Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2027 insertions, 0 deletions

diff --git a/src/ui/tools/pen-tool.cpp b/src/ui/tools/pen-tool.cpp
new file mode 100644
index 0000000..d85a3b7
--- /dev/null
+++ b/src/ui/tools/pen-tool.cpp
@@ -0,0 +1,2027 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** \file
+ * Pen event context implementation.
+ */
+
+/*
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   bulia byak <buliabyak@users.sf.net>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2000 Lauris Kaplinski
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2002 Lauris Kaplinski
+ * Copyright (C) 2004 Monash University
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstring>
+#include <string>
+
+#include <gdk/gdkkeysyms.h>
+#include <glibmm/i18n.h>
+
+#include <2geom/curves.h>
+
+#include "context-fns.h"
+#include "desktop.h"
+#include "include/macros.h"
+#include "inkscape-application.h" // Undo check
+#include "message-context.h"
+#include "message-stack.h"
+#include "selection-chemistry.h"
+#include "selection.h"
+
+#include "display/curve.h"
+#include "display/control/canvas-item-bpath.h"
+#include "display/control/canvas-item-ctrl.h"
+#include "display/control/canvas-item-curve.h"
+
+#include "object/sp-path.h"
+
+#include "ui/draw-anchor.h"
+#include "ui/shortcuts.h"
+#include "ui/tools/pen-tool.h"
+
+// we include the necessary files for BSpline & Spiro
+#include "live_effects/lpeobject.h"
+#include "live_effects/lpeobject-reference.h"
+#include "live_effects/parameter/path.h"
+
+#define INKSCAPE_LPE_SPIRO_C
+#include "live_effects/lpe-spiro.h"
+
+#include "helper/geom-nodetype.h"
+
+// For handling un-continuous paths:
+#include "inkscape.h"
+
+#include "live_effects/spiro.h"
+
+#define INKSCAPE_LPE_BSPLINE_C
+#include "live_effects/lpe-bspline.h"
+
+
+namespace Inkscape {
+namespace UI {
+namespace Tools {
+
+static Geom::Point pen_drag_origin_w(0, 0);
+static bool pen_within_tolerance = false;
+const double HANDLE_CUBIC_GAP = 0.001;
+
+PenTool::PenTool(SPDesktop *desktop, std::string prefs_path, const std::string &cursor_filename)
+    : FreehandBase(desktop, prefs_path, cursor_filename)
+{
+    tablet_enabled = false;
+
+    // Pen indicators (temporary handles shown when adding a new node).
+    c0 = new Inkscape::CanvasItemCtrl(desktop->getCanvasControls(), Inkscape::CANVAS_ITEM_CTRL_TYPE_ROTATE);
+    c1 = new Inkscape::CanvasItemCtrl(desktop->getCanvasControls(), Inkscape::CANVAS_ITEM_CTRL_TYPE_ROTATE);
+    c0->set_fill(0x0);
+    c1->set_fill(0x0);
+    c0->hide();
+    c1->hide();
+
+    cl0 = new Inkscape::CanvasItemCurve(desktop->getCanvasControls());
+    cl1 = new Inkscape::CanvasItemCurve(desktop->getCanvasControls());
+    cl0->hide();
+    cl1->hide();
+
+    sp_event_context_read(this, "mode");
+
+    this->anchor_statusbar = false;
+
+    this->setPolylineMode();
+
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (prefs->getBool("/tools/freehand/pen/selcue")) {
+        this->enableSelectionCue();
+    }
+
+    _desktop_destroy = _desktop->connectDestroy([=](SPDesktop *) { state = State::DEAD; });
+}
+
+PenTool::~PenTool() {
+    _desktop_destroy.disconnect();
+    this->discard_delayed_snap_event();
+
+    if (this->npoints != 0) {
+        // switching context - finish path
+        this->ea = nullptr; // unset end anchor if set (otherwise crashes)
+        if (state != State::DEAD) {
+            _finish(false);
+        }
+    }
+
+    if (this->c0) {
+        delete c0;
+    }
+    if (this->c1) {
+        delete c1;
+    }
+
+    if (this->cl0) {
+        delete cl0;
+    }
+    if (this->cl1) {
+        delete cl1;
+    }
+
+    if (this->waiting_item && this->expecting_clicks_for_LPE > 0) {
+        // we received too few clicks to sanely set the parameter path so we remove the LPE from the item
+        this->waiting_item->removeCurrentPathEffect(false);
+    }
+}
+
+void PenTool::setPolylineMode() {
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    guint mode = prefs->getInt("/tools/freehand/pen/freehand-mode", 0);
+    // change the nodes to make space for bspline mode
+    this->polylines_only = (mode == 3 || mode == 4);
+    this->polylines_paraxial = (mode == 4);
+    this->spiro = (mode == 1);
+    this->bspline = (mode == 2);
+    this->_bsplineSpiroColor();
+    if (!this->green_bpaths.empty()) {
+        this->_redrawAll();
+    }
+}
+
+
+void PenTool::_cancel() {
+    this->num_clicks = 0;
+    this->state = PenTool::STOP;
+    this->_resetColors();
+    c0->hide();
+    c1->hide();
+    cl0->hide();
+    cl1->hide();
+    this->message_context->clear();
+    this->message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
+}
+
+/**
+ * Callback that sets key to value in pen context.
+ */
+void PenTool::set(const Inkscape::Preferences::Entry& val) {
+    Glib::ustring name = val.getEntryName();
+
+    if (name == "mode") {
+        if ( val.getString() == "drag" ) {
+            this->mode = MODE_DRAG;
+        } else {
+            this->mode = MODE_CLICK;
+        }
+    }
+}
+
+bool PenTool::hasWaitingLPE() {
+    // note: waiting_LPE_type is defined in SPDrawContext
+    return (this->waiting_LPE != nullptr ||
+            this->waiting_LPE_type != Inkscape::LivePathEffect::INVALID_LPE);
+}
+
+/**
+ * Snaps new node relative to the previous node.
+ */
+void PenTool::_endpointSnap(Geom::Point &p, guint const state) {
+    // Paraxial kicks in after first line has set the angle (before then it's a free line)
+    bool poly = this->polylines_paraxial && !this->green_curve->is_unset();
+
+    if ((state & GDK_CONTROL_MASK) && !poly) { //CTRL enables angular snapping
+        if (this->npoints > 0) {
+            spdc_endpoint_snap_rotation(this, p, this->p[0], state);
+        } else {
+            std::optional<Geom::Point> origin = std::optional<Geom::Point>();
+            spdc_endpoint_snap_free(this, p, origin, state);
+        }
+    } else {
+        // We cannot use shift here to disable snapping because the shift-key is already used
+        // to toggle the paraxial direction; if the user wants to disable snapping (s)he will
+        // have to use the %-key, the menu, or the snap toolbar
+        if ((this->npoints > 0) && poly) {
+            // snap constrained
+            this->_setToNearestHorizVert(p, state);
+        } else {
+            // snap freely
+            std::optional<Geom::Point> origin = this->npoints > 0 ? this->p[0] : std::optional<Geom::Point>();
+            spdc_endpoint_snap_free(this, p, origin, state); // pass the origin, to allow for perpendicular / tangential snapping
+        }
+    }
+}
+
+/**
+ * Snaps new node's handle relative to the new node.
+ */
+void PenTool::_endpointSnapHandle(Geom::Point &p, guint const state) {
+    g_return_if_fail(( this->npoints == 2 ||
+            this->npoints == 5   ));
+
+    if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
+        spdc_endpoint_snap_rotation(this, p, this->p[this->npoints - 2], state);
+    } else {
+        if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
+            std::optional<Geom::Point> origin = this->p[this->npoints - 2];
+            spdc_endpoint_snap_free(this, p, origin, state);
+        }
+    }
+}
+
+bool PenTool::item_handler(SPItem* item, GdkEvent* event) {
+    bool ret = false;
+
+    switch (event->type) {
+        case GDK_BUTTON_PRESS:
+            ret = this->_handleButtonPress(event->button);
+            break;
+        case GDK_BUTTON_RELEASE:
+            ret = this->_handleButtonRelease(event->button);
+            break;
+        default:
+            break;
+    }
+
+    if (!ret) {
+        ret = FreehandBase::item_handler(item, event);
+    }
+
+    return ret;
+}
+
+/**
+ * Callback to handle all pen events.
+ */
+bool PenTool::root_handler(GdkEvent* event) {
+    bool ret = false;
+
+    switch (event->type) {
+        case GDK_BUTTON_PRESS:
+            ret = this->_handleButtonPress(event->button);
+            break;
+
+        case GDK_MOTION_NOTIFY:
+            ret = this->_handleMotionNotify(event->motion);
+            break;
+
+        case GDK_BUTTON_RELEASE:
+            ret = this->_handleButtonRelease(event->button);
+            break;
+
+        case GDK_2BUTTON_PRESS:
+            ret = this->_handle2ButtonPress(event->button);
+            break;
+
+        case GDK_KEY_PRESS:
+            ret = this->_handleKeyPress(event);
+            break;
+
+        default:
+            break;
+    }
+
+    if (!ret) {
+        ret = FreehandBase::root_handler(event);
+    }
+
+    return ret;
+}
+
+/**
+ * Handle mouse button press event.
+ */
+bool PenTool::_handleButtonPress(GdkEventButton const &bevent) {
+    if (this->events_disabled) {
+        // skip event processing if events are disabled
+        return false;
+    }
+
+    Geom::Point const event_w(bevent.x, bevent.y);
+    Geom::Point event_dt(_desktop->w2d(event_w));
+    //Test whether we hit any anchor.
+    SPDrawAnchor * const anchor = spdc_test_inside(this, event_w);
+
+    //with this we avoid creating a new point over the existing one
+    if(bevent.button != 3 && (this->spiro || this->bspline) && this->npoints > 0 && this->p[0] == this->p[3]){
+        if( anchor && anchor == this->sa && this->green_curve->is_unset()){
+            //remove the following line to avoid having one node on top of another
+            _finishSegment(event_dt, bevent.state);
+            _finish(true);
+            return true;
+        }
+        return false;
+    }
+
+    bool ret = false;
+    if (bevent.button == 1
+        // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
+        && this->expecting_clicks_for_LPE != 1) {
+        if (Inkscape::have_viable_layer(_desktop, defaultMessageContext()) == false) {
+            return true;
+        }
+
+        grabCanvasEvents();
+
+        pen_drag_origin_w = event_w;
+        pen_within_tolerance = true;
+
+        switch (this->mode) {
+
+            case PenTool::MODE_CLICK:
+                // In click mode we add point on release
+                switch (this->state) {
+                    case PenTool::POINT:
+                    case PenTool::CONTROL:
+                    case PenTool::CLOSE:
+                        break;
+                    case PenTool::STOP:
+                        // This is allowed, if we just canceled curve
+                        this->state = PenTool::POINT;
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            case PenTool::MODE_DRAG:
+                switch (this->state) {
+                    case PenTool::STOP:
+                        // This is allowed, if we just canceled curve
+                    case PenTool::POINT:
+                        if (this->npoints == 0) {
+                            this->_bsplineSpiroColor();
+                            Geom::Point p;
+                            if ((bevent.state & GDK_CONTROL_MASK) && (this->polylines_only || this->polylines_paraxial)) {
+                                p = event_dt;
+                                if (!(bevent.state & GDK_SHIFT_MASK)) {
+                                    SnapManager &m = _desktop->namedview->snap_manager;
+                                    m.setup(_desktop);
+                                    m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
+                                    m.unSetup();
+                                }
+                              spdc_create_single_dot(this, p, "/tools/freehand/pen", bevent.state);
+                              ret = true;
+                              break;
+                            }
+
+                            // TODO: Perhaps it would be nicer to rearrange the following case
+                            // distinction so that the case of a waiting LPE is treated separately
+
+                            // Set start anchor
+
+                            this->sa = anchor;
+                            if (anchor) {
+                                //Put the start overwrite curve always on the same direction
+                                if (anchor->start) {
+                                    this->sa_overwrited = this->sa->curve->create_reverse();
+                                } else {
+                                    this->sa_overwrited = this->sa->curve->copy();
+                                }
+                                this->_bsplineSpiroStartAnchor(bevent.state & GDK_SHIFT_MASK);
+                            }
+                            if (anchor && (!this->hasWaitingLPE()|| this->bspline || this->spiro)) {
+                                // Adjust point to anchor if needed; if we have a waiting LPE, we need
+                                // a fresh path to be created so don't continue an existing one
+                                p = anchor->dp;
+                                _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
+                            } else {
+                                // This is the first click of a new curve; deselect item so that
+                                // this curve is not combined with it (unless it is drawn from its
+                                // anchor, which is handled by the sibling branch above)
+                                Inkscape::Selection * const selection = _desktop->getSelection();
+                                if (!(bevent.state & GDK_SHIFT_MASK) || this->hasWaitingLPE()) {
+                                    // if we have a waiting LPE, we need a fresh path to be created
+                                    // so don't append to an existing one
+                                    selection->clear();
+                                    _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
+                                } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
+                                    _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
+                                }
+
+                                // Create green anchor
+                                p = event_dt;
+                                this->_endpointSnap(p, bevent.state);
+                                this->green_anchor.reset(new SPDrawAnchor(this, this->green_curve.get(), true, p));
+                            }
+                            this->_setInitialPoint(p);
+                        } else {
+                            // Set end anchor
+                            this->ea = anchor;
+                            Geom::Point p;
+                            if (anchor) {
+                                p = anchor->dp;
+                                // we hit an anchor, will finish the curve (either with or without closing)
+                                // in release handler
+                                this->state = PenTool::CLOSE;
+
+                                if (this->green_anchor && this->green_anchor->active) {
+                                    // we clicked on the current curve start, so close it even if
+                                    // we drag a handle away from it
+                                    this->green_closed = true;
+                                }
+                                ret = true;
+                                break;
+
+                            } else {
+                                p = event_dt;
+                                this->_endpointSnap(p, bevent.state); // Snap node only if not hitting anchor.
+                                this->_setSubsequentPoint(p, true);
+                            }
+                        }
+                        // avoid the creation of a control point so a node is created in the release event
+                        this->state = (this->spiro || this->bspline || this->polylines_only) ? PenTool::POINT : PenTool::CONTROL;
+                        ret = true;
+                        break;
+                    case PenTool::CONTROL:
+                        g_warning("Button down in CONTROL state");
+                        break;
+                    case PenTool::CLOSE:
+                        g_warning("Button down in CLOSE state");
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            default:
+                break;
+        }
+    } else if (this->expecting_clicks_for_LPE == 1 && this->npoints != 0) {
+        // when the last click for a waiting LPE occurs we want to finish the path
+        this->_finishSegment(event_dt, bevent.state);
+        if (this->green_closed) {
+            // finishing at the start anchor, close curve
+            this->_finish(true);
+        } else {
+            // finishing at some other anchor, finish curve but not close
+            this->_finish(false);
+        }
+
+        ret = true;
+    } else if (bevent.button == 3 && this->npoints != 0 && !_button1on) {
+        // right click - finish path, but only if the left click isn't pressed.
+        this->ea = nullptr; // unset end anchor if set (otherwise crashes)
+        this->_finish(false);
+        ret = true;
+    }
+
+    if (this->expecting_clicks_for_LPE > 0) {
+        --this->expecting_clicks_for_LPE;
+    }
+
+    return ret;
+}
+
+/**
+ * Handle motion_notify event.
+ */
+bool PenTool::_handleMotionNotify(GdkEventMotion const &mevent) {
+    bool ret = false;
+
+    if (mevent.state & GDK_BUTTON2_MASK) {
+        // allow scrolling
+        return false;
+    }
+
+    if (this->events_disabled) {
+        // skip motion events if pen events are disabled
+        return false;
+    }
+
+    Geom::Point const event_w(mevent.x, mevent.y);
+
+    //we take out the function the const "tolerance" because we need it later
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
+
+    if (pen_within_tolerance) {
+        if ( Geom::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
+            return false;   // Do not drag if we're within tolerance from origin.
+        }
+    }
+    // Once the user has moved farther than tolerance from the original location
+    // (indicating they intend to move the object, not click), then always process the
+    // motion notify coordinates as given (no snapping back to origin)
+    pen_within_tolerance = false;
+
+    // Find desktop coordinates
+    Geom::Point p = _desktop->w2d(event_w);
+
+    // Test, whether we hit any anchor
+    SPDrawAnchor *anchor = spdc_test_inside(this, event_w);
+
+    switch (this->mode) {
+        case PenTool::MODE_CLICK:
+            switch (this->state) {
+                case PenTool::POINT:
+                    if ( this->npoints != 0 ) {
+                        // Only set point, if we are already appending
+                        this->_endpointSnap(p, mevent.state);
+                        this->_setSubsequentPoint(p, true);
+                        ret = true;
+                    } else if (!this->sp_event_context_knot_mouseover()) {
+                        SnapManager &m = _desktop->namedview->snap_manager;
+                        m.setup(_desktop);
+                        m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
+                        m.unSetup();
+                    }
+                    break;
+                case PenTool::CONTROL:
+                case PenTool::CLOSE:
+                    // Placing controls is last operation in CLOSE state
+                    this->_endpointSnap(p, mevent.state);
+                    this->_setCtrl(p, mevent.state);
+                    ret = true;
+                    break;
+                case PenTool::STOP:
+                    if (!this->sp_event_context_knot_mouseover()) {
+                        SnapManager &m = _desktop->namedview->snap_manager;
+                        m.setup(_desktop);
+                        m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
+                        m.unSetup();
+                    }
+                    break;
+                default:
+                    break;
+            }
+            break;
+        case PenTool::MODE_DRAG:
+            switch (this->state) {
+                case PenTool::POINT:
+                    if ( this->npoints > 0 ) {
+                        // Only set point, if we are already appending
+
+                        if (!anchor) {   // Snap node only if not hitting anchor
+                            this->_endpointSnap(p, mevent.state);
+                            this->_setSubsequentPoint(p, true, mevent.state);
+                        } else {
+                            this->_setSubsequentPoint(anchor->dp, false, mevent.state);
+                        }
+
+                        if (anchor && !this->anchor_statusbar) {
+                            if(!this->spiro && !this->bspline){
+                                this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
+                            }else{
+                                this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path. Shift+Click make a cusp node"));
+                            }
+                            this->anchor_statusbar = true;
+                        } else if (!anchor && this->anchor_statusbar) {
+                            this->message_context->clear();
+                            this->anchor_statusbar = false;
+                        }
+
+                        ret = true;
+                    } else {
+                        if (anchor && !this->anchor_statusbar) {
+                            if(!this->spiro && !this->bspline){
+                                this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
+                            }else{
+                                this->message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point. Shift+Click make a cusp node"));
+                            }
+                            this->anchor_statusbar = true;
+                        } else if (!anchor && this->anchor_statusbar) {
+                            this->message_context->clear();
+                            this->anchor_statusbar = false;
+
+                        }
+                        if (!this->sp_event_context_knot_mouseover()) {
+                            SnapManager &m = _desktop->namedview->snap_manager;
+                            m.setup(_desktop);
+                            m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
+                            m.unSetup();
+                        }
+                    }
+                    break;
+                case PenTool::CONTROL:
+                case PenTool::CLOSE:
+                    // Placing controls is last operation in CLOSE state
+
+                    // snap the handle
+
+                    this->_endpointSnapHandle(p, mevent.state);
+
+                    if (!this->polylines_only) {
+                        this->_setCtrl(p, mevent.state);
+                    } else {
+                        this->_setCtrl(this->p[1], mevent.state);
+                    }
+
+                    gobble_motion_events(GDK_BUTTON1_MASK);
+                    ret = true;
+                    break;
+                case PenTool::STOP:
+                    // Don't break; fall through to default to do preSnapping
+                default:
+                    if (!this->sp_event_context_knot_mouseover()) {
+                        SnapManager &m = _desktop->namedview->snap_manager;
+                        m.setup(_desktop);
+                        m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
+                        m.unSetup();
+                    }
+                    break;
+            }
+            break;
+        default:
+            break;
+    }
+    // calls the function "bspline_spiro_motion" when the mouse starts or stops moving
+    if(this->bspline){
+        this->_bsplineSpiroMotion(mevent.state);
+    }else{
+        if ( Geom::LInfty( event_w - pen_drag_origin_w ) > (tolerance/2) || mevent.time == 0) {
+            this->_bsplineSpiroMotion(mevent.state);
+            pen_drag_origin_w = event_w;
+        }
+    }
+
+    return ret;
+}
+
+/**
+ * Handle mouse button release event.
+ */
+bool PenTool::_handleButtonRelease(GdkEventButton const &revent) {
+    if (this->events_disabled) {
+        // skip event processing if events are disabled
+        return false;
+    }
+
+    bool ret = false;
+
+    if (revent.button == 1) {
+        Geom::Point const event_w(revent.x, revent.y);
+
+        // Find desktop coordinates
+        Geom::Point p = _desktop->w2d(event_w);
+
+        // Test whether we hit any anchor.
+
+        SPDrawAnchor *anchor = spdc_test_inside(this, event_w);
+        // if we try to create a node in the same place as another node, we skip
+        if((!anchor || anchor == this->sa) && (this->spiro || this->bspline) && this->npoints > 0 && this->p[0] == this->p[3]){
+            return true;
+        }
+
+        switch (this->mode) {
+            case PenTool::MODE_CLICK:
+                switch (this->state) {
+                    case PenTool::POINT:
+                        this->ea = anchor;
+                        if (anchor) {
+                            p = anchor->dp;
+                        }
+                        this->state = PenTool::CONTROL;
+                        break;
+                    case PenTool::CONTROL:
+                        // End current segment
+                        this->_endpointSnap(p, revent.state);
+                        this->_finishSegment(p, revent.state);
+                        this->state = PenTool::POINT;
+                        break;
+                    case PenTool::CLOSE:
+                        // End current segment
+                        if (!anchor) {   // Snap node only if not hitting anchor
+                            this->_endpointSnap(p, revent.state);
+                        }
+                        this->_finishSegment(p, revent.state);
+                        // hude the guide of the penultimate node when closing the curve
+                        if(this->spiro){
+                            c1->hide();
+                        }
+                        this->_finish(true);
+                        this->state = PenTool::POINT;
+                        break;
+                    case PenTool::STOP:
+                        // This is allowed, if we just canceled curve
+                        this->state = PenTool::POINT;
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            case PenTool::MODE_DRAG:
+                switch (this->state) {
+                    case PenTool::POINT:
+                    case PenTool::CONTROL:
+                        this->_endpointSnap(p, revent.state);
+                        this->_finishSegment(p, revent.state);
+                        break;
+                    case PenTool::CLOSE:
+                        this->_endpointSnap(p, revent.state);
+                        this->_finishSegment(p, revent.state);
+                        // hide the penultimate node guide when closing the curve
+                        if(this->spiro){
+                            c1->hide();
+                        }
+                        if (this->green_closed) {
+                            // finishing at the start anchor, close curve
+                            this->_finish(true);
+                        } else {
+                            // finishing at some other anchor, finish curve but not close
+                            this->_finish(false);
+                        }
+                        break;
+                    case PenTool::STOP:
+                        // This is allowed, if we just cancelled curve
+                        break;
+                    default:
+                        break;
+                }
+                this->state = PenTool::POINT;
+                break;
+            default:
+                break;
+        }
+
+        ungrabCanvasEvents();
+
+        ret = true;
+
+        this->green_closed = false;
+    }
+
+    // TODO: can we be sure that the path was created correctly?
+    // TODO: should we offer an option to collect the clicks in a list?
+    if (this->expecting_clicks_for_LPE == 0 && this->hasWaitingLPE()) {
+        this->setPolylineMode();
+
+        Inkscape::Selection *selection = _desktop->getSelection();
+
+        if (this->waiting_LPE) {
+            // we have an already created LPE waiting for a path
+            this->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
+            selection->add(this->waiting_item);
+            this->waiting_LPE = nullptr;
+        } else {
+            // the case that we need to create a new LPE and apply it to the just-drawn path is
+            // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
+        }
+    }
+
+    return ret;
+}
+
+bool PenTool::_handle2ButtonPress(GdkEventButton const &bevent) {
+    bool ret = false;
+    // only end on LMB double click. Otherwise horizontal scrolling causes ending of the path
+    if (this->npoints != 0 && bevent.button == 1 && this->state != PenTool::CLOSE) {
+        this->_finish(false);
+        ret = true;
+    }
+    return ret;
+}
+
+void PenTool::_redrawAll() {
+    // green
+    if (! this->green_bpaths.empty()) {
+        // remove old piecewise green canvasitems
+        for (auto path : this->green_bpaths) {
+            delete path;
+        }
+        this->green_bpaths.clear();
+
+        // one canvas bpath for all of green_curve
+        auto canvas_shape = new Inkscape::CanvasItemBpath(_desktop->getCanvasSketch(), green_curve.get(), true);
+        canvas_shape->set_stroke(green_color);
+        canvas_shape->set_fill(0x0, SP_WIND_RULE_NONZERO);
+        this->green_bpaths.push_back(canvas_shape);
+    }
+    if (this->green_anchor) {
+        this->green_anchor->ctrl->set_position(this->green_anchor->dp);
+    }
+
+    this->red_curve->reset();
+    this->red_curve->moveto(this->p[0]);
+    this->red_curve->curveto(this->p[1], this->p[2], this->p[3]);
+    red_bpath->set_bpath(red_curve.get(), true);
+
+    // handles
+    // hide the handlers in bspline and spiro modes
+    if (this->p[0] != this->p[1] && !this->spiro && !this->bspline) {
+        c1->set_position(p[1]);
+        c1->show();
+        cl1->set_coords(p[0], p[1]);
+        cl1->show();
+    } else {
+        c1->hide();
+        cl1->hide();
+    }
+
+    Geom::Curve const * last_seg = this->green_curve->last_segment();
+    if (last_seg) {
+        Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
+        // hide the handlers in bspline and spiro modes
+        if ( cubic &&
+             (*cubic)[2] != this->p[0] && !this->spiro && !this->bspline )
+        {
+            Geom::Point p2 = (*cubic)[2];
+            c0->set_position(p2);
+            c0->show();
+            cl0->set_coords(p2, p[0]);
+            cl0->show();
+        } else {
+            c0->hide();
+            cl0->hide();
+        }
+    }
+
+    // simply redraw the spiro. because its a redrawing, we don't call the global function,
+    // but we call the redrawing at the ending.
+     this->_bsplineSpiroBuild();
+}
+
+void PenTool::_lastpointMove(gdouble x, gdouble y) {
+    if (this->npoints != 5)
+        return;
+
+    y *= -_desktop->yaxisdir();
+
+    // green
+    if (!this->green_curve->is_unset()) {
+        this->green_curve->last_point_additive_move( Geom::Point(x,y) );
+    } else {
+        // start anchor too
+        if (this->green_anchor) {
+            this->green_anchor->dp += Geom::Point(x, y);
+        }
+    }
+
+    // red
+
+    this->p[0] += Geom::Point(x, y);
+    this->p[1] += Geom::Point(x, y);
+    this->_redrawAll();
+}
+
+void PenTool::_lastpointMoveScreen(gdouble x, gdouble y) {
+    this->_lastpointMove(x / _desktop->current_zoom(), y / _desktop->current_zoom());
+}
+
+void PenTool::_lastpointToCurve() {
+    // avoid that if the "red_curve" contains only two points ( rect ), it doesn't stop here.
+    if (this->npoints != 5 && !this->spiro && !this->bspline)
+        return;
+
+    this->p[1] = this->red_curve->last_segment()->initialPoint() + (1./3.)*(*this->red_curve->last_point() - this->red_curve->last_segment()->initialPoint());
+    //modificate the last segment of the green curve so it creates the type of node we need
+    if (this->spiro||this->bspline) {
+        if (!this->green_curve->is_unset()) {
+            Geom::Point A(0,0);
+            Geom::Point B(0,0);
+            Geom::Point C(0,0);
+            Geom::Point D(0,0);
+            Geom::CubicBezier const *cubic = dynamic_cast<Geom::CubicBezier const *>( this->green_curve->last_segment() );
+            //We obtain the last segment 4 points in the previous curve
+            if ( cubic ){
+                A = (*cubic)[0];
+                B = (*cubic)[1];
+                if (this->spiro) {
+                    C = this->p[0] + (this->p[0] - this->p[1]);
+                } else {
+                    C = *this->green_curve->last_point() + (1./3.)*(this->green_curve->last_segment()->initialPoint() - *this->green_curve->last_point());
+                }
+                D = (*cubic)[3];
+            } else {
+                A = this->green_curve->last_segment()->initialPoint();
+                B = this->green_curve->last_segment()->initialPoint();
+                if (this->spiro) {
+                    C = this->p[0] + (this->p[0] - this->p[1]);
+                } else {
+                    C = *this->green_curve->last_point() + (1./3.)*(this->green_curve->last_segment()->initialPoint() - *this->green_curve->last_point());
+                }
+                D = *this->green_curve->last_point();
+            }
+            auto previous = std::make_unique<SPCurve>();
+            previous->moveto(A);
+            previous->curveto(B, C, D);
+            if ( this->green_curve->get_segment_count() == 1) {
+                this->green_curve = std::move(previous);
+            } else {
+                //we eliminate the last segment
+                this->green_curve->backspace();
+                //and we add it again with the recreation
+                green_curve->append_continuous(*previous);
+            }
+        }
+        //if the last node is an union with another curve
+        if (this->green_curve->is_unset() && this->sa && !this->sa->curve->is_unset()) {
+            this->_bsplineSpiroStartAnchor(false);
+        }
+    }
+
+    this->_redrawAll();
+}
+
+
+void PenTool::_lastpointToLine() {
+    // avoid that if the "red_curve" contains only two points ( rect) it doesn't stop here.
+    if (this->npoints != 5 && !this->bspline)
+        return;
+
+    // modify the last segment of the green curve so the type of node we want is created.
+    if(this->spiro || this->bspline){
+        if(!this->green_curve->is_unset()){
+            Geom::Point A(0,0);
+            Geom::Point B(0,0);
+            Geom::Point C(0,0);
+            Geom::Point D(0,0);
+            auto previous = std::make_unique<SPCurve>();
+            Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( this->green_curve->last_segment() );
+            if ( cubic ) {
+                A = this->green_curve->last_segment()->initialPoint();
+                B = (*cubic)[1];
+                C = *this->green_curve->last_point();
+                D = C;
+            } else {
+                //We obtain the last segment 4 points in the previous curve
+                A = this->green_curve->last_segment()->initialPoint();
+                B = A;
+                C = *this->green_curve->last_point();
+                D = C;
+            }
+            previous->moveto(A);
+            previous->curveto(B, C, D);
+            if( this->green_curve->get_segment_count() == 1){
+                this->green_curve = std::move(previous);
+            }else{
+                //we eliminate the last segment
+                this->green_curve->backspace();
+                //and we add it again with the recreation
+                green_curve->append_continuous(*previous);
+            }
+        }
+        // if the last node is an union with another curve
+        if(this->green_curve->is_unset() && this->sa && !this->sa->curve->is_unset()){
+            this->_bsplineSpiroStartAnchor(true);
+        }
+    }
+
+    this->p[1] = this->p[0];
+    this->_redrawAll();
+}
+
+
+bool PenTool::_handleKeyPress(GdkEvent *event) {
+    bool ret = false;
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    gdouble const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000, "px"); // in px
+
+    // Check for undo if we have started drawing a path. User might have change shortcut.
+    if (this->npoints > 0) {
+        Gtk::AccelKey shortcut = Inkscape::Shortcuts::get_from_event((GdkEventKey*)event);
+        auto app = InkscapeApplication::instance();
+        auto gapp = app->gtk_app();
+        auto actions = gapp->get_actions_for_accel(shortcut.get_abbrev());
+        if (std::find(actions.begin(), actions.end(), "win.undo") != actions.end()) {
+            return _undoLastPoint();
+        }
+    }
+
+    switch (get_latin_keyval (&event->key)) {
+        case GDK_KEY_Left: // move last point left
+        case GDK_KEY_KP_Left:
+            if (!MOD__CTRL(event)) { // not ctrl
+                if (MOD__ALT(event)) { // alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMoveScreen(-10, 0); // shift
+                    }
+                    else {
+                        this->_lastpointMoveScreen(-1, 0); // no shift
+                    }
+                }
+                else { // no alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMove(-10*nudge, 0); // shift
+                    }
+                    else {
+                        this->_lastpointMove(-nudge, 0); // no shift
+                    }
+                }
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Up: // move last point up
+        case GDK_KEY_KP_Up:
+            if (!MOD__CTRL(event)) { // not ctrl
+                if (MOD__ALT(event)) { // alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMoveScreen(0, 10); // shift
+                    }
+                    else {
+                        this->_lastpointMoveScreen(0, 1); // no shift
+                    }
+                }
+                else { // no alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMove(0, 10*nudge); // shift
+                    }
+                    else {
+                        this->_lastpointMove(0, nudge); // no shift
+                    }
+                }
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Right: // move last point right
+        case GDK_KEY_KP_Right:
+            if (!MOD__CTRL(event)) { // not ctrl
+                if (MOD__ALT(event)) { // alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMoveScreen(10, 0); // shift
+                    }
+                    else {
+                        this->_lastpointMoveScreen(1, 0); // no shift
+                    }
+                }
+                else { // no alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMove(10*nudge, 0); // shift
+                    }
+                    else {
+                        this->_lastpointMove(nudge, 0); // no shift
+                    }
+                }
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Down: // move last point down
+        case GDK_KEY_KP_Down:
+            if (!MOD__CTRL(event)) { // not ctrl
+                if (MOD__ALT(event)) { // alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMoveScreen(0, -10); // shift
+                    }
+                    else {
+                        this->_lastpointMoveScreen(0, -1); // no shift
+                    }
+                }
+                else { // no alt
+                    if (MOD__SHIFT(event)) {
+                        this->_lastpointMove(0, -10*nudge); // shift
+                    }
+                    else {
+                        this->_lastpointMove(0, -nudge); // no shift
+                    }
+                }
+                ret = true;
+            }
+            break;
+
+/*TODO: this is not yet enabled?? looks like some traces of the Geometry tool
+        case GDK_KEY_P:
+        case GDK_KEY_p:
+            if (MOD__SHIFT_ONLY(event)) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
+                ret = true;
+            }
+            break;
+
+        case GDK_KEY_C:
+        case GDK_KEY_c:
+            if (MOD__SHIFT_ONLY(event)) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
+                ret = true;
+            }
+            break;
+
+        case GDK_KEY_B:
+        case GDK_KEY_b:
+            if (MOD__SHIFT_ONLY(event)) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
+                ret = true;
+            }
+            break;
+
+        case GDK_KEY_A:
+        case GDK_KEY_a:
+            if (MOD__SHIFT_ONLY(event)) {
+                sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
+                ret = true;
+            }
+            break;
+*/
+
+        case GDK_KEY_U:
+        case GDK_KEY_u:
+            if (MOD__SHIFT_ONLY(event)) {
+                this->_lastpointToCurve();
+                ret = true;
+            }
+            break;
+        case GDK_KEY_L:
+        case GDK_KEY_l:
+            if (MOD__SHIFT_ONLY(event)) {
+                this->_lastpointToLine();
+                ret = true;
+            }
+            break;
+
+        case GDK_KEY_Return:
+        case GDK_KEY_KP_Enter:
+            if (this->npoints != 0) {
+                this->ea = nullptr; // unset end anchor if set (otherwise crashes)
+                if(MOD__SHIFT_ONLY(event)) {
+                    // All this is needed to stop the last control
+                    // point dispeating and stop making an n-1 shape.
+                    Geom::Point const p(0, 0);
+                    if(this->red_curve->is_unset()) {
+                        this->red_curve->moveto(p);
+                    }
+                    this->_finishSegment(p, 0);
+                    this->_finish(true);
+                } else {
+                  this->_finish(false);
+                }
+                ret = true;
+            }
+            break;
+        case GDK_KEY_Escape:
+            if (this->npoints != 0) {
+                // if drawing, cancel, otherwise pass it up for deselecting
+                this->_cancel ();
+                ret = true;
+            }
+            break;
+        case GDK_KEY_g:
+        case GDK_KEY_G:
+            if (MOD__SHIFT_ONLY(event)) {
+                _desktop->selection->toGuides();
+                ret = true;
+            }
+            break;
+        case GDK_KEY_BackSpace:
+        case GDK_KEY_Delete:
+        case GDK_KEY_KP_Delete:
+            ret = _undoLastPoint();
+            break;
+        case GDK_KEY_Z:
+        case GDK_KEY_z:
+            if (event->key.state & INK_GDK_PRIMARY_MASK) {
+                ret = _undoLastPoint();
+            }
+            break;
+        default:
+            break;
+    }
+    return ret;
+}
+
+void PenTool::_resetColors() {
+    // Red
+    this->red_curve->reset();
+    this->red_bpath->set_bpath(nullptr);
+
+    // Blue
+    this->blue_curve->reset();
+    this->blue_bpath->set_bpath(nullptr);
+
+    // Green
+    for (auto path : this->green_bpaths) {
+        delete path;
+    }
+    this->green_bpaths.clear();
+    this->green_curve->reset();
+    this->green_anchor.reset();
+
+    this->sa = nullptr;
+    this->ea = nullptr;
+
+    if (this->sa_overwrited) {
+        this->sa_overwrited->reset();
+    }
+
+    this->npoints = 0;
+    this->red_curve_is_valid = false;
+}
+
+
+void PenTool::_setInitialPoint(Geom::Point const p) {
+    g_assert( this->npoints == 0 );
+
+    this->p[0] = p;
+    this->p[1] = p;
+    this->npoints = 2;
+    this->red_bpath->set_bpath(nullptr);
+}
+
+/**
+ * Show the status message for the current line/curve segment.
+ * This type of message always shows angle/distance as the last
+ * two parameters ("angle %3.2f&#176;, distance %s").
+ */
+void PenTool::_setAngleDistanceStatusMessage(Geom::Point const p, int pc_point_to_compare, gchar const *message) {
+    g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
+    g_assert(message != nullptr);
+
+    Geom::Point rel = p - this->p[pc_point_to_compare];
+    Inkscape::Util::Quantity q = Inkscape::Util::Quantity(Geom::L2(rel), "px");
+    Glib::ustring dist = q.string(_desktop->namedview->display_units);
+    double angle = atan2(rel[Geom::Y], rel[Geom::X]) * 180 / M_PI;
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (prefs->getBool("/options/compassangledisplay/value", false) != 0) {
+        angle = 90 - angle;
+
+        if (_desktop->is_yaxisdown()) {
+            angle = 180 - angle;
+        }
+
+        if (angle < 0) {
+            angle += 360;
+        }
+    }
+
+    this->message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist.c_str());
+}
+
+// this function changes the colors red, green and blue making them transparent or not, depending on if spiro is being used.
+void PenTool::_bsplineSpiroColor()
+{
+    static Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    if (this->spiro){
+        this->red_color = 0xff000000;
+        this->green_color = 0x00ff0000;
+    } else if(this->bspline) {
+        this->highlight_color = currentLayer()->highlight_color();
+        if((unsigned int)prefs->getInt("/tools/nodes/highlight_color", 0xff0000ff) == this->highlight_color){
+            this->green_color = 0xff00007f;
+            this->red_color = 0xff00007f;
+        } else {
+            this->green_color = this->highlight_color;
+            this->red_color = this->highlight_color;
+        }
+    } else {
+        this->highlight_color = currentLayer()->highlight_color();
+        this->red_color = 0xff00007f;
+        if((unsigned int)prefs->getInt("/tools/nodes/highlight_color", 0xff0000ff) == this->highlight_color){
+            this->green_color = 0x00ff007f;
+        } else {
+            this->green_color = this->highlight_color;
+        }
+        blue_bpath->hide();
+    }
+
+    //We erase all the "green_bpaths" to recreate them after with the colour
+    //transparency recently modified
+    if (!this->green_bpaths.empty()) {
+        // remove old piecewise green canvasitems
+        for (auto path : this->green_bpaths) {
+            delete path;
+        }
+        this->green_bpaths.clear();
+
+        // one canvas bpath for all of green_curve
+        auto canvas_shape = new Inkscape::CanvasItemBpath(_desktop->getCanvasSketch(), green_curve.get(), true);
+        canvas_shape->set_stroke(green_color);
+        canvas_shape->set_fill(0x0, SP_WIND_RULE_NONZERO);
+        this->green_bpaths.push_back(canvas_shape);
+    }
+
+    this->red_bpath->set_stroke(red_color);
+}
+
+
+void PenTool::_bsplineSpiro(bool shift)
+{
+    if(!this->spiro && !this->bspline){
+        return;
+    }
+
+    shift?this->_bsplineSpiroOff():this->_bsplineSpiroOn();
+    this->_bsplineSpiroBuild();
+}
+
+void PenTool::_bsplineSpiroOn()
+{
+    if(!this->red_curve->is_unset()){
+        using Geom::X;
+        using Geom::Y;
+        this->npoints = 5;
+        this->p[0] = *this->red_curve->first_point();
+        this->p[3] = this->red_curve->first_segment()->finalPoint();
+        this->p[2] = this->p[3] + (1./3)*(this->p[0] - this->p[3]);
+        this->p[2] = Geom::Point(this->p[2][X] + HANDLE_CUBIC_GAP,this->p[2][Y] + HANDLE_CUBIC_GAP);
+    }
+}
+
+void PenTool::_bsplineSpiroOff()
+{
+    if(!this->red_curve->is_unset()){
+        this->npoints = 5;
+        this->p[0] = *this->red_curve->first_point();
+        this->p[3] = this->red_curve->first_segment()->finalPoint();
+        this->p[2] = this->p[3];
+    }
+}
+
+void PenTool::_bsplineSpiroStartAnchor(bool shift)
+{
+    if(this->sa->curve->is_unset()){
+        return;
+    }
+
+    LivePathEffect::LPEBSpline *lpe_bsp = nullptr;
+
+    if (SP_IS_LPE_ITEM(this->white_item) && SP_LPE_ITEM(this->white_item)->hasPathEffect()){
+        Inkscape::LivePathEffect::Effect *thisEffect =
+            SP_LPE_ITEM(this->white_item)->getFirstPathEffectOfType(Inkscape::LivePathEffect::BSPLINE);
+        if(thisEffect){
+            lpe_bsp = dynamic_cast<LivePathEffect::LPEBSpline*>(thisEffect->getLPEObj()->get_lpe());
+        }
+    }
+    if(lpe_bsp){
+        this->bspline = true;
+    }else{
+        this->bspline = false;
+    }
+    LivePathEffect::LPESpiro *lpe_spi = nullptr;
+
+    if (SP_IS_LPE_ITEM(this->white_item) && SP_LPE_ITEM(this->white_item)->hasPathEffect()){
+        Inkscape::LivePathEffect::Effect *thisEffect =
+            SP_LPE_ITEM(this->white_item)->getFirstPathEffectOfType(Inkscape::LivePathEffect::SPIRO);
+        if(thisEffect){
+            lpe_spi = dynamic_cast<LivePathEffect::LPESpiro*>(thisEffect->getLPEObj()->get_lpe());
+        }
+    }
+    if(lpe_spi){
+        this->spiro = true;
+    }else{
+        this->spiro = false;
+    }
+    if(!this->spiro && !this->bspline){
+        _bsplineSpiroColor();
+        return;
+    }
+    if(shift){
+        this->_bsplineSpiroStartAnchorOff();
+    } else {
+        this->_bsplineSpiroStartAnchorOn();
+    }
+}
+
+void PenTool::_bsplineSpiroStartAnchorOn()
+{
+    using Geom::X;
+    using Geom::Y;
+    Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*this->sa_overwrited ->last_segment());
+    auto last_segment = std::make_unique<SPCurve>();
+    Geom::Point point_a = this->sa_overwrited->last_segment()->initialPoint();
+    Geom::Point point_d = *this->sa_overwrited->last_point();
+    Geom::Point point_c = point_d + (1./3)*(point_a - point_d);
+    point_c = Geom::Point(point_c[X] + HANDLE_CUBIC_GAP, point_c[Y] + HANDLE_CUBIC_GAP);
+    if(cubic){
+        last_segment->moveto(point_a);
+        last_segment->curveto((*cubic)[1],point_c,point_d);
+    }else{
+        last_segment->moveto(point_a);
+        last_segment->curveto(point_a,point_c,point_d);
+    }
+    if( this->sa_overwrited->get_segment_count() == 1){
+        this->sa_overwrited = std::move(last_segment);
+    }else{
+        //we eliminate the last segment
+        this->sa_overwrited->backspace();
+        //and we add it again with the recreation
+        sa_overwrited->append_continuous(*last_segment);
+    }
+}
+
+void PenTool::_bsplineSpiroStartAnchorOff()
+{
+    Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*this->sa_overwrited->last_segment());
+    if(cubic){
+        auto last_segment = std::make_unique<SPCurve>();
+        last_segment->moveto((*cubic)[0]);
+        last_segment->curveto((*cubic)[1],(*cubic)[3],(*cubic)[3]);
+        if( this->sa_overwrited->get_segment_count() == 1){
+            this->sa_overwrited = std::move(last_segment);
+        }else{
+            //we eliminate the last segment
+            this->sa_overwrited->backspace();
+            //and we add it again with the recreation
+            sa_overwrited->append_continuous(*last_segment);
+        }
+    }
+}
+
+void PenTool::_bsplineSpiroMotion(guint const state){
+    bool shift = state & GDK_SHIFT_MASK;
+    if(!this->spiro && !this->bspline){
+        return;
+    }
+    using Geom::X;
+    using Geom::Y;
+    if(this->red_curve->is_unset()) return;
+    this->npoints = 5;
+    std::unique_ptr<SPCurve> tmp_curve(new SPCurve());
+    this->p[2] = this->p[3] + (1./3)*(this->p[0] - this->p[3]);
+    this->p[2] = Geom::Point(this->p[2][X] + HANDLE_CUBIC_GAP,this->p[2][Y] + HANDLE_CUBIC_GAP);
+    if (this->green_curve->is_unset() && !this->sa) {
+        this->p[1] = this->p[0] + (1./3)*(this->p[3] - this->p[0]);
+        this->p[1] = Geom::Point(this->p[1][X] + HANDLE_CUBIC_GAP, this->p[1][Y] + HANDLE_CUBIC_GAP);
+        if(shift){
+            this->p[2] = this->p[3];
+        }
+    } else if (!this->green_curve->is_unset()){
+        tmp_curve = this->green_curve->copy();
+    } else {
+        tmp_curve = this->sa_overwrited->copy();
+    }
+    if ((state & GDK_MOD1_MASK ) && previous != Geom::Point(0,0)) { //ALT drag
+        this->p[0] = this->p[0] + (this->p[3] - previous);
+    }
+    if(!tmp_curve ->is_unset()){
+        Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*tmp_curve ->last_segment());
+        if ((state & GDK_MOD1_MASK ) &&
+            !Geom::are_near(*tmp_curve ->last_point(), this->p[0], 0.1))
+        {
+            auto previous_weight_power = std::make_unique<SPCurve>();
+            Geom::D2< Geom::SBasis > SBasisweight_power;
+            previous_weight_power->moveto(tmp_curve ->last_segment()->initialPoint());
+            previous_weight_power->lineto(this->p[0]);
+            SBasisweight_power = previous_weight_power->first_segment()->toSBasis();
+            if( tmp_curve ->get_segment_count() == 1){
+                Geom::Point initial = tmp_curve ->last_segment()->initialPoint();
+                tmp_curve->reset();
+                tmp_curve->moveto(initial);
+            }else{
+                tmp_curve->backspace();
+            }
+            if(this->bspline && cubic && !Geom::are_near((*cubic)[2],(*cubic)[3])){
+                tmp_curve->curveto(SBasisweight_power.valueAt(0.33334), SBasisweight_power.valueAt(0.66667), this->p[0]);
+            } else if(this->bspline && cubic) {
+                tmp_curve->curveto(SBasisweight_power.valueAt(0.33334), this->p[0], this->p[0]);
+            } else if (cubic && !Geom::are_near((*cubic)[2],(*cubic)[3])) {
+                tmp_curve->curveto((*cubic)[1], (*cubic)[2] + (this->p[3] - previous), this->p[0]);
+            } else if (cubic){
+                tmp_curve->curveto((*cubic)[1], this->p[0], this->p[0]);
+            } else {
+                tmp_curve->lineto(this->p[0]);
+            }
+            cubic = dynamic_cast<Geom::CubicBezier const*>(&*tmp_curve ->last_segment());
+            if (this->sa && this->green_curve->is_unset()) {
+                this->sa_overwrited = tmp_curve->copy();
+            }
+            this->green_curve = tmp_curve->copy();
+        }
+        if (cubic) {
+            if (this->bspline) {
+                auto weight_power = std::make_unique<SPCurve>();
+                Geom::D2< Geom::SBasis > SBasisweight_power;
+                weight_power->moveto(this->red_curve->last_segment()->initialPoint());
+                weight_power->lineto(*this->red_curve->last_point());
+                SBasisweight_power = weight_power->first_segment()->toSBasis();
+                this->p[1] = SBasisweight_power.valueAt(0.33334);
+                if(!Geom::are_near(this->p[1],this->p[0])){
+                    this->p[1] = Geom::Point(this->p[1][X] + HANDLE_CUBIC_GAP,this->p[1][Y] + HANDLE_CUBIC_GAP);
+                } else {
+                    this->p[1] = this->p[0];
+                }
+                if (shift) {
+                    this->p[2] = this->p[3];
+                }
+                if(Geom::are_near((*cubic)[3], (*cubic)[2])) {
+                    this->p[1] = this->p[0];
+                }
+            } else {
+                this->p[1] =  (*cubic)[3] + ((*cubic)[3] - (*cubic)[2] );
+            }
+        } else {
+            this->p[1] = this->p[0];
+            if (shift) {
+                this->p[2] = this->p[3];
+            }
+        }
+        previous = *this->red_curve->last_point();
+        auto red = std::make_unique<SPCurve>();
+        red->moveto(this->p[0]);
+        red->curveto(this->p[1],this->p[2],this->p[3]);
+        this->red_bpath->set_bpath(red.get(), true);
+    }
+
+    if(this->anchor_statusbar && !this->red_curve->is_unset()){
+        if(shift){
+            this->_bsplineSpiroEndAnchorOff();
+        }else{
+            this->_bsplineSpiroEndAnchorOn();
+        }
+    }
+
+    // remove old piecewise green canvasitems
+    for (auto path: this->green_bpaths) {
+        delete path;
+    }
+    this->green_bpaths.clear();
+
+    // one canvas bpath for all of green_curve
+    auto canvas_shape = new Inkscape::CanvasItemBpath(_desktop->getCanvasSketch(), green_curve.get(), true);
+    canvas_shape->set_stroke(green_color);
+    canvas_shape->set_fill(0x0, SP_WIND_RULE_NONZERO);
+    this->green_bpaths.push_back(canvas_shape);
+
+    this->_bsplineSpiroBuild();
+}
+
+void PenTool::_bsplineSpiroEndAnchorOn()
+{
+
+    using Geom::X;
+    using Geom::Y;
+    this->p[2] = this->p[3] + (1./3)*(this->p[0] - this->p[3]);
+    this->p[2] = Geom::Point(this->p[2][X] + HANDLE_CUBIC_GAP,this->p[2][Y] + HANDLE_CUBIC_GAP);
+    std::unique_ptr<SPCurve> tmp_curve(new SPCurve());
+    std::unique_ptr<SPCurve> last_segment(new SPCurve());
+    Geom::Point point_c(0,0);
+    if( this->green_anchor && this->green_anchor->active ){
+        tmp_curve = this->green_curve->create_reverse();
+        if(this->green_curve->get_segment_count()==0){
+            return;
+        }
+    } else if(this->sa){
+        tmp_curve = this->sa_overwrited->create_reverse();
+    }else{
+        return;
+    }
+    Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*tmp_curve ->last_segment());
+    if(this->bspline){
+        point_c = *tmp_curve ->last_point() + (1./3)*(tmp_curve ->last_segment()->initialPoint() - *tmp_curve ->last_point());
+        point_c = Geom::Point(point_c[X] + HANDLE_CUBIC_GAP, point_c[Y] + HANDLE_CUBIC_GAP);
+    }else{
+        point_c = this->p[3] + this->p[3] - this->p[2];
+    }
+    if(cubic){
+        last_segment->moveto((*cubic)[0]);
+        last_segment->curveto((*cubic)[1],point_c,(*cubic)[3]);
+    }else{
+        last_segment->moveto(tmp_curve ->last_segment()->initialPoint());
+        last_segment->lineto(*tmp_curve ->last_point());
+    }
+    if( tmp_curve ->get_segment_count() == 1){
+        tmp_curve  = std::move(last_segment);
+    }else{
+        //we eliminate the last segment
+        tmp_curve ->backspace();
+        //and we add it again with the recreation
+        tmp_curve ->append_continuous(*last_segment);
+    }
+    tmp_curve = tmp_curve->create_reverse();
+    if( this->green_anchor && this->green_anchor->active )
+    {
+        this->green_curve->reset();
+        this->green_curve = std::move(tmp_curve);
+    }else{
+        this->sa_overwrited->reset();
+        this->sa_overwrited = std::move(tmp_curve);
+    }
+}
+
+void PenTool::_bsplineSpiroEndAnchorOff()
+{
+
+    std::unique_ptr<SPCurve> tmp_curve(new SPCurve());
+    std::unique_ptr<SPCurve> last_segment(new SPCurve());
+    this->p[2] = this->p[3];
+    if( this->green_anchor && this->green_anchor->active ){
+        tmp_curve = this->green_curve->create_reverse();
+        if(this->green_curve->get_segment_count()==0){
+            return;
+        }
+    } else if(this->sa){
+        tmp_curve = this->sa_overwrited->create_reverse();
+    }else{
+        return;
+    }
+    Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*tmp_curve ->last_segment());
+    if(cubic){
+        last_segment->moveto((*cubic)[0]);
+        last_segment->curveto((*cubic)[1],(*cubic)[3],(*cubic)[3]);
+    }else{
+        last_segment->moveto(tmp_curve ->last_segment()->initialPoint());
+        last_segment->lineto(*tmp_curve ->last_point());
+    }
+    if( tmp_curve ->get_segment_count() == 1){
+        tmp_curve  = std::move(last_segment);
+    }else{
+        //we eliminate the last segment
+        tmp_curve ->backspace();
+        //and we add it again with the recreation
+        tmp_curve ->append_continuous(*last_segment);
+    }
+    tmp_curve = tmp_curve->create_reverse();
+
+    if( this->green_anchor && this->green_anchor->active )
+    {
+        this->green_curve->reset();
+        this->green_curve = std::move(tmp_curve);
+    }else{
+        this->sa_overwrited->reset();
+        this->sa_overwrited = std::move(tmp_curve);
+    }
+}
+
+//prepares the curves for its transformation into BSpline curve.
+void PenTool::_bsplineSpiroBuild()
+{
+    if(!this->spiro && !this->bspline){
+        return;
+    }
+
+    //We create the base curve
+    auto curve = std::make_unique<SPCurve>();
+    //If we continuate the existing curve we add it at the start
+    if(this->sa && !this->sa->curve->is_unset()){
+        curve = this->sa_overwrited->copy();
+    }
+
+    if (!this->green_curve->is_unset()){
+        curve->append_continuous(*green_curve);
+    }
+
+    //and the red one
+    if (!this->red_curve->is_unset()){
+        this->red_curve->reset();
+        this->red_curve->moveto(this->p[0]);
+        if(this->anchor_statusbar && !this->sa && !(this->green_anchor && this->green_anchor->active)){
+            this->red_curve->curveto(this->p[1],this->p[3],this->p[3]);
+        }else{
+            this->red_curve->curveto(this->p[1],this->p[2],this->p[3]);
+        }
+        red_bpath->set_bpath(red_curve.get(), true);
+        curve->append_continuous(*red_curve);
+    }
+    previous = *this->red_curve->last_point();
+    if(!curve->is_unset()){
+        // close the curve if the final points of the curve are close enough
+        if(Geom::are_near(curve->first_path()->initialPoint(), curve->last_path()->finalPoint())){
+            curve->closepath_current();
+        }
+        //TODO: CALL TO CLONED FUNCTION SPIRO::doEffect IN lpe-spiro.cpp
+        //For example
+        //using namespace Inkscape::LivePathEffect;
+        //LivePathEffectObject *lpeobj = static_cast<LivePathEffectObject*> (curve);
+        //Effect *spr = static_cast<Effect*> ( new LPEbspline(lpeobj) );
+        //spr->doEffect(curve);
+        if (this->bspline) {
+            Geom::PathVector hp;
+            LivePathEffect::sp_bspline_do_effect(curve.get(), 0, hp);
+        } else {
+            LivePathEffect::sp_spiro_do_effect(curve.get());
+        }
+
+        blue_bpath->set_bpath(curve.get(), true);
+        blue_bpath->set_stroke(blue_color);
+        blue_bpath->show();
+
+        this->blue_curve->reset();
+        //We hide the holders that doesn't contribute anything
+        if (this->spiro){
+            c1->set_position(p[0]);
+            c1->show();
+        } else {
+            c1->hide();
+        }
+        c0->hide();
+        cl0->hide();
+        cl1->hide();
+    } else {
+        //if the curve is empty
+        blue_bpath->hide();
+    }
+}
+
+void PenTool::_setSubsequentPoint(Geom::Point const p, bool statusbar, guint status) {
+    g_assert( this->npoints != 0 );
+
+    // todo: Check callers to see whether 2 <= npoints is guaranteed.
+
+    this->p[2] = p;
+    this->p[3] = p;
+    this->p[4] = p;
+    this->npoints = 5;
+    this->red_curve->reset();
+    bool is_curve;
+    this->red_curve->moveto(this->p[0]);
+    if (this->polylines_paraxial && !statusbar) {
+        // we are drawing horizontal/vertical lines and hit an anchor;
+        Geom::Point const origin = this->p[0];
+        // if the previous point and the anchor are not aligned either horizontally or vertically...
+        if ((std::abs(p[Geom::X] - origin[Geom::X]) > 1e-9) && (std::abs(p[Geom::Y] - origin[Geom::Y]) > 1e-9)) {
+            // ...then we should draw an L-shaped path, consisting of two paraxial segments
+            Geom::Point intermed = p;
+            this->_setToNearestHorizVert(intermed, status);
+            this->red_curve->lineto(intermed);
+        }
+        this->red_curve->lineto(p);
+        is_curve = false;
+    } else {
+        // one of the 'regular' modes
+        if (this->p[1] != this->p[0] || this->spiro) {
+            this->red_curve->curveto(this->p[1], p, p);
+            is_curve = true;
+        } else {
+            this->red_curve->lineto(p);
+            is_curve = false;
+        }
+    }
+
+    red_bpath->set_bpath(red_curve.get(), true);
+
+    if (statusbar) {
+        gchar *message;
+        if(this->spiro || this->bspline){
+            message = is_curve ?
+            _("<b>Curve segment</b>: angle %3.2f&#176;; <b>Shift+Click</b> creates cusp node, <b>ALT</b> moves previous, <b>Enter</b> or <b>Shift+Enter</b> to finish" ):
+            _("<b>Line segment</b>: angle %3.2f&#176;; <b>Shift+Click</b> creates cusp node, <b>ALT</b> moves previous, <b>Enter</b> or <b>Shift+Enter</b> to finish");
+            this->_setAngleDistanceStatusMessage(p, 0, message);
+        } else {
+            message = is_curve ?
+            _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> or <b>Shift+Enter</b> to finish the path" ):
+            _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> or <b>Shift+Enter</b> to finish the path");
+            this->_setAngleDistanceStatusMessage(p, 0, message);
+        }
+
+    }
+}
+
+
+void PenTool::_setCtrl(Geom::Point const q, guint const state) { // use 'q' as 'p' shadows member variable.
+    c1->show();
+    cl1->show();
+
+    if ( this->npoints == 2 ) {
+        this->p[1] = q;
+        c0->hide();
+        cl0->hide();
+        c1->set_position(p[1]);
+        cl1->set_coords(p[0], p[1]);
+        this->_setAngleDistanceStatusMessage(q, 0, _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle"));
+    } else if ( this->npoints == 5 ) {
+        this->p[4] = q;
+        c0->show();
+        cl0->show();
+        bool is_symm = false;
+        if ( ( ( this->mode == PenTool::MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
+             ( ( this->mode == PenTool::MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
+            Geom::Point delta = q - this->p[3];
+            this->p[2] = this->p[3] - delta;
+            is_symm = true;
+            this->red_curve->reset();
+            this->red_curve->moveto(this->p[0]);
+            this->red_curve->curveto(this->p[1], this->p[2], this->p[3]);
+            red_bpath->set_bpath(red_curve.get(), true);
+        }
+        c0->set_position(this->p[2]);
+        cl0->set_coords(this->p[3], this->p[2]);
+        c1->set_position(this->p[4]);
+        cl1->set_coords(this->p[3], this->p[4]);
+
+
+
+        gchar *message = is_symm ?
+            _("<b>Curve handle, symmetric</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only") :
+            _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only");
+        this->_setAngleDistanceStatusMessage(q, 3, message);
+    } else {
+        g_warning("Something bad happened - npoints is %d", this->npoints);
+    }
+}
+
+void PenTool::_finishSegment(Geom::Point const q, guint const state) { // use 'q' as 'p' shadows member variable.
+    if (this->polylines_paraxial) {
+        this->nextParaxialDirection(q, this->p[0], state);
+    }
+
+    ++num_clicks;
+
+
+    if (!this->red_curve->is_unset()) {
+        this->_bsplineSpiro(state & GDK_SHIFT_MASK);
+        if(!this->green_curve->is_unset() &&
+           !Geom::are_near(*this->green_curve->last_point(),this->p[0]))
+        {
+          std::unique_ptr<SPCurve> lsegment(new SPCurve());
+            Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const*>(&*this->green_curve->last_segment());
+            if (cubic) {
+                lsegment->moveto((*cubic)[0]);
+                lsegment->curveto((*cubic)[1], this->p[0] - ((*cubic)[2] - (*cubic)[3]), *this->red_curve->first_point());
+                this->green_curve->backspace();
+                green_curve->append_continuous(*lsegment);
+            }
+        }
+        this->green_curve->append_continuous(*red_curve);
+        auto curve = this->red_curve->copy();
+
+        /// \todo fixme:
+        auto canvas_shape = new Inkscape::CanvasItemBpath(_desktop->getCanvasSketch(), curve.get(), true);
+        canvas_shape->set_stroke(green_color);
+        canvas_shape->set_fill(0x0, SP_WIND_RULE_NONZERO);
+        this->green_bpaths.push_back(canvas_shape);
+
+        this->p[0] = this->p[3];
+        this->p[1] = this->p[4];
+        this->npoints = 2;
+
+        this->red_curve->reset();
+    }
+}
+
+// Partial fix for https://bugs.launchpad.net/inkscape/+bug/171990
+// TODO: implement the redo feature
+bool PenTool::_undoLastPoint() {
+    bool ret = false;
+
+    if ( this->green_curve->is_unset() || (this->green_curve->last_segment() == nullptr) ) {
+        if (!this->red_curve->is_unset()) {
+            this->_cancel ();
+            ret = true;
+        } else {
+            // do nothing; this event should be handled upstream
+        }
+    } else {
+        // Reset red curve
+        this->red_curve->reset();
+        // Get last segment
+        if ( this->green_curve->is_unset() ) {
+            g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
+            return false;
+        }
+        // The code below assumes that this->green_curve has only ONE path !
+        Geom::Curve const * crv = this->green_curve->last_segment();
+        this->p[0] = crv->initialPoint();
+        if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
+            this->p[1] = (*cubic)[1];
+
+        } else {
+            this->p[1] = this->p[0];
+        }
+
+        // assign the value in a third of the distance of the last segment.
+        if (this->bspline){
+            this->p[1] = this->p[0] + (1./3)*(this->p[3] - this->p[0]);
+        }
+
+        Geom::Point const pt( (this->npoints < 4) ? crv->finalPoint() : this->p[3] );
+
+        this->npoints = 2;
+        // delete the last segment of the green curve and green bpath
+        if (this->green_curve->get_segment_count() == 1) {
+            this->npoints = 5;
+            if (!this->green_bpaths.empty()) {
+                delete this->green_bpaths.back();
+                this->green_bpaths.pop_back();
+            }
+            this->green_curve->reset();
+        } else {
+            this->green_curve->backspace();
+            if (this->green_bpaths.size() > 1) {
+                delete this->green_bpaths.back();
+                this->green_bpaths.pop_back();
+            } else if (this->green_bpaths.size() == 1) {
+                green_bpaths.back()->set_bpath(green_curve.get(), true);
+            }
+        }
+
+        // assign the value of this->p[1] to the opposite of the green line last segment
+        if (this->spiro){
+            Geom::CubicBezier const *cubic = dynamic_cast<Geom::CubicBezier const *>(this->green_curve->last_segment());
+            if ( cubic ) {
+                this->p[1] = (*cubic)[3] + (*cubic)[3] - (*cubic)[2];
+                c1->set_position(this->p[0]);
+            } else {
+                this->p[1] = this->p[0];
+            }
+        }
+
+        c0->hide();
+        c1->hide();
+        cl0->hide();
+        cl1->hide();
+        this->state = PenTool::POINT;
+
+        if(this->polylines_paraxial) {
+            // We compare the point we're removing with the nearest horiz/vert to
+            // see if the line was added with SHIFT or not.
+            Geom::Point compare(pt);
+            this->_setToNearestHorizVert(compare, 0);
+            if ((std::abs(compare[Geom::X] - pt[Geom::X]) > 1e-9)
+                || (std::abs(compare[Geom::Y] - pt[Geom::Y]) > 1e-9)) {
+                this->paraxial_angle = this->paraxial_angle.cw();
+            }
+        }
+        this->_setSubsequentPoint(pt, true);
+
+        //redraw
+        this->_bsplineSpiroBuild();
+        ret = true;
+    }
+
+    return ret;
+}
+
+void PenTool::_finish(gboolean const closed) {
+    if (this->expecting_clicks_for_LPE > 1) {
+        // don't let the path be finished before we have collected the required number of mouse clicks
+        return;
+    }
+
+
+    this->num_clicks = 0;
+
+    this->_disableEvents();
+
+    this->message_context->clear();
+
+    _desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
+
+    // cancelate line without a created segment
+    this->red_curve->reset();
+    spdc_concat_colors_and_flush(this, closed);
+    this->sa = nullptr;
+    this->ea = nullptr;
+
+    this->npoints = 0;
+    this->state = PenTool::POINT;
+
+    c0->hide();
+    c1->hide();
+    cl0->hide();
+    cl1->hide();
+
+    this->green_anchor.reset();
+
+    this->_enableEvents();
+}
+
+void PenTool::_disableEvents() {
+    this->events_disabled = true;
+}
+
+void PenTool::_enableEvents() {
+    g_return_if_fail(this->events_disabled != 0);
+
+    this->events_disabled = false;
+}
+
+void PenTool::waitForLPEMouseClicks(Inkscape::LivePathEffect::EffectType effect_type, unsigned int num_clicks, bool use_polylines) {
+    if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
+        return;
+
+    this->waiting_LPE_type = effect_type;
+    this->expecting_clicks_for_LPE = num_clicks;
+    this->polylines_only = use_polylines;
+    this->polylines_paraxial = false; // TODO: think if this is correct for all cases
+}
+
+void PenTool::nextParaxialDirection(Geom::Point const &pt, Geom::Point const &origin, guint state) {
+    //
+    // after the first mouse click we determine whether the mouse pointer is closest to a
+    // horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
+    // orthogonal to the last one; pressing Shift toggles the direction
+    //
+    // num_clicks is not reliable because spdc_pen_finish_segment is sometimes called too early
+    // (on first mouse release), in which case num_clicks immediately becomes 1.
+    // if (this->num_clicks == 0) {
+
+    if (this->green_curve->is_unset()) {
+        // first mouse click
+        double h = pt[Geom::X] - origin[Geom::X];
+        double v = pt[Geom::Y] - origin[Geom::Y];
+        this->paraxial_angle = Geom::Point(h, v).ccw();
+    }
+    if(!(state & GDK_SHIFT_MASK)) {
+        this->paraxial_angle = this->paraxial_angle.ccw();
+    }
+}
+
+void PenTool::_setToNearestHorizVert(Geom::Point &pt, guint const state) const {
+    Geom::Point const origin = this->p[0];
+    Geom::Point const target = (state & GDK_SHIFT_MASK) ? this->paraxial_angle : this->paraxial_angle.ccw();
+
+    // Create a horizontal or vertical constraint line
+    Inkscape::Snapper::SnapConstraint cl(origin, target);
+
+    // Snap along the constraint line; if we didn't snap then still the constraint will be applied
+    SnapManager &m = _desktop->namedview->snap_manager;
+
+    Inkscape::Selection *selection = _desktop->getSelection();
+    // selection->singleItem() is the item that is currently being drawn. This item will not be snapped to (to avoid self-snapping)
+    // TODO: Allow snapping to the stationary parts of the item, and only ignore the last segment
+
+    m.setup(_desktop, true, selection->singleItem());
+    m.constrainedSnapReturnByRef(pt, Inkscape::SNAPSOURCE_NODE_HANDLE, cl);
+    m.unSetup();
+}
+
+}
+}
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :