moving trunk for module inkscape

(bzr r1)

1 files changed, 1084 insertions, 0 deletions

diff --git a/src/pen-context.cpp b/src/pen-context.cpp
new file mode 100644
index 000000000..95593f25b
--- /dev/null
+++ b/src/pen-context.cpp
@@ -0,0 +1,1084 @@
+/** \file 
+ * Pen event context implementation. 
+ */
+
+/*
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   bulia byak <buliabyak@users.sf.net>
+ *
+ * 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, read the file 'COPYING' for more information
+ */
+
+#include <gdk/gdkkeysyms.h>
+
+#include "pen-context.h"
+#include "sp-namedview.h"
+#include "sp-metrics.h"
+#include "desktop.h"
+#include "desktop-handles.h"
+#include "selection.h"
+#include "draw-anchor.h"
+#include "message-stack.h"
+#include "message-context.h"
+#include "prefs-utils.h"
+#include "sp-path.h"
+
+#include "pixmaps/cursor-pen.xpm"
+#include "display/canvas-bpath.h"
+#include "display/sp-ctrlline.h"
+#include "display/sodipodi-ctrl.h"
+#include <glibmm/i18n.h>
+#include "libnr/n-art-bpath.h"
+#include "helper/units.h"
+#include "macros.h"
+#include "context-fns.h"
+
+
+static void sp_pen_context_class_init(SPPenContextClass *klass);
+static void sp_pen_context_init(SPPenContext *pc);
+static void sp_pen_context_dispose(GObject *object);
+
+static void sp_pen_context_setup(SPEventContext *ec);
+static void sp_pen_context_finish(SPEventContext *ec);
+static void sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
+static gint sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event);
+
+static void spdc_pen_set_initial_point(SPPenContext *pc, NR::Point const p);
+static void spdc_pen_set_subsequent_point(SPPenContext *pc, NR::Point const p, bool statusbar);
+static void spdc_pen_set_ctrl(SPPenContext *pc, NR::Point const p, guint state);
+static void spdc_pen_finish_segment(SPPenContext *pc, NR::Point p, guint state);
+
+static void spdc_pen_finish(SPPenContext *pc, gboolean closed);
+
+static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent);
+static gint pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent);
+static gint pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent);
+static gint pen_handle_2button_press(SPPenContext *const pc);
+static gint pen_handle_key_press(SPPenContext *const pc, GdkEvent *event);
+static void spdc_reset_colors(SPPenContext *pc);
+
+
+static NR::Point pen_drag_origin_w(0, 0);
+static bool pen_within_tolerance = false;
+
+static SPDrawContextClass *pen_parent_class;
+
+/**
+ * Register SPPenContext with Gdk and return its type.
+ */
+GType
+sp_pen_context_get_type(void)
+{
+    static GType type = 0;
+    if (!type) {
+        GTypeInfo info = {
+            sizeof(SPPenContextClass),
+            NULL, NULL,
+            (GClassInitFunc) sp_pen_context_class_init,
+            NULL, NULL,
+            sizeof(SPPenContext),
+            4,
+            (GInstanceInitFunc) sp_pen_context_init,
+            NULL,   /* value_table */
+        };
+        type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPenContext", &info, (GTypeFlags)0);
+    }
+    return type;
+}
+
+/**
+ * Initialize the SPPenContext vtable.
+ */
+static void
+sp_pen_context_class_init(SPPenContextClass *klass)
+{
+    GObjectClass *object_class;
+    SPEventContextClass *event_context_class;
+
+    object_class = (GObjectClass *) klass;
+    event_context_class = (SPEventContextClass *) klass;
+
+    pen_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
+
+    object_class->dispose = sp_pen_context_dispose;
+
+    event_context_class->setup = sp_pen_context_setup;
+    event_context_class->finish = sp_pen_context_finish;
+    event_context_class->set = sp_pen_context_set;
+    event_context_class->root_handler = sp_pen_context_root_handler;
+}
+
+/**
+ * Callback to initialize SPPenContext object.
+ */
+static void
+sp_pen_context_init(SPPenContext *pc)
+{
+
+    SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
+
+    event_context->cursor_shape = cursor_pen_xpm;
+    event_context->hot_x = 4;
+    event_context->hot_y = 4;
+    
+    pc->npoints = 0;
+    pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
+    pc->state = SP_PEN_CONTEXT_POINT;
+
+    pc->c0 = NULL;
+    pc->c1 = NULL;
+    pc->cl0 = NULL;
+    pc->cl1 = NULL;
+}
+
+/**
+ * Callback to destroy the SPPenContext object's members and itself.
+ */
+static void
+sp_pen_context_dispose(GObject *object)
+{
+    SPPenContext *pc;
+
+    pc = SP_PEN_CONTEXT(object);
+
+    if (pc->c0) {
+        gtk_object_destroy(GTK_OBJECT(pc->c0));
+        pc->c0 = NULL;
+    }
+    if (pc->c1) {
+        gtk_object_destroy(GTK_OBJECT(pc->c1));
+        pc->c1 = NULL;
+    }
+    if (pc->cl0) {
+        gtk_object_destroy(GTK_OBJECT(pc->cl0));
+        pc->cl0 = NULL;
+    }
+    if (pc->cl1) {
+        gtk_object_destroy(GTK_OBJECT(pc->cl1));
+        pc->cl1 = NULL;
+    }
+
+    G_OBJECT_CLASS(pen_parent_class)->dispose(object);
+}
+
+/**
+ * Callback to initialize SPPenContext object.
+ */
+static void
+sp_pen_context_setup(SPEventContext *ec)
+{
+    SPPenContext *pc;
+
+    pc = SP_PEN_CONTEXT(ec);
+
+    if (((SPEventContextClass *) pen_parent_class)->setup) {
+        ((SPEventContextClass *) pen_parent_class)->setup(ec);
+    }
+
+    /* Pen indicators */
+    pc->c0 = sp_canvas_item_new(SP_DT_CONTROLS(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
+                                "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
+    pc->c1 = sp_canvas_item_new(SP_DT_CONTROLS(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
+                                "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
+    pc->cl0 = sp_canvas_item_new(SP_DT_CONTROLS(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
+    sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl0), 0x0000007f);
+    pc->cl1 = sp_canvas_item_new(SP_DT_CONTROLS(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
+    sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl1), 0x0000007f);
+
+    sp_canvas_item_hide(pc->c0);
+    sp_canvas_item_hide(pc->c1);
+    sp_canvas_item_hide(pc->cl0);
+    sp_canvas_item_hide(pc->cl1);
+
+    sp_event_context_read(ec, "mode");
+
+    pc->anchor_statusbar = false;
+
+    if (prefs_get_int_attribute("tools.freehand.pen", "selcue", 0) != 0) {
+        ec->enableSelectionCue();
+    }
+}
+
+/**
+ * Finalization callback.
+ */
+static void
+sp_pen_context_finish(SPEventContext *ec)
+{
+    spdc_pen_finish(SP_PEN_CONTEXT(ec), FALSE);
+
+    if (((SPEventContextClass *) pen_parent_class)->finish) {
+        ((SPEventContextClass *) pen_parent_class)->finish(ec);
+    }
+}
+
+/**
+ * Callback that sets key to value in pen context.
+ */
+static void
+sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
+{
+    SPPenContext *pc = SP_PEN_CONTEXT(ec);
+
+    if (!strcmp(key, "mode")) {
+        if ( val && !strcmp(val, "drag") ) {
+            pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
+        } else {
+            pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
+        }
+    }
+}
+
+/** 
+ * Snaps new node relative to the previous node.
+ */
+static void
+spdc_endpoint_snap(SPPenContext const *const pc, NR::Point &p, guint const state)
+{
+    if (pc->npoints > 0) {
+        spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
+    }
+
+    spdc_endpoint_snap_free(pc, p, state);
+}
+
+/** 
+ * Snaps new node's handle relative to the new node.
+ */
+static void
+spdc_endpoint_snap_handle(SPPenContext const *const pc, NR::Point &p, guint const state)
+{
+    g_return_if_fail(( pc->npoints == 2 ||
+                       pc->npoints == 5   ));
+
+    spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
+    spdc_endpoint_snap_free(pc, p, state);
+}
+
+/**
+ * Callback to handle all pen events.
+ */
+static gint
+sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
+{
+    SPPenContext *const pc = SP_PEN_CONTEXT(ec);
+
+    gint ret = FALSE;
+
+    switch (event->type) {
+        case GDK_BUTTON_PRESS:
+            ret = pen_handle_button_press(pc, event->button);
+            break;
+
+        case GDK_MOTION_NOTIFY:
+            ret = pen_handle_motion_notify(pc, event->motion);
+            break;
+
+        case GDK_BUTTON_RELEASE:
+            ret = pen_handle_button_release(pc, event->button);
+            break;
+
+        case GDK_2BUTTON_PRESS:
+            ret = pen_handle_2button_press(pc);
+            break;
+
+        case GDK_KEY_PRESS:
+            ret = pen_handle_key_press(pc, event);
+            break;
+
+        default:
+            break;
+    }
+
+    if (!ret) {
+        gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
+            = ((SPEventContextClass *) pen_parent_class)->root_handler;
+        if (parent_root_handler) {
+            ret = parent_root_handler(ec, event);
+        }
+    }
+
+    return ret;
+}
+
+/**
+ * Handle mouse button press event.
+ */
+static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
+{
+    gint ret = FALSE;
+    if (bevent.button == 1) {
+
+        SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
+        SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
+
+        if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
+            return TRUE;
+        }
+        
+        NR::Point const event_w(bevent.x, bevent.y);
+        pen_drag_origin_w = event_w;
+        pen_within_tolerance = true;
+
+        /* Test whether we hit any anchor. */
+        SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
+
+        NR::Point const event_dt(desktop->w2d(event_w));
+        switch (pc->mode) {
+            case SP_PEN_CONTEXT_MODE_CLICK:
+                /* In click mode we add point on release */
+                switch (pc->state) {
+                    case SP_PEN_CONTEXT_POINT:
+                    case SP_PEN_CONTEXT_CONTROL:
+                    case SP_PEN_CONTEXT_CLOSE:
+                        break;
+                    case SP_PEN_CONTEXT_STOP:
+                        /* This is allowed, if we just cancelled curve */
+                        pc->state = SP_PEN_CONTEXT_POINT;
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            case SP_PEN_CONTEXT_MODE_DRAG:
+                switch (pc->state) {
+                    case SP_PEN_CONTEXT_STOP:
+                        /* This is allowed, if we just cancelled curve */
+                    case SP_PEN_CONTEXT_POINT:
+                        if (pc->npoints == 0) {
+                            
+                            /* Set start anchor */
+                            pc->sa = anchor;
+                            NR::Point p;
+                            if (anchor) {
+                                
+                                /* Adjust point to anchor if needed */
+                                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 = SP_DT_SELECTION(desktop);
+                                if (!(bevent.state & GDK_SHIFT_MASK)) {
+                                    
+                                    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;
+                                spdc_endpoint_snap(pc, p, bevent.state);
+                                pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
+                            }
+                            spdc_pen_set_initial_point(pc, p);
+                        } else {
+                            
+                            /* Set end anchor */
+                            pc->ea = anchor;
+                            NR::Point p;
+                            if (anchor) {
+                                
+                                p = anchor->dp;
+                                // we hit an anchor, will finish the curve (either with or without closing)
+                                // in release handler
+                                pc->state = SP_PEN_CONTEXT_CLOSE;
+
+                                if (pc->green_anchor && pc->green_anchor->active) {
+                                    // we clicked on the current curve start, so close it even if
+                                    // we drag a handle away from it
+                                    dc->green_closed = TRUE; 
+                                }
+                                ret = TRUE;
+                                break;
+                                
+                            } else {
+                                
+                                p = event_dt;
+                                spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
+                                spdc_pen_set_subsequent_point(pc, p, true);
+                            }
+                            
+                        }
+                        pc->state = SP_PEN_CONTEXT_CONTROL;
+                        ret = TRUE;
+                        break;
+                    case SP_PEN_CONTEXT_CONTROL:
+                        g_warning("Button down in CONTROL state");
+                        break;
+                    case SP_PEN_CONTEXT_CLOSE:
+                        g_warning("Button down in CLOSE state");
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            default:
+                break;
+        }
+    } else if (bevent.button == 3) {
+        if (pc->npoints != 0) {
+            spdc_pen_finish(pc, FALSE);
+            ret = TRUE;
+        }
+    }
+    
+    return ret;
+}
+
+/**
+ * Handle motion_notify event.
+ */
+static gint
+pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
+{
+    gint ret = FALSE;
+
+    if (mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
+        // allow middle-button scrolling
+        return FALSE;
+    }
+
+    NR::Point const event_w(mevent.x,
+                            mevent.y);
+    if (pen_within_tolerance) {
+        gint const tolerance = prefs_get_int_attribute_limited("options.dragtolerance",
+                                                               "value", 0, 0, 100);
+        if ( NR::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;
+
+    SPDesktop *const dt = pc->desktop;
+    if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab ) {
+        /* Grab mouse, so release will not pass unnoticed */
+        pc->grab = SP_CANVAS_ITEM(dt->acetate);
+        sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
+                                        GDK_BUTTON_RELEASE_MASK |
+                                        GDK_POINTER_MOTION_MASK  ),
+                            NULL, mevent.time);
+    }
+
+    /* Find desktop coordinates */
+    NR::Point p = dt->w2d(event_w);
+
+    /* Test, whether we hit any anchor */
+    SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
+
+    switch (pc->mode) {
+        case SP_PEN_CONTEXT_MODE_CLICK:
+            switch (pc->state) {
+                case SP_PEN_CONTEXT_POINT:
+                    if ( pc->npoints != 0 ) {
+                        /* Only set point, if we are already appending */
+                        spdc_endpoint_snap(pc, p, mevent.state);
+                        spdc_pen_set_subsequent_point(pc, p, true);
+                        ret = TRUE;
+                    }
+                    break;
+                case SP_PEN_CONTEXT_CONTROL:
+                case SP_PEN_CONTEXT_CLOSE:
+                    /* Placing controls is last operation in CLOSE state */
+                    spdc_endpoint_snap(pc, p, mevent.state);
+                    spdc_pen_set_ctrl(pc, p, mevent.state);
+                    ret = TRUE;
+                    break;
+                case SP_PEN_CONTEXT_STOP:
+                    /* This is perfectly valid */
+                    break;
+                default:
+                    break;
+            }
+            break;
+        case SP_PEN_CONTEXT_MODE_DRAG:
+            switch (pc->state) {
+                case SP_PEN_CONTEXT_POINT:
+                    if ( pc->npoints > 0 ) {
+                        /* Only set point, if we are already appending */
+
+                        if (!anchor) {   /* Snap node only if not hitting anchor */
+                            spdc_endpoint_snap(pc, p, mevent.state);
+                        }
+
+                        spdc_pen_set_subsequent_point(pc, p, !anchor);
+
+                        if (anchor && !pc->anchor_statusbar) {
+                            pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
+                            pc->anchor_statusbar = true;
+                        } else if (!anchor && pc->anchor_statusbar) {
+                            pc->_message_context->clear();
+                            pc->anchor_statusbar = false;
+                        }
+
+                        ret = TRUE;
+                    } else {
+                        if (anchor && !pc->anchor_statusbar) {
+                            pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
+                            pc->anchor_statusbar = true;
+                        } else if (!anchor && pc->anchor_statusbar) {
+                            pc->_message_context->clear();
+                            pc->anchor_statusbar = false;
+                        }
+                    }
+                    break;
+                case SP_PEN_CONTEXT_CONTROL:
+                case SP_PEN_CONTEXT_CLOSE:
+                    /* Placing controls is last operation in CLOSE state */
+
+                    // snap the handle
+                    spdc_endpoint_snap_handle(pc, p, mevent.state);
+
+                    spdc_pen_set_ctrl(pc, p, mevent.state);
+                    ret = TRUE;
+                    break;
+                case SP_PEN_CONTEXT_STOP:
+                    /* This is perfectly valid */
+                    break;
+                default:
+                    break;
+            }
+            break;
+        default:
+            break;
+    }
+    return ret;
+}
+
+/**
+ * Handle mouse button release event.
+ */
+static gint
+pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
+{
+    gint ret = FALSE;
+    if ( revent.button == 1 ) {
+
+        SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
+
+        NR::Point const event_w(revent.x,
+                                revent.y);
+        /* Find desktop coordinates */
+        NR::Point p = pc->desktop->w2d(event_w);
+
+        /* Test whether we hit any anchor. */
+        SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
+
+        switch (pc->mode) {
+            case SP_PEN_CONTEXT_MODE_CLICK:
+                switch (pc->state) {
+                    case SP_PEN_CONTEXT_POINT:
+                        if ( pc->npoints == 0 ) {
+                            /* Start new thread only with button release */
+                            if (anchor) {
+                                p = anchor->dp;
+                            }
+                            pc->sa = anchor;
+                            spdc_pen_set_initial_point(pc, p);
+                        } else {
+                            /* Set end anchor here */
+                            pc->ea = anchor;
+                            if (anchor) {
+                                p = anchor->dp;
+                            }
+                        }
+                        pc->state = SP_PEN_CONTEXT_CONTROL;
+                        ret = TRUE;
+                        break;
+                    case SP_PEN_CONTEXT_CONTROL:
+                        /* End current segment */
+                        spdc_endpoint_snap(pc, p, revent.state);
+                        spdc_pen_finish_segment(pc, p, revent.state);
+                        pc->state = SP_PEN_CONTEXT_POINT;
+                        ret = TRUE;
+                        break;
+                    case SP_PEN_CONTEXT_CLOSE:
+                        /* End current segment */
+                        if (!anchor) {   /* Snap node only if not hitting anchor */
+                            spdc_endpoint_snap(pc, p, revent.state);
+                        }
+                        spdc_pen_finish_segment(pc, p, revent.state);
+                        spdc_pen_finish(pc, TRUE);
+                        pc->state = SP_PEN_CONTEXT_POINT;
+                        ret = TRUE;
+                        break;
+                    case SP_PEN_CONTEXT_STOP:
+                        /* This is allowed, if we just cancelled curve */
+                        pc->state = SP_PEN_CONTEXT_POINT;
+                        ret = TRUE;
+                        break;
+                    default:
+                        break;
+                }
+                break;
+            case SP_PEN_CONTEXT_MODE_DRAG:
+                switch (pc->state) {
+                    case SP_PEN_CONTEXT_POINT:
+                    case SP_PEN_CONTEXT_CONTROL:
+                        spdc_endpoint_snap(pc, p, revent.state);
+                        spdc_pen_finish_segment(pc, p, revent.state);
+                        break;
+                    case SP_PEN_CONTEXT_CLOSE:
+                        spdc_endpoint_snap(pc, p, revent.state);
+                        spdc_pen_finish_segment(pc, p, revent.state);
+                        if (pc->green_closed) {
+                            // finishing at the start anchor, close curve
+                            spdc_pen_finish(pc, TRUE);
+                        } else {
+                            // finishing at some other anchor, finish curve but not close
+                            spdc_pen_finish(pc, FALSE);
+                        }
+                        break;
+                    case SP_PEN_CONTEXT_STOP:
+                        /* This is allowed, if we just cancelled curve */
+                        break;
+                    default:
+                        break;
+                }
+                pc->state = SP_PEN_CONTEXT_POINT;
+                ret = TRUE;
+                break;
+            default:
+                break;
+        }
+
+        if (pc->grab) {
+            /* Release grab now */
+            sp_canvas_item_ungrab(pc->grab, revent.time);
+            pc->grab = NULL;
+        }
+
+        ret = TRUE;
+
+        dc->green_closed = FALSE;
+    }
+
+    return ret;
+}
+
+static gint
+pen_handle_2button_press(SPPenContext *const pc)
+{
+    gint ret = FALSE;
+    if (pc->npoints != 0) {
+        spdc_pen_finish(pc, FALSE);
+        ret = TRUE;
+    }
+    return ret;
+}
+
+void
+pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
+{
+    if (pc->npoints != 5)
+        return;
+
+    // green
+    NArtBpath *const bpath = sp_curve_last_bpath(pc->green_curve);
+    if (bpath) {
+        if (bpath->code == NR_CURVETO) {
+            bpath->x2 += x;
+            bpath->y2 += y;
+        }
+        bpath->x3 += x;
+        bpath->y3 += y;
+        if (pc->green_bpaths && pc->green_bpaths->data) {
+            // remove old piecewise green canvasitems
+            while (pc->green_bpaths) {
+                gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
+                pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
+            }
+            // one canvas bpath for all of green_curve
+            SPCanvasItem *cshape = sp_canvas_bpath_new(SP_DT_SKETCH(pc->desktop), pc->green_curve);
+            sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
+            sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
+
+            pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
+        }
+    } else {
+        // start anchor too
+        if (pc->green_anchor) {
+            pc->green_anchor->dp += NR::Point(x, y);
+            SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
+        }
+    }
+
+    // red
+    pc->p[0] += NR::Point(x, y);
+    pc->p[1] += NR::Point(x, y);
+    sp_curve_reset(pc->red_curve);
+    sp_curve_moveto(pc->red_curve, pc->p[0]);
+    sp_curve_curveto(pc->red_curve, pc->p[1], pc->p[2], pc->p[3]);
+    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
+
+    // handles
+    if (pc->p[0] != pc->p[1]) {
+        SP_CTRL(pc->c1)->moveto(pc->p[1]);
+        sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
+    }
+    if (bpath && bpath->code == NR_CURVETO && NR::Point(bpath->x2, bpath->y2) != pc->p[0]) {
+        SP_CTRL(pc->c0)->moveto(NR::Point(bpath->x2, bpath->y2));
+        sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), NR::Point(bpath->x2, bpath->y2), pc->p[0]);
+    }
+}
+
+void
+pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
+{
+    pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
+}
+
+static gint
+pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
+{
+    gint ret = FALSE;
+    gdouble const nudge = prefs_get_double_attribute_limited("options.nudgedistance", "value", 2, 0, 1000); // in px
+
+    switch (get_group0_keyval (&event->key)) {
+
+        case GDK_Left: // move last point left
+        case GDK_KP_Left:
+        case GDK_KP_4:
+            if (!MOD__CTRL) { // not ctrl
+                if (MOD__ALT) { // alt
+                    if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
+                    else pen_lastpoint_move_screen(pc, -1, 0); // no shift
+                }
+                else { // no alt
+                    if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
+                    else pen_lastpoint_move(pc, -nudge, 0); // no shift
+                }
+                ret = TRUE;
+            }
+            break;
+        case GDK_Up: // move last point up
+        case GDK_KP_Up:
+        case GDK_KP_8:
+            if (!MOD__CTRL) { // not ctrl
+                if (MOD__ALT) { // alt
+                    if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
+                    else pen_lastpoint_move_screen(pc, 0, 1); // no shift
+                }
+                else { // no alt
+                    if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
+                    else pen_lastpoint_move(pc, 0, nudge); // no shift
+                }
+                ret = TRUE;
+            }
+            break;
+        case GDK_Right: // move last point right
+        case GDK_KP_Right:
+        case GDK_KP_6:
+            if (!MOD__CTRL) { // not ctrl
+                if (MOD__ALT) { // alt
+                    if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
+                    else pen_lastpoint_move_screen(pc, 1, 0); // no shift
+                }
+                else { // no alt
+                    if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
+                    else pen_lastpoint_move(pc, nudge, 0); // no shift
+                }
+                ret = TRUE;
+            }
+            break;
+        case GDK_Down: // move last point down
+        case GDK_KP_Down:
+        case GDK_KP_2:
+            if (!MOD__CTRL) { // not ctrl
+                if (MOD__ALT) { // alt
+                    if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
+                    else pen_lastpoint_move_screen(pc, 0, -1); // no shift
+                }
+                else { // no alt
+                    if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
+                    else pen_lastpoint_move(pc, 0, -nudge); // no shift
+                }
+                ret = TRUE;
+            }
+            break;
+
+        case GDK_Return:
+        case GDK_KP_Enter:
+            if (pc->npoints != 0) {
+                spdc_pen_finish(pc, FALSE);
+                ret = TRUE;
+            }
+            break;
+        case GDK_Escape:
+            if (pc->npoints != 0) {
+                // if drawing, cancel, otherwise pass it up for deselecting
+                pc->state = SP_PEN_CONTEXT_STOP;
+                spdc_reset_colors(pc);
+                sp_canvas_item_hide(pc->c0);
+                sp_canvas_item_hide(pc->c1);
+                sp_canvas_item_hide(pc->cl0);
+                sp_canvas_item_hide(pc->cl1);
+                ret = TRUE;
+            }
+            break;
+        case GDK_z:
+        case GDK_Z:
+            if (MOD__CTRL_ONLY && pc->npoints != 0) {
+                // if drawing, cancel, otherwise pass it up for undo
+                pc->state = SP_PEN_CONTEXT_STOP;
+                spdc_reset_colors(pc);
+                sp_canvas_item_hide(pc->c0);
+                sp_canvas_item_hide(pc->c1);
+                sp_canvas_item_hide(pc->cl0);
+                sp_canvas_item_hide(pc->cl1);
+                ret = TRUE;
+            }
+            break;
+        case GDK_BackSpace:
+        case GDK_Delete:
+        case GDK_KP_Delete:
+            if (sp_curve_is_empty(pc->green_curve)) {
+                /* Same as cancel */
+                pc->state = SP_PEN_CONTEXT_STOP;
+                spdc_reset_colors(pc);
+                sp_canvas_item_hide(pc->c0);
+                sp_canvas_item_hide(pc->c1);
+                sp_canvas_item_hide(pc->cl0);
+                sp_canvas_item_hide(pc->cl1);
+                ret = TRUE;
+            } else {
+                /* Reset red curve */
+                sp_curve_reset(pc->red_curve);
+                /* Destroy topmost green bpath */
+                if (pc->green_bpaths) {
+                    if (pc->green_bpaths->data)
+                        gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
+                    pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
+                }    
+                /* Get last segment */
+                NArtBpath const *const p = SP_CURVE_BPATH(pc->green_curve);
+                gint const e = SP_CURVE_LENGTH(pc->green_curve);
+                if ( e < 2 ) {
+                    g_warning("Green curve length is %d", e);
+                    break;
+                }
+                pc->p[0] = p[e - 2].c(3);
+                pc->p[1] = p[e - 1].c(1);
+                NR::Point const pt(( pc->npoints < 4
+                                     ? p[e - 1].c(3)
+                                     : pc->p[3] ));
+                pc->npoints = 2;
+                sp_curve_backspace(pc->green_curve);
+                sp_canvas_item_hide(pc->c0);
+                sp_canvas_item_hide(pc->c1);
+                sp_canvas_item_hide(pc->cl0);
+                sp_canvas_item_hide(pc->cl1);
+                pc->state = SP_PEN_CONTEXT_POINT;
+                spdc_pen_set_subsequent_point(pc, pt, true);
+                ret = TRUE;
+            }
+            break;
+        default:
+            break;
+    }
+    return ret;
+}
+
+static void
+spdc_reset_colors(SPPenContext *pc)
+{
+    /* Red */
+    sp_curve_reset(pc->red_curve);
+    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
+    /* Blue */
+    sp_curve_reset(pc->blue_curve);
+    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
+    /* Green */
+    while (pc->green_bpaths) {
+        gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
+        pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
+    }
+    sp_curve_reset(pc->green_curve);
+    if (pc->green_anchor) {
+        pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
+    }
+    pc->sa = NULL;
+    pc->ea = NULL;
+    pc->npoints = 0;
+    pc->red_curve_is_valid = false;
+}
+
+
+static void
+spdc_pen_set_initial_point(SPPenContext *const pc, NR::Point const p)
+{
+    g_assert( pc->npoints == 0 );
+
+    pc->p[0] = p;
+    pc->p[1] = p;
+    pc->npoints = 2;
+    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
+}
+
+static void
+spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar)
+{
+    g_assert( pc->npoints != 0 );
+    /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
+
+    pc->p[2] = p;
+    pc->p[3] = p;
+    pc->p[4] = p;
+    pc->npoints = 5;
+    sp_curve_reset(pc->red_curve);
+    sp_curve_moveto(pc->red_curve, pc->p[0]);
+    bool is_curve;
+    if ( (pc->onlycurves)
+         || ( pc->p[1] != pc->p[0] ) )
+    {
+        sp_curve_curveto(pc->red_curve, pc->p[1], p, p);
+        is_curve = true;
+    } else {
+        sp_curve_lineto(pc->red_curve, p);
+        is_curve = false;
+    }
+    sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
+
+    if (statusbar) {
+        // status text
+        SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
+        NR::Point rel = p - pc->p[0];
+        GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
+        double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
+        if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
+            angle = angle_to_compass (angle);
+        pc->_message_context->setF(Inkscape::NORMAL_MESSAGE, _("<b>%s</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path"), is_curve? "Curve segment" : "Line segment", angle, dist->str);
+        g_string_free(dist, FALSE);
+    }
+}
+
+static void
+spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
+{
+    sp_canvas_item_show(pc->c1);
+    sp_canvas_item_show(pc->cl1);
+
+    if ( pc->npoints == 2 ) {
+        pc->p[1] = p;
+        sp_canvas_item_hide(pc->c0);
+        sp_canvas_item_hide(pc->cl0);
+        SP_CTRL(pc->c1)->moveto(pc->p[1]);
+        sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
+
+        // status text
+        SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
+        NR::Point rel = p - pc->p[0];
+        GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
+        double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
+        if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
+            angle = angle_to_compass (angle);
+        pc->_message_context->setF(Inkscape::NORMAL_MESSAGE, _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle"), angle, dist->str);
+        g_string_free(dist, FALSE);
+
+    } else if ( pc->npoints == 5 ) {
+        pc->p[4] = p;
+        sp_canvas_item_show(pc->c0);
+        sp_canvas_item_show(pc->cl0);
+        bool is_symm = false;
+        if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
+             ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
+            NR::Point delta = p - pc->p[3];
+            pc->p[2] = pc->p[3] - delta;
+            is_symm = true;
+            sp_curve_reset(pc->red_curve);
+            sp_curve_moveto(pc->red_curve, pc->p[0]);
+            sp_curve_curveto(pc->red_curve, pc->p[1], pc->p[2], pc->p[3]);
+            sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
+        }
+        SP_CTRL(pc->c0)->moveto(pc->p[2]);
+        sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
+        SP_CTRL(pc->c1)->moveto(pc->p[4]);
+        sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
+
+        // status text
+        SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
+        NR::Point rel = p - pc->p[3];
+        GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
+        double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
+        if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
+            angle = angle_to_compass (angle);
+        pc->_message_context->setF(Inkscape::NORMAL_MESSAGE, _("<b>%s</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only"), is_symm? "Curve handle, symmetric" : "Curve handle", angle, dist->str);
+        g_string_free(dist, FALSE);
+
+    } else {
+        g_warning("Something bad happened - npoints is %d", pc->npoints);
+    }
+}
+
+static void
+spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const p, guint const state)
+{
+    if (!sp_curve_empty(pc->red_curve)) {
+        sp_curve_append_continuous(pc->green_curve, pc->red_curve, 0.0625);
+        SPCurve *curve = sp_curve_copy(pc->red_curve);
+        /// \todo fixme: 
+        SPCanvasItem *cshape = sp_canvas_bpath_new(SP_DT_SKETCH(pc->desktop), curve);
+        sp_curve_unref(curve);
+        sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
+
+        pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
+
+        pc->p[0] = pc->p[3];
+        pc->p[1] = pc->p[4];
+        pc->npoints = 2;
+
+        sp_curve_reset(pc->red_curve);
+    }
+}
+
+static void
+spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
+{
+    SPDesktop *const desktop = pc->desktop;
+    pc->_message_context->clear();
+    desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing pen"));
+
+    sp_curve_reset(pc->red_curve);
+    spdc_concat_colors_and_flush(pc, closed);
+    pc->sa = NULL;
+    pc->ea = NULL;
+
+    pc->npoints = 0;
+    pc->state = SP_PEN_CONTEXT_POINT;
+
+    sp_canvas_item_hide(pc->c0);
+    sp_canvas_item_hide(pc->c1);
+    sp_canvas_item_hide(pc->cl0);
+    sp_canvas_item_hide(pc->cl1);
+
+    if (pc->green_anchor) {
+        pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
+    }
+}
+
+
+/*
+  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:encoding=utf-8:textwidth=99 :