@@ -27,6 +27,7 @@ import sys

 import subprocess

 import math

 import colorsys

+import time

 import gobject

 import gtk

@@ -598,6 +599,70 @@ class XDotParser:

         return x, y

+class Animation(object):

+

+    step = 0.03 # seconds

+

+    def __init__(self, dot_widget):

+        self.dot_widget = dot_widget

+        self.timeout_id = None

+

+    def start(self):

+        self.timeout_id = gobject.timeout_add(int(self.step * 1000), self.tick)

+

+    def stop(self):

+        self.dot_widget.animation = NoAnimation(self.dot_widget)

+        if self.timeout_id is not None:

+            gobject.source_remove(self.timeout_id)

+            self.timeout_id = None

+

+    def tick(self):

+        self.stop()

+

+

+class NoAnimation(Animation):

+

+    def start(self):

+        pass

+

+    def stop(self):

+        pass

+

+

+class LinearAnimation(Animation):

+

+    duration = 0.6

+

+    def start(self):

+        self.started = time.time()

+        Animation.start(self)

+

+    def tick(self):

+        t = (time.time() - self.started) / self.duration

+        self.animate(max(0, min(t, 1)))

+        return (t < 1)

+

+    def animate(self, t):

+        pass

+

+

+class MoveToAnimation(LinearAnimation):

+

+    def __init__(self, dot_widget, target_x, target_y):

+        Animation.__init__(self, dot_widget)

+        self.source_x = dot_widget.x

+        self.source_y = dot_widget.y

+        self.target_x = target_x

+        self.target_y = target_y

+

+    def animate(self, t):

+        sx, sy = self.source_x, self.source_y

+        tx, ty = self.target_x, self.target_y

+        self.dot_widget.x = tx * t + sx * (1-t)

+        self.dot_widget.y = ty * t + sy * (1-t)

+        self.dot_widget.queue_draw()

+

+

 class DotWidget(gtk.DrawingArea):

     """PyGTK widget that draws dot graphs."""

@@ -742,12 +807,9 @@ class DotWidget(gtk.DrawingArea):

             return True

         jump = self.get_jump(x, y)

-        x, y = self.window2graph(x, y)

         if jump is not None:

             jumpx, jumpy = jump

-            self.x += jumpx - x

-            self.y += jumpy - y

-            self.queue_draw()

+            self.animate_to(jumpx, jumpy)

         return False

     def on_area_button_release(self, area, event):

@@ -787,6 +849,10 @@ class DotWidget(gtk.DrawingArea):

         return True

+    def animate_to(self, x, y):

+        self.animation = MoveToAnimation(self, x, y)

+        self.animation.start()

+

     def window2graph(self, x, y):

         rect = self.get_allocation()

         x -= 0.5*rect.width