6 files changed, 87 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;
 
diff --git a/src/ui/widget/preferences-widget.h b/src/ui/widget/preferences-widget.h
index 758ab38cd..6caab11ae 100644
--- a/src/ui/widget/preferences-widget.h
+++ b/src/ui/widget/preferences-widget.h
@@ -33,6 +33,7 @@
 #include "ui/widget/color-picker.h"
 #include "ui/widget/unit-menu.h"
 #include "ui/widget/spinbutton.h"
+#include "ui/widget/scalar-unit.h"
 
 namespace Inkscape {
 namespace UI {
@@ -82,6 +83,21 @@ protected:
     void on_value_changed();
 };
 
+class PrefSpinUnit : public ScalarUnit
+{
+public:
+    PrefSpinUnit() : ScalarUnit("", "") {};
+
+    void init(Glib::ustring const &prefs_path,
+              double lower, double upper, double step_increment,
+              double default_value,
+              UnitType unit_type, Glib::ustring const &default_unit);
+protected:
+    Glib::ustring _prefs_path;
+    bool _is_percent;
+    void on_my_value_changed();
+};
+
 class ZoomCorrRuler : public Gtk::DrawingArea {
 public:
     ZoomCorrRuler(int width = 100, int height = 20);
diff --git a/src/ui/widget/scalar-unit.cpp b/src/ui/widget/scalar-unit.cpp
index e713f3e06..1c0fdff68 100644
--- a/src/ui/widget/scalar-unit.cpp
+++ b/src/ui/widget/scalar-unit.cpp
@@ -130,6 +130,22 @@ ScalarUnit::setUnit(Glib::ustring const &unit) {
     return true;
 }
 
+/** Adds the unit type to the ScalarUnit widget */
+void
+ScalarUnit::setUnitType(UnitType unit_type) {
+    g_assert(_unit_menu != NULL);
+    _unit_menu->setUnitType(unit_type);
+    lastUnits = _unit_menu->getUnitAbbr();
+}
+
+/** Resets the unit type for the ScalarUnit widget */
+void
+ScalarUnit::resetUnitType(UnitType unit_type) {
+    g_assert(_unit_menu != NULL);
+    _unit_menu->resetUnitType(unit_type);
+    lastUnits = _unit_menu->getUnitAbbr();
+}
+
 /** Gets the object for the currently selected unit */
 Unit
 ScalarUnit::getUnit() const {
diff --git a/src/ui/widget/scalar-unit.h b/src/ui/widget/scalar-unit.h
index 4e08d63f4..ed3728e69 100644
--- a/src/ui/widget/scalar-unit.h
+++ b/src/ui/widget/scalar-unit.h
@@ -45,6 +45,8 @@ public:
     double    getValue(Glib::ustring const &units) const;
 
     bool      setUnit(Glib::ustring const &units);
+    void      setUnitType(UnitType unit_type);
+    void      resetUnitType(UnitType unit_type);
     void      setValue(double number, Glib::ustring const &units);
     void      setValueKeepUnit(double number, Glib::ustring const &units);
     void      setValue(double number);
diff --git a/src/ui/widget/unit-menu.cpp b/src/ui/widget/unit-menu.cpp
index b4271762c..5c68f7196 100644
--- a/src/ui/widget/unit-menu.cpp
+++ b/src/ui/widget/unit-menu.cpp
@@ -54,6 +54,19 @@ UnitMenu::setUnitType(UnitType unit_type)
     return true;
 }
 
+/** Removes all unit entries, then adds the unit type to the widget.
+    This extracts the corresponding
+    units from the unit map matching the given type, and appends them
+    to the dropdown widget.  It causes the primary unit for the given
+    unit_type to be selected.  */
+bool
+UnitMenu::resetUnitType(UnitType unit_type) 
+{
+    clear_text();
+
+    return setUnitType(unit_type);
+}
+
 /** Returns the Unit object corresponding to the current selection
     in the dropdown widget */
 Unit
diff --git a/src/ui/widget/unit-menu.h b/src/ui/widget/unit-menu.h
index 60a9702b4..efeb10ead 100644
--- a/src/ui/widget/unit-menu.h
+++ b/src/ui/widget/unit-menu.h
@@ -28,6 +28,7 @@ public:
     virtual ~UnitMenu();
 
     bool          setUnitType(UnitType unit_type);
+    bool          resetUnitType(UnitType unit_type);
 
     bool          setUnit(Glib::ustring const &unit);