5 files changed, 25 insertions, 3 deletions
diff --git a/src/live_effects/lpe-powerstroke.cpp b/src/live_effects/lpe-powerstroke.cpp
index fc6026d31..25cb72b42 100644
--- a/src/live_effects/lpe-powerstroke.cpp
+++ b/src/live_effects/lpe-powerstroke.cpp
@@ -77,6 +77,9 @@ LPEPowerStroke::LPEPowerStroke(LivePathEffectObject *lpeobject) :
 
     /// @todo offset_points are initialized with empty path, is that bug-save?
 
+    interpolator_beta.addSlider(true);
+    interpolator_beta.param_set_range(0.,1.);
+
     registerParameter( dynamic_cast<Parameter *>(&offset_points) );
     registerParameter( dynamic_cast<Parameter *>(&sort_points) );
     registerParameter( dynamic_cast<Parameter *>(&interpolator_type) );
diff --git a/src/live_effects/parameter/parameter.cpp b/src/live_effects/parameter/parameter.cpp
index 5454a5408..cc8982860 100644
--- a/src/live_effects/parameter/parameter.cpp
+++ b/src/live_effects/parameter/parameter.cpp
@@ -58,7 +58,8 @@ ScalarParam::ScalarParam( const Glib::ustring& label, const Glib::ustring& tip,
       defvalue(default_value),
       digits(2),
       inc_step(0.1),
-      inc_page(1)
+      inc_page(1),
+      add_slider(false)
 {
 }
 
@@ -134,6 +135,9 @@ ScalarParam::param_newWidget(Gtk::Tooltips * /*tooltips*/)
     rsu->setIncrements(inc_step, inc_page);
     rsu->setRange(min, max);
     rsu->setProgrammatically = false;
+    if (add_slider) {
+        rsu->addSlider();
+    }
 
     rsu->set_undo_parameters(SP_VERB_DIALOG_LIVE_PATH_EFFECT, _("Change scalar parameter"));
 
diff --git a/src/live_effects/parameter/parameter.h b/src/live_effects/parameter/parameter.h
index cee10bc70..fe93e8dca 100644
--- a/src/live_effects/parameter/parameter.h
+++ b/src/live_effects/parameter/parameter.h
@@ -109,6 +109,8 @@ public:
     void param_set_digits(unsigned digits);
     void param_set_increments(double step, double page);
 
+    void addSlider(bool add_slider_widget) { add_slider = add_slider_widget; };
+
     virtual Gtk::Widget * param_newWidget(Gtk::Tooltips * tooltips);
 
     inline operator gdouble()
@@ -123,6 +125,7 @@ protected:
     unsigned digits;
     double inc_step;
     double inc_page;
+    bool add_slider;
 
 private:
     ScalarParam(const ScalarParam&);
diff --git a/src/ui/widget/scalar.cpp b/src/ui/widget/scalar.cpp
index 220498561..cc051599c 100644
--- a/src/ui/widget/scalar.cpp
+++ b/src/ui/widget/scalar.cpp
@@ -3,8 +3,9 @@
  *   Carl Hetherington <inkscape@carlh.net>
  *   Derek P. Moore <derekm@hackunix.org>
  *   Bryce Harrington <bryce@bryceharrington.org>
+ *   Johan Engelen <j.b.c.engelen@alumnus.utwente.nl>
  *
- * Copyright (C) 2004 Carl Hetherington
+ * Copyright (C) 2004-2011 authors
  *
  * Released under GNU GPL.  Read the file 'COPYING' for more information.
  */
@@ -16,6 +17,7 @@
 
 #include "scalar.h"
 #include "spinbutton.h"
+#include <gtkmm/scale.h>
 
 namespace Inkscape {
 namespace UI {
@@ -133,7 +135,12 @@ void Scalar::update()
     static_cast<SpinButton*>(_widget)->update();
 }
 
-
+void Scalar::addSlider()
+{
+    Gtk::HScale *scale = new Gtk::HScale( * static_cast<SpinButton*>(_widget)->get_adjustment() );
+    scale->set_draw_value(false);
+    add (*manage (scale));
+}
 
 Glib::SignalProxy0<void> Scalar::signal_value_changed()
 {
diff --git a/src/ui/widget/scalar.h b/src/ui/widget/scalar.h
index c73bcc62a..19ccb7ae0 100644
--- a/src/ui/widget/scalar.h
+++ b/src/ui/widget/scalar.h
@@ -143,6 +143,11 @@ public:
     void    update();
 
     /**
+     * Adds a slider (HScale) to the left of the spinbox.
+     */
+    void    addSlider();
+
+    /**
      * Signal raised when the spin button's value changes.
      */
     Glib::SignalProxy0<void> signal_value_changed();