Update to trunk

(bzr r13090.1.38)

9 files changed, 160 insertions, 92 deletions

diff --git a/src/ui/dialog/dialog.cpp b/src/ui/dialog/dialog.cpp
index 3cc3f3d88..645294bb5 100644
--- a/src/ui/dialog/dialog.cpp
+++ b/src/ui/dialog/dialog.cpp
@@ -26,11 +26,11 @@
 #include "ui/tools/tool-base.h"
 #include "desktop.h"
 #include "desktop-handles.h"
-#include "modifier-fns.h"
 #include "shortcuts.h"
 #include "preferences.h"
 #include "interface.h"
 #include "verbs.h"
+#include "ui/tool/event-utils.h"
 
 #include <gtk/gtk.h>
 
@@ -279,7 +279,7 @@ bool Dialog::_onEvent(GdkEvent *event)
                 case GDK_KEY_F4:
                 case GDK_KEY_w:
                 case GDK_KEY_W: {
-                    if (mod_ctrl_only(event->key.state)) {
+                    if (Inkscape::UI::held_only_control(event->key)) {
                         _close();
                         ret = true;
                     }
diff --git a/src/ui/dialog/guides.cpp b/src/ui/dialog/guides.cpp
index e84f25733..80740113c 100644
--- a/src/ui/dialog/guides.cpp
+++ b/src/ui/dialog/guides.cpp
@@ -68,20 +68,6 @@ void GuidelinePropertiesDialog::showDialog(SPGuide *guide, SPDesktop *desktop) {
     dialog.run();
 }
 
-void GuidelinePropertiesDialog::_colorChanged()
-{
-#if WITH_GTKMM_3_0
-    const Gdk::RGBA c = _color.get_rgba();
-    unsigned r = c.get_red_u()/257, g = c.get_green_u()/257, b = c.get_blue_u()/257;
-#else
-    const Gdk::Color c = _color.get_color();
-    unsigned r = c.get_red()/257, g = c.get_green()/257, b = c.get_blue()/257;
-#endif
-    //TODO: why 257? verify this!
-
-    sp_guide_set_color(*_guide, r, g, b, true);
-}
-
 void GuidelinePropertiesDialog::_modeChanged()
 {
     _mode = !_relative_toggle.get_active();
@@ -100,7 +86,7 @@ void GuidelinePropertiesDialog::_modeChanged()
     }
 }
 
-void GuidelinePropertiesDialog::_onApply()
+void GuidelinePropertiesDialog::_onOK()
 {
     double deg_angle = _spin_angle.getValue(DEG);
     if (!_mode)
@@ -124,18 +110,26 @@ void GuidelinePropertiesDialog::_onApply()
 
     sp_guide_moveto(*_guide, newpos, true);
 
-    const gchar* name = _label_entry.getEntry()->get_text().c_str();
+    const gchar* name = g_strdup( _label_entry.getEntry()->get_text().c_str() );
+
     sp_guide_set_label(*_guide, name, true);
+    g_free((gpointer) name);
+
+#if WITH_GTKMM_3_0
+    const Gdk::RGBA c = _color.get_rgba();
+    unsigned r = c.get_red_u()/257, g = c.get_green_u()/257, b = c.get_blue_u()/257;
+#else
+    const Gdk::Color c = _color.get_color();
+    unsigned r = c.get_red()/257, g = c.get_green()/257, b = c.get_blue()/257;
+#endif
+    //TODO: why 257? verify this!
+
+    sp_guide_set_color(*_guide, r, g, b, true);
 
     DocumentUndo::done(_guide->document, SP_VERB_NONE, 
                        _("Set guide properties"));
 }
 
-void GuidelinePropertiesDialog::_onOK()
-{
-    _onApply();
-}
-
 void GuidelinePropertiesDialog::_onDelete()
 {
     SPDocument *doc = _guide->document;
@@ -157,10 +151,6 @@ void GuidelinePropertiesDialog::_response(gint response)
             break;
 	case Gtk::RESPONSE_DELETE_EVENT:
             break;
-/*	case GTK_RESPONSE_APPLY:
-        _onApply();
-        break;
-*/
 	default:
             g_assert_not_reached();
     }
@@ -222,9 +212,6 @@ void GuidelinePropertiesDialog::_setup() {
                          1, 3, 3, 4, Gtk::EXPAND | Gtk::FILL, Gtk::FILL);
 #endif
 
-    _color.signal_color_set().connect(sigc::mem_fun(*this, &GuidelinePropertiesDialog::_colorChanged));
-
-
     // unitmenus
     /* fixme: We should allow percents here too, as percents of the canvas size */
     _unit_menu.setUnitType(UNIT_TYPE_LINEAR);
diff --git a/src/ui/dialog/guides.h b/src/ui/dialog/guides.h
index 422fed7fe..22bf5097a 100644
--- a/src/ui/dialog/guides.h
+++ b/src/ui/dialog/guides.h
@@ -62,13 +62,11 @@ public:
 protected:
     void _setup();
 
-    void _onApply();
     void _onOK();
     void _onDelete();
 
     void _response(gint response);
     void _modeChanged();
-    void _colorChanged();
 
 private:
     GuidelinePropertiesDialog(GuidelinePropertiesDialog const &); // no copy
diff --git a/src/ui/dialog/pixelartdialog.cpp b/src/ui/dialog/pixelartdialog.cpp
index ce5b6584d..31449d4e7 100644
--- a/src/ui/dialog/pixelartdialog.cpp
+++ b/src/ui/dialog/pixelartdialog.cpp
@@ -16,6 +16,16 @@
 # include <config.h>
 #endif
 
+#ifdef GLIBMM_DISABLE_DEPRECATED
+#  undef GLIBMM_DISABLE_DEPRECATED
+#  include <glibmm/thread.h>
+#  include <glibmm/dispatcher.h>
+#  define GLIBMM_DISABLE_DEPRECATED 1
+#else // GLIBMM_DISABLE_DEPRECATED
+#  include <glibmm/thread.h>
+#  include <glibmm/dispatcher.h>
+#endif // GLIBMM_DISABLE_DEPRECATED
+
 #include "pixelartdialog.h"
 #include <gtkmm/radiobutton.h>
 #include <gtkmm/stock.h>
@@ -54,18 +64,6 @@ namespace Inkscape {
 namespace UI {
 namespace Dialog {
 
-template<class T>
-T move(T &obj)
-{
-#ifdef LIBDEPIXELIZE_ENABLE_CPP11
-    return std::move(obj);
-#else
-    T ret;
-    std::swap(obj, ret);
-    return ret;
-#endif // LIBDEPIXELIZE_ENABLE_CPP11
-}
-
 /**
  * A dialog for adjusting pixel art -> vector tracing parameters
  */
@@ -77,6 +75,23 @@ public:
     ~PixelArtDialogImpl();
 
 private:
+    struct Input
+    {
+        Glib::RefPtr<Gdk::Pixbuf> pixbuf;
+        SVGLength x;
+        SVGLength y;
+    };
+    struct Output
+    {
+        Output(Tracer::Splines splines, SVGLength x, SVGLength y) :
+            splines(splines), x(x), y(y)
+        {}
+
+        Tracer::Splines splines;
+        SVGLength x;
+        SVGLength y;
+    };
+
     void setDesktop(SPDesktop *desktop);
     void setTargetDesktop(SPDesktop *desktop);
 
@@ -89,7 +104,8 @@ private:
     Tracer::Kopf2011::Options options();
 
     void vectorize();
-    void processLibdepixelize(SPImage *img);
+    void processLibdepixelize(const Input &image);
+    void importOutput(const Output &out);
     void setDefaults();
     void updatePreview();
 
@@ -133,9 +149,21 @@ private:
     Gtk::RadioButton optimizeRadioButton;
 #endif // LIBDEPIXELIZE_INKSCAPE_ENABLE_SMOOTH
 
+    //############ UI Logic data
+
     SPDesktop *desktop;
     DesktopTracker deskTrack;
     sigc::connection desktopChangeConn;
+
+    //############ Threads
+    void workerThread();
+    void onWorkerThreadFinished();
+    Glib::Thread *thread;
+    volatile gint abortThread; // C++11's atomic stuff is sooo much nicer
+    Glib::Dispatcher dispatcher;
+    std::vector<Input> queue;
+    std::vector<Output> output;
+    Tracer::Kopf2011::Options lastOptions;
 };
 
 void PixelArtDialogImpl::setDesktop(SPDesktop *desktop)
@@ -288,6 +316,9 @@ PixelArtDialogImpl::PixelArtDialogImpl() :
     deskTrack.connect(GTK_WIDGET(gobj()));
 
     signalResponse().connect(sigc::mem_fun(*this, &PixelArtDialogImpl::responseCallback));
+
+    dispatcher.connect(
+        sigc::mem_fun(*this, &PixelArtDialogImpl::onWorkerThreadFinished) );
 }
 
 void PixelArtDialogImpl::responseCallback(int response_id)
@@ -295,7 +326,8 @@ void PixelArtDialogImpl::responseCallback(int response_id)
     if (response_id == GTK_RESPONSE_OK) {
         vectorize();
     } else if (response_id == GTK_RESPONSE_CANCEL) {
-        // TODO
+        // libdepixelize's interface need to be extended to allow aborts
+        g_atomic_int_set(&abortThread, true);
     } else if (response_id == GTK_RESPONSE_HELP) {
         setDefaults();
     } else {
@@ -340,39 +372,53 @@ void PixelArtDialogImpl::vectorize()
         return;
     }
 
-    bool found = false;
-
     for ( GSList const *list = desktop->selection->itemList() ; list
               ; list = list->next ) {
         if ( !SP_IS_IMAGE(list->data) )
             continue;
 
-        found = true;
+        SPImage *img = SP_IMAGE(list->data);
+        Input input;
+        input.pixbuf = Glib::wrap(img->pixbuf->getPixbufRaw(), true);
+        input.x = img->x;
+        input.y = img->y;
+
+        if ( input.pixbuf->get_width() > 256
+             || input.pixbuf->get_height() > 256 ) {
+            char *msg = _("Image looks too big. Process may take a while and is"
+                          " wise to save your document before continue."
+                          "\n\nContinue the procedure (without saving)?");
+            Gtk::MessageDialog dialog(msg, false, Gtk::MESSAGE_WARNING,
+                                      Gtk::BUTTONS_OK_CANCEL, true);
+
+            if ( dialog.run() != Gtk::RESPONSE_OK )
+                continue;
+        }
 
-        processLibdepixelize(SP_IMAGE(list->data));
+        queue.push_back(input);
     }
 
-    if ( !found ) {
+    if ( !queue.size() ) {
         char *msg = _("Select an <b>image</b> to trace");
         msgStack->flash(Inkscape::ERROR_MESSAGE, msg);
         return;
     }
 
-    DocumentUndo::done(desktop->doc(), SP_VERB_SELECTION_PIXEL_ART,
-                       _("Trace pixel art"));
+    mainCancelButton->set_sensitive(true);
+    mainOkButton->set_sensitive(false);
 
-    // Flush pending updates
-    desktop->doc()->ensureUpToDate();
+    lastOptions = options();
+
+    g_atomic_int_set(&abortThread, false);
+    thread = Glib::Thread::create(
+        sigc::mem_fun(*this, &PixelArtDialogImpl::workerThread) );
 }
 
-void PixelArtDialogImpl::processLibdepixelize(SPImage *img)
+void PixelArtDialogImpl::processLibdepixelize(const Input &input)
 {
     Tracer::Splines out;
 
-    Glib::RefPtr<Gdk::Pixbuf> pixbuf
-        = Glib::wrap(img->pixbuf->getPixbufRaw(), true);
-
-    if ( pixbuf->get_width() > 256 || pixbuf->get_height() > 256 ) {
+    if ( input.pixbuf->get_width() > 256 || input.pixbuf->get_height() > 256 ) {
         char *msg = _("Image looks too big. Process may take a while and it is"
                       " wise to save your document before continuing."
                       "\n\nContinue the procedure (without saving)?");
@@ -384,16 +430,23 @@ void PixelArtDialogImpl::processLibdepixelize(SPImage *img)
     }
 
     if ( voronoiRadioButton.get_active() ) {
-        out = Tracer::Kopf2011::to_voronoi(pixbuf, options());
+        output.push_back(Output(Tracer::Kopf2011::to_voronoi(input.pixbuf,
+                                                             lastOptions),
+                                input.x, input.y));
     } else {
-        out = Tracer::Kopf2011::to_splines(pixbuf, options());
+        output.push_back(Output(Tracer::Kopf2011::to_splines(input.pixbuf,
+                                                             lastOptions),
+                                input.x, input.y));
     }
+}
 
+void PixelArtDialogImpl::importOutput(const Output &output)
+{
     Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();
     Inkscape::XML::Node *group = xml_doc->createElement("svg:g");
 
-    for ( Tracer::Splines::iterator it = out.begin(), end = out.end()
-              ; it != end ; ++it ) {
+    for ( Tracer::Splines::const_iterator it = output.splines.begin(),
+              end = output.splines.end() ; it != end ; ++it ) {
         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 
         {
@@ -421,7 +474,7 @@ void PixelArtDialogImpl::processLibdepixelize(SPImage *img)
             sp_repr_css_attr_unref(css);
         }
 
-        gchar *str = sp_svg_write_path(Dialog::move(it->pathVector));
+        gchar *str = sp_svg_write_path(it->pathVector);
         repr->setAttribute("d", str);
         g_free(str);
 
@@ -433,14 +486,20 @@ void PixelArtDialogImpl::processLibdepixelize(SPImage *img)
     {
         group->setAttribute("transform",
                             (std::string("translate(")
-                             + sp_svg_length_write_with_units(img->x)
-                             + ' ' + sp_svg_length_write_with_units(img->y)
+                             + sp_svg_length_write_with_units(output.x)
+                             + ' ' + sp_svg_length_write_with_units(output.y)
                              + ')').c_str());
     }
 
     desktop->currentLayer()->appendChildRepr(group);
 
     Inkscape::GC::release(group);
+
+    DocumentUndo::done(desktop->doc(), SP_VERB_SELECTION_PIXEL_ART,
+                       _("Trace pixel art"));
+
+    // Flush pending updates
+    desktop->doc()->ensureUpToDate();
 }
 
 void PixelArtDialogImpl::setDefaults()
@@ -481,6 +540,29 @@ void PixelArtDialogImpl::updatePreview()
     pendingPreview = false;
 }
 
+void PixelArtDialogImpl::workerThread()
+{
+    for ( std::vector<Input>::iterator it = queue.begin(), end = queue.end()
+              ; it != end && !g_atomic_int_get(&abortThread) ; ++it ) {
+        processLibdepixelize(*it);
+    }
+    queue.clear();
+    dispatcher();
+}
+
+void PixelArtDialogImpl::onWorkerThreadFinished()
+{
+    thread->join();
+    thread = NULL;
+    for ( std::vector<Output>::const_iterator it = output.begin(),
+              end = output.end() ; it != end ; ++it ) {
+        importOutput(*it);
+    }
+    output.clear();
+    mainCancelButton->set_sensitive(false);
+    mainOkButton->set_sensitive(true);
+}
+
 /**
  * Factory method.  Use this to create a new PixelArtDialog
  */
diff --git a/src/ui/tools/connector-tool.cpp b/src/ui/tools/connector-tool.cpp
index 4f918b483..d1355e807 100644
--- a/src/ui/tools/connector-tool.cpp
+++ b/src/ui/tools/connector-tool.cpp
@@ -366,7 +366,7 @@ cc_select_handle(SPKnot* knot)
     knot->setSize(10);
     knot->setAnchor(SP_ANCHOR_CENTER);
     knot->setFill(0x0000ffff, 0x0000ffff, 0x0000ffff);
-    knot->update_ctrl();
+    knot->updateCtrl();
 }
 
 static void
@@ -376,7 +376,7 @@ cc_deselect_handle(SPKnot* knot)
     knot->setSize(8);
     knot->setAnchor(SP_ANCHOR_CENTER);
     knot->setFill(0xffffff00, 0xff0000ff, 0xff0000ff);
-    knot->update_ctrl();
+    knot->updateCtrl();
 }
 
 bool ConnectorTool::item_handler(SPItem* item, GdkEvent* event) {
@@ -981,7 +981,7 @@ cc_generic_knot_handler(SPCanvasItem *, GdkEvent *event, SPKnot *knot)
     gchar const *knot_tip = "Click to join at this point";
     switch (event->type) {
         case GDK_ENTER_NOTIFY:
-            knot->set_flag(SP_KNOT_MOUSEOVER, TRUE);
+            knot->setFlag(SP_KNOT_MOUSEOVER, TRUE);
 
             cc->active_handle = knot;
             if (knot_tip)
@@ -993,7 +993,7 @@ cc_generic_knot_handler(SPCanvasItem *, GdkEvent *event, SPKnot *knot)
             consumed = TRUE;
             break;
         case GDK_LEAVE_NOTIFY:
-            knot->set_flag(SP_KNOT_MOUSEOVER, FALSE);
+            knot->setFlag(SP_KNOT_MOUSEOVER, FALSE);
 
             /* FIXME: the following test is a workaround for LP Bug #1273510.
              * It seems that a signal is not correctly disconnected, maybe
@@ -1076,7 +1076,7 @@ void ConnectorTool::_activeShapeAddKnot(SPItem* item) {
         knot->setSize(8);
         knot->setAnchor(SP_ANCHOR_CENTER);
         knot->setFill(0xffffff00, 0xff0000ff, 0xff0000ff);
-        knot->update_ctrl();
+        knot->updateCtrl();
 
         // We don't want to use the standard knot handler.
         g_signal_handler_disconnect(G_OBJECT(knot->item),
@@ -1087,7 +1087,7 @@ void ConnectorTool::_activeShapeAddKnot(SPItem* item) {
         g_signal_connect(G_OBJECT(knot->item), "event",
                 G_CALLBACK(cc_generic_knot_handler), knot);
 
-        knot->set_position(item->avoidRef->getConnectionPointPos() * desktop->doc2dt(), 0);
+        knot->setPosition(item->avoidRef->getConnectionPointPos() * desktop->doc2dt(), 0);
         knot->show();
         this->knots[knot] = 1;
 }
@@ -1159,10 +1159,10 @@ void ConnectorTool::cc_set_active_conn(SPItem *item) {
         {
             // Just adjust handle positions.
             Geom::Point startpt = *(curve->first_point()) * i2dt;
-            this->endpt_handle[0]->set_position(startpt, 0);
+            this->endpt_handle[0]->setPosition(startpt, 0);
 
             Geom::Point endpt = *(curve->last_point()) * i2dt;
-            this->endpt_handle[1]->set_position(endpt, 0);
+            this->endpt_handle[1]->setPosition(endpt, 0);
         }
 
         return;
@@ -1195,7 +1195,7 @@ void ConnectorTool::cc_set_active_conn(SPItem *item) {
             knot->setAnchor(SP_ANCHOR_CENTER);
             knot->setFill(0xffffff00, 0xff0000ff, 0xff0000ff);
             knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
-            knot->update_ctrl();
+            knot->updateCtrl();
 
             // We don't want to use the standard knot handler,
             // since we don't want this knot to be draggable.
@@ -1235,10 +1235,10 @@ void ConnectorTool::cc_set_active_conn(SPItem *item) {
     }
 
     Geom::Point startpt = *(curve->first_point()) * i2dt;
-    this->endpt_handle[0]->set_position(startpt, 0);
+    this->endpt_handle[0]->setPosition(startpt, 0);
 
     Geom::Point endpt = *(curve->last_point()) * i2dt;
-    this->endpt_handle[1]->set_position(endpt, 0);
+    this->endpt_handle[1]->setPosition(endpt, 0);
 
     this->endpt_handle[0]->show();
     this->endpt_handle[1]->show();
diff --git a/src/ui/tools/pencil-tool.cpp b/src/ui/tools/pencil-tool.cpp
index 374846539..fb4e82c32 100644
--- a/src/ui/tools/pencil-tool.cpp
+++ b/src/ui/tools/pencil-tool.cpp
@@ -26,7 +26,6 @@
 #include "draw-anchor.h"
 #include "message-stack.h"
 #include "message-context.h"
-#include "modifier-fns.h"
 #include "sp-path.h"
 #include "preferences.h"
 #include "snap.h"
@@ -45,6 +44,7 @@
 #include "display/curve.h"
 #include "livarot/Path.h"
 #include "tool-factory.h"
+#include "ui/tool/event-utils.h"
 
 namespace Inkscape {
 namespace UI {
@@ -131,11 +131,11 @@ bool PencilTool::root_handler(GdkEvent* event) {
             break;
 
         case GDK_KEY_PRESS:
-            ret = this->_handleKeyPress(get_group0_keyval (&event->key), event->key.state);
+            ret = this->_handleKeyPress(event->key);
             break;
 
         case GDK_KEY_RELEASE:
-            ret = this->_handleKeyRelease(get_group0_keyval (&event->key), event->key.state);
+            ret = this->_handleKeyRelease(event->key);
             break;
 
         default:
@@ -467,16 +467,16 @@ void PencilTool::_cancel() {
     this->desktop->canvas->endForcedFullRedraws();
 }
 
-bool PencilTool::_handleKeyPress(guint const keyval, guint const state) {
+bool PencilTool::_handleKeyPress(GdkEventKey const &event) {
     bool ret = false;
 
-    switch (keyval) {
+    switch (get_group0_keyval(&event)) {
         case GDK_KEY_Up:
         case GDK_KEY_Down:
         case GDK_KEY_KP_Up:
         case GDK_KEY_KP_Down:
             // Prevent the zoom field from activation.
-            if (!mod_ctrl_only(state)) {
+            if (!Inkscape::UI::held_only_control(event)) {
                 ret = true;
             }
             break;
@@ -491,7 +491,7 @@ bool PencilTool::_handleKeyPress(guint const keyval, guint const state) {
             break;
         case GDK_KEY_z:
         case GDK_KEY_Z:
-            if (mod_ctrl_only(state) && this->npoints != 0) {
+            if (Inkscape::UI::held_only_control(event) && this->npoints != 0) {
                 // if drawing, cancel, otherwise pass it up for undo
                 if (this->state != SP_PENCIL_CONTEXT_IDLE) {
                     this->_cancel();
@@ -501,7 +501,7 @@ bool PencilTool::_handleKeyPress(guint const keyval, guint const state) {
             break;
         case GDK_KEY_g:
         case GDK_KEY_G:
-            if (mod_shift_only(state)) {
+            if (Inkscape::UI::held_only_shift(event)) {
                 sp_selection_to_guides(this->desktop);
                 ret = true;
             }
@@ -520,9 +520,10 @@ bool PencilTool::_handleKeyPress(guint const keyval, guint const state) {
     return ret;
 }
 
-bool PencilTool::_handleKeyRelease(guint const keyval, guint const /*state*/) {
+bool PencilTool::_handleKeyRelease(GdkEventKey const &event) {
     bool ret = false;
-    switch (keyval) {
+
+    switch (get_group0_keyval(&event)) {
         case GDK_KEY_Alt_L:
         case GDK_KEY_Alt_R:
         case GDK_KEY_Meta_L:
diff --git a/src/ui/tools/pencil-tool.h b/src/ui/tools/pencil-tool.h
index e01b0afb5..e8d156dbd 100644
--- a/src/ui/tools/pencil-tool.h
+++ b/src/ui/tools/pencil-tool.h
@@ -57,8 +57,8 @@ private:
 	bool _handleButtonPress(GdkEventButton const &bevent);
 	bool _handleMotionNotify(GdkEventMotion const &mevent);
 	bool _handleButtonRelease(GdkEventButton const &revent);
-	bool _handleKeyPress(guint const keyval, guint const state);
-	bool _handleKeyRelease(guint const keyval, guint const state);
+	bool _handleKeyPress(GdkEventKey const &event);
+	bool _handleKeyRelease(GdkEventKey const &event);
 
 	void _setStartpoint(Geom::Point const &p);
 	void _setEndpoint(Geom::Point const &p);
diff --git a/src/ui/tools/tool-base.cpp b/src/ui/tools/tool-base.cpp
index 96ac95926..4195c9eb2 100644
--- a/src/ui/tools/tool-base.cpp
+++ b/src/ui/tools/tool-base.cpp
@@ -1132,7 +1132,7 @@ void sp_event_show_modifier_tip(Inkscape::MessageContext *message_context,
  * Use this instead of simply event->keyval, so that your keyboard shortcuts
  * work regardless of layouts (e.g., in Cyrillic).
  */
-guint get_group0_keyval(GdkEventKey *event) {
+guint get_group0_keyval(GdkEventKey const *event) {
     guint keyval = 0;
 
     gdk_keymap_translate_keyboard_state(gdk_keymap_get_for_display(
diff --git a/src/ui/tools/tool-base.h b/src/ui/tools/tool-base.h
index e11a22296..b27de9030 100644
--- a/src/ui/tools/tool-base.h
+++ b/src/ui/tools/tool-base.h
@@ -244,7 +244,7 @@ gint gobble_motion_events(gint mask);
 void sp_event_show_modifier_tip(Inkscape::MessageContext *message_context, GdkEvent *event,
                                 gchar const *ctrl_tip, gchar const *shift_tip, gchar const *alt_tip);
 
-guint get_group0_keyval(GdkEventKey *event);
+guint get_group0_keyval(GdkEventKey const *event);
 
 SPItem *sp_event_context_find_item (SPDesktop *desktop, Geom::Point const &p, bool select_under, bool into_groups);
 SPItem *sp_event_context_over_item (SPDesktop *desktop, SPItem *item, Geom::Point const &p);