcoinUnit>() == m_display_bitcoin_unit) return;
+    m_display_bitcoin_unit = new_unit.value<BitcoinUnit>();
+    QSettings settings;
+    settings.setValue("DisplayBitcoinUnit", QVariant::fromValue(m_display_bitcoin_unit));
+    Q_EMIT displayUnitChanged(m_display_bitcoin_unit);
 }
 
 void OptionsModel::setRestartRequired(bool fRequired)

src/qt/optionsmodel.h

@@ -77,8 +77,8 @@ class OptionsModel : public QAbstractListModel
     int rowCount(const QModelIndex & parent = QModelIndex()) const override;
     QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const override;
     bool setData(const QModelIndex & index, const QVariant & value, int role = Qt::EditRole) override;
-    /** Updates current unit in memory, settings and emits displayUnitChanged(newUnit) signal */
-    void setDisplayUnit(const QVariant &value);
+    /** Updates current unit in memory, settings and emits displayUnitChanged(new_unit) signal */
+    void setDisplayUnit(const QVariant& new_unit);
 
     /* Explicit getters */
     bool getShowTrayIcon() const { return m_show_tray_icon; }