Code

Merge from trunk.
[inkscape.git] / src / knot.cpp
index 15fde68ff287cd43e8ab003989e7f28bcb7808c1..28c991fdec590cb479cc3df875db2493452acfa2 100644 (file)
@@ -1,11 +1,10 @@
-#define __SP_KNOT_C__
-
 /** \file
  * SPKnot implementation
  *
  * Authors:
  *   Lauris Kaplinski <lauris@kaplinski.com>
  *   bulia byak <buliabyak@users.sf.net>
+ *   Abhishek Sharma
  *
  * Copyright (C) 1999-2005 authors
  * Copyright (C) 2001-2002 Ximian, Inc.
 #include "desktop-handles.h"
 #include "knot.h"
 #include "document.h"
-#include "prefs-utils.h"
+#include "preferences.h"
 #include "message-stack.h"
 #include "message-context.h"
 #include "event-context.h"
 
+using Inkscape::DocumentUndo;
 
 #define KNOT_EVENT_MASK (GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | \
-                        GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | \
+                        GDK_POINTER_MOTION_MASK | \
+                        GDK_POINTER_MOTION_HINT_MASK | \
                         GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK)
 
 static bool nograb = false;
@@ -45,23 +46,6 @@ static bool within_tolerance = false;
 
 static bool transform_escaped = false; // true iff resize or rotate was cancelled by esc.
 
-enum {
-    PROP_0,
-
-    PROP_SIZE,
-    PROP_ANCHOR,
-    PROP_SHAPE,
-    PROP_MODE,
-    PROP_FILL, PROP_FILL_MOUSEOVER, PROP_FILL_DRAGGING,
-    PROP_STROKE, PROP_STROKE_MOUSEOVER, PROP_STROKE_DRAGGING,
-    PROP_IMAGE, PROP_IMAGE_MOUSEOVER, PROP_IMAGE_DRAGGING,
-    PROP_CURSOR, PROP_CURSOR_MOUSEOVER, PROP_CURSOR_DRAGGING,
-    PROP_PIXBUF,
-    PROP_TIP,
-
-    PROP_LAST
-};
-
 enum {
     EVENT,
     CLICKED,
@@ -77,12 +61,8 @@ enum {
 static void sp_knot_class_init(SPKnotClass *klass);
 static void sp_knot_init(SPKnot *knot);
 static void sp_knot_dispose(GObject *object);
-static void sp_knot_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
-static void sp_knot_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
 
 static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot);
-static void sp_knot_set_flag(SPKnot *knot, guint flag, bool set);
-static void sp_knot_update_ctrl(SPKnot *knot);
 static void sp_knot_set_ctrl_state(SPKnot *knot);
 
 static GObjectClass *parent_class;
@@ -117,135 +97,11 @@ GType sp_knot_get_type()
  */
 static void sp_knot_class_init(SPKnotClass *klass)
 {
-    GObjectClass *object_class = (GObjectClass *) klass;
+    GObjectClass *object_class = (GObjectClass*)klass;
 
     parent_class = (GObjectClass*) g_type_class_peek_parent(klass);
 
     object_class->dispose = sp_knot_dispose;
-    object_class->set_property = sp_knot_set_property;
-    object_class->get_property = sp_knot_get_property;
-
-    /* Huh :) */
-
-    g_object_class_install_property(object_class,
-                                    PROP_SIZE,
-                                    g_param_spec_uint("size", "Size", "",
-                                                       0,
-                                                       0xffffffff,
-                                                       0xff000000,
-                                                       (GParamFlags) G_PARAM_READWRITE));
-    g_object_class_install_property(object_class,
-                                    PROP_ANCHOR,
-                                    g_param_spec_enum("anchor", "Anchor", "",
-                                                       GTK_TYPE_ANCHOR_TYPE,
-                                                       GTK_ANCHOR_CENTER,
-                                                       (GParamFlags) G_PARAM_READWRITE));
-    g_object_class_install_property(object_class,
-                                    PROP_SHAPE,
-                                    g_param_spec_int("shape", "Shape", "",
-                                                     SP_KNOT_SHAPE_SQUARE,
-                                                     SP_KNOT_SHAPE_IMAGE,
-                                                     SP_KNOT_SHAPE_SQUARE,
-                                                     (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_MODE,
-                                    g_param_spec_int("mode", "Mode", "",
-                                                     SP_KNOT_MODE_COLOR,
-                                                     SP_KNOT_MODE_XOR,
-                                                     SP_KNOT_MODE_XOR,
-                                                     (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_FILL,
-                                    g_param_spec_uint("fill", "Fill", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0xff000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_FILL_MOUSEOVER,
-                                    g_param_spec_uint("fill_mouseover", "Fill mouse over", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0xff000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_FILL_DRAGGING,
-                                    g_param_spec_uint("fill_dragging", "Fill dragging", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0xff000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_STROKE,
-                                    g_param_spec_uint("stroke", "Stroke", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0x01000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_STROKE_MOUSEOVER,
-                                    g_param_spec_uint("stroke_mouseover", "Stroke mouseover", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0x01000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_STROKE_DRAGGING,
-                                    g_param_spec_uint("stroke_dragging", "Stroke dragging", "",
-                                                      0,
-                                                      0xffffffff,
-                                                      0x01000000,
-                                                      (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_IMAGE,
-                                    g_param_spec_pointer("image", "Image", "",
-                                                         (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_IMAGE_MOUSEOVER,
-                                    g_param_spec_pointer("image_mouseover", "Image mouseover", "",
-                                                         (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_IMAGE_DRAGGING,
-                                    g_param_spec_pointer("image_dragging", "Image dragging", "",
-                                                         (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                     PROP_CURSOR,
-                                     g_param_spec_boxed("cursor", "Cursor", "",
-                                                         GDK_TYPE_CURSOR,
-                                                            (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_CURSOR_MOUSEOVER,
-                                    g_param_spec_boxed("cursor_mouseover", "Cursor mouseover", "",
-                                                       GDK_TYPE_CURSOR,
-                                                       (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_CURSOR_DRAGGING,
-                                    g_param_spec_boxed("cursor_dragging", "Cursor dragging", "",
-                                                       GDK_TYPE_CURSOR,
-                                                       (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_PIXBUF,
-                                    g_param_spec_pointer("pixbuf", "Pixbuf", "",
-                                                         (GParamFlags) G_PARAM_READWRITE));
-
-    g_object_class_install_property(object_class,
-                                    PROP_TIP,
-                                    g_param_spec_pointer("tip", "Tip", "",
-                                                         (GParamFlags) G_PARAM_READWRITE));
 
     knot_signals[EVENT] = g_signal_new("event",
                                        G_TYPE_FROM_CLASS(klass),
@@ -261,7 +117,7 @@ static void sp_knot_class_init(SPKnotClass *klass)
                                          G_SIGNAL_RUN_FIRST,
                                          G_STRUCT_OFFSET(SPKnotClass, clicked),
                                          NULL, NULL,
-                                         sp_marshal_NONE__UINT,
+                                         g_cclosure_marshal_VOID__UINT,
                                          G_TYPE_NONE, 1,
                                          G_TYPE_UINT);
 
@@ -270,7 +126,7 @@ static void sp_knot_class_init(SPKnotClass *klass)
                                                G_SIGNAL_RUN_FIRST,
                                                G_STRUCT_OFFSET(SPKnotClass, doubleclicked),
                                                NULL, NULL,
-                                               sp_marshal_NONE__UINT,
+                                               g_cclosure_marshal_VOID__UINT,
                                                G_TYPE_NONE, 1,
                                                G_TYPE_UINT);
 
@@ -279,7 +135,7 @@ static void sp_knot_class_init(SPKnotClass *klass)
                                           G_SIGNAL_RUN_FIRST,
                                           G_STRUCT_OFFSET(SPKnotClass, grabbed),
                                           NULL, NULL,
-                                          sp_marshal_NONE__UINT,
+                                          g_cclosure_marshal_VOID__UINT,
                                           G_TYPE_NONE, 1,
                                           G_TYPE_UINT);
 
@@ -288,7 +144,7 @@ static void sp_knot_class_init(SPKnotClass *klass)
                                            G_SIGNAL_RUN_FIRST,
                                            G_STRUCT_OFFSET(SPKnotClass, ungrabbed),
                                            NULL, NULL,
-                                           sp_marshal_NONE__UINT,
+                                           g_cclosure_marshal_VOID__UINT,
                                            G_TYPE_NONE, 1,
                                            G_TYPE_UINT);
 
@@ -333,12 +189,14 @@ static void sp_knot_init(SPKnot *knot)
     knot->flags = 0;
 
     knot->size = 8;
-    knot->pos = NR::Point(0, 0);
-    knot->grabbed_rel_pos = NR::Point(0, 0);
+    knot->pos = Geom::Point(0, 0);
+    knot->grabbed_rel_pos = Geom::Point(0, 0);
     knot->anchor = GTK_ANCHOR_CENTER;
     knot->shape = SP_KNOT_SHAPE_SQUARE;
     knot->mode = SP_KNOT_MODE_XOR;
     knot->tip = NULL;
+    knot->_event_handler_id = 0;
+    knot->pressure = 0;
 
     knot->fill[SP_KNOT_STATE_NORMAL] = 0xffffff00;
     knot->fill[SP_KNOT_STATE_MOUSEOVER] = 0xff0000ff;
@@ -372,6 +230,12 @@ static void sp_knot_dispose(GObject *object)
         gdk_pointer_ungrab (GDK_CURRENT_TIME);
     }
 
+    if (knot->_event_handler_id > 0)
+        {
+        g_signal_handler_disconnect(G_OBJECT (knot->item), knot->_event_handler_id);
+        knot->_event_handler_id = 0;
+        }
+
     if (knot->item) {
         gtk_object_destroy (GTK_OBJECT (knot->item));
         knot->item = NULL;
@@ -389,124 +253,15 @@ static void sp_knot_dispose(GObject *object)
         knot->tip = NULL;
     }
 
-    if (((GObjectClass *) (parent_class))->dispose) {
-        (* ((GObjectClass *) (parent_class))->dispose) (object);
+    if (parent_class->dispose) {
+        (*parent_class->dispose) (object);
     }
 }
 
-/**
- * Callback to set property.
- */
-static void sp_knot_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
-{
-    GdkCursor *cursor;
-
-    SPKnot *knot = SP_KNOT(object);
-
-    switch (prop_id) {
-       case PROP_SIZE:
-            knot->size = g_value_get_uint(value);
-            break;
-       case PROP_ANCHOR:
-            knot->anchor = (GtkAnchorType) g_value_get_enum(value);
-            break;
-       case PROP_SHAPE:
-            knot->shape = (SPKnotShapeType) g_value_get_int(value);
-            break;
-       case PROP_MODE:
-            knot->mode = (SPKnotModeType) g_value_get_int(value);
-            break;
-       case PROP_FILL:
-            knot->fill[SP_KNOT_STATE_NORMAL] =
-               knot->fill[SP_KNOT_STATE_MOUSEOVER] =
-               knot->fill[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_FILL_MOUSEOVER:
-            knot->fill[SP_KNOT_STATE_MOUSEOVER] =
-               knot->fill[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_FILL_DRAGGING:
-            knot->fill[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_STROKE:
-            knot->stroke[SP_KNOT_STATE_NORMAL] =
-               knot->stroke[SP_KNOT_STATE_MOUSEOVER] =
-               knot->stroke[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_STROKE_MOUSEOVER:
-            knot->stroke[SP_KNOT_STATE_MOUSEOVER] =
-               knot->stroke[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_STROKE_DRAGGING:
-            knot->stroke[SP_KNOT_STATE_DRAGGING] = g_value_get_uint(value);
-            break;
-       case PROP_IMAGE:
-            knot->image[SP_KNOT_STATE_NORMAL] =
-               knot->image[SP_KNOT_STATE_MOUSEOVER] =
-               knot->image[SP_KNOT_STATE_DRAGGING] = (guchar*) g_value_get_pointer(value);
-            break;
-       case PROP_IMAGE_MOUSEOVER:
-            knot->image[SP_KNOT_STATE_MOUSEOVER] = (guchar*) g_value_get_pointer(value);
-            break;
-       case PROP_IMAGE_DRAGGING:
-            knot->image[SP_KNOT_STATE_DRAGGING] = (guchar*) g_value_get_pointer(value);
-            break;
-       case PROP_CURSOR:
-            cursor = (GdkCursor*) g_value_get_boxed(value);
-            for (gint i = 0; i < SP_KNOT_VISIBLE_STATES; i++) {
-                if (knot->cursor[i]) {
-                    gdk_cursor_unref(knot->cursor[i]);
-                }
-                knot->cursor[i] = cursor;
-                if (cursor) {
-                    gdk_cursor_ref(cursor);
-                }
-            }
-            break;
-       case PROP_CURSOR_MOUSEOVER:
-            cursor = (GdkCursor*) g_value_get_boxed(value);
-            if (knot->cursor[SP_KNOT_STATE_MOUSEOVER]) {
-                gdk_cursor_unref(knot->cursor[SP_KNOT_STATE_MOUSEOVER]);
-            }
-            knot->cursor[SP_KNOT_STATE_MOUSEOVER] = cursor;
-            if (cursor) {
-                gdk_cursor_ref(cursor);
-            }
-            break;
-       case PROP_CURSOR_DRAGGING:
-            cursor = (GdkCursor*) g_value_get_boxed(value);
-            if (knot->cursor[SP_KNOT_STATE_DRAGGING]) {
-                gdk_cursor_unref(knot->cursor[SP_KNOT_STATE_DRAGGING]);
-            }
-            knot->cursor[SP_KNOT_STATE_DRAGGING] = cursor;
-            if (cursor) {
-                gdk_cursor_ref(cursor);
-            }
-            break;
-       case PROP_PIXBUF:
-            knot->pixbuf = g_value_get_pointer(value);
-            break;
-       case PROP_TIP:
-            knot->tip = g_strdup((const gchar *) g_value_get_pointer(value));
-            break;
-       default:
-            g_assert_not_reached();
-            break;
-    }
-
-    sp_knot_update_ctrl(knot);
-}
-
-/// Not reached.
-static void sp_knot_get_property(GObject *, guint, GValue *, GParamSpec *)
-{
-    g_assert_not_reached();
-}
-
 /**
  * Update knot for dragging and tell canvas an item was grabbed.
  */
-void sp_knot_start_dragging(SPKnot *knot, NR::Point p, gint x, gint y, guint32 etime)
+void sp_knot_start_dragging(SPKnot *knot, Geom::Point const &p, gint x, gint y, guint32 etime)
 {
     // save drag origin
     xp = x;
@@ -528,42 +283,52 @@ void sp_knot_start_dragging(SPKnot *knot, NR::Point p, gint x, gint y, guint32 e
 /**
  * Called to handle events on knots.
  */
-static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
+static int sp_knot_handler(SPCanvasItem */*item*/, GdkEvent *event, SPKnot *knot)
 {
     g_assert(knot != NULL);
     g_assert(SP_IS_KNOT(knot));
 
-    tolerance = prefs_get_int_attribute_limited("options.dragtolerance", "value", 0, 0, 100);
+    /* Run client universal event handler, if present */
 
     gboolean consumed = FALSE;
 
-    /* Run client universal event handler, if present */
-
-    g_signal_emit(G_OBJECT(knot), knot_signals[EVENT], 0, event, &consumed);
+    g_signal_emit(knot, knot_signals[EVENT], 0, event, &consumed);
 
     if (consumed) {
         return TRUE;
     }
 
+    g_object_ref(knot);
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
+
     switch (event->type) {
-       case GDK_2BUTTON_PRESS:
+    case GDK_2BUTTON_PRESS:
             if (event->button.button == 1) {
-                g_signal_emit(G_OBJECT(knot), knot_signals[DOUBLECLICKED], 0, event->button.state);
+                g_signal_emit(knot, knot_signals[DOUBLECLICKED], 0, event->button.state);
 
                 grabbed = FALSE;
                 moved = FALSE;
                 consumed = TRUE;
             }
             break;
-       case GDK_BUTTON_PRESS:
-            if (event->button.button == 1) {
-                NR::Point const p = knot->desktop->w2d(NR::Point(event->button.x, event->button.y));
+    case GDK_BUTTON_PRESS:
+            if (event->button.button == 1 && !knot->desktop->event_context->space_panning) {
+                Geom::Point const p = knot->desktop->w2d(Geom::Point(event->button.x, event->button.y));
                 sp_knot_start_dragging(knot, p, (gint) event->button.x, (gint) event->button.y, event->button.time);
                 consumed = TRUE;
             }
             break;
-       case GDK_BUTTON_RELEASE:
-            if (event->button.button == 1) {
+    case GDK_BUTTON_RELEASE:
+            if (event->button.button == 1 && !knot->desktop->event_context->space_panning) {
+                // If we have any pending snap event, then invoke it now
+                if (knot->desktop->event_context->_delayed_snap_event) {
+                    sp_event_context_snap_watchdog_callback(knot->desktop->event_context->_delayed_snap_event);
+                }
+
+                sp_event_context_discard_delayed_snap_event(knot->desktop->event_context);
+
+                knot->pressure = 0;
                 if (transform_escaped) {
                     transform_escaped = false;
                     consumed = TRUE;
@@ -576,13 +341,15 @@ static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
                         sp_knot_set_flag(knot,
                                          SP_KNOT_DRAGGING,
                                          FALSE);
-                        g_signal_emit(G_OBJECT (knot),
+                        g_signal_emit(knot,
                                       knot_signals[UNGRABBED], 0,
                                       event->button.state);
+                        knot->_ungrabbed_signal.emit(knot);
                     } else {
-                        g_signal_emit(G_OBJECT (knot),
+                        g_signal_emit(knot,
                                       knot_signals[CLICKED], 0,
                                       event->button.state);
+                        knot->_click_signal.emit(knot, event->button.state);
                     }
                     grabbed = FALSE;
                     moved = FALSE;
@@ -590,8 +357,8 @@ static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
                 }
             }
             break;
-       case GDK_MOTION_NOTIFY:
-            if (grabbed) {
+    case GDK_MOTION_NOTIFY:
+            if (grabbed && !knot->desktop->event_context->space_panning) {
                 consumed = TRUE;
 
                 if ( within_tolerance
@@ -605,23 +372,25 @@ static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
                 // motion notify coordinates as given (no snapping back to origin)
                 within_tolerance = false;
 
+                if (gdk_event_get_axis (event, GDK_AXIS_PRESSURE, &knot->pressure))
+                    knot->pressure = CLAMP (knot->pressure, 0, 1);
+                else
+                    knot->pressure = 0.5;
+
                 if (!moved) {
-                    g_signal_emit(G_OBJECT (knot),
+                    g_signal_emit(knot,
                                   knot_signals[GRABBED], 0,
                                   event->motion.state);
                     sp_knot_set_flag(knot,
                                      SP_KNOT_DRAGGING,
                                      TRUE);
                 }
-                NR::Point const motion_w(event->motion.x, event->motion.y);
-                NR::Point const motion_dt = knot->desktop->w2d(motion_w);
-                NR::Point p = motion_dt - knot->grabbed_rel_pos;
-                sp_knot_request_position (knot, &p, event->motion.state);
-                knot->desktop->scroll_to_point (&motion_dt);
+                sp_event_context_snap_delay_handler(knot->desktop->event_context, NULL, (gpointer) knot, (GdkEventMotion *)event, DelayedSnapEvent::KNOT_HANDLER);
+                sp_knot_handler_request_position(event, knot);
                 moved = TRUE;
             }
             break;
-       case GDK_ENTER_NOTIFY:
+    case GDK_ENTER_NOTIFY:
             sp_knot_set_flag(knot, SP_KNOT_MOUSEOVER, TRUE);
             sp_knot_set_flag(knot, SP_KNOT_GRABBED, FALSE);
 
@@ -633,7 +402,7 @@ static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
             moved = FALSE;
             consumed = TRUE;
             break;
-       case GDK_LEAVE_NOTIFY:
+    case GDK_LEAVE_NOTIFY:
             sp_knot_set_flag(knot, SP_KNOT_MOUSEOVER, FALSE);
             sp_knot_set_flag(knot, SP_KNOT_GRABBED, FALSE);
 
@@ -643,42 +412,55 @@ static int sp_knot_handler(SPCanvasItem *item, GdkEvent *event, SPKnot *knot)
 
             grabbed = FALSE;
             moved = FALSE;
-
             consumed = TRUE;
             break;
-       case GDK_KEY_PRESS: // keybindings for knot
+    case GDK_KEY_PRESS: // keybindings for knot
             switch (get_group0_keyval(&event->key)) {
-               case GDK_Escape:
-                    sp_knot_set_flag(knot, SP_KNOT_GRABBED, FALSE);
-                    if (!nograb) {
-                        sp_canvas_item_ungrab(knot->item, event->button.time);
-                    }
-                    if (moved) {
-                        sp_knot_set_flag(knot,
-                                         SP_KNOT_DRAGGING,
-                                         FALSE);
-                        g_signal_emit(G_OBJECT(knot),
-                                      knot_signals[UNGRABBED], 0,
-                                      event->button.state);
-                        sp_document_undo(SP_DT_DOCUMENT(knot->desktop));
-                        knot->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Node or handle drag canceled."));
-                        transform_escaped = true;
-                        consumed = TRUE;
+                case GDK_Escape:
+                            sp_knot_set_flag(knot, SP_KNOT_GRABBED, FALSE);
+                            if (!nograb) {
+                                sp_canvas_item_ungrab(knot->item, event->button.time);
+                            }
+                            if (moved) {
+                                sp_knot_set_flag(knot,
+                                                 SP_KNOT_DRAGGING,
+                                                 FALSE);
+                                g_signal_emit(knot,
+                                              knot_signals[UNGRABBED], 0,
+                                              event->button.state);
+                                DocumentUndo::undo(sp_desktop_document(knot->desktop));
+                                knot->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Node or handle drag canceled."));
+                                transform_escaped = true;
+                                consumed = TRUE;
+                            }
+                            grabbed = FALSE;
+                            moved = FALSE;
+                            sp_event_context_discard_delayed_snap_event(knot->desktop->event_context);
+                            break;
+                default:
+                            consumed = FALSE;
+                            break;
                     }
-                    grabbed = FALSE;
-                    moved = FALSE;
-                    break;
-               default:
-                    consumed = FALSE;
                     break;
-            }
-            break;
-       default:
+    default:
             break;
     }
 
+    g_object_unref(knot);
 
-    return consumed;
+    return consumed || grabbed;
+}
+
+void sp_knot_handler_request_position(GdkEvent *event, SPKnot *knot)
+{
+    Geom::Point const motion_w(event->motion.x, event->motion.y);
+    Geom::Point const motion_dt = knot->desktop->w2d(motion_w);
+    Geom::Point p = motion_dt - knot->grabbed_rel_pos;
+    sp_knot_request_position (knot, p, event->motion.state);
+    knot->desktop->scroll_to_point (motion_dt);
+    knot->desktop->set_coordinate_status(knot->pos); // display the coordinate of knot, not cursor - they may be different!
+    if (event->motion.state & GDK_BUTTON1_MASK)
+        gobble_motion_events(GDK_BUTTON1_MASK);
 }
 
 /**
@@ -696,7 +478,7 @@ SPKnot *sp_knot_new(SPDesktop *desktop, const gchar *tip)
         knot->tip = g_strdup (tip);
     }
 
-    knot->item = sp_canvas_item_new(SP_DT_CONTROLS (desktop),
+    knot->item = sp_canvas_item_new(sp_desktop_controls (desktop),
                                     SP_TYPE_CTRL,
                                     "anchor", GTK_ANCHOR_CENTER,
                                     "size", 8.0,
@@ -707,8 +489,8 @@ SPKnot *sp_knot_new(SPDesktop *desktop, const gchar *tip)
                                     "mode", SP_KNOT_MODE_XOR,
                                     NULL);
 
-    gtk_signal_connect(GTK_OBJECT(knot->item), "event",
-                       GTK_SIGNAL_FUNC(sp_knot_handler), knot);
+    knot->_event_handler_id = gtk_signal_connect(GTK_OBJECT(knot->item), "event",
+                                                 GTK_SIGNAL_FUNC(sp_knot_handler), knot);
 
     return knot;
 }
@@ -738,16 +520,16 @@ void sp_knot_hide(SPKnot *knot)
 /**
  * Request or set new position for knot.
  */
-void sp_knot_request_position(SPKnot *knot, NR::Point *p, guint state)
+void sp_knot_request_position(SPKnot *knot, Geom::Point const &p, guint state)
 {
     g_return_if_fail(knot != NULL);
     g_return_if_fail(SP_IS_KNOT(knot));
 
     gboolean done = FALSE;
 
-    g_signal_emit(G_OBJECT (knot),
+    g_signal_emit(knot,
                   knot_signals[REQUEST], 0,
-                  p,
+                  &p,
                   state,
                   &done);
 
@@ -761,16 +543,16 @@ void sp_knot_request_position(SPKnot *knot, NR::Point *p, guint state)
 /**
  * Return distance of point to knot's position; unused.
  */
-gdouble sp_knot_distance(SPKnot * knot, NR::Point *p, guint state)
+gdouble sp_knot_distance(SPKnot * knot, Geom::Point const &p, guint state)
 {
     g_return_val_if_fail(knot != NULL, 1e18);
     g_return_val_if_fail(SP_IS_KNOT(knot), 1e18);
 
-    gdouble distance = NR::L2(*p - knot->pos);
+    gdouble distance = Geom::L2(p - knot->pos);
 
-    g_signal_emit(G_OBJECT(knot),
+    g_signal_emit(knot,
                   knot_signals[DISTANCE], 0,
-                  p,
+                  &p,
                   state,
                   &distance);
 
@@ -780,45 +562,43 @@ gdouble sp_knot_distance(SPKnot * knot, NR::Point *p, guint state)
 /**
  * Move knot to new position.
  */
-void sp_knot_set_position(SPKnot *knot, NR::Point *p, guint state)
+void sp_knot_set_position(SPKnot *knot, Geom::Point const &p, guint state)
 {
     g_return_if_fail(knot != NULL);
     g_return_if_fail(SP_IS_KNOT (knot));
 
-    knot->pos = *p;
+    knot->pos = p;
 
     if (knot->item) {
-        SP_CTRL(knot->item)->moveto (*p);
+        SP_CTRL(knot->item)->moveto (p);
     }
 
-    g_signal_emit(G_OBJECT (knot),
+    g_signal_emit(knot,
                   knot_signals[MOVED], 0,
-                  p,
+                  &p,
                   state);
+    knot->_moved_signal.emit(knot, p, state);
 }
 
 /**
- * Move knot to new position, without emitting a MOVED signal. We can't be sure this artificial
- * move has moved the knot from under cursor, but it seems likely, so we clear SP_KNOT_MOUSEOVER.
+ * Move knot to new position, without emitting a MOVED signal.
  */
-void sp_knot_moveto(SPKnot *knot, NR::Point *p)
+void sp_knot_moveto(SPKnot *knot, Geom::Point const &p)
 {
     g_return_if_fail(knot != NULL);
     g_return_if_fail(SP_IS_KNOT(knot));
 
-    knot->pos = *p;
+    knot->pos = p;
 
     if (knot->item) {
-        SP_CTRL(knot->item)->moveto (*p);
+        SP_CTRL(knot->item)->moveto (p);
     }
-
-    sp_knot_set_flag(knot, SP_KNOT_MOUSEOVER, FALSE);
 }
 
 /**
  * Returns position of knot.
  */
-NR::Point sp_knot_position(SPKnot const *knot)
+Geom::Point sp_knot_position(SPKnot const *knot)
 {
     g_assert(knot != NULL);
     g_assert(SP_IS_KNOT (knot));
@@ -829,7 +609,7 @@ NR::Point sp_knot_position(SPKnot const *knot)
 /**
  * Set flag in knot, with side effects.
  */
-static void sp_knot_set_flag(SPKnot *knot, guint flag, bool set)
+void sp_knot_set_flag(SPKnot *knot, guint flag, bool set)
 {
     g_assert(knot != NULL);
     g_assert(SP_IS_KNOT(knot));
@@ -841,20 +621,20 @@ static void sp_knot_set_flag(SPKnot *knot, guint flag, bool set)
     }
 
     switch (flag) {
-       case SP_KNOT_VISIBLE:
+    case SP_KNOT_VISIBLE:
             if (set) {
                 sp_canvas_item_show(knot->item);
             } else {
                 sp_canvas_item_hide(knot->item);
             }
             break;
-       case SP_KNOT_MOUSEOVER:
-       case SP_KNOT_DRAGGING:
+    case SP_KNOT_MOUSEOVER:
+    case SP_KNOT_DRAGGING:
             sp_knot_set_ctrl_state(knot);
             break;
-       case SP_KNOT_GRABBED:
+    case SP_KNOT_GRABBED:
             break;
-       default:
+    default:
             g_assert_not_reached();
             break;
     }
@@ -863,7 +643,7 @@ static void sp_knot_set_flag(SPKnot *knot, guint flag, bool set)
 /**
  * Update knot's pixbuf and set its control state.
  */
-static void sp_knot_update_ctrl(SPKnot *knot)
+void sp_knot_update_ctrl(SPKnot *knot)
 {
     if (!knot->item) {
         return;