modify python sat examples to use visualization when run from IPython; change corresponding notebooks

examples/notebook/gate_scheduling_sat.ipynb

@@ -27,12 +27,13 @@
     "We have two parallel machines that can perform this job.\n",
     "One machine can only perform one job at a time.\n",
     "At any point in time, the sum of the width of the two active jobs does not\n",
-    "exceed a max_width.\n",
+    "exceed a max_length.\n",
     "\n",
     "The objective is to minimize the max end time of all jobs.\n",
     "\"\"\"\n",
     "\n",
     "from ortools.sat.python import cp_model\n",
+    "from ortools.sat.python import visualization\n",
     "\n",
     "\n",
     "def main():\n",
@@ -122,17 +123,39 @@
     "  # Solve model.\n",
     "  solver = cp_model.CpSolver()\n",
     "  solver.Solve(model)\n",
-    "  print('Solution')\n",
-    "  print('  - makespan = %i' % solver.ObjectiveValue())\n",
-    "  for i in all_jobs:\n",
-    "    performed_machine = 1 - solver.Value(performed[i])\n",
-    "    start = solver.Value(starts[i])\n",
-    "    print('  - Job %i starts at %i on machine %i' %\n",
-    "          (i, start, performed_machine))\n",
-    "  print('Statistics')\n",
-    "  print('  - conflicts : %i' % solver.NumConflicts())\n",
-    "  print('  - branches  : %i' % solver.NumBranches())\n",
-    "  print('  - wall time : %f ms' % solver.WallTime())\n",
+    "\n",
+    "\n",
+    "  # Output solution.\n",
+    "  if visualization.RunFromIPython():\n",
+    "    output = visualization.SvgWrapper(solver.ObjectiveValue(), max_length, 40.0)\n",
+    "    output.AddTitle('Makespan = %i' % solver.ObjectiveValue())\n",
+    "    color_manager = visualization.ColorManager()\n",
+    "    color_manager.SeedRandomColor(0)\n",
+    "\n",
+    "    for i in all_jobs:\n",
+    "      performed_machine = 1 - solver.Value(performed[i])\n",
+    "      start = solver.Value(starts[i])\n",
+    "      dx = jobs[i][0]\n",
+    "      dy = jobs[i][1]\n",
+    "      sy = performed_machine * (max_length - dy)\n",
+    "      output.AddRectangle(start, sy, dx, dy, color_manager.RandomColor(),\n",
+    "                          'black', 'j%i' % i)\n",
+    "\n",
+    "    output.AddXScale()\n",
+    "    output.AddYScale()\n",
+    "    output.Display()\n",
+    "  else:\n",
+    "    print('Solution')\n",
+    "    print('  - makespan = %i' % solver.ObjectiveValue())\n",
+    "    for i in all_jobs:\n",
+    "      performed_machine = 1 - solver.Value(performed[i])\n",
+    "      start = solver.Value(starts[i])\n",
+    "      print('  - Job %i starts at %i on machine %i' %\n",
+    "            (i, start, performed_machine))\n",
+    "    print('Statistics')\n",
+    "    print('  - conflicts : %i' % solver.NumConflicts())\n",
+    "    print('  - branches  : %i' % solver.NumBranches())\n",
+    "    print('  - wall time : %f ms' % solver.WallTime())\n",
     "\n",
     "\n",
     "if __name__ == '__main__':\n",