updated to latest trunk

(bzr r14876.2.4)

20 files changed, 446 insertions, 408 deletions

diff --git a/src/extension/param/bool.cpp b/src/extension/param/bool.cpp
index d64f798ba..2c7e32480 100644
--- a/src/extension/param/bool.cpp
+++ b/src/extension/param/bool.cpp
@@ -23,9 +23,15 @@
 namespace Inkscape {
 namespace Extension {
 
-ParamBool::ParamBool(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml) :
-        Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-                  _value(false), _indent(0)
+ParamBool::ParamBool(const gchar * name,
+                     const gchar * text,
+                     const gchar * description,
+                     bool hidden,
+                     int indent,
+                     Inkscape::Extension::Extension * ext,
+                     Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(false)
 {
     const char * defaultval = NULL;
     if (xml->firstChild() != NULL) {
@@ -38,11 +44,6 @@ ParamBool::ParamBool(const gchar * name, const gchar * guitext, const gchar * de
         _value = false;
     }
 
-    const char * indent = xml->attribute("indent");
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
-    }
-
     gchar * pref_name = this->pref_name();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     _value = prefs->getBool(extension_pref_root + pref_name, _value);
@@ -65,7 +66,7 @@ bool ParamBool::set( bool in, SPDocument * /*doc*/, Inkscape::XML::Node * /*node
 
 bool ParamBool::get(const SPDocument * /*doc*/, const Inkscape::XML::Node * /*node*/) const
 {
-    return _value; 
+    return _value;
 }
 
 /**
@@ -125,16 +126,12 @@ void ParamBool::string(std::string &string) const
 
 Gtk::Widget *ParamBool::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-#if WITH_GTKMM_3_0
-    Gtk::Box * hbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL, 4));
+    auto hbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL, Parameter::GUI_PARAM_WIDGETS_SPACING));
     hbox->set_homogeneous(false);
-#else
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
-#endif
 
     Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START));
     label->show();
@@ -142,7 +139,7 @@ Gtk::Widget *ParamBool::get_widget(SPDocument * doc, Inkscape::XML::Node * node,
 
     ParamBoolCheckButton * checkbox = Gtk::manage(new ParamBoolCheckButton(this, doc, node, changeSignal));
     checkbox->show();
-    hbox->pack_start(*checkbox, false, false, _indent);
+    hbox->pack_start(*checkbox, false, false);
 
     hbox->show();
 
diff --git a/src/extension/param/bool.h b/src/extension/param/bool.h
index 5d190b9d3..826a98927 100644
--- a/src/extension/param/bool.h
+++ b/src/extension/param/bool.h
@@ -32,7 +32,13 @@ public:
     /**
      * Use the superclass' allocator and set the \c _value.
      */
-    ParamBool(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
+    ParamBool(const gchar * name,
+              const gchar * text,
+              const gchar * description,
+              bool hidden,
+              int indent,
+              Inkscape::Extension::Extension * ext,
+              Inkscape::XML::Node * xml);
 
     /**
      * Returns the current state/value.
@@ -69,7 +75,6 @@ public:
 private:
     /** Internal value. */
     bool _value;
-    int _indent;
 };
 
 }  // namespace Extension
diff --git a/src/extension/param/color.cpp b/src/extension/param/color.cpp
index 0b58c5011..035c43ba8 100644
--- a/src/extension/param/color.cpp
+++ b/src/extension/param/color.cpp
@@ -52,9 +52,15 @@ guint32 ParamColor::set( guint32 in, SPDocument * /*doc*/, Inkscape::XML::Node *
     return in;
 }
 
-ParamColor::ParamColor (const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-    _changeSignal(0)
+ParamColor::ParamColor(const gchar * name,
+                       const gchar * text,
+                       const gchar * description,
+                       bool hidden,
+                       int indent,
+                       Inkscape::Extension::Extension * ext,
+                       Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _changeSignal(0)
 {
     const char * defaulthex = NULL;
     if (xml->firstChild() != NULL)
@@ -86,7 +92,7 @@ Gtk::Widget *ParamColor::get_widget( SPDocument * /*doc*/, Inkscape::XML::Node *
 {
     using Inkscape::UI::Widget::ColorNotebook;
 
-    if (_gui_hidden) return NULL; 
+    if (_hidden) return NULL;
 
     if (changeSignal) {
         _changeSignal = new sigc::signal<void>(*changeSignal);
@@ -98,9 +104,9 @@ Gtk::Widget *ParamColor::get_widget( SPDocument * /*doc*/, Inkscape::XML::Node *
         _color_changed.block(false);
     }
 
-    Gtk::HBox *hbox = Gtk::manage(new Gtk::HBox(false, 4));
+    Gtk::HBox *hbox = Gtk::manage(new Gtk::HBox(false, Parameter::GUI_PARAM_WIDGETS_SPACING));
     Gtk::Widget *selector = Gtk::manage(new ColorNotebook(_color));
-    hbox->pack_start (*selector, true, true, 0);
+    hbox->pack_start(*selector, true, true, 0);
     selector->show();
     hbox->show();
     return hbox;
diff --git a/src/extension/param/color.h b/src/extension/param/color.h
index ed2e57ceb..890f5ba5f 100644
--- a/src/extension/param/color.h
+++ b/src/extension/param/color.h
@@ -31,8 +31,13 @@ private:
     Inkscape::UI::SelectedColor _color;
     sigc::connection _color_changed;
 public:
-    ParamColor(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
-
+    ParamColor(const gchar * name,
+               const gchar * text,
+               const gchar * description,
+               bool hidden,
+               int indent,
+               Inkscape::Extension::Extension * ext,
+               Inkscape::XML::Node * xml);
     virtual ~ParamColor(void);
 
     /** Returns \c _value, with a \i const to protect it. */
diff --git a/src/extension/param/description.cpp b/src/extension/param/description.cpp
index 326e75e4a..cf94918f7 100644
--- a/src/extension/param/description.cpp
+++ b/src/extension/param/description.cpp
@@ -16,6 +16,8 @@
 #include <gtkmm/box.h>
 #include <gtkmm/label.h>
 #include <glibmm/i18n.h>
+#include <glibmm/markup.h>
+#include <glibmm/regex.h>
 
 #include "xml/node.h"
 #include "extension/extension.h"
@@ -26,35 +28,61 @@ namespace Extension {
 
 
 /** \brief  Initialize the object, to do that, copy the data. */
-ParamDescription::ParamDescription (const gchar * name,
-                                    const gchar * guitext,
-                                    const gchar * desc,
-                                    const Parameter::_scope_t scope,
-                                    bool gui_hidden,
-                                    const gchar * gui_tip,
-                                    Inkscape::Extension::Extension * ext,
-                                    Inkscape::XML::Node * xml,
-                                    AppearanceMode mode) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-              _value(NULL), _mode(mode), _indent(0)
+ParamDescription::ParamDescription(const gchar * name,
+                                   const gchar * text,
+                                   const gchar * description,
+                                   bool hidden,
+                                   int indent,
+                                   Inkscape::Extension::Extension * ext,
+                                   Inkscape::XML::Node * xml,
+                                   AppearanceMode mode)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(NULL)
+    , _mode(mode)
 {
-    // printf("Building Description\n");
-    const char * defaultval = NULL;
-    if (xml->firstChild() != NULL) {
-        defaultval = xml->firstChild()->content();
+    // construct the text content by concatenating all (non-empty) text nodes,
+    // removing all other nodes (e.g. comment nodes) and replacing <extension:br> elements with "<br/>"
+    Glib::ustring value;
+    Inkscape::XML::Node * cur_child = xml->firstChild();
+    while (cur_child != NULL) {
+        if (cur_child->type() == XML::TEXT_NODE && cur_child->content() != NULL) {
+            value += cur_child->content();
+        } else if (cur_child->type() == XML::ELEMENT_NODE && !g_strcmp0(cur_child->name(), "extension:br")) {
+            value += "<br/>";
+        }
+        cur_child = cur_child->next();
     }
 
-    if (defaultval != NULL) {
-        _value = g_strdup(defaultval);
+    // if there is no text content we can return immediately (the description will be invisible)
+    if (value == Glib::ustring("")) {
+        return;
     }
 
-    _context = xml->attribute("msgctxt");
+    // do replacements in the source string to account for the attribute xml:space="preserve"
+    // (those should match replacements potentially performed by xgettext to allow for proper translation)
+    if (g_strcmp0(xml->attribute("xml:space"), "preserve") == 0) {
+        // xgettext copies the source string verbatim in this case, so no changes needed
+    } else {
+        // remove all whitespace from start/end of string and replace intermediate whitespace with a single space
+        value = Glib::Regex::create("^\\s+|\\s+$")->replace_literal(value, 0, "", (Glib::RegexMatchFlags)0);
+        value = Glib::Regex::create("\\s+")->replace_literal(value, 0, " ", (Glib::RegexMatchFlags)0);
+    }
 
-    const char * indent = xml->attribute("indent");
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
+    // translate if underscored version (_param) was used
+    if (g_str_has_prefix(xml->name(), "extension:_")) {
+        const gchar * context = xml->attribute("msgctxt");
+        if (context != NULL) {
+            value = g_dpgettext2(NULL, context, value.c_str());
+        } else {
+            value = _(value.c_str());
+        }
     }
 
+    // finally replace all remaining <br/> with a real newline character
+    value = Glib::Regex::create("<br/>")->replace_literal(value, 0, "\n", (Glib::RegexMatchFlags)0);
+
+    _value = g_strdup(value.c_str());
+
     return;
 }
 
@@ -62,36 +90,48 @@ ParamDescription::ParamDescription (const gchar * name,
 Gtk::Widget *
 ParamDescription::get_widget (SPDocument * /*doc*/, Inkscape::XML::Node * /*node*/, sigc::signal<void> * /*changeSignal*/)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
     if (_value == NULL) {
         return NULL;
     }
 
-    Glib::ustring newguitext;
+    Glib::ustring newtext = _value;
 
-    if (_context != NULL) {
-        newguitext = g_dpgettext2(NULL, _context, _value);
-    } else {
-        newguitext = _(_value);
-    }
-    
-    Gtk::Label * label;
-    int padding = 12 + _indent;
+    Gtk::Label * label = Gtk::manage(new Gtk::Label());
     if (_mode == HEADER) {
-        label = Gtk::manage(new Gtk::Label(Glib::ustring("<b>") +newguitext + Glib::ustring("</b>"), Gtk::ALIGN_START));
-        label->set_padding(0,5);
-        label->set_use_markup(true);
-        padding = _indent;
+        label->set_markup(Glib::ustring("<b>") + Glib::Markup::escape_text(newtext) + Glib::ustring("</b>"));
+        label->set_margin_top(5);
+        label->set_margin_bottom(5);
+    } else if (_mode == URL) {
+        Glib::ustring escaped_url = Glib::Markup::escape_text(newtext);
+        label->set_markup(Glib::ustring::compose("<a href='%1'>%1</a>", escaped_url));
     } else {
-        label = Gtk::manage(new Gtk::Label(newguitext, Gtk::ALIGN_START));
+        label->set_text(newtext);
     }
     label->set_line_wrap();
+#if (GTKMM_MAJOR_VERSION == 3 && GTKMM_MINOR_VERSION >= 16)
+    label->set_xalign(0);
+#else
+    label->set_alignment(Gtk::ALIGN_START);
+#endif
+
+    // TODO: Ugly "fix" for gtk3 width/height calculation of labels.
+    //   - If not applying any limits long labels will make the window grow horizontally until it uses up
+    //     most of the available space (i.e. most of the screen area) which is ridicously wide
+    //   - By using "set_default_size(0,0)" in prefidalog.cpp we tell the window to shrink as much as possible,
+    //     however this can result in a much to narrow dialog instead and much unnecessary wrapping
+    //   - Here we set a lower limit of GUI_MAX_LINE_LENGTH characters per line that long texts will always use
+    //     This means texts can not shrink anymore (they can still grow, though) and it's also necessary
+    //     to prevent https://bugzilla.gnome.org/show_bug.cgi?id=773572
+    int len = newtext.length();
+    label->set_width_chars(len > Parameter::GUI_MAX_LINE_LENGTH ? Parameter::GUI_MAX_LINE_LENGTH : len);
+
     label->show();
 
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
-    hbox->pack_start(*label, true, true, padding);
+    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox());
+    hbox->pack_start(*label, true, true);
     hbox->show();
 
     return hbox;
diff --git a/src/extension/param/description.h b/src/extension/param/description.h
index 3a72c4112..599c4db78 100644
--- a/src/extension/param/description.h
+++ b/src/extension/param/description.h
@@ -27,24 +27,22 @@ namespace Extension {
 class ParamDescription : public Parameter {
 public:
     enum AppearanceMode {
-        DESC, HEADER
+        DESCRIPTION, HEADER, URL
     };
     ParamDescription(const gchar * name,
-                     const gchar * guitext,
-                     const gchar * desc,
-                     const Parameter::_scope_t scope,
-                     bool gui_hidden,
-                     const gchar * gui_tip, 
+                     const gchar * text,
+                     const gchar * description,
+                     bool hidden,
+                     int indent,
                      Inkscape::Extension::Extension * ext,
                      Inkscape::XML::Node * xml,
                      AppearanceMode mode);
+
     Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
 private:
     /** \brief  Internal value. */
     gchar * _value;
     AppearanceMode _mode;
-    int _indent;
-    const gchar* _context;
 };
 
 }  /* namespace Extension */
diff --git a/src/extension/param/enum.cpp b/src/extension/param/enum.cpp
index 4e7420807..7cd860465 100644
--- a/src/extension/param/enum.cpp
+++ b/src/extension/param/enum.cpp
@@ -33,25 +33,28 @@ namespace Inkscape {
 namespace Extension {
 
 /* For internal use only.
-     Note that value and guitext MUST be non-NULL. This is ensured by newing only at one location in the code where non-NULL checks are made. */
+     Note that value and text MUST be non-NULL. This is ensured by newing only at one location in the code where non-NULL checks are made. */
 class enumentry {
 public:
     enumentry (Glib::ustring &val, Glib::ustring &text) :
         value(val),
-        guitext(text)
+        text(text)
     {}
 
     Glib::ustring value;
-    Glib::ustring guitext;
+    Glib::ustring text;
 };
 
 
-ParamComboBox::ParamComboBox(const gchar *name, const gchar *guitext, const gchar *desc,
-                             const Parameter::_scope_t scope, bool gui_hidden, const gchar *gui_tip,
-                             Inkscape::Extension::Extension *ext, Inkscape::XML::Node *xml)
-    : Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext)
+ParamComboBox::ParamComboBox(const gchar * name,
+                             const gchar * text,
+                             const gchar * description,
+                             bool hidden,
+                             int indent,
+                             Inkscape::Extension::Extension * ext,
+                             Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, indent, ext)
     , _value(NULL)
-    , _indent(0)
     , choices(NULL)
 {
     const char *xmlval = NULL; // the value stored in XML
@@ -61,7 +64,7 @@ ParamComboBox::ParamComboBox(const gchar *name, const gchar *guitext, const gcha
         for (Inkscape::XML::Node *node = xml->firstChild(); node; node = node->next()) {
             char const * chname = node->name();
             if (!strcmp(chname, INKSCAPE_EXTENSION_NS "item") || !strcmp(chname, INKSCAPE_EXTENSION_NS "_item")) {
-                Glib::ustring newguitext, newvalue;
+                Glib::ustring newtext, newvalue;
                 const char * contents = NULL;
                 if (node->firstChild()) {
                     contents = node->firstChild()->content();
@@ -72,12 +75,12 @@ ParamComboBox::ParamComboBox(const gchar *name, const gchar *guitext, const gcha
                     //       still need to include if are to be localized
                     if (!strcmp(chname, INKSCAPE_EXTENSION_NS "_item")) {
                         if (node->attribute("msgctxt") != NULL) {
-                            newguitext =  g_dpgettext2(NULL, node->attribute("msgctxt"), contents);
+                            newtext =  g_dpgettext2(NULL, node->attribute("msgctxt"), contents);
                         } else {
-                            newguitext =  _(contents);
+                            newtext =  _(contents);
                         }
                     } else {
-                        newguitext =  contents;
+                        newtext =  contents;
                     }
                 } else
                     continue;
@@ -89,22 +92,17 @@ ParamComboBox::ParamComboBox(const gchar *name, const gchar *guitext, const gcha
                     newvalue = contents;
                 }
 
-                if ( (!newguitext.empty()) && (!newvalue.empty()) ) {   // logical error if this is not true here
-                    choices = g_slist_append( choices, new enumentry(newvalue, newguitext) );
+                if ( (!newtext.empty()) && (!newvalue.empty()) ) {   // logical error if this is not true here
+                    choices = g_slist_append( choices, new enumentry(newvalue, newtext) );
                 }
             }
         }
-    
+
         // Initialize _value with the default value from xml
         // for simplicity : default to the contents of the first xml-child
         if (xml->firstChild() && xml->firstChild()->firstChild()) {
             xmlval = xml->firstChild()->attribute("value");
         }
-
-        const char *indent = xml->attribute("indent");
-        if (indent != NULL) {
-            _indent = atoi(indent) * 12;
-        }
     }
 
     gchar * pref_name = this->pref_name();
@@ -155,7 +153,7 @@ const gchar *ParamComboBox::set(const gchar * in, SPDocument * /*doc*/, Inkscape
     Glib::ustring settext;
     for (GSList * list = choices; list != NULL; list = g_slist_next(list)) {
         enumentry * entr = reinterpret_cast<enumentry *>(list->data);
-        if ( !entr->guitext.compare(in) ) {
+        if ( !entr->text.compare(in) ) {
             settext = entr->value;
             break;  // break out of for loop
         }
@@ -175,20 +173,20 @@ const gchar *ParamComboBox::set(const gchar * in, SPDocument * /*doc*/, Inkscape
 }
 
 /**
- * function to test if \c guitext is selectable
+ * function to test if \c text is selectable
  */
-bool ParamComboBox::contains(const gchar * guitext, SPDocument const * /*doc*/, Inkscape::XML::Node const * /*node*/) const
+bool ParamComboBox::contains(const gchar * text, SPDocument const * /*doc*/, Inkscape::XML::Node const * /*node*/) const
 {
-    if (guitext == NULL) {
+    if (text == NULL) {
         return false; /* Can't have NULL string */
     }
 
     for (GSList * list = choices; list != NULL; list = g_slist_next(list)) {
         enumentry * entr = reinterpret_cast<enumentry *>(list->data);
-        if ( !entr->guitext.compare(guitext) )
+        if ( !entr->text.compare(text) )
             return true;
     }
-    // if we did not find the guitext in this ParamComboBox:
+    // if we did not find the text in this ParamComboBox:
     return false;
 }
 
@@ -246,25 +244,25 @@ ParamComboBoxEntry::changed (void)
  */
 Gtk::Widget *ParamComboBox::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
+    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, Parameter::GUI_PARAM_WIDGETS_SPACING));
     Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START));
     label->show();
-    hbox->pack_start(*label, false, false, _indent);
+    hbox->pack_start(*label, false, false);
 
     ParamComboBoxEntry * combo = Gtk::manage(new ParamComboBoxEntry(this, doc, node, changeSignal));
     // add choice strings:
     Glib::ustring settext;
     for (GSList * list = choices; list != NULL; list = g_slist_next(list)) {
         enumentry * entr = reinterpret_cast<enumentry *>(list->data);
-        Glib::ustring text = entr->guitext;
+        Glib::ustring text = entr->text;
         combo->append(text);
 
         if ( _value && !entr->value.compare(_value) ) {
-            settext = entr->guitext;
+            settext = entr->text;
         }
     }
     if (!settext.empty()) {
diff --git a/src/extension/param/enum.h b/src/extension/param/enum.h
index 52e018469..143a648d7 100644
--- a/src/extension/param/enum.h
+++ b/src/extension/param/enum.h
@@ -34,12 +34,18 @@ private:
                 been allocated in memory.  And should be free'd.
                 It is the value of the current selected string */
     gchar * _value;
-    int _indent;
     GSList * choices; /**< A table to store the choice strings  */
 
 public:
-    ParamComboBox(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
+    ParamComboBox(const gchar * name,
+                  const gchar * text,
+                  const gchar * description,
+                  bool hidden,
+                  int indent,
+                  Inkscape::Extension::Extension * ext,
+                  Inkscape::XML::Node * xml);
     virtual ~ParamComboBox(void);
+
     Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
 
     // Explicitly call superclass version to avoid method being hidden.
@@ -52,9 +58,9 @@ public:
     const gchar * set (const gchar * in, SPDocument * doc, Inkscape::XML::Node * node);
 
     /**
-     * @returns true if guitext is part of this enum
+     * @returns true if text is part of this enum
      */
-    bool contains(const gchar * guitext, SPDocument const * /*doc*/, Inkscape::XML::Node const * /*node*/) const;
+    bool contains(const gchar * text, SPDocument const * /*doc*/, Inkscape::XML::Node const * /*node*/) const;
 
     void changed (void);
 }; /* class ParamComboBox */
diff --git a/src/extension/param/float.cpp b/src/extension/param/float.cpp
index dff7cbf46..69283a572 100644
--- a/src/extension/param/float.cpp
+++ b/src/extension/param/float.cpp
@@ -26,17 +26,19 @@ namespace Extension {
 
 
 /** Use the superclass' allocator and set the \c _value. */
-ParamFloat::ParamFloat (const gchar * name,
-                        const gchar * guitext,
-                        const gchar * desc,
-                        const Parameter::_scope_t scope,
-                        bool gui_hidden,
-                        const gchar * gui_tip,
-                        Inkscape::Extension::Extension * ext,
-                        Inkscape::XML::Node * xml,
-                        AppearanceMode mode) :
-        Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-                  _value(0.0), _mode(mode), _indent(0), _min(0.0), _max(10.0)
+ParamFloat::ParamFloat(const gchar * name,
+                       const gchar * text,
+                       const gchar * description,
+                       bool hidden,
+                       int indent,
+                       Inkscape::Extension::Extension * ext,
+                       Inkscape::XML::Node * xml,
+                       AppearanceMode mode)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(0.0)
+    , _mode(mode)
+    , _min(0.0)
+    , _max(10.0)
 {
     const gchar * defaultval = NULL;
     if (xml->firstChild() != NULL) {
@@ -68,11 +70,6 @@ ParamFloat::ParamFloat (const gchar * name,
         _min = 0.0;
     }
 
-    const char * indent = xml->attribute("indent");
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
-    }
-
     gchar * pref_name = this->pref_name();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     _value = prefs->getDouble(extension_pref_root + pref_name, _value);
@@ -170,38 +167,30 @@ void ParamFloatAdjustment::val_changed(void)
  */
 Gtk::Widget * ParamFloat::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
+    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, Parameter::GUI_PARAM_WIDGETS_SPACING));
 
-#if WITH_GTKMM_3_0
-    ParamFloatAdjustment * pfa = new ParamFloatAdjustment(this, doc, node, changeSignal);
+    auto pfa = new ParamFloatAdjustment(this, doc, node, changeSignal);
     Glib::RefPtr<Gtk::Adjustment> fadjust(pfa);
-#else
-    ParamFloatAdjustment * fadjust = Gtk::manage(new ParamFloatAdjustment(this, doc, node, changeSignal));
-#endif
-    
+
     if (_mode == FULL) {
 
         UI::Widget::SpinScale *scale = new UI::Widget::SpinScale(_text, fadjust, _precision);
         scale->set_size_request(400, -1);
         scale->show();
-        hbox->pack_start(*scale, false, false);
+        hbox->pack_start(*scale, true, true);
 
     }
     else if (_mode == MINIMAL) {
 
         Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START));
         label->show();
-        hbox->pack_start(*label, true, true, _indent);
+        hbox->pack_start(*label, true, true);
 
-#if WITH_GTKMM_3_0
-    Inkscape::UI::Widget::SpinButton * spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(fadjust, 0.1, _precision));
-#else
-    Inkscape::UI::Widget::SpinButton * spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(*fadjust, 0.1, _precision));
-#endif
+	auto spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(fadjust, 0.1, _precision));
         spin->show();
         hbox->pack_start(*spin, false, false);
     }
diff --git a/src/extension/param/float.h b/src/extension/param/float.h
index 42b1698b1..d58253ccb 100644
--- a/src/extension/param/float.h
+++ b/src/extension/param/float.h
@@ -29,15 +29,15 @@ public:
     enum AppearanceMode {
         FULL, MINIMAL
     };
-    ParamFloat (const gchar * name,
-                const gchar * guitext,
-                const gchar * desc,
-                const Parameter::_scope_t scope,
-                bool gui_hidden,
-                const gchar * gui_tip,
-                Inkscape::Extension::Extension * ext,
-                Inkscape::XML::Node * xml,
-                AppearanceMode mode);
+    ParamFloat(const gchar * name,
+               const gchar * text,
+               const gchar * description,
+               bool hidden,
+               int indent,
+               Inkscape::Extension::Extension * ext,
+               Inkscape::XML::Node * xml,
+               AppearanceMode mode);
+
     /** Returns \c _value. */
     float get(const SPDocument * /*doc*/, const Inkscape::XML::Node * /*node*/) const { return _value; }
 
@@ -60,7 +60,6 @@ private:
     /** Internal value. */
     float _value;
     AppearanceMode _mode;
-    int _indent;
     float _min;
     float _max;
     int _precision;
diff --git a/src/extension/param/int.cpp b/src/extension/param/int.cpp
index dda801282..357f98590 100644
--- a/src/extension/param/int.cpp
+++ b/src/extension/param/int.cpp
@@ -26,17 +26,19 @@ namespace Extension {
 
 
 /** Use the superclass' allocator and set the \c _value. */
-ParamInt::ParamInt (const gchar * name,
-                    const gchar * guitext,
-                    const gchar * desc,
-                    const Parameter::_scope_t scope,
-                    bool gui_hidden,
-                    const gchar * gui_tip,
-                    Inkscape::Extension::Extension * ext,
-                    Inkscape::XML::Node * xml,
-                    AppearanceMode mode) :
-        Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-                  _value(0), _mode(mode), _indent(0), _min(0), _max(10)
+ParamInt::ParamInt(const gchar * name,
+                   const gchar * text,
+                   const gchar * description,
+                   bool hidden,
+                   int indent,
+                   Inkscape::Extension::Extension * ext,
+                   Inkscape::XML::Node * xml,
+                   AppearanceMode mode)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(0)
+    , _mode(mode)
+    , _min(0)
+    , _max(10)
 {
     const char * defaultval = NULL;
     if (xml->firstChild() != NULL) {
@@ -61,11 +63,6 @@ ParamInt::ParamInt (const gchar * name,
         _min = 0;
     }
 
-    const char * indent = xml->attribute("indent");
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
-    }
-
     gchar *pref_name = this->pref_name();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     _value = prefs->getInt(extension_pref_root + pref_name, _value);
@@ -151,38 +148,28 @@ void ParamIntAdjustment::val_changed(void)
 Gtk::Widget *
 ParamInt::get_widget (SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
-
+    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, Parameter::GUI_PARAM_WIDGETS_SPACING));
 
-#if WITH_GTKMM_3_0
-    ParamIntAdjustment * pia = new ParamIntAdjustment(this, doc, node, changeSignal);
+    auto pia = new ParamIntAdjustment(this, doc, node, changeSignal);
     Glib::RefPtr<Gtk::Adjustment> fadjust(pia);
-#else
-    ParamIntAdjustment * fadjust = Gtk::manage(new ParamIntAdjustment(this, doc, node, changeSignal));
-#endif
 
     if (_mode == FULL) {
 
         UI::Widget::SpinScale *scale = new UI::Widget::SpinScale(_text, fadjust, 0);
         scale->set_size_request(400, -1);
         scale->show();
-        hbox->pack_start(*scale, false, false);
+        hbox->pack_start(*scale, true, true);
     }
     else if (_mode == MINIMAL) {
-   
         Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START));
         label->show();
-        hbox->pack_start(*label, true, true, _indent);
+        hbox->pack_start(*label, true, true);
 
-#if WITH_GTKMM_3_0 
-    Inkscape::UI::Widget::SpinButton * spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(fadjust, 1.0, 0));
-#else
-    Inkscape::UI::Widget::SpinButton * spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(*fadjust, 1.0, 0));
-#endif
+	auto spin = Gtk::manage(new Inkscape::UI::Widget::SpinButton(fadjust, 1.0, 0));
         spin->show();
         hbox->pack_start(*spin, false, false);
     }
diff --git a/src/extension/param/int.h b/src/extension/param/int.h
index 3fd6cea9b..fcb1ef3f1 100644
--- a/src/extension/param/int.h
+++ b/src/extension/param/int.h
@@ -29,15 +29,14 @@ public:
     enum AppearanceMode {
         FULL, MINIMAL
     };
-    ParamInt (const gchar * name,
-              const gchar * guitext,
-              const gchar * desc,
-              const Parameter::_scope_t scope,
-              bool gui_hidden,
-              const gchar * gui_tip,
-              Inkscape::Extension::Extension * ext,
-              Inkscape::XML::Node * xml,
-              AppearanceMode mode);
+    ParamInt(const gchar * name,
+             const gchar * text,
+             const gchar * description,
+             bool hidden,
+             int indent,
+             Inkscape::Extension::Extension * ext,
+             Inkscape::XML::Node * xml,
+             AppearanceMode mode);
 
     /** Returns \c _value. */
     int get(const SPDocument * /*doc*/, const Inkscape::XML::Node * /*node*/) const { return _value; }
@@ -59,7 +58,6 @@ private:
     /** Internal value. */
     int _value;
     AppearanceMode _mode;
-    int _indent;
     int _min;
     int _max;
 };
diff --git a/src/extension/param/notebook.cpp b/src/extension/param/notebook.cpp
index 20c8e8481..4e94b5216 100644
--- a/src/extension/param/notebook.cpp
+++ b/src/extension/param/notebook.cpp
@@ -54,17 +54,28 @@ private:
 public:
     static ParamNotebookPage * makepage (Inkscape::XML::Node * in_repr, Inkscape::Extension::Extension * in_ext);
 
-    ParamNotebookPage(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
+    ParamNotebookPage(const gchar * name,
+                      const gchar * text,
+                      const gchar * description,
+                      bool hidden,
+                      Inkscape::Extension::Extension * ext,
+                      Inkscape::XML::Node * xml);
     ~ParamNotebookPage(void);
+
     Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
     void paramString (std::list <std::string> &list);
-    gchar * get_guitext (void) {return _text;};
+    gchar * get_text (void) {return _text;};
     Parameter * get_param (const gchar * name);
 }; /* class ParamNotebookPage */
 
 
-ParamNotebookPage::ParamNotebookPage (const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext)
+ParamNotebookPage::ParamNotebookPage(const gchar * name,
+                                     const gchar * text,
+                                     const gchar * description,
+                                     bool hidden,
+                                     Inkscape::Extension::Extension * ext,
+                                     Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, /*indent*/ 0, ext)
 {
     parameters = NULL;
 
@@ -136,30 +147,23 @@ ParamNotebookPage *
 ParamNotebookPage::makepage (Inkscape::XML::Node * in_repr, Inkscape::Extension::Extension * in_ext)
 {
     const char * name;
-    const char * guitext;
-    const char * desc;
-    const char * scope_str;
-    Parameter::_scope_t scope = Parameter::SCOPE_USER;
-    bool gui_hidden = false;
-    const char * gui_hide;
-    const char * gui_tip;
+    const char * text;
+    const char * description;
+    bool hidden = false;
+    const char * hide;
 
     name = in_repr->attribute("name");
-    guitext = in_repr->attribute("gui-text");
-    if (guitext == NULL)
-        guitext = in_repr->attribute("_gui-text");
-    gui_tip = in_repr->attribute("gui-tip");
-    if (gui_tip == NULL)
-        gui_tip = in_repr->attribute("_gui-tip");
-    desc = in_repr->attribute("gui-description");
-    if (desc == NULL)
-        desc = in_repr->attribute("_gui-description");
-    scope_str = in_repr->attribute("scope");
-    gui_hide = in_repr->attribute("gui-hidden");
-    if (gui_hide != NULL) {
-        if (strcmp(gui_hide, "1") == 0 ||
-            strcmp(gui_hide, "true") == 0) {
-                gui_hidden = true;
+    text = in_repr->attribute("gui-text");
+    if (text == NULL)
+        text = in_repr->attribute("_gui-text");
+    description = in_repr->attribute("gui-description");
+    if (description == NULL)
+        description = in_repr->attribute("_gui-description");
+    hide = in_repr->attribute("gui-hidden");
+    if (hide != NULL) {
+        if (strcmp(hide, "1") == 0 ||
+            strcmp(hide, "true") == 0) {
+                hidden = true;
         }
         /* else stays false */
     }
@@ -169,17 +173,7 @@ ParamNotebookPage::makepage (Inkscape::XML::Node * in_repr, Inkscape::Extension:
         return NULL;
     }
 
-    if (scope_str != NULL) {
-        if (!strcmp(scope_str, "user")) {
-            scope = Parameter::SCOPE_USER;
-        } else if (!strcmp(scope_str, "document")) {
-            scope = Parameter::SCOPE_DOCUMENT;
-        } else if (!strcmp(scope_str, "node")) {
-            scope = Parameter::SCOPE_NODE;
-        }
-    }
-
-    ParamNotebookPage * page = new ParamNotebookPage(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+    ParamNotebookPage * page = new ParamNotebookPage(name, text, description, hidden, in_ext, in_repr);
 
     /* Note: page could equal NULL */
     return page;
@@ -194,23 +188,30 @@ ParamNotebookPage::makepage (Inkscape::XML::Node * in_repr, Inkscape::Extension:
  */
 Gtk::Widget * ParamNotebookPage::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
     Gtk::VBox * vbox = Gtk::manage(new Gtk::VBox);
-    vbox->set_border_width(5);
+    vbox->set_border_width(Parameter::GUI_BOX_MARGIN);
+    vbox->set_spacing(Parameter::GUI_BOX_SPACING);
 
     // add parameters onto page (if any)
     for (GSList * list = parameters; list != NULL; list = g_slist_next(list)) {
         Parameter * param = reinterpret_cast<Parameter *>(list->data);
         Gtk::Widget * widg = param->get_widget(doc, node, changeSignal);
         if (widg) {
+            int indent = param->get_indent();
+#if GTK_CHECK_VERSION(3,12,0)
+            widg->set_margin_start(indent * Parameter::GUI_INDENTATION);
+#else
+            widg->set_margin_left(indent * Parameter::GUI_INDENTATION);
+#endif
+            vbox->pack_start(*widg, false, false, 0);
+
             gchar const * tip = param->get_tooltip();
-    //        printf("Tip: '%s'\n", tip);
-            vbox->pack_start(*widg, false, false, 2);
             if (tip) {
-                widg->set_tooltip_text(_(tip));
+                widg->set_tooltip_text(tip);
             } else {
                 widg->set_tooltip_text("");
                 widg->set_has_tooltip(false);
@@ -224,8 +225,14 @@ Gtk::Widget * ParamNotebookPage::get_widget(SPDocument * doc, Inkscape::XML::Nod
 }
 
 
-ParamNotebook::ParamNotebook (const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext)
+ParamNotebook::ParamNotebook(const gchar * name,
+                             const gchar * text,
+                             const gchar * description,
+                             bool hidden,
+                             int indent,
+                             Inkscape::Extension::Extension * ext,
+                             Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, indent, ext)
 {
     pages = NULL;
 
@@ -353,11 +360,7 @@ public:
         // hook function
         this->signal_switch_page().connect(sigc::mem_fun(this, &ParamNotebookWdg::changed_page));
     };
-#if WITH_GTKMM_3_0
     void changed_page(Gtk::Widget *page, guint pagenum);
-#else
-    void changed_page(GtkNotebookPage *page, guint pagenum);
-#endif
     bool activated;
 };
 
@@ -368,11 +371,7 @@ public:
  * is actually visible. This to exclude 'fake' changes when the
  * notebookpages are added or removed.
  */
-#if WITH_GTKMM_3_0
 void ParamNotebookWdg::changed_page(Gtk::Widget * /*page*/, guint pagenum)
-#else
-void ParamNotebookWdg::changed_page(GtkNotebookPage * /*page*/, guint pagenum)
-#endif
 {
     if (get_visible()) {
         _pref->set((int)pagenum, _doc, _node);
@@ -424,7 +423,7 @@ Parameter *ParamNotebookPage::get_param(const gchar * name)
  */
 Gtk::Widget * ParamNotebook::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
@@ -437,7 +436,7 @@ Gtk::Widget * ParamNotebook::get_widget(SPDocument * doc, Inkscape::XML::Node *
         i++;
         ParamNotebookPage * page = reinterpret_cast<ParamNotebookPage *>(list->data);
         Gtk::Widget * widg = page->get_widget(doc, node, changeSignal);
-        nb->append_page(*widg, _(page->get_guitext()));
+        nb->append_page(*widg, _(page->get_text()));
         if (!strcmp(_value, page->name())) {
             pagenr = i; // this is the page to be displayed?
         }
diff --git a/src/extension/param/notebook.h b/src/extension/param/notebook.h
index 3c90964fd..8475de61d 100644
--- a/src/extension/param/notebook.h
+++ b/src/extension/param/notebook.h
@@ -41,8 +41,15 @@ private:
                               This only gets created if there are pages in this
                               notebook */
 public:
-    ParamNotebook(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
+    ParamNotebook(const gchar * name,
+                  const gchar * text,
+                  const gchar * description,
+                  bool hidden,
+                  int indent,
+                  Inkscape::Extension::Extension * ext,
+                  Inkscape::XML::Node * xml);
     virtual ~ParamNotebook(void);
+
     Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
 
     /**
diff --git a/src/extension/param/parameter.cpp b/src/extension/param/parameter.cpp
index e4a614667..5c4fe591f 100644
--- a/src/extension/param/parameter.cpp
+++ b/src/extension/param/parameter.cpp
@@ -50,100 +50,112 @@ Parameter *Parameter::make(Inkscape::XML::Node *in_repr, Inkscape::Extension::Ex
     const char *name = in_repr->attribute("name");
     const char *type = in_repr->attribute("type");
 
-    // In this case we just don't have enough information
-    if (!name || !type) {
+    // we can't create a parameter without type
+    if (!type) {
         return NULL;
     }
+    // also require name unless it's a pure UI element that does not store its value
+    if (!name) {
+        static std::vector<std::string> ui_elements = {"description"};
+        if (std::find(ui_elements.begin(), ui_elements.end(), type) == ui_elements.end()) {
+            return NULL;
+        }
+    }
 
-    const char *guitext = in_repr->attribute("gui-text");
-    if (guitext == NULL) {
-        guitext = in_repr->attribute("_gui-text");
-        if (guitext == NULL) {
-            // guitext = ""; // propably better to require devs to explicitly set an empty gui-text if this is what they want
+    const char *text = in_repr->attribute("gui-text");
+    if (text == NULL) {
+        text = in_repr->attribute("_gui-text");
+        if (text == NULL) {
+            // text = ""; // propably better to require devs to explicitly set an empty gui-text if this is what they want
         } else {
             const char *context = in_repr->attribute("msgctxt");
             if (context != NULL) {
-                guitext = g_dpgettext2(NULL, context, guitext);
+                text = g_dpgettext2(NULL, context, text);
             } else {
-                guitext = _(guitext);
+                text = _(text);
             }
         }
     }
-    const char *gui_tip = in_repr->attribute("gui-tip");
-    if (gui_tip == NULL) {
-        gui_tip = in_repr->attribute("_gui-tip");
-    }
-    const char *desc = in_repr->attribute("gui-description");
-    if (desc == NULL) {
-        desc = in_repr->attribute("_gui-description");
+    const char *description = in_repr->attribute("gui-description");
+    if (description == NULL) {
+        description = in_repr->attribute("_gui-description");
+        if (description != NULL) {
+            const char *context = in_repr->attribute("msgctxt");
+            if (context != NULL) {
+                description = g_dpgettext2(NULL, context, description);
+            } else {
+                description = _(description);
+            }
+        }
     }
-    bool gui_hidden = false;
+    bool hidden = false;
     {
         const char *gui_hide = in_repr->attribute("gui-hidden");
         if (gui_hide != NULL) {
             if (strcmp(gui_hide, "1") == 0 ||
                 strcmp(gui_hide, "true") == 0) {
-                gui_hidden = true;
+                hidden = true;
             }
             /* else stays false */
         }
     }
-    const gchar* appearance = in_repr->attribute("appearance");
-
-    Parameter::_scope_t scope = Parameter::SCOPE_USER;
+    int indent = 0;
     {
-        const char *scope_str = in_repr->attribute("scope");
-        if (scope_str != NULL) {
-            if (!strcmp(scope_str, "user")) {
-                scope = Parameter::SCOPE_USER;
-            } else if (!strcmp(scope_str, "document")) {
-                scope = Parameter::SCOPE_DOCUMENT;
-            } else if (!strcmp(scope_str, "node")) {
-                scope = Parameter::SCOPE_NODE;
+        const char *indent_attr = in_repr->attribute("indent");
+        if (indent_attr != NULL) {
+            if (strcmp(indent_attr, "true") == 0) {
+                indent = 1;
+            } else {
+                indent = atoi(indent_attr);
             }
         }
     }
+    const gchar* appearance = in_repr->attribute("appearance");
 
     Parameter * param = NULL;
     if (!strcmp(type, "boolean")) {
-        param = new ParamBool(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+        param = new ParamBool(name, text, description, hidden, indent, in_ext, in_repr);
     } else if (!strcmp(type, "int")) {
         if (appearance && !strcmp(appearance, "full")) {
-            param = new ParamInt(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamInt::FULL);
+            param = new ParamInt(name, text, description, hidden, indent, in_ext, in_repr, ParamInt::FULL);
         } else {
-            param = new ParamInt(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamInt::MINIMAL);
+            param = new ParamInt(name, text, description, hidden, indent, in_ext, in_repr, ParamInt::MINIMAL);
         }
     } else if (!strcmp(type, "float")) {
         if (appearance && !strcmp(appearance, "full")) {
-            param = new ParamFloat(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamFloat::FULL);
+            param = new ParamFloat(name, text, description, hidden, indent, in_ext, in_repr, ParamFloat::FULL);
         } else {
-            param = new ParamFloat(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamFloat::MINIMAL);
+            param = new ParamFloat(name, text, description, hidden, indent, in_ext, in_repr, ParamFloat::MINIMAL);
         }
     } else if (!strcmp(type, "string")) {
-        param = new ParamString(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+        param = new ParamString(name, text, description, hidden, indent, in_ext, in_repr);
         gchar const * max_length = in_repr->attribute("max_length");
         if (max_length != NULL) {
             ParamString * ps = dynamic_cast<ParamString *>(param);
             ps->setMaxLength(atoi(max_length));
         }
     } else if (!strcmp(type, "description")) {
-        if (appearance && !strcmp(appearance, "header")) {
-            param = new ParamDescription(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamDescription::HEADER);
-        } else {
-            param = new ParamDescription(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamDescription::DESC);
-        }   
+        ParamDescription::AppearanceMode appearance_mode = ParamDescription::DESCRIPTION;
+        if (appearance) {
+            if (!strcmp(appearance, "header")) {
+                appearance_mode = ParamDescription::HEADER;
+            } else if (!strcmp(appearance, "url")) {
+                appearance_mode = ParamDescription::URL;
+            }
+        }
+        param = new ParamDescription(name, text, description, hidden, indent, in_ext, in_repr, appearance_mode);
     } else if (!strcmp(type, "enum")) {
-        param = new ParamComboBox(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+        param = new ParamComboBox(name, text, description, hidden, indent, in_ext, in_repr);
     } else if (!strcmp(type, "notebook")) {
-        param = new ParamNotebook(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+        param = new ParamNotebook(name, text, description, hidden, indent, in_ext, in_repr);
     } else if (!strcmp(type, "optiongroup")) {
         if (appearance && !strcmp(appearance, "minimal")) {
-            param = new ParamRadioButton(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamRadioButton::MINIMAL);
+            param = new ParamRadioButton(name, text, description, hidden, indent, in_ext, in_repr, ParamRadioButton::MINIMAL);
         } else {
-            param = new ParamRadioButton(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr, ParamRadioButton::FULL);
+            param = new ParamRadioButton(name, text, description, hidden, indent, in_ext, in_repr, ParamRadioButton::FULL);
         }
     } else if (!strcmp(type, "color")) {
-        param = new ParamColor(name, guitext, desc, scope, gui_hidden, gui_tip, in_ext, in_repr);
+        param = new ParamColor(name, text, description, hidden, indent, in_ext, in_repr);
     }
 
     // Note: param could equal NULL
@@ -290,28 +302,24 @@ Parameter::set_color (guint32 in, SPDocument * doc, Inkscape::XML::Node * node)
 
 
 /** Oop, now that we need a parameter, we need it's name. */
-Parameter::Parameter(gchar const * name, gchar const * guitext, gchar const * desc, const Parameter::_scope_t scope, bool gui_hidden, gchar const * gui_tip, Inkscape::Extension::Extension * ext) :
-    _desc(0),
-    _scope(scope),
+Parameter::Parameter(gchar const * name, gchar const * text, gchar const * description, bool hidden, int indent, Inkscape::Extension::Extension * ext) :
+    _description(0),
     _text(0),
-    _gui_hidden(gui_hidden),
-    _gui_tip(0),
-    extension(ext),
+    _hidden(hidden),
+    _indent(indent),
+    _extension(ext),
     _name(0)
 {
     if (name != NULL) {
         _name = g_strdup(name);
     }
-    if (desc != NULL) {
-        _desc = g_strdup(desc);
-//        printf("Adding description: '%s' on '%s'\n", _desc, _name);
-    }
-    if (gui_tip != NULL) {
-        _gui_tip = g_strdup(gui_tip);
+
+    if (description != NULL) {
+        _description = g_strdup(description);
     }
 
-    if (guitext != NULL) {
-        _text = g_strdup(guitext);
+    if (text != NULL) {
+        _text = g_strdup(text);
     } else {
         _text = g_strdup(name);
     }
@@ -320,20 +328,19 @@ Parameter::Parameter(gchar const * name, gchar const * guitext, gchar const * de
 }
 
 /** Oop, now that we need a parameter, we need it's name. */
-Parameter::Parameter (gchar const * name, gchar const * guitext, Inkscape::Extension::Extension * ext) :
-    _desc(0),
-    _scope(Parameter::SCOPE_USER),
+Parameter::Parameter (gchar const * name, gchar const * text, Inkscape::Extension::Extension * ext) :
+    _description(0),
     _text(0),
-    _gui_hidden(false),
-    _gui_tip(0),
-    extension(ext),
+    _hidden(false),
+    _indent(0),
+    _extension(ext),
     _name(0)
 {
     if (name != NULL) {
         _name = g_strdup(name);
     }
-    if (guitext != NULL) {
-        _text = g_strdup(guitext);
+    if (text != NULL) {
+        _text = g_strdup(text);
     } else {
         _text = g_strdup(name);
     }
@@ -349,16 +356,13 @@ Parameter::~Parameter(void)
     g_free(_text);
     _text = 0;
 
-    g_free(_gui_tip);
-    _gui_tip = 0;
-
-    g_free(_desc);
-    _desc = 0;
+    g_free(_description);
+    _description = 0;
 }
 
 gchar *Parameter::pref_name(void) const
 {
-    return g_strdup_printf("%s.%s", extension->get_id(), _name);
+    return g_strdup_printf("%s.%s", _extension->get_id(), _name);
 }
 
 Inkscape::XML::Node *
@@ -391,7 +395,7 @@ Inkscape::XML::Node *Parameter::document_param_node(SPDocument * doc)
             child != NULL;
             child = child->next()) {
         if ((GQuark)child->code() == name_quark &&
-                !strcmp(child->attribute("extension"), extension->get_id())) {
+                !strcmp(child->attribute("extension"), _extension->get_id())) {
             params = child;
             break;
         }
@@ -399,7 +403,7 @@ Inkscape::XML::Node *Parameter::document_param_node(SPDocument * doc)
 
     if (params == NULL) {
         params = xml_doc->createElement("inkscape:extension-param");
-        params->setAttribute("extension", extension->get_id());
+        params->setAttribute("extension", _extension->get_id());
         defs->appendChild(params);
         Inkscape::GC::release(params);
     }
diff --git a/src/extension/param/parameter.h b/src/extension/param/parameter.h
index 5e1e3897f..96cc055d8 100644
--- a/src/extension/param/parameter.h
+++ b/src/extension/param/parameter.h
@@ -37,7 +37,7 @@ class Extension;
  */
 extern Glib::ustring const extension_pref_root;
 
-/** 
+/**
  * A class to represent the parameter of an extension.
  *
  * This is really a super class that allows them to abstract all
@@ -47,25 +47,16 @@ extern Glib::ustring const extension_pref_root;
  */
 class Parameter {
 
-protected:
-    /** List of possible scopes. */
-    typedef enum {
-        SCOPE_USER,     /**<  Parameter value is saved in the user's configuration file. (default) */
-        SCOPE_DOCUMENT, /**<  Parameter value is saved in the document. */
-        SCOPE_NODE      /**<  Parameter value is attached to the node. */
-    } _scope_t;
-
 public:
     Parameter(gchar const *name,
-              gchar const *guitext,
-              gchar const *desc,
-              const Parameter::_scope_t scope,
-              bool gui_hidden,
-              gchar const *gui_tip,
+              gchar const *text,
+              gchar const *description,
+              bool hidden,
+              int indent,
               Inkscape::Extension::Extension * ext);
 
     Parameter(gchar const *name,
-              gchar const *guitext,
+              gchar const *text,
               Inkscape::Extension::Extension * ext);
 
     virtual ~Parameter(void);
@@ -139,10 +130,13 @@ public:
 
     virtual Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
 
-    gchar const * get_tooltip(void) const { return _desc; }
+    gchar const * get_tooltip(void) const { return _description; }
 
     /** Indicates if the GUI for this parameter is hidden or not */
-    bool get_gui_hidden() const { return _gui_hidden; }
+    bool get_hidden() const { return _hidden; }
+
+    /** Indentation level of the parameter */
+    int get_indent() const { return _indent; }
 
     virtual void string(std::list <std::string> &list) const;
 
@@ -155,21 +149,31 @@ public:
     /** All the code in Notebook::get_param to get the notebook content. */
     virtual Parameter *get_param(gchar const *name);
 
-protected:
-    /** Description of the parameter. */
-    gchar *       _desc;
 
-    /** Scope of the parameter. */
-    _scope_t _scope;
+    /** Recommended margin of boxes containing multiple Parameters (in px) */
+    const static int GUI_BOX_MARGIN = 10;
+    /** Recommended spacing between multiple Parameters packed into a box (in px) */
+    const static int GUI_BOX_SPACING = 4;
+    /** Recommended spacing between the widgets making up a signle Parameter (e.g. label and input) (in px) */
+    const static int GUI_PARAM_WIDGETS_SPACING = 4;
+    /** Recommended indentation width of parameters (in px) */
+    const static int GUI_INDENTATION = 12;
+    /** Recommended maximum line lenght for wrapping textual parameters (in chars) */
+    const static int GUI_MAX_LINE_LENGTH = 60;
+
+
+protected:
+    /** Parameter text to show as the GUI label. */
+    gchar * _text;
 
-    /** Text for the GUI selection of this. */
-    gchar *  _text;
+    /** Extended description of the parameter (crrently shown as tooltip on hover). */
+    gchar * _description;
 
-    /** Whether the GUI is visible. */
-    bool _gui_hidden;
+    /** Whether the parameter is visible. */
+    bool _hidden;
 
-    /** A tip for the GUI if there is one. */
-    gchar *  _gui_tip;
+    /** Indentation level of the parameter. */
+    int _indent;
 
 
     /* **** funcs **** */
@@ -187,7 +191,7 @@ protected:
 
 private:
     /** Which extension is this parameter attached to. */
-    Inkscape::Extension::Extension *extension;
+    Inkscape::Extension::Extension *_extension;
 
     /** The name of this parameter. */
     gchar *_name;
diff --git a/src/extension/param/radiobutton.cpp b/src/extension/param/radiobutton.cpp
index 1d1b860c6..a08ba6860 100644
--- a/src/extension/param/radiobutton.cpp
+++ b/src/extension/param/radiobutton.cpp
@@ -41,33 +41,34 @@ namespace Inkscape {
 namespace Extension {
 
 /* For internal use only.
-     Note that value and guitext MUST be non-NULL. This is ensured by newing only at one location in the code where non-NULL checks are made. */
+     Note that value and text MUST be non-NULL. This is ensured by newing only at one location in the code where non-NULL checks are made. */
 class optionentry {
 public:
-    optionentry (Glib::ustring * val, Glib::ustring * text) {
+    optionentry (Glib::ustring * val, Glib::ustring * txt) {
         value = val;
-        guitext = text;
+        text = txt;
     }
     ~optionentry() {
         delete value;
-        delete guitext;
+        delete text;
     }
 
     Glib::ustring * value;
-    Glib::ustring * guitext;
+    Glib::ustring * text;
 };
 
-ParamRadioButton::ParamRadioButton (const gchar * name,
-                                    const gchar * guitext,
-                                    const gchar * desc,
-                                    const Parameter::_scope_t scope,
-                                    bool gui_hidden,
-                                    const gchar * gui_tip,
-                                    Inkscape::Extension::Extension * ext,
-                                    Inkscape::XML::Node * xml,
-                                    AppearanceMode mode) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-    _value(0), _mode(mode), _indent(0), choices(0)
+ParamRadioButton::ParamRadioButton(const gchar * name,
+                                   const gchar * text,
+                                   const gchar * description,
+                                   bool hidden,
+                                   int indent,
+                                   Inkscape::Extension::Extension * ext,
+                                   Inkscape::XML::Node * xml,
+                                   AppearanceMode mode)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(0)
+    , _mode(mode)
+    , choices(0)
 {
     // Read XML tree to add enumeration items:
     // printf("Extension Constructor: ");
@@ -76,7 +77,7 @@ ParamRadioButton::ParamRadioButton (const gchar * name,
         while (child_repr != NULL) {
             char const * chname = child_repr->name();
             if (!strcmp(chname, INKSCAPE_EXTENSION_NS "option") || !strcmp(chname, INKSCAPE_EXTENSION_NS "_option")) {
-                Glib::ustring * newguitext = NULL;
+                Glib::ustring * newtext = NULL;
                 Glib::ustring * newvalue = NULL;
                 const char * contents = child_repr->firstChild()->content();
 
@@ -84,12 +85,12 @@ ParamRadioButton::ParamRadioButton (const gchar * name,
                     // don't translate when 'item' but do translate when '_option'
                     if (!strcmp(chname, INKSCAPE_EXTENSION_NS "_option")) {
                         if (child_repr->attribute("msgctxt") != NULL) {
-                            newguitext =  new Glib::ustring(g_dpgettext2(NULL, child_repr->attribute("msgctxt"), contents));
+                            newtext =  new Glib::ustring(g_dpgettext2(NULL, child_repr->attribute("msgctxt"), contents));
                         } else {
-                            newguitext =  new Glib::ustring(_(contents));
+                            newtext =  new Glib::ustring(_(contents));
                         }
                     } else {
-                        newguitext =  new Glib::ustring(contents);
+                        newtext =  new Glib::ustring(contents);
                     }
                 } else {
                     continue;
@@ -103,8 +104,8 @@ ParamRadioButton::ParamRadioButton (const gchar * name,
                     newvalue = new Glib::ustring(contents);
                 }
 
-                if ( (newguitext) && (newvalue) ) {   // logical error if this is not true here
-                    choices = g_slist_append( choices, new optionentry(newvalue, newguitext) );
+                if ( (newtext) && (newvalue) ) {   // logical error if this is not true here
+                    choices = g_slist_append( choices, new optionentry(newvalue, newtext) );
                 }
             }
             child_repr = child_repr->next();
@@ -118,11 +119,6 @@ ParamRadioButton::ParamRadioButton (const gchar * name,
         defaultval = (static_cast<optionentry*> (choices->data))->value->c_str();
     }
 
-    const char *indent = xml ? xml->attribute("indent") : NULL;
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
-    }
-
     gchar * pref_name = this->pref_name();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     Glib::ustring paramval = prefs->getString(extension_pref_root + pref_name);
@@ -284,7 +280,7 @@ Glib::ustring ParamRadioButton::value_from_label(const Glib::ustring label)
 
     for (GSList * list = choices; list != NULL; list = g_slist_next(list)) {
         optionentry * entr = reinterpret_cast<optionentry *>(list->data);
-        if ( !entr->guitext->compare(label) ) {
+        if ( !entr->text->compare(label) ) {
             value = *(entr->value);
             break;
         }
@@ -299,23 +295,18 @@ Glib::ustring ParamRadioButton::value_from_label(const Glib::ustring label)
  */
 Gtk::Widget * ParamRadioButton::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-#if WITH_GTKMM_3_0
-    Gtk::Box * hbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL, 4));
+    auto hbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_HORIZONTAL, Parameter::GUI_PARAM_WIDGETS_SPACING));
     hbox->set_homogeneous(false);
-    Gtk::Box * vbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0));
+    auto vbox = Gtk::manage(new Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0));
     vbox->set_homogeneous(false);
-#else
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
-    Gtk::VBox * vbox = Gtk::manage(new Gtk::VBox(false, 0));
-#endif
 
     Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START, Gtk::ALIGN_START));
     label->show();
-    hbox->pack_start(*label, false, false, _indent);
+    hbox->pack_start(*label, false, false);
 
     Gtk::ComboBoxText* cbt = 0;
     bool comboSet = false;
@@ -330,7 +321,7 @@ Gtk::Widget * ParamRadioButton::get_widget(SPDocument * doc, Inkscape::XML::Node
     Gtk::RadioButtonGroup group;
     for (GSList * list = choices; list != NULL; list = g_slist_next(list)) {
         optionentry * entr = reinterpret_cast<optionentry *>(list->data);
-        Glib::ustring * text = entr->guitext;
+        Glib::ustring * text = entr->text;
         switch ( _mode ) {
             case MINIMAL:
             {
diff --git a/src/extension/param/radiobutton.h b/src/extension/param/radiobutton.h
index 0e0f643c9..b91b11ea3 100644
--- a/src/extension/param/radiobutton.h
+++ b/src/extension/param/radiobutton.h
@@ -35,15 +35,15 @@ public:
     };
 
     ParamRadioButton(const gchar * name,
-                     const gchar * guitext,
-                     const gchar * desc,
-                     const Parameter::_scope_t scope,
-                     bool gui_hidden,
-                     const gchar * gui_tip,
+                     const gchar * text,
+                     const gchar * description,
+                     bool hidden,
+                     int indent,
                      Inkscape::Extension::Extension * ext,
                      Inkscape::XML::Node * xml,
                      AppearanceMode mode);
     virtual ~ParamRadioButton(void);
+
     Gtk::Widget * get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal);
 
     // Explicitly call superclass version to avoid method being hidden.
@@ -63,7 +63,6 @@ private:
                 It is the value of the current selected string */
     gchar * _value;
     AppearanceMode _mode;
-    int _indent;
     GSList * choices; /**< A table to store the choice strings  */
 
 }; /* class ParamRadioButton */
diff --git a/src/extension/param/string.cpp b/src/extension/param/string.cpp
index 6b082b133..51b5dfdf3 100644
--- a/src/extension/param/string.cpp
+++ b/src/extension/param/string.cpp
@@ -24,7 +24,7 @@
 
 namespace Inkscape {
 namespace Extension {
-    
+
 
 /** Free the allocated data. */
 ParamString::~ParamString(void)
@@ -76,20 +76,21 @@ void ParamString::string(std::string &string) const
 }
 
 /** Initialize the object, to do that, copy the data. */
-ParamString::ParamString (const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml) :
-    Parameter(name, guitext, desc, scope, gui_hidden, gui_tip, ext),
-              _value(NULL), _indent(0)
+ParamString::ParamString(const gchar * name,
+                         const gchar * text,
+                         const gchar * description,
+                         bool hidden,
+                         int indent,
+                         Inkscape::Extension::Extension * ext,
+                         Inkscape::XML::Node * xml)
+    : Parameter(name, text, description, hidden, indent, ext)
+    , _value(NULL)
 {
     const char * defaultval = NULL;
     if (xml->firstChild() != NULL) {
         defaultval = xml->firstChild()->content();
     }
 
-    const char * indent = xml->attribute("indent");
-    if (indent != NULL) {
-        _indent = atoi(indent) * 12;
-    }
-
     gchar * pref_name = this->pref_name();
     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
     Glib::ustring paramval = prefs->getString(extension_pref_root + pref_name);
@@ -161,14 +162,14 @@ void ParamStringEntry::changed_text(void)
  */
 Gtk::Widget * ParamString::get_widget(SPDocument * doc, Inkscape::XML::Node * node, sigc::signal<void> * changeSignal)
 {
-    if (_gui_hidden) {
+    if (_hidden) {
         return NULL;
     }
 
-    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, 4));
+    Gtk::HBox * hbox = Gtk::manage(new Gtk::HBox(false, Parameter::GUI_PARAM_WIDGETS_SPACING));
     Gtk::Label * label = Gtk::manage(new Gtk::Label(_text, Gtk::ALIGN_START));
     label->show();
-    hbox->pack_start(*label, false, false, _indent);
+    hbox->pack_start(*label, false, false);
 
     ParamStringEntry * textbox = new ParamStringEntry(this, doc, node, changeSignal);
     textbox->show();
diff --git a/src/extension/param/string.h b/src/extension/param/string.h
index 3b137aeac..d338f83b9 100644
--- a/src/extension/param/string.h
+++ b/src/extension/param/string.h
@@ -19,12 +19,17 @@ private:
     /** \brief  Internal value.  This should point to a string that has
                 been allocated in memory.  And should be free'd. */
     gchar * _value;
-    /** \brief Internal value. This indicates the maximum leght of the string. Zero meaning unlimited. 
+    /** \brief Internal value. This indicates the maximum lenth of the string. Zero meaning unlimited.
       */
-    int _indent;
     gint _max_length;
 public:
-    ParamString(const gchar * name, const gchar * guitext, const gchar * desc, const Parameter::_scope_t scope, bool gui_hidden, const gchar * gui_tip, Inkscape::Extension::Extension * ext, Inkscape::XML::Node * xml);
+    ParamString(const gchar * name,
+                const gchar * text,
+                const gchar * description,
+                bool hidden,
+                int indent,
+                Inkscape::Extension::Extension * ext,
+                Inkscape::XML::Node * xml);
     virtual ~ParamString(void);
 
     /** \brief  Returns \c _value, with a \i const to protect it. */