1 files changed, 39 insertions, 0 deletions
diff --git a/src/ui/widget/preferences-widget.cpp b/src/ui/widget/preferences-widget.cpp
index f92e2518d..9cf80153a 100644
--- a/src/ui/widget/preferences-widget.cpp
+++ b/src/ui/widget/preferences-widget.cpp
@@ -255,6 +255,45 @@ void PrefSpinButton::on_value_changed()
     }
 }
 
+void PrefSpinUnit::init(Glib::ustring const &prefs_path,
+              double lower, double upper, double step_increment,
+              double default_value, UnitType unit_type, Glib::ustring const &default_unit)
+{
+    _prefs_path = prefs_path;
+    _is_percent = (unit_type == UNIT_TYPE_DIMENSIONLESS);
+
+    setUnitType(unit_type);
+    setUnit(default_unit);
+    setRange (lower, upper); /// @fixme  this disregards changes of units
+    setIncrements (step_increment, 0);
+    if (step_increment < 0.1) {
+        setDigits(4);
+    } else {
+        setDigits(2);
+    }
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    double value = prefs->getDoubleLimited(prefs_path, default_value, lower, upper);
+    Glib::ustring unitstr = prefs->getUnit(prefs_path);
+    if (unitstr.length() == 0) {
+        unitstr = default_unit;
+        // write the assumed unit to preferences:
+        prefs->setDoubleUnit(_prefs_path, value, unitstr);
+    }
+    setValue(value, unitstr);
+
+    signal_value_changed().connect_notify(sigc::mem_fun(*this, &PrefSpinUnit::on_my_value_changed));
+}
+
+void PrefSpinUnit::on_my_value_changed()
+{
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (getWidget()->is_visible()) //only take action if user changed value
+    {
+        prefs->setDoubleUnit(_prefs_path, getValue(getUnit().abbr), getUnit().abbr);
+    }
+}
+
 const double ZoomCorrRuler::textsize = 7;
 const double ZoomCorrRuler::textpadding = 5;