Merge Google Summer of Code unit refactor.

(bzr r12471)

31 files changed, 223 insertions, 381 deletions

diff --git a/src/widgets/arc-toolbar.cpp b/src/widgets/arc-toolbar.cpp
index 809050ad9..42f696bec 100644
--- a/src/widgets/arc-toolbar.cpp
+++ b/src/widgets/arc-toolbar.cpp
@@ -56,14 +56,10 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-ellipse.h"
 #include "../mod360.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -341,7 +337,7 @@ void sp_arc_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObjec
                                          _("Start"), _("Start:"),
                                          _("The angle (in degrees) from the horizontal to the arc's start point"),
                                          "/tools/shapes/arc/start", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, TRUE, "altx-arc",
+                                         GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-arc",
                                          -360.0, 360.0, 1.0, 10.0,
                                          0, 0, 0,
                                          sp_arctb_start_value_changed);
@@ -354,7 +350,7 @@ void sp_arc_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObjec
                                          _("End"), _("End:"),
                                          _("The angle (in degrees) from the horizontal to the arc's end point"),
                                          "/tools/shapes/arc/end", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -360.0, 360.0, 1.0, 10.0,
                                          0, 0, 0,
                                          sp_arctb_end_value_changed);
diff --git a/src/widgets/box3d-toolbar.cpp b/src/widgets/box3d-toolbar.cpp
index e8b330375..91d4ebdec 100644
--- a/src/widgets/box3d-toolbar.cpp
+++ b/src/widgets/box3d-toolbar.cpp
@@ -58,16 +58,11 @@
 
 #include "../ui/icon-names.h"
 
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
-
 #include "../pen-context.h"
 
 #include "../box3d-context.h"
 #include "../box3d.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -321,7 +316,7 @@ void box3d_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObject
                                          // Translators: PL is short for 'perspective line'
                                          _("Angle of PLs in X direction"),
                                          "/tools/shapes/3dbox/box3d_angle_x", 30,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-box3d",
+                                         GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-box3d",
                                          -360.0, 360.0, 1.0, 10.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          box3d_angle_x_value_changed );
@@ -361,7 +356,7 @@ void box3d_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObject
                                          // Translators: PL is short for 'perspective line'
                                          _("Angle of PLs in Y direction"),
                                          "/tools/shapes/3dbox/box3d_angle_y", 30,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -360.0, 360.0, 1.0, 10.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          box3d_angle_y_value_changed );
@@ -400,7 +395,7 @@ void box3d_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObject
                                          // Translators: PL is short for 'perspective line'
                                          _("Angle of PLs in Z direction"),
                                          "/tools/shapes/3dbox/box3d_angle_z", 30,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -360.0, 360.0, 1.0, 10.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          box3d_angle_z_value_changed );
diff --git a/src/widgets/calligraphy-toolbar.cpp b/src/widgets/calligraphy-toolbar.cpp
index 4cb4813b5..1f91b9fe2 100644
--- a/src/widgets/calligraphy-toolbar.cpp
+++ b/src/widgets/calligraphy-toolbar.cpp
@@ -56,13 +56,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 
 #include "../pen-context.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -451,7 +447,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Pen Width"), _("Width:"),
                                                               _("The width of the calligraphic pen (relative to the visible canvas area)"),
                                                               "/tools/calligraphic/width", 15,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-calligraphy",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-calligraphy",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_width_value_changed,  1, 0 );
@@ -468,7 +464,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Stroke Thinning"), _("Thinning:"),
                                                               _("How much velocity thins the stroke (> 0 makes fast strokes thinner, < 0 makes them broader, 0 makes width independent of velocity)"),
                                                               "/tools/calligraphic/thinning", 10,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               -100, 100, 1, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_velthin_value_changed, 1, 0);
@@ -484,7 +480,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Pen Angle"), _("Angle:"),
                                                               _("The angle of the pen's nib (in degrees; 0 = horizontal; has no effect if fixation = 0)"),
                                                               "/tools/calligraphic/angle", 30,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "calligraphy-angle",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "calligraphy-angle",
                                                               -90.0, 90.0, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_angle_value_changed, 1, 0 );
@@ -502,7 +498,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Fixation"), _("Fixation:"),
                                                               _("Angle behavior (0 = nib always perpendicular to stroke direction, 100 = fixed angle)"),
                                                               "/tools/calligraphic/flatness", 90,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               0.0, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_flatness_value_changed, 1, 0);
@@ -519,7 +515,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Cap rounding"), _("Caps:"),
                                                               _("Increase to make caps at the ends of strokes protrude more (0 = no caps, 1 = round caps)"),
                                                               "/tools/calligraphic/cap_rounding", 0.0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               0.0, 5.0, 0.01, 0.1,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_cap_rounding_value_changed, 0.01, 2 );
@@ -535,7 +531,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Stroke Tremor"), _("Tremor:"),
                                                               _("Increase to make strokes rugged and trembling"),
                                                               "/tools/calligraphic/tremor", 0.0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               0.0, 100, 1, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_tremor_value_changed, 1, 0);
@@ -553,7 +549,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Pen Wiggle"), _("Wiggle:"),
                                                               _("Increase to make the pen waver and wiggle"),
                                                               "/tools/calligraphic/wiggle", 0.0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               0.0, 100, 1, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_wiggle_value_changed, 1, 0);
@@ -570,7 +566,7 @@ void sp_calligraphy_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
                                                               _("Pen Mass"), _("Mass:"),
                                                               _("Increase to make the pen drag behind, as if slowed by inertia"),
                                                               "/tools/calligraphic/mass", 2.0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                                              GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                                               0.0, 100, 1, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_ddc_mass_value_changed, 1, 0);
diff --git a/src/widgets/connector-toolbar.cpp b/src/widgets/connector-toolbar.cpp
index 7c72f8e0c..54344e446 100644
--- a/src/widgets/connector-toolbar.cpp
+++ b/src/widgets/connector-toolbar.cpp
@@ -55,9 +55,6 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
 #include "../conn-avoid-ref.h"
@@ -66,7 +63,6 @@
 #include "../sp-path.h"
 
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -365,7 +361,7 @@ void sp_connector_toolbox_prep( SPDesktop *desktop, GtkActionGroup* mainActions,
                                     _("Connector Curvature"), _("Curvature:"),
                                     _("The amount of connectors curvature"),
                                     "/tools/connector/curvature", defaultConnCurvature,
-                                    GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "inkscape:connector-curvature",
+                                    GTK_WIDGET(desktop->canvas), holder, TRUE, "inkscape:connector-curvature",
                                     0, 100, 1.0, 10.0,
                                     0, 0, 0,
                                     connector_curvature_changed, 1, 0 );
@@ -376,7 +372,7 @@ void sp_connector_toolbox_prep( SPDesktop *desktop, GtkActionGroup* mainActions,
                                     _("Connector Spacing"), _("Spacing:"),
                                     _("The amount of space left around objects by auto-routing connectors"),
                                     "/tools/connector/spacing", defaultConnSpacing,
-                                    GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "inkscape:connector-spacing",
+                                    GTK_WIDGET(desktop->canvas), holder, TRUE, "inkscape:connector-spacing",
                                     0, 100, 1.0, 10.0,
                                     0, 0, 0,
                                     connector_spacing_changed, 1, 0 );
@@ -398,7 +394,7 @@ void sp_connector_toolbox_prep( SPDesktop *desktop, GtkActionGroup* mainActions,
                                      _("Connector Length"), _("Length:"),
                                      _("Ideal length for connectors when layout is applied"),
                                      "/tools/connector/length", 100,
-                                     GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "inkscape:connector-length",
+                                     GTK_WIDGET(desktop->canvas), holder, TRUE, "inkscape:connector-length",
                                      10, 1000, 10.0, 100.0,
                                      0, 0, 0,
                                      connector_length_changed, 1, 0 );
diff --git a/src/widgets/desktop-widget.cpp b/src/widgets/desktop-widget.cpp
index c1214c1a4..6493da84d 100644
--- a/src/widgets/desktop-widget.cpp
+++ b/src/widgets/desktop-widget.cpp
@@ -43,8 +43,8 @@
 #include "file.h"
 #include "helper/action.h"
 #include "helper/action-context.h"
-#include "helper/units.h"
-#include "helper/unit-tracker.h"
+#include "util/units.h"
+#include "ui/widget/unit-tracker.h"
 #include "inkscape-private.h"
 #include "interface.h"
 #include "macros.h"
@@ -79,10 +79,11 @@
 using Inkscape::round;
 #endif
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::UI::ToolboxFactory;
 using ege::AppearTimeTracker;
+using Inkscape::Util::unit_table;
 
 enum {
     ACTIVATE,
@@ -393,8 +394,9 @@ void SPDesktopWidget::init( SPDesktopWidget *dtw )
     GtkWidget *eventbox = gtk_event_box_new ();
     dtw->hruler = sp_ruler_new(GTK_ORIENTATION_HORIZONTAL);
     dtw->hruler_box = eventbox;
-    sp_ruler_set_unit(SP_RULER(dtw->hruler), SP_PT);
-    gtk_widget_set_tooltip_text (dtw->hruler_box, gettext(sp_unit_get_plural (&sp_unit_get_by_id(SP_UNIT_PT))));
+    Inkscape::Util::Unit pt = unit_table.getUnit("pt");
+    sp_ruler_set_unit(SP_RULER(dtw->hruler), pt);
+    gtk_widget_set_tooltip_text (dtw->hruler_box, gettext(pt.name_plural.c_str()));
     gtk_container_add (GTK_CONTAINER (eventbox), dtw->hruler);
     g_signal_connect (G_OBJECT (eventbox), "button_press_event", G_CALLBACK (sp_dt_hruler_event), dtw);
     g_signal_connect (G_OBJECT (eventbox), "button_release_event", G_CALLBACK (sp_dt_hruler_event), dtw);
@@ -422,8 +424,8 @@ void SPDesktopWidget::init( SPDesktopWidget *dtw )
     eventbox = gtk_event_box_new ();
     dtw->vruler = sp_ruler_new(GTK_ORIENTATION_VERTICAL);
     dtw->vruler_box = eventbox;
-    sp_ruler_set_unit (SP_RULER (dtw->vruler), SP_PT);
-    gtk_widget_set_tooltip_text (dtw->vruler_box, gettext(sp_unit_get_plural (&sp_unit_get_by_id(SP_UNIT_PT))));
+    sp_ruler_set_unit (SP_RULER (dtw->vruler), pt);
+    gtk_widget_set_tooltip_text (dtw->vruler_box, gettext(pt.name_plural.c_str()));
     gtk_container_add (GTK_CONTAINER (eventbox), GTK_WIDGET (dtw->vruler));
 
 #if GTK_CHECK_VERSION(3,0,0)
@@ -1674,7 +1676,7 @@ SPDesktopWidget* SPDesktopWidget::createInstance(SPNamedView *namedview)
 {
     SPDesktopWidget *dtw = static_cast<SPDesktopWidget*>(g_object_new(SP_TYPE_DESKTOP_WIDGET, NULL));
 
-    dtw->dt2r = 1.0 / namedview->doc_units->unittobase;
+    dtw->dt2r = 1. / namedview->doc_units->factor;
 
     dtw->ruler_origin = Geom::Point(0,0); //namedview->gridorigin;   Why was the grid origin used here?
 
@@ -1746,11 +1748,11 @@ void SPDesktopWidget::namedviewModified(SPObject *obj, guint flags)
     SPNamedView *nv=SP_NAMEDVIEW(obj);
 
     if (flags & SP_OBJECT_MODIFIED_FLAG) {
-        this->dt2r = 1.0 / nv->doc_units->unittobase;
+        this->dt2r = 1. / nv->doc_units->factor;
         this->ruler_origin = Geom::Point(0,0); //nv->gridorigin;   Why was the grid origin used here?
 
-        sp_ruler_set_unit(SP_RULER (this->vruler), nv->getDefaultMetric());
-        sp_ruler_set_unit(SP_RULER (this->hruler), nv->getDefaultMetric());
+        sp_ruler_set_unit(SP_RULER (this->vruler), nv->getDefaultUnit());
+        sp_ruler_set_unit(SP_RULER (this->hruler), nv->getDefaultUnit());
 
         /* This loops through all the grandchildren of aux toolbox,
          * and for each that it finds, it performs an sp_search_by_data_recursive(),
@@ -1786,8 +1788,8 @@ void SPDesktopWidget::namedviewModified(SPObject *obj, guint flags)
             } // children
         } // if aux_toolbox is a container
 
-        gtk_widget_set_tooltip_text(this->hruler_box, gettext(sp_unit_get_plural (nv->doc_units)));
-        gtk_widget_set_tooltip_text(this->vruler_box, gettext(sp_unit_get_plural (nv->doc_units)));
+        gtk_widget_set_tooltip_text(this->hruler_box, gettext(nv->doc_units->name_plural.c_str()));
+        gtk_widget_set_tooltip_text(this->vruler_box, gettext(nv->doc_units->name_plural.c_str()));
 
         sp_desktop_widget_update_rulers(this);
         ToolboxFactory::updateSnapToolbox(this->desktop, 0, this->snap_toolbox);
diff --git a/src/widgets/dropper-toolbar.cpp b/src/widgets/dropper-toolbar.cpp
index cf58aa507..054955d8f 100644
--- a/src/widgets/dropper-toolbar.cpp
+++ b/src/widgets/dropper-toolbar.cpp
@@ -54,13 +54,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../tools-switch.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
diff --git a/src/widgets/eraser-toolbar.cpp b/src/widgets/eraser-toolbar.cpp
index aca960c00..3f5e60780 100644
--- a/src/widgets/eraser-toolbar.cpp
+++ b/src/widgets/eraser-toolbar.cpp
@@ -55,13 +55,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -149,7 +145,7 @@ void sp_eraser_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
                                                               _("Pen Width"), _("Width:"),
                                                               _("The width of the eraser pen (relative to the visible canvas area)"),
                                                               "/tools/eraser/width", 15,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-eraser",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-eraser",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_erc_width_value_changed, 1, 0);
diff --git a/src/widgets/font-selector.cpp b/src/widgets/font-selector.cpp
index 7fa848f1e..5f9098d44 100644
--- a/src/widgets/font-selector.cpp
+++ b/src/widgets/font-selector.cpp
@@ -33,7 +33,6 @@
 #include "desktop.h"
 #include "widgets/font-selector.h"
 #include "preferences.h"
-#include "unit-constants.h"
 
 /* SPFontSelector */
 
diff --git a/src/widgets/gradient-toolbar.cpp b/src/widgets/gradient-toolbar.cpp
index ea125a380..c1eb13ceb 100644
--- a/src/widgets/gradient-toolbar.cpp
+++ b/src/widgets/gradient-toolbar.cpp
@@ -1171,7 +1171,7 @@ void sp_gradient_toolbox_prep(SPDesktop * desktop, GtkActionGroup* mainActions,
         eact = create_adjustment_action( "GradientEditOffsetAction",
                                          _("Offset"), _("Offset:"), _("Offset of selected stop"),
                                          "/tools/gradient/stopoffset", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0.0, 1.0, 0.01, 0.1,
                                          0, 0, 0,
                                          gr_stop_offset_adjustment_changed
diff --git a/src/widgets/lpe-toolbar.cpp b/src/widgets/lpe-toolbar.cpp
index c7659ab42..55cce90cd 100644
--- a/src/widgets/lpe-toolbar.cpp
+++ b/src/widgets/lpe-toolbar.cpp
@@ -57,9 +57,8 @@
 #include "../ui/icon-names.h"
 #include "../helper/action.h"
 #include "../helper/action-context.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
+#include "util/units.h"
+#include "ui/widget/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
 #include "../tools-switch.h"
@@ -67,7 +66,9 @@
 #include "../live_effects/lpe-angle_bisector.h"
 #include "../lpe-tool-context.h"
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
+using Inkscape::Util::Unit;
+using Inkscape::Util::Quantity;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -197,9 +198,9 @@ static void lpetool_toggle_show_measuring_info(GtkToggleAction *act, GObject *tb
 static void lpetool_unit_changed(GtkAction* /*act*/, GObject* tbl)
 {
     UnitTracker* tracker = reinterpret_cast<UnitTracker*>(g_object_get_data(tbl, "tracker"));
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    prefs->setInt("/tools/lpetool/unitid", unit->unit_id);
+    prefs->setString("/tools/lpetool/unit", unit.abbr);
 
     SPDesktop *desktop = static_cast<SPDesktop *>(g_object_get_data( tbl, "desktop" ));
     if (SP_IS_LPETOOL_CONTEXT(desktop->event_context)) {
@@ -295,13 +296,13 @@ static void lpetool_open_lpe_dialog(GtkToggleAction *act, gpointer data)
 
 void sp_lpetool_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObject* holder)
 {
-    UnitTracker* tracker = new UnitTracker(SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE);
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
     tracker->setActiveUnit(sp_desktop_namedview(desktop)->doc_units);
     g_object_set_data(holder, "tracker", tracker);
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    prefs->setInt("/tools/lpetool/unitid", unit->unit_id);
+    prefs->setString("/tools/lpetool/unit", unit.abbr);
 
     /** Automatically create a list of LPEs that get added to the toolbar **/
     {
diff --git a/src/widgets/measure-toolbar.cpp b/src/widgets/measure-toolbar.cpp
index 21df4c6d9..53ed2d275 100644
--- a/src/widgets/measure-toolbar.cpp
+++ b/src/widgets/measure-toolbar.cpp
@@ -52,13 +52,12 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
+#include "ui/widget/unit-tracker.h"
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
+using Inkscape::Util::Unit;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -83,15 +82,17 @@ sp_measure_fontsize_value_changed(GtkAdjustment *adj, GObject *tbl)
 static void measure_unit_changed(GtkAction* /*act*/, GObject* tbl)
 {
     UnitTracker* tracker = reinterpret_cast<UnitTracker*>(g_object_get_data(tbl, "tracker"));
-    SPUnit const *unit = tracker->getActiveUnit();
+    Glib::ustring const unit = tracker->getActiveUnit().abbr;
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-    prefs->setInt("/tools/measure/unitid", unit->unit_id);
+    prefs->setString("/tools/measure/unit", unit);
 }
 
 void sp_measure_toolbox_prep(SPDesktop * desktop, GtkActionGroup* mainActions, GObject* holder)
 {
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
-    tracker->setActiveUnit( sp_desktop_namedview(desktop)->doc_units );
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    tracker->setActiveUnitByAbbr(prefs->getString("/tools/measure/unit").c_str());
+    
     g_object_set_data( holder, "tracker", tracker );
 
     EgeAdjustmentAction *eact = 0;
@@ -102,7 +103,7 @@ void sp_measure_toolbox_prep(SPDesktop * desktop, GtkActionGroup* mainActions, G
                                          _("Font Size"), _("Font Size:"),
                                          _("The font size to be used in the measurement labels"),
                                          "/tools/measure/fontsize", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          10, 36, 1.0, 4.0,
                                          0, 0, 0,
                                          sp_measure_fontsize_value_changed);
diff --git a/src/widgets/mesh-toolbar.cpp b/src/widgets/mesh-toolbar.cpp
index 99a34fbda..37763ab34 100644
--- a/src/widgets/mesh-toolbar.cpp
+++ b/src/widgets/mesh-toolbar.cpp
@@ -262,7 +262,7 @@ void sp_mesh_toolbox_prep(SPDesktop * desktop, GtkActionGroup* mainActions, GObj
         eact = create_adjustment_action( "MeshRowAction",
                                          _("Rows"), _("Rows:"), _("Number of rows in new mesh"),
                                          "/tools/mesh/mesh_rows", 1,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          1, 20, 1, 1,
                                          labels, values, G_N_ELEMENTS(labels),
                                          ms_row_changed,
@@ -278,7 +278,7 @@ void sp_mesh_toolbox_prep(SPDesktop * desktop, GtkActionGroup* mainActions, GObj
         eact = create_adjustment_action( "MeshColumnAction",
                                          _("Columns"), _("Columns:"), _("Number of columns in new mesh"),
                                          "/tools/mesh/mesh_cols", 1,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          1, 20, 1, 1,
                                          labels, values, G_N_ELEMENTS(labels),
                                          ms_col_changed,
diff --git a/src/widgets/node-toolbar.cpp b/src/widgets/node-toolbar.cpp
index 849de874d..a9e298f1d 100644
--- a/src/widgets/node-toolbar.cpp
+++ b/src/widgets/node-toolbar.cpp
@@ -58,17 +58,19 @@
 #include "../ui/tool/node-tool.h"
 #include "../ui/tool/multi-path-manipulator.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
+#include "util/units.h"
+#include "ui/widget/unit-tracker.h"
 #include "../lpe-tool-context.h"
 #include "../sp-namedview.h"
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
+using Inkscape::Util::Unit;
+using Inkscape::Util::Quantity;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
 using Inkscape::UI::PrefPusher;
+using Inkscape::Util::unit_table;
 
 //####################################
 //# node editing callbacks
@@ -238,7 +240,7 @@ static void sp_node_toolbox_coord_changed(gpointer /*shape_editor*/, GObject *tb
     if (!tracker) {
         return;
     }
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     InkNodeTool *nt = get_node_tool();
     if (!nt || nt->_selected_nodes->empty()) {
@@ -248,15 +250,15 @@ static void sp_node_toolbox_coord_changed(gpointer /*shape_editor*/, GObject *tb
     } else {
         gtk_action_set_sensitive(xact, TRUE);
         gtk_action_set_sensitive(yact, TRUE);
-        Geom::Coord oldx = sp_units_get_pixels(gtk_adjustment_get_value(xadj), *unit);
-        Geom::Coord oldy = sp_units_get_pixels(gtk_adjustment_get_value(xadj), *unit);
+        Geom::Coord oldx = Quantity::convert(gtk_adjustment_get_value(xadj), unit, "px");
+        Geom::Coord oldy = Quantity::convert(gtk_adjustment_get_value(yadj), unit, "px");
         Geom::Point mid = nt->_selected_nodes->pointwiseBounds()->midpoint();
 
         if (oldx != mid[Geom::X]) {
-            gtk_adjustment_set_value(xadj, sp_pixels_get_units(mid[Geom::X], *unit));
+            gtk_adjustment_set_value(xadj, Quantity::convert(mid[Geom::X], "px", unit));
         }
         if (oldy != mid[Geom::Y]) {
-            gtk_adjustment_set_value(yadj, sp_pixels_get_units(mid[Geom::Y], *unit));
+            gtk_adjustment_set_value(yadj, Quantity::convert(mid[Geom::Y], "px", unit));
         }
     }
 
@@ -272,11 +274,11 @@ static void sp_node_path_value_changed(GtkAdjustment *adj, GObject *tbl, Geom::D
     if (!tracker) {
         return;
     }
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     if (DocumentUndo::getUndoSensitive(sp_desktop_document(desktop))) {
         prefs->setDouble(Glib::ustring("/tools/nodes/") + (d == Geom::X ? "x" : "y"),
-            sp_units_get_pixels(gtk_adjustment_get_value(adj), *unit));
+            Quantity::convert(gtk_adjustment_get_value(adj), unit, "px"));
     }
 
     // quit if run by the attr_changed listener
@@ -289,7 +291,7 @@ static void sp_node_path_value_changed(GtkAdjustment *adj, GObject *tbl, Geom::D
 
     InkNodeTool *nt = get_node_tool();
     if (nt && !nt->_selected_nodes->empty()) {
-        double val = sp_units_get_pixels(gtk_adjustment_get_value(adj), *unit);
+        double val = Quantity::convert(gtk_adjustment_get_value(adj), unit, "px");
         double oldval = nt->_selected_nodes->pointwiseBounds()->midpoint()[d];
         Geom::Point delta(0,0);
         delta[d] = val - oldval;
@@ -339,8 +341,9 @@ static void sp_node_toolbox_sel_modified(Inkscape::Selection *selection, guint /
 
 void sp_node_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObject* holder)
 {
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
-    tracker->setActiveUnit( sp_desktop_namedview(desktop)->doc_units );
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
+    Unit doc_units = *sp_desktop_namedview(desktop)->doc_units;
+    tracker->setActiveUnit(&doc_units);
     g_object_set_data( holder, "tracker", tracker );
 
     Inkscape::IconSize secondarySize = ToolboxFactory::prefToSize("/toolbox/secondary", 1);
@@ -589,7 +592,7 @@ void sp_node_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "NodeXAction",
                                          _("X coordinate:"), _("X:"), _("X coordinate of selected node(s)"),
                                          "/tools/nodes/Xcoord", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, TRUE, "altx-nodes",
+                                         GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-nodes",
                                          -1e6, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_node_path_x_value_changed );
@@ -607,7 +610,7 @@ void sp_node_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "NodeYAction",
                                          _("Y coordinate:"), _("Y:"), _("Y coordinate of selected node(s)"),
                                          "/tools/nodes/Ycoord", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -1e6, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_node_path_y_value_changed );
diff --git a/src/widgets/paintbucket-toolbar.cpp b/src/widgets/paintbucket-toolbar.cpp
index 73815b86d..7c23379cd 100644
--- a/src/widgets/paintbucket-toolbar.cpp
+++ b/src/widgets/paintbucket-toolbar.cpp
@@ -54,9 +54,8 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
+#include "util/units.h"
+#include "ui/widget/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
 #include "../flood-context.h"
@@ -64,11 +63,12 @@
 #include <gtk/gtk.h>
 
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
 using Inkscape::UI::PrefPusher;
+using Inkscape::Util::unit_table;
 
 
 
@@ -97,13 +97,13 @@ static void paintbucket_autogap_changed(EgeSelectOneAction* act, GObject * /*tbl
 static void paintbucket_offset_changed(GtkAdjustment *adj, GObject *tbl)
 {
     UnitTracker* tracker = static_cast<UnitTracker*>(g_object_get_data( tbl, "tracker" ));
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 
     // Don't adjust the offset value because we're saving the
     // unit and it'll be correctly handled on load.
     prefs->setDouble("/tools/paintbucket/offset", (gdouble)gtk_adjustment_get_value(adj));
-    prefs->setString("/tools/paintbucket/offsetunits", sp_unit_get_abbreviation(unit));
+    prefs->setString("/tools/paintbucket/offsetunits", unit.abbr);
 }
 
 static void paintbucket_defaults(GtkWidget *, GObject *tbl)
@@ -165,7 +165,7 @@ void sp_paintbucket_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
             "ThresholdAction",
             _("Fill Threshold"), _("Threshold:"),
             _("The maximum allowed difference between the clicked pixel and the neighboring pixels to be counted in the fill"),
-            "/tools/paintbucket/threshold", 5, GTK_WIDGET(desktop->canvas), NULL, holder, TRUE,
+            "/tools/paintbucket/threshold", 5, GTK_WIDGET(desktop->canvas), holder, TRUE,
             "inkscape:paintbucket-threshold", 0, 100.0, 1.0, 10.0,
             0, 0, 0,
             paintbucket_threshold_changed, 1, 0 );
@@ -175,10 +175,11 @@ void sp_paintbucket_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
     }
 
     // Create the units menu.
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
     Glib::ustring stored_unit = prefs->getString("/tools/paintbucket/offsetunits");
     if (!stored_unit.empty()) {
-        tracker->setActiveUnit(sp_unit_get_by_abbreviation(stored_unit.data()));
+        Unit u = unit_table.getUnit(stored_unit);
+        tracker->setActiveUnit(&u);
     }
     g_object_set_data( holder, "tracker", tracker );
     {
@@ -192,7 +193,7 @@ void sp_paintbucket_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions
             "OffsetAction",
             _("Grow/shrink by"), _("Grow/shrink by:"),
             _("The amount to grow (positive) or shrink (negative) the created fill path"),
-            "/tools/paintbucket/offset", 0, GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, TRUE,
+            "/tools/paintbucket/offset", 0, GTK_WIDGET(desktop->canvas), holder, TRUE,
             "inkscape:paintbucket-offset", -1e4, 1e4, 0.1, 0.5,
             0, 0, 0,
             paintbucket_offset_changed, 1, 2);
diff --git a/src/widgets/pencil-toolbar.cpp b/src/widgets/pencil-toolbar.cpp
index e0cf67bd0..851ad7134 100644
--- a/src/widgets/pencil-toolbar.cpp
+++ b/src/widgets/pencil-toolbar.cpp
@@ -67,15 +67,10 @@
 //#include "../ui/tool/multi-path-manipulator.h"
 #include "../ui/icon-names.h"
 
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
-
 #include "../pen-context.h"
 //#include "../sp-namedview.h"
 #include "../tools-switch.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -307,7 +302,7 @@ void sp_pencil_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
                  _("How much smoothing (simplifying) is applied to the line"),
                                          "/tools/freehand/pencil/tolerance",
                                          3.0,
-                                         GTK_WIDGET(desktop->canvas), NULL,
+                                         GTK_WIDGET(desktop->canvas),
                                          holder, TRUE, "altx-pencil",
                                          1, 100.0, 0.5, 1.0,
                                          labels, values, G_N_ELEMENTS(labels),
diff --git a/src/widgets/rect-toolbar.cpp b/src/widgets/rect-toolbar.cpp
index 8c1a735c5..6dfd9cfcb 100644
--- a/src/widgets/rect-toolbar.cpp
+++ b/src/widgets/rect-toolbar.cpp
@@ -53,18 +53,20 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
+#include "util/units.h"
+#include "ui/widget/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
 #include "../sp-rect.h"
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
 using Inkscape::UI::PrefPusher;
+using Inkscape::Util::Unit;
+using Inkscape::Util::Quantity;
+using Inkscape::Util::unit_table;
 
 
 //########################
@@ -91,12 +93,12 @@ static void sp_rtb_value_changed(GtkAdjustment *adj, GObject *tbl, gchar const *
     SPDesktop *desktop = static_cast<SPDesktop *>(g_object_get_data( tbl, "desktop" ));
 
     UnitTracker* tracker = reinterpret_cast<UnitTracker*>(g_object_get_data( tbl, "tracker" ));
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     if (DocumentUndo::getUndoSensitive(sp_desktop_document(desktop))) {
         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
         prefs->setDouble(Glib::ustring("/tools/shapes/rect/") + value_name,
-            sp_units_get_pixels(gtk_adjustment_get_value(adj), *unit));
+            Quantity::convert(gtk_adjustment_get_value(adj), unit, "px"));
     }
 
     // quit if run by the attr_changed listener
@@ -113,7 +115,7 @@ static void sp_rtb_value_changed(GtkAdjustment *adj, GObject *tbl, gchar const *
         if (SP_IS_RECT(items->data)) {
             if (gtk_adjustment_get_value(adj) != 0) {
                 setter(SP_RECT(items->data),
-                sp_units_get_pixels(gtk_adjustment_get_value(adj), *unit));
+                Quantity::convert(gtk_adjustment_get_value(adj), unit, "px"));
             } else {
                 SP_OBJECT(items->data)->getRepr()->setAttribute(value_name, NULL);
             }
@@ -184,32 +186,32 @@ static void rect_tb_event_attr_changed(Inkscape::XML::Node * /*repr*/, gchar con
     g_object_set_data( tbl, "freeze", GINT_TO_POINTER(TRUE) );
 
     UnitTracker* tracker = reinterpret_cast<UnitTracker*>( g_object_get_data( tbl, "tracker" ) );
-    SPUnit const *unit = tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     gpointer item = g_object_get_data( tbl, "item" );
     if (item && SP_IS_RECT(item)) {
         {
             GtkAdjustment *adj = GTK_ADJUSTMENT( g_object_get_data( tbl, "rx" ) );
             gdouble rx = sp_rect_get_visible_rx(SP_RECT(item));
-            gtk_adjustment_set_value(adj, sp_pixels_get_units(rx, *unit));
+            gtk_adjustment_set_value(adj, Quantity::convert(rx, "px", unit));
         }
 
         {
             GtkAdjustment *adj = GTK_ADJUSTMENT( g_object_get_data( tbl, "ry" ) );
             gdouble ry = sp_rect_get_visible_ry(SP_RECT(item));
-            gtk_adjustment_set_value(adj, sp_pixels_get_units(ry, *unit));
+            gtk_adjustment_set_value(adj, Quantity::convert(ry, "px", unit));
         }
 
         {
             GtkAdjustment *adj = GTK_ADJUSTMENT( g_object_get_data( tbl, "width" ) );
             gdouble width = sp_rect_get_visible_width (SP_RECT(item));
-            gtk_adjustment_set_value(adj, sp_pixels_get_units(width, *unit));
+            gtk_adjustment_set_value(adj, Quantity::convert(width, "px", unit));
         }
 
         {
             GtkAdjustment *adj = GTK_ADJUSTMENT( g_object_get_data( tbl, "height" ) );
             gdouble height = sp_rect_get_visible_height (SP_RECT(item));
-            gtk_adjustment_set_value(adj, sp_pixels_get_units(height, *unit));
+            gtk_adjustment_set_value(adj, Quantity::convert(height, "px", unit));
         }
     }
 
@@ -301,7 +303,7 @@ void sp_rect_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
     }
 
     // rx/ry units menu: create
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
     //tracker->addUnit( SP_UNIT_PERCENT, 0 );
     // fixme: add % meaning per cent of the width/height
     tracker->setActiveUnit( sp_desktop_namedview(desktop)->doc_units );
@@ -314,7 +316,7 @@ void sp_rect_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RectWidthAction",
                                          _("Width"), _("W:"), _("Width of rectangle"),
                                          "/tools/shapes/rect/width", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, TRUE, "altx-rect",
+                                         GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-rect",
                                          0, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_rtb_width_value_changed );
@@ -331,7 +333,7 @@ void sp_rect_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RectHeightAction",
                                          _("Height"), _("H:"), _("Height of rectangle"),
                                          "/tools/shapes/rect/height", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_rtb_height_value_changed );
@@ -348,7 +350,7 @@ void sp_rect_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RadiusXAction",
                                          _("Horizontal radius"), _("Rx:"), _("Horizontal radius of rounded corners"),
                                          "/tools/shapes/rect/rx", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_rtb_rx_value_changed);
@@ -363,7 +365,7 @@ void sp_rect_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RadiusYAction",
                                          _("Vertical radius"), _("Ry:"), _("Vertical radius of rounded corners"),
                                          "/tools/shapes/rect/ry", 0,
-                                         GTK_WIDGET(desktop->canvas), NULL/*us*/, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0, 1e6, SPIN_STEP, SPIN_PAGE_STEP,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_rtb_ry_value_changed);
diff --git a/src/widgets/ruler.cpp b/src/widgets/ruler.cpp
index c1f9be2a5..e4e72d86e 100644
--- a/src/widgets/ruler.cpp
+++ b/src/widgets/ruler.cpp
@@ -33,9 +33,9 @@
 
 #include "widget-sizes.h"
 #include "ruler.h"
-#include "unit-constants.h"
 #include "round.h"
 #include <glibmm/i18n.h>
+#include "util/units.h"
 
 #define ROUND(x) ((int) ((x) + 0.5))
 
@@ -44,6 +44,7 @@
 #define DEFAULT_RULER_FONT_SCALE  PANGO_SCALE_X_SMALL
 #define MINIMUM_INCR              5
 
+using Inkscape::Util::unit_table;
 
 enum {
   PROP_0,
@@ -62,7 +63,7 @@ enum {
 typedef struct
 {
   GtkOrientation   orientation;
-  SPMetric         unit;
+  Inkscape::Util::Unit *unit;
   gdouble          lower;
   gdouble          upper;
   gdouble          position;
@@ -196,11 +197,10 @@ sp_ruler_class_init (SPRulerClass *klass)
   /* FIXME: Should probably use g_param_spec_enum */
   g_object_class_install_property (object_class,
                                    PROP_UNIT,
-                                   g_param_spec_uint ("unit",
+                                   g_param_spec_string ("unit",
 						      _("Unit"),
 						      _("Unit of the ruler"),
-						      0, 8,
-						      SP_PX,
+						      "px",
 						      static_cast<GParamFlags>(GTK_PARAM_READWRITE)));
   
   g_object_class_install_property (object_class,
@@ -260,7 +260,7 @@ sp_ruler_init (SPRuler *ruler)
   gtk_widget_set_has_window (GTK_WIDGET (ruler), FALSE);
 
   priv->orientation   = GTK_ORIENTATION_HORIZONTAL;
-  priv->unit          = SP_PX;
+  priv->unit          = new Inkscape::Util::Unit(unit_table.getUnit("px"));
   priv->lower         = 0;
   priv->upper         = 0;
   priv->position      = 0;
@@ -387,7 +387,7 @@ sp_ruler_set_property (GObject      *object,
       break;
     
     case PROP_UNIT:
-      sp_ruler_set_unit (ruler, static_cast<SPMetric>(g_value_get_int (value)));
+      sp_ruler_set_unit (ruler, unit_table.getUnit(g_value_get_string (value)));
       break;
 
     case PROP_LOWER:
@@ -436,7 +436,7 @@ sp_ruler_get_property (GObject      *object,
       break;
     
     case PROP_UNIT:
-      g_value_set_int (value, priv->unit);
+      g_value_set_string (value, priv->unit->abbr.c_str());
       break;
     case PROP_LOWER:
       g_value_set_double (value, priv->lower);
@@ -1071,15 +1071,15 @@ sp_ruler_remove_track_widget (SPRuler   *ruler,
  */
 void
 sp_ruler_set_unit (SPRuler  *ruler,
-                   SPMetric  unit)
+                   const Inkscape::Util::Unit &unit)
 {
   SPRulerPrivate *priv = SP_RULER_GET_PRIVATE (ruler);
   
   g_return_if_fail (SP_IS_RULER (ruler));
 
-  if (priv->unit != unit)
+  if (*priv->unit != unit)
     {
-      priv->unit = unit;
+      priv->unit = new Inkscape::Util::Unit(unit);
       g_object_notify(G_OBJECT(ruler), "unit");
 
       gtk_widget_queue_draw (GTK_WIDGET (ruler));
@@ -1092,11 +1092,9 @@ sp_ruler_set_unit (SPRuler  *ruler,
  *
  * Return value: the unit currently used in the @ruler widget.
  **/
-SPMetric
+Inkscape::Util::Unit*
 sp_ruler_get_unit (SPRuler *ruler)
 {
-  g_return_val_if_fail(SP_IS_RULER(ruler), static_cast<SPMetric>(0));
-
   return SP_RULER_GET_PRIVATE (ruler)->unit;
 }
 
@@ -1184,7 +1182,7 @@ sp_ruler_draw_ticks (SPRuler *ruler)
     gint             text_size;
     gint             pos;
     gdouble          max_size;
-    SPMetric         unit;
+    Inkscape::Util::Unit *unit;
     SPRulerMetric    ruler_metric = ruler_metric_general; /* The metric to use for this unit system */
     PangoLayout     *layout;
     PangoRectangle   logical_rect, ink_rect;
@@ -1300,7 +1298,7 @@ sp_ruler_draw_ticks (SPRuler *ruler)
 
     /* Inkscape change to ruler: Use a 1,2,4,8... scale for inches
      * or a 1,2,5,10... scale for everything else */
-    if (sp_ruler_get_unit (ruler) == SP_IN)
+    if (*sp_ruler_get_unit (ruler) == unit_table.getUnit("in"))
       ruler_metric = ruler_metric_inches;
 
     for (scale = 0; scale < G_N_ELEMENTS (ruler_metric.ruler_scale); scale++)
@@ -1319,7 +1317,7 @@ sp_ruler_draw_ticks (SPRuler *ruler)
         gdouble subd_incr;
        
         /* hack to get proper subdivisions at full pixels */
-        if (unit == SP_PX && scale == 1 && i == 1)
+        if (*unit == unit_table.getUnit("px") && scale == 1 && i == 1)
           subd_incr = 1.0;
         else
           subd_incr = ((gdouble) ruler_metric.ruler_scale[scale] / 
diff --git a/src/widgets/ruler.h b/src/widgets/ruler.h
index f0d866fff..08760f584 100644
--- a/src/widgets/ruler.h
+++ b/src/widgets/ruler.h
@@ -14,10 +14,15 @@
  */
 
 #include <gtk/gtk.h>
-#include "sp-metric.h"
 #include <iostream>
 #include <glib.h>
 
+namespace Inkscape {
+    namespace Util {
+        class Unit;
+    }
+}
+
 G_BEGIN_DECLS
 
 #define SP_TYPE_RULER            (sp_ruler_get_type ())
@@ -51,8 +56,8 @@ void            sp_ruler_remove_track_widget (SPRuler        *ruler,
 		                              GtkWidget      *widget);
 
 void            sp_ruler_set_unit            (SPRuler        *ruler,
-                                              SPMetric        unit);
-SPMetric        sp_ruler_get_unit            (SPRuler        *ruler);
+                                              const Inkscape::Util::Unit &unit);
+Inkscape::Util::Unit *sp_ruler_get_unit            (SPRuler        *ruler);
 void            sp_ruler_set_position        (SPRuler        *ruler,
                                               gdouble         set_position);
 gdouble         sp_ruler_get_position        (SPRuler        *ruler);
diff --git a/src/widgets/select-toolbar.cpp b/src/widgets/select-toolbar.cpp
index 1bfc841e3..e4a5a2905 100644
--- a/src/widgets/select-toolbar.cpp
+++ b/src/widgets/select-toolbar.cpp
@@ -39,8 +39,7 @@
 #include <glibmm/i18n.h>
 #include "helper/action.h"
 #include "helper/action-context.h"
-#include "helper/unit-menu.h"
-#include "helper/units.h"
+#include "util/units.h"
 #include "inkscape.h"
 #include "verbs.h"
 #include "selection.h"
@@ -48,7 +47,7 @@
 #include "sp-item-transform.h"
 #include "message-stack.h"
 #include "display/sp-canvas.h"
-#include "helper/unit-tracker.h"
+#include "ui/widget/unit-tracker.h"
 #include "ege-adjustment-action.h"
 #include "ege-output-action.h"
 #include "ink-action.h"
@@ -56,8 +55,11 @@
 #include "ui/icon-names.h"
 #include "select-toolbar.h"
 
-using Inkscape::UnitTracker;
+using Inkscape::UI::Widget::UnitTracker;
+using Inkscape::Util::Unit;
+using Inkscape::Util::Quantity;
 using Inkscape::DocumentUndo;
+using Inkscape::Util::unit_table;
 
 static void
 sp_selection_layout_widget_update(SPWidget *spw, Inkscape::Selection *sel)
@@ -78,7 +80,7 @@ sp_selection_layout_widget_update(SPWidget *spw, Inkscape::Selection *sel)
         Geom::OptRect const bbox(sel->bounds(bbox_type));
         if ( bbox ) {
             UnitTracker *tracker = reinterpret_cast<UnitTracker*>(g_object_get_data(G_OBJECT(spw), "tracker"));
-            SPUnit const &unit = *tracker->getActiveUnit();
+            Unit const unit = tracker->getActiveUnit();
 
             struct { char const *key; double val; } const keyval[] = {
                 { "X", bbox->min()[X] },
@@ -87,8 +89,8 @@ sp_selection_layout_widget_update(SPWidget *spw, Inkscape::Selection *sel)
                 { "height", bbox->dimensions()[Y] }
             };
 
-            if (unit.base == SP_UNIT_DIMENSIONLESS) {
-                double const val = 1. / unit.unittobase;
+            if (unit.type == Inkscape::Util::UNIT_TYPE_DIMENSIONLESS) {
+                double const val = unit.factor * 100;
                 for (unsigned i = 0; i < G_N_ELEMENTS(keyval); ++i) {
                     GtkAdjustment *a = GTK_ADJUSTMENT(g_object_get_data(G_OBJECT(spw), keyval[i].key));
                     gtk_adjustment_set_value(a, val);
@@ -97,7 +99,7 @@ sp_selection_layout_widget_update(SPWidget *spw, Inkscape::Selection *sel)
             } else {
                 for (unsigned i = 0; i < G_N_ELEMENTS(keyval); ++i) {
                     GtkAdjustment *a = GTK_ADJUSTMENT(g_object_get_data(G_OBJECT(spw), keyval[i].key));
-                    gtk_adjustment_set_value(a, sp_pixels_get_units(keyval[i].val, unit));
+                    gtk_adjustment_set_value(a, Quantity::convert(keyval[i].val, "px", unit));
                 }
             }
         }
@@ -183,28 +185,28 @@ sp_object_layout_any_value_changed(GtkAdjustment *adj, SPWidget *spw)
     gdouble y1 = 0;
     gdouble xrel = 0;
     gdouble yrel = 0;
-    SPUnit const &unit = *tracker->getActiveUnit();
+    Unit const unit = tracker->getActiveUnit();
 
     GtkAdjustment* a_x = GTK_ADJUSTMENT( g_object_get_data( G_OBJECT(spw), "X" ) );
     GtkAdjustment* a_y = GTK_ADJUSTMENT( g_object_get_data( G_OBJECT(spw), "Y" ) );
     GtkAdjustment* a_w = GTK_ADJUSTMENT( g_object_get_data( G_OBJECT(spw), "width" ) );
     GtkAdjustment* a_h = GTK_ADJUSTMENT( g_object_get_data( G_OBJECT(spw), "height" ) );
 
-    if (unit.base == SP_UNIT_ABSOLUTE || unit.base == SP_UNIT_DEVICE) {
-        x0 = sp_units_get_pixels (gtk_adjustment_get_value (a_x), unit);
-        y0 = sp_units_get_pixels (gtk_adjustment_get_value (a_y), unit);
-        x1 = x0 + sp_units_get_pixels (gtk_adjustment_get_value (a_w), unit);
-        xrel = sp_units_get_pixels (gtk_adjustment_get_value (a_w), unit) / bbox_user->dimensions()[Geom::X];
-        y1 = y0 + sp_units_get_pixels (gtk_adjustment_get_value (a_h), unit);
-        yrel = sp_units_get_pixels (gtk_adjustment_get_value (a_h), unit) / bbox_user->dimensions()[Geom::Y];
+    if (unit.type == Inkscape::Util::UNIT_TYPE_LINEAR) {
+        x0 = Quantity::convert(gtk_adjustment_get_value(a_x), unit, "px");
+        y0 = Quantity::convert(gtk_adjustment_get_value(a_y), unit, "px");
+        x1 = x0 + Quantity::convert(gtk_adjustment_get_value(a_w), unit, "px");
+        xrel = Quantity::convert(gtk_adjustment_get_value(a_w), unit, "px") / bbox_user->dimensions()[Geom::X];
+        y1 = y0 + Quantity::convert(gtk_adjustment_get_value(a_h), unit, "px");;
+        yrel = Quantity::convert(gtk_adjustment_get_value(a_h), unit, "px") / bbox_user->dimensions()[Geom::Y];
     } else {
-        double const x0_propn = gtk_adjustment_get_value (a_x) * unit.unittobase;
+        double const x0_propn = gtk_adjustment_get_value (a_x) / 100 / unit.factor;
         x0 = bbox_user->min()[Geom::X] * x0_propn;
-        double const y0_propn = gtk_adjustment_get_value (a_y) * unit.unittobase;
+        double const y0_propn = gtk_adjustment_get_value (a_y) / 100 / unit.factor;
         y0 = y0_propn * bbox_user->min()[Geom::Y];
-        xrel = gtk_adjustment_get_value (a_w) * unit.unittobase;
+        xrel = gtk_adjustment_get_value (a_w) / (100 / unit.factor);
         x1 = x0 + xrel * bbox_user->dimensions()[Geom::X];
-        yrel = gtk_adjustment_get_value (a_h) * unit.unittobase;
+        yrel = gtk_adjustment_get_value (a_h) / (100 / unit.factor);
         y1 = y0 + yrel * bbox_user->dimensions()[Geom::Y];
     }
 
@@ -225,11 +227,11 @@ sp_object_layout_any_value_changed(GtkAdjustment *adj, SPWidget *spw)
     double sv = fabs(y1 - bbox_user->max()[Geom::Y]);
 
     // unless the unit is %, convert the scales and moves to the unit
-    if (unit.base == SP_UNIT_ABSOLUTE || unit.base == SP_UNIT_DEVICE) {
-        mh = sp_pixels_get_units (mh, unit);
-        sh = sp_pixels_get_units (sh, unit);
-        mv = sp_pixels_get_units (mv, unit);
-        sv = sp_pixels_get_units (sv, unit);
+    if (unit.type == Inkscape::Util::UNIT_TYPE_LINEAR) {
+        mh = Quantity::convert(mh, "px", unit);
+        sh = Quantity::convert(sh, "px", unit);
+        mv = Quantity::convert(mv, "px", unit);
+        sv = Quantity::convert(sv, "px", unit);
     }
 
     // do the action only if one of the scales/moves is greater than half the last significant
@@ -488,8 +490,8 @@ void sp_select_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
     gtk_container_add(GTK_CONTAINER(spw), vb);
 
     // Create the units menu.
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
-    tracker->addUnit( SP_UNIT_PERCENT, 0 );
+    UnitTracker* tracker = new UnitTracker(Inkscape::Util::UNIT_TYPE_LINEAR);
+    tracker->addUnit(unit_table.getUnit("%"));
     tracker->setActiveUnit( sp_desktop_namedview(desktop)->doc_units );
 
     g_object_set_data( G_OBJECT(spw), "tracker", tracker );
diff --git a/src/widgets/spiral-toolbar.cpp b/src/widgets/spiral-toolbar.cpp
index 08d26f3d1..cccaf5154 100644
--- a/src/widgets/spiral-toolbar.cpp
+++ b/src/widgets/spiral-toolbar.cpp
@@ -53,13 +53,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-spiral.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -263,7 +259,7 @@ void sp_spiral_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
         eact = create_adjustment_action( "SpiralRevolutionAction",
                                          _("Number of turns"), _("Turns:"), _("Number of revolutions"),
                                          "/tools/shapes/spiral/revolution", 3.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-spiral",
+                                         GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-spiral",
                                          0.01, 1024.0, 0.1, 1.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_spl_tb_revolution_value_changed, 1, 2);
@@ -277,7 +273,7 @@ void sp_spiral_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
         eact = create_adjustment_action( "SpiralExpansionAction",
                                          _("Divergence"), _("Divergence:"), _("How much denser/sparser are outer revolutions; 1 = uniform"),
                                          "/tools/shapes/spiral/expansion", 1.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0.0, 1000.0, 0.01, 1.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_spl_tb_expansion_value_changed);
@@ -291,7 +287,7 @@ void sp_spiral_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GOb
         eact = create_adjustment_action( "SpiralT0Action",
                                          _("Inner radius"), _("Inner radius:"), _("Radius of the innermost revolution (relative to the spiral size)"),
                                          "/tools/shapes/spiral/t0", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0.0, 0.999, 0.01, 1.0,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_spl_tb_t0_value_changed);
diff --git a/src/widgets/spray-toolbar.cpp b/src/widgets/spray-toolbar.cpp
index 06850d261..fe221f695 100644
--- a/src/widgets/spray-toolbar.cpp
+++ b/src/widgets/spray-toolbar.cpp
@@ -52,13 +52,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../spray-context.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -131,7 +127,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
         EgeAdjustmentAction *eact = create_adjustment_action( "SprayWidthAction",
                                                               _("Width"), _("Width:"), _("The width of the spray area (relative to the visible canvas area)"),
                                                               "/tools/spray/width", 15,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-spray",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-spray",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_width_value_changed,  1, 0 );
@@ -147,7 +143,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
         EgeAdjustmentAction *eact = create_adjustment_action( "SprayMeanAction",
                                                               _("Focus"), _("Focus:"), _("0 to spray a spot; increase to enlarge the ring radius"),
                                                               "/tools/spray/mean", 0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "spray-mean",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "spray-mean",
                                                               0, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_mean_value_changed,  1, 0 );
@@ -163,7 +159,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
         EgeAdjustmentAction *eact = create_adjustment_action( "SprayStandard_deviationAction",
                                                               C_("Spray tool", "Scatter"), C_("Spray tool", "Scatter:"), _("Increase to scatter sprayed objects"),
                                                               "/tools/spray/standard_deviation", 70,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "spray-standard_deviation",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "spray-standard_deviation",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_standard_deviation_value_changed,  1, 0 );
@@ -224,7 +220,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
                                                               _("Amount"), _("Amount:"),
                                                               _("Adjusts the number of items sprayed per click"),
                                                               "/tools/spray/population", 70,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "spray-population",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "spray-population",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_population_value_changed,  1, 0 );
@@ -255,7 +251,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
                                                               // xgettext:no-c-format
                                                               _("Variation of the rotation of the sprayed objects; 0% for the same rotation than the original object"),
                                                               "/tools/spray/rotation_variation", 0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "spray-rotation",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "spray-rotation",
                                                               0, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_rotation_value_changed,  1, 0 );
@@ -273,7 +269,7 @@ void sp_spray_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
                                                               // xgettext:no-c-format
                                                               _("Variation in the scale of the sprayed objects; 0% for the same scale than the original object"),
                                                               "/tools/spray/scale_variation", 0,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "spray-scale",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "spray-scale",
                                                               0, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_spray_scale_value_changed,  1, 0 );
diff --git a/src/widgets/spw-utilities.cpp b/src/widgets/spw-utilities.cpp
index 87ca80f2f..d0a3ed1c5 100644
--- a/src/widgets/spw-utilities.cpp
+++ b/src/widgets/spw-utilities.cpp
@@ -32,7 +32,6 @@
 
 #include "selection.h"
 
-#include "helper/unit-menu.h"
 #include "spw-utilities.h"
 
 #include <gtk/gtk.h>
@@ -231,51 +230,6 @@ spw_dropdown(GtkWidget * dialog, GtkWidget * table,
   return selector;
 }
 
-/**
- * Creates a unit selector widget, used for selecting whether one wishes
- * to measure screen elements in millimeters, points, etc.  This is a
- * compound unit that includes a label as well as the dropdown selector.
- */
-GtkWidget *
-spw_unit_selector(GtkWidget * dialog, GtkWidget * table,
-		  const gchar * label_text, gchar * key, int row,
-		GtkWidget * us, GCallback cb, bool can_be_negative)
-{
-  g_assert(dialog != NULL);
-  g_assert(table  != NULL);
-  g_assert(us     != NULL);
-
-  spw_label_old(table, label_text, 0, row);
-
-#if GTK_CHECK_VERSION(3,0,0)
-  GtkAdjustment * a = gtk_adjustment_new(0.0, can_be_negative?-1e6:0, 1e6, 1.0, 10.0, 10.0);
-#else
-  GtkObject * a = gtk_adjustment_new(0.0, can_be_negative?-1e6:0, 1e6, 1.0, 10.0, 10.0);
-#endif
-
-  g_assert(a != NULL);
-  g_object_set_data (G_OBJECT (a), "key", key);
-  g_object_set_data (G_OBJECT (a), "unit_selector", us);
-  g_object_set_data (G_OBJECT (dialog), key, a);
-  sp_unit_selector_add_adjustment (SP_UNIT_SELECTOR (us), GTK_ADJUSTMENT (a));
-  GtkWidget * sb = gtk_spin_button_new (GTK_ADJUSTMENT (a), 1.0, 4);
-  g_assert(sb != NULL);
-  gtk_widget_show (sb);
-
-#if GTK_CHECK_VERSION(3,0,0)
-  gtk_widget_set_halign(sb, GTK_ALIGN_FILL);
-  gtk_widget_set_hexpand(sb, TRUE);
-  gtk_widget_set_valign(sb, GTK_ALIGN_CENTER);
-  gtk_grid_attach(GTK_GRID(table), sb, 1, row, 1, 1);
-#else
-  gtk_table_attach (GTK_TABLE (table), sb, 1, 2, row, row+1,
-		    (GtkAttachOptions)(GTK_EXPAND | GTK_FILL), (GtkAttachOptions)0, 0, 0);
-#endif
-
-  g_signal_connect (G_OBJECT (a), "value_changed", cb, dialog);
-  return sb;
-}
-
 static void
 sp_set_font_size_recursive (GtkWidget *w, gpointer font)
 {
diff --git a/src/widgets/spw-utilities.h b/src/widgets/spw-utilities.h
index fb8c04ebf..d52cbd888 100644
--- a/src/widgets/spw-utilities.h
+++ b/src/widgets/spw-utilities.h
@@ -56,11 +56,6 @@ spw_dropdown(GtkWidget *dialog, GtkWidget *table,
 	     GtkWidget *selector
 	     );
 
-GtkWidget *
-spw_unit_selector(GtkWidget *dialog, GtkWidget *table,
-		  gchar const *label, gchar *key, int row,
-		GtkWidget *us, GCallback cb, bool can_be_negative = false);
-
 void sp_set_font_size (GtkWidget *w, guint font);
 void sp_set_font_size_smaller (GtkWidget *w);
 
diff --git a/src/widgets/star-toolbar.cpp b/src/widgets/star-toolbar.cpp
index 8c07c6473..9f7dd95e0 100644
--- a/src/widgets/star-toolbar.cpp
+++ b/src/widgets/star-toolbar.cpp
@@ -53,14 +53,10 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-star.h"
 
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -505,7 +501,7 @@ void sp_star_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "MagnitudeAction",
                                          _("Corners"), _("Corners:"), _("Number of corners of a polygon or star"),
                                          "/tools/shapes/star/magnitude", 3,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          3, 1024, 1, 5,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_stb_magnitude_value_changed,
@@ -524,7 +520,7 @@ void sp_star_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
                                          // Base radius is the same for the closest handle.
                                          _("Base radius to tip radius ratio"),
                                          "/tools/shapes/star/proportion", 0.5,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          0.01, 1.0, 0.01, 0.1,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_stb_proportion_value_changed );
@@ -545,7 +541,7 @@ void sp_star_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RoundednessAction",
                                          _("Rounded"), _("Rounded:"), _("How much rounded are the corners (0 for sharp)"),
                                          "/tools/shapes/star/rounded", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -10.0, 10.0, 0.01, 0.1,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_stb_rounded_value_changed );
@@ -560,7 +556,7 @@ void sp_star_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
         eact = create_adjustment_action( "RandomizationAction",
                                          _("Randomized"), _("Randomized:"), _("Scatter randomly the corners and angles"),
                                          "/tools/shapes/star/randomized", 0.0,
-                                         GTK_WIDGET(desktop->canvas), NULL, holder, FALSE, NULL,
+                                         GTK_WIDGET(desktop->canvas), holder, FALSE, NULL,
                                          -10.0, 10.0, 0.001, 0.01,
                                          labels, values, G_N_ELEMENTS(labels),
                                          sp_stb_randomized_value_changed, 0.1, 3 );
diff --git a/src/widgets/stroke-style.cpp b/src/widgets/stroke-style.cpp
index 0a5b3781b..12d4002b8 100644
--- a/src/widgets/stroke-style.cpp
+++ b/src/widgets/stroke-style.cpp
@@ -22,8 +22,11 @@
 #include "sp-gradient.h"
 #include "sp-stop.h"
 #include "svg/svg-color.h"
+#include "util/units.h"
+#include "ui/widget/unit-menu.h"
 
 using Inkscape::DocumentUndo;
+using Inkscape::Util::unit_table;
 
 /**
  * Creates a new widget for the line stroke paint.
@@ -189,22 +192,22 @@ StrokeStyle::StrokeStyle() :
     sp_dialog_defocus_on_enter_cpp(widthSpin);
 
     hb->pack_start(*widthSpin, false, false, 0);
-    unitSelector = sp_unit_selector_new(SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE);
-    Gtk::Widget *us = manage(Glib::wrap(unitSelector));
+    unitSelector = new Inkscape::UI::Widget::UnitMenu();
+    unitSelector->setUnitType(Inkscape::Util::UNIT_TYPE_LINEAR);
+    Gtk::Widget *us = manage(unitSelector);
     SPDesktop *desktop = SP_ACTIVE_DESKTOP;
 
-    if (desktop)
-        sp_unit_selector_set_unit (SP_UNIT_SELECTOR(unitSelector), sp_desktop_namedview(desktop)->doc_units);
-    sp_unit_selector_add_unit(SP_UNIT_SELECTOR(unitSelector), &sp_unit_get_by_id(SP_UNIT_PERCENT), 0);
-    g_signal_connect ( G_OBJECT (unitSelector), "set_unit", G_CALLBACK (StrokeStyle::setStrokeWidthUnit), this );
+    unitSelector->addUnit(unit_table.getUnit("%"));
+    if (desktop) {
+        unitSelector->setUnit(sp_desktop_namedview(desktop)->doc_units->abbr);
+        _old_unit = new Inkscape::Util::Unit(*sp_desktop_namedview(desktop)->doc_units);
+    }
+    _old_unit = new Inkscape::Util::Unit(unitSelector->getUnit());
+    widthSpin->setUnitMenu(unitSelector);
+    unitChangedConn = unitSelector->signal_changed().connect(sigc::mem_fun(*this, &StrokeStyle::unitChangedCB));
+    
     us->show();
 
-#if WITH_GTKMM_3_0
-    sp_unit_selector_add_adjustment( SP_UNIT_SELECTOR(unitSelector), GTK_ADJUSTMENT((*widthAdj)->gobj()) );
-#else
-    sp_unit_selector_add_adjustment( SP_UNIT_SELECTOR(unitSelector), GTK_ADJUSTMENT(widthAdj->gobj()) );
-#endif
-
     hb->pack_start(*us, FALSE, FALSE, 0);
 
 #if WITH_GTKMM_3_0
@@ -519,75 +522,17 @@ void StrokeStyle::updateMarkerHist(SPMarkerLoc const which)
 }
 
 /**
- * Sets the stroke width units for all selected items.
- * Also handles absolute and dimensionless units.
+ * Callback for when UnitMenu widget is modified.
+ * Triggers update action.
  */
-gboolean StrokeStyle::setStrokeWidthUnit(SPUnitSelector *,
-                                      SPUnit const *old,
-                                      SPUnit const *new_units,
-                                      StrokeStyle *spw)
+void StrokeStyle::unitChangedCB()
 {
-    if (spw->update) {
-        return FALSE;
-    }
-
-    if (!spw->desktop) {
-        return FALSE;
+    Inkscape::Util::Unit new_unit = unitSelector->getUnit();
+    if (new_unit.type == Inkscape::Util::UNIT_TYPE_DIMENSIONLESS) {
+        widthSpin->set_value(100);
     }
-
-    Inkscape::Selection *selection = sp_desktop_selection (spw->desktop);
-
-    if (selection->isEmpty())
-        return FALSE;
-
-    GSList const *objects = selection->itemList();
-
-    if ((old->base == SP_UNIT_ABSOLUTE || old->base == SP_UNIT_DEVICE) &&
-       (new_units->base == SP_UNIT_DIMENSIONLESS)) {
-
-        /* Absolute to percentage */
-        spw->update = true;
-
-#if WITH_GTKMM_3_0
-        float w = sp_units_get_pixels( (*spw->widthAdj)->get_value(), *old);
-#else
-        float w = sp_units_get_pixels(spw->widthAdj->get_value(), *old);
-#endif
-
-        gdouble average = stroke_average_width (objects);
-
-        if ((average == Geom::infinity()) || (average < 1e-8)){ //less than 1e-8: to campare against zero, while taking numeric accuracy into account
-            return FALSE;
-        }
-
-#if WITH_GTKMM_3_0
-        (*spw->widthAdj)->set_value(100.0 * w / average);
-#else
-        spw->widthAdj->set_value(100.0 * w / average);
-#endif
-
-        spw->update = false;
-        return TRUE;
-
-    } else if ((old->base == SP_UNIT_DIMENSIONLESS) &&
-              (new_units->base == SP_UNIT_ABSOLUTE || new_units->base == SP_UNIT_DEVICE)) {
-
-        /* Percentage to absolute */
-        spw->update = true;
-
-        gdouble average = stroke_average_width (objects);
-
-#if WITH_GTKMM_3_0
-        (*spw->widthAdj)->set_value (sp_pixels_get_units (0.01 * (*spw->widthAdj)->get_value() * average, *new_units));
-#else
-        spw->widthAdj->set_value (sp_pixels_get_units (0.01 * spw->widthAdj->get_value() * average, *new_units));
-#endif
-
-        spw->update = false;
-        return TRUE;
-    }
-
-    return FALSE;
+    widthSpin->set_value(Inkscape::Util::Quantity::convert(widthSpin->get_value(), *_old_unit, new_unit));
+    _old_unit = new Inkscape::Util::Unit(new_unit);
 }
 
 /**
@@ -877,21 +822,21 @@ StrokeStyle::updateLine()
     } else {
         table->set_sensitive(true);
 
-        SPUnit const *unit = sp_unit_selector_get_unit(SP_UNIT_SELECTOR(unitSelector));
+        Inkscape::Util::Unit const *unit = new Inkscape::Util::Unit(unitSelector->getUnit());
 
         if (result_sw == QUERY_STYLE_MULTIPLE_AVERAGED) {
-            sp_unit_selector_set_unit(SP_UNIT_SELECTOR(unitSelector), &sp_unit_get_by_id(SP_UNIT_PERCENT));
+            unitSelector->setUnit("%");
         } else {
             // same width, or only one object; no sense to keep percent, switch to absolute
-            if (unit->base != SP_UNIT_ABSOLUTE && unit->base != SP_UNIT_DEVICE) {
-                sp_unit_selector_set_unit(SP_UNIT_SELECTOR(unitSelector), sp_desktop_namedview(SP_ACTIVE_DESKTOP)->doc_units);
+            if (unit->type != Inkscape::Util::UNIT_TYPE_LINEAR) {
+                unitSelector->setUnit(sp_desktop_namedview(SP_ACTIVE_DESKTOP)->doc_units->abbr);
             }
         }
 
-        unit = sp_unit_selector_get_unit(SP_UNIT_SELECTOR(unitSelector));
+        unit = new Inkscape::Util::Unit(unitSelector->getUnit());
 
-        if (unit->base == SP_UNIT_ABSOLUTE || unit->base == SP_UNIT_DEVICE) {
-            double avgwidth = sp_pixels_get_units (query->stroke_width.computed, *unit);
+        if (unit->type == Inkscape::Util::UNIT_TYPE_LINEAR) {
+            double avgwidth = Inkscape::Util::Quantity::convert(query->stroke_width.computed, "px", *unit);
 #if WITH_GTKMM_3_0
             (*widthAdj)->set_value(avgwidth);
 #else
@@ -1017,7 +962,7 @@ StrokeStyle::scaleLine()
         double const miterlimit = miterLimitAdj->get_value();
 #endif
 
-        SPUnit const *const unit = sp_unit_selector_get_unit(SP_UNIT_SELECTOR(unitSelector));
+        Inkscape::Util::Unit const *const unit = new Inkscape::Util::Unit(unitSelector->getUnit());
 
         double *dash, offset;
         int ndash;
@@ -1026,8 +971,8 @@ StrokeStyle::scaleLine()
         for (GSList const *i = items; i != NULL; i = i->next) {
             /* Set stroke width */
             double width;
-            if (unit->base == SP_UNIT_ABSOLUTE || unit->base == SP_UNIT_DEVICE) {
-                width = sp_units_get_pixels (width_typed, *unit);
+            if (unit->type == Inkscape::Util::UNIT_TYPE_LINEAR) {
+                width = Inkscape::Util::Quantity::convert(width_typed, *unit, "px");
             } else { // percentage
                 gdouble old_w = SP_OBJECT(i->data)->style->stroke_width.computed;
                 width = old_w * width_typed / 100;
@@ -1053,7 +998,7 @@ StrokeStyle::scaleLine()
 
         g_free(dash);
 
-        if (unit->base != SP_UNIT_ABSOLUTE && unit->base != SP_UNIT_DEVICE) {
+        if (unit->type != Inkscape::Util::UNIT_TYPE_LINEAR) {
             // reset to 100 percent
 #if WITH_GTKMM_3_0
             (*widthAdj)->set_value(100.0);
diff --git a/src/widgets/stroke-style.h b/src/widgets/stroke-style.h
index fd9940db1..440881c6d 100644
--- a/src/widgets/stroke-style.h
+++ b/src/widgets/stroke-style.h
@@ -40,8 +40,6 @@
 #include "document-undo.h"
 #include "gradient-chemistry.h"
 #include "helper/stock-items.h"
-#include "helper/unit-menu.h"
-#include "helper/units.h"
 #include "inkscape.h"
 #include "io/sys.h"
 #include "marker.h"
@@ -77,6 +75,17 @@ class Widget;
 class Container;
 }
 
+namespace Inkscape {
+    namespace Util {
+        class Unit;
+    }
+    namespace UI {
+        namespace Widget {
+            class UnitMenu;
+        }
+    }
+}
+
 struct { gchar const *key; gint value; } const SPMarkerNames[] = {
     {"marker-all", SP_MARKER_LOC},
     {"marker-start", SP_MARKER_LOC_START},
@@ -162,17 +171,13 @@ private:
                                         StrokeStyleButtonType  button_type,
                                         gchar const           *stroke_style);
 
-    static gboolean setStrokeWidthUnit(SPUnitSelector *,
-                                          SPUnit const *old,
-                                          SPUnit const *new_units,
-                                          StrokeStyle *spw);
-
     // Callback functions
     void selectionModifiedCB(guint flags);
     void selectionChangedCB();
     void widthChangedCB();
     void miterLimitChangedCB();
     void lineDashChangedCB();
+    void unitChangedCB();
     static void markerSelectCB(MarkerComboBox *marker_combo, StrokeStyle *spw, SPMarkerLoc const which);
     static void buttonToggledCB(StrokeStyleButton *tb, StrokeStyle *spw);
 
@@ -191,7 +196,7 @@ private:
 #endif
     Inkscape::UI::Widget::SpinButton *miterLimitSpin;
     Inkscape::UI::Widget::SpinButton *widthSpin;
-    GtkWidget *unitSelector;
+    Inkscape::UI::Widget::UnitMenu *unitSelector;
     StrokeStyleButton *joinMiter;
     StrokeStyleButton *joinRound;
     StrokeStyleButton *joinBevel;
@@ -207,6 +212,9 @@ private:
     sigc::connection startMarkerConn;
     sigc::connection midMarkerConn;
     sigc::connection endMarkerConn;
+    sigc::connection unitChangedConn;
+    
+    Inkscape::Util::Unit *_old_unit;
 };
 
 } // namespace Inkscape
diff --git a/src/widgets/text-toolbar.cpp b/src/widgets/text-toolbar.cpp
index 87cb54d10..7554f4faf 100644
--- a/src/widgets/text-toolbar.cpp
+++ b/src/widgets/text-toolbar.cpp
@@ -56,9 +56,6 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../sp-namedview.h"
 #include "../svg/css-ostringstream.h"
@@ -72,7 +69,6 @@
 #include "widgets/font-selector.h"
 
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -1217,11 +1213,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     Inkscape::IconSize secondarySize = ToolboxFactory::prefToSize("/toolbox/secondary", 1);
 
-    // Is this used?
-    UnitTracker* tracker = new UnitTracker( SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE );
-    tracker->setActiveUnit( sp_desktop_namedview(desktop)->doc_units );
-    g_object_set_data( holder, "tracker", tracker );
-
     /* Font family */
     {
         // Font list
@@ -1462,7 +1453,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/lineheight",             /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
@@ -1493,7 +1483,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/wordspacing",            /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
@@ -1524,7 +1513,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/letterspacing",          /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
@@ -1555,7 +1543,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/dx",                     /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
@@ -1586,7 +1573,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/dy",                     /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
@@ -1617,7 +1603,6 @@ void sp_text_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObje
             "/tools/text/rotation",               /* preferences path */
             0.0,                                  /* default */
             GTK_WIDGET(desktop->canvas),          /* focusTarget */
-            NULL,                                 /* unit selector */
             holder,                               /* dataKludge */
             FALSE,                                /* set alt-x keyboard shortcut? */
             NULL,                                 /* altx_mark */
diff --git a/src/widgets/toolbox.cpp b/src/widgets/toolbox.cpp
index 98a0ff51e..f3a83e84a 100644
--- a/src/widgets/toolbox.cpp
+++ b/src/widgets/toolbox.cpp
@@ -49,9 +49,6 @@
 #include "../graphlayout.h"
 #include "../helper/action.h"
 #include "../helper/action-context.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "icon.h"
 #include "../ink-action.h"
 #include "../ink-comboboxentry-action.h"
@@ -101,7 +98,6 @@
 
 //#define DEBUG_TEXT
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::PrefPusher;
@@ -1031,7 +1027,6 @@ EgeAdjustmentAction * create_adjustment_action( gchar const *name,
                                                        gchar const *label, gchar const *shortLabel, gchar const *tooltip,
                                                        Glib::ustring const &path, gdouble def,
                                                        GtkWidget *focusTarget,
-                                                       GtkWidget *us,
                                                        GObject *dataKludge,
                                                        gboolean altx, gchar const *altx_mark,
                                                        gdouble lower, gdouble upper, gdouble step, gdouble page,
@@ -1048,9 +1043,6 @@ EgeAdjustmentAction * create_adjustment_action( gchar const *name,
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     GtkAdjustment* adj = GTK_ADJUSTMENT( gtk_adjustment_new( prefs->getDouble(path, def) * factor,
                                                              lower, upper, step, page, 0 ) );
-    if (us) {
-        sp_unit_selector_add_adjustment( SP_UNIT_SELECTOR(us), adj );
-    }
 
     g_signal_connect( G_OBJECT(adj), "value-changed", G_CALLBACK(callback), dataKludge );
 
diff --git a/src/widgets/toolbox.h b/src/widgets/toolbox.h
index 9c839a8fe..197f0fb5e 100644
--- a/src/widgets/toolbox.h
+++ b/src/widgets/toolbox.h
@@ -118,7 +118,6 @@ void delete_connection(GObject * /*obj*/, sigc::connection *connection);
                                                        gchar const *label, gchar const *shortLabel, gchar const *tooltip,
                                                        Glib::ustring const &path, gdouble def,
                                                        GtkWidget *focusTarget,
-                                                       GtkWidget *us,
                                                        GObject *dataKludge,
                                                        gboolean altx, gchar const *altx_mark,
                                                        gdouble lower, gdouble upper, gdouble step, gdouble page,
diff --git a/src/widgets/tweak-toolbar.cpp b/src/widgets/tweak-toolbar.cpp
index beb527a17..d5fe67ef7 100644
--- a/src/widgets/tweak-toolbar.cpp
+++ b/src/widgets/tweak-toolbar.cpp
@@ -52,13 +52,9 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../tweak-context.h"
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;
@@ -145,7 +141,7 @@ void sp_tweak_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
         EgeAdjustmentAction *eact = create_adjustment_action( "TweakWidthAction",
                                                               _("Width"), _("Width:"), _("The width of the tweak area (relative to the visible canvas area)"),
                                                               "/tools/tweak/width", 15,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "altx-tweak",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "altx-tweak",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_tweak_width_value_changed,  0.01, 0, 100 );
@@ -162,7 +158,7 @@ void sp_tweak_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
         EgeAdjustmentAction *eact = create_adjustment_action( "TweakForceAction",
                                                               _("Force"), _("Force:"), _("The force of the tweak action"),
                                                               "/tools/tweak/force", 20,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "tweak-force",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "tweak-force",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_tweak_force_value_changed,  0.01, 0, 100 );
@@ -371,7 +367,7 @@ void sp_tweak_toolbox_prep(SPDesktop *desktop, GtkActionGroup* mainActions, GObj
                                                               _("Fidelity"), _("Fidelity:"),
                                                               _("Low fidelity simplifies paths; high fidelity preserves path features but may generate a lot of new nodes"),
                                                               "/tools/tweak/fidelity", 50,
-                                                              GTK_WIDGET(desktop->canvas), NULL, holder, TRUE, "tweak-fidelity",
+                                                              GTK_WIDGET(desktop->canvas), holder, TRUE, "tweak-fidelity",
                                                               1, 100, 1.0, 10.0,
                                                               labels, values, G_N_ELEMENTS(labels),
                                                               sp_tweak_fidelity_value_changed,  0.01, 0, 100 );
diff --git a/src/widgets/zoom-toolbar.cpp b/src/widgets/zoom-toolbar.cpp
index 7d7f2c774..9cdbc3d6a 100644
--- a/src/widgets/zoom-toolbar.cpp
+++ b/src/widgets/zoom-toolbar.cpp
@@ -51,14 +51,10 @@
 #include "../xml/repr.h"
 #include "ui/uxmanager.h"
 #include "../ui/icon-names.h"
-#include "../helper/unit-menu.h"
-#include "../helper/units.h"
-#include "../helper/unit-tracker.h"
 #include "../pen-context.h"
 #include "../tweak-context.h"
 
 
-using Inkscape::UnitTracker;
 using Inkscape::UI::UXManager;
 using Inkscape::DocumentUndo;
 using Inkscape::UI::ToolboxFactory;