From 36b1d4f1d0e20721bb337de62607a6d366298132 Mon Sep 17 00:00:00 2001
From: Alexander Kryklia <kryklia@gmail.com>
Date: Wed, 26 Dec 2012 15:34:15 +0200
Subject: [PATCH] graders for draganddrop

---
 common/lib/capa/capa/graders/__init__.py    |  0
 common/lib/capa/capa/graders/draganddrop.py | 98 +++++++++++++++++++++
 common/lib/capa/capa/graders/tests.py       | 23 +++++
 3 files changed, 121 insertions(+)
 create mode 100644 common/lib/capa/capa/graders/__init__.py
 create mode 100644 common/lib/capa/capa/graders/draganddrop.py
 create mode 100644 common/lib/capa/capa/graders/tests.py

diff --git a/common/lib/capa/capa/graders/__init__.py b/common/lib/capa/capa/graders/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/common/lib/capa/capa/graders/draganddrop.py b/common/lib/capa/capa/graders/draganddrop.py
new file mode 100644
index 0000000000..d8618820cf
--- /dev/null
+++ b/common/lib/capa/capa/graders/draganddrop.py
@@ -0,0 +1,98 @@
+""" Grader of drag and drop input.
+
+Client side behavior: user can drag and drop images from list on base image.
+Parameter 'use_targets' in xml can control two use cases.
+
+if use_targets is true (defaut), then json returned from client is:
+ {
+    "use_targets": true,
+    "draggable": [
+        { "image1": "t1"  },
+        { "ant": "t2"  },
+        { "molecule": "t3"  },
+                ]
+}
+values are target names.
+
+If use_targets is false:
+ {
+    "use_targets": false,
+    "draggable": [
+        { "image1": "(10, 20)"  },
+        { "ant": "(30, 40)"  },
+        { "molecule": "(100, 200)"  },
+                ]
+}
+values are (x,y) coordinates of centers of dragged images.
+
+"""
+
+import json
+import math
+
+
+def grade(user_input, correct_answer):
+    '''
+    Grade drag and drop problem.
+    If use_targets is True - checks if image placed on proper target.
+    If use_targets is False - checks if image placed on proper coordinates,
+    with setted radius of forgiveness (default is 10)
+
+    Args:
+        user_input, correct_answer: json. Format:
+
+        user_input: see module docstring
+
+        correct_answer:
+            if use_targets is True:
+                {'1': 't1',  'name_with_icon': 't2'}
+            else:
+                {'1': '(10, 10)',  'name_with_icon': '[(10, 10), 20]'}
+
+    Returns:
+        True or False.
+    '''
+
+    user_answer = json.loads(user_input)
+
+    if len(correct_answer.keys()) != len(user_answer['draggables']):
+        return False
+
+    key = ['position']
+
+    def is_equal(user_answer, correct_answer):
+        """ Checks if user_answer is  equal to correct_answer inside radius
+        of forgiveness (default 10 px).
+
+            Args:
+                user_answer: (x, y) tuple of floats;
+                correct_answer is one of variants:
+                    - (x, y) tuple of floats
+                    - [(x, y), r], r - radius of forgiveness;
+
+            Returns: bool.
+        """
+        r = 10
+        if type(correct_answer) is type(()):  # (x, y) case
+            corr_x = correct_answer[0]
+            corr_y = correct_answer[1]
+        else:  # [(x, y), r] case
+            r = correct_answer[1]
+            corr_x = correct_answer[0][0]
+            corr_y = correct_answer[0][1]
+
+        if ((user_answer[0] - corr_x) ** 2 +
+            (user_answer[1] - corr_y) ** 2) > r * r:
+            return False
+
+        return True
+
+    if user_answer["use_targets"]:
+        key = ['target_id']
+        is_equal = lambda x, y: x == y
+
+    for draggable in user_answer['draggables']:
+        if not is_equal(draggable[key], correct_answer[key]):
+            return False
+
+    return True
diff --git a/common/lib/capa/capa/graders/tests.py b/common/lib/capa/capa/graders/tests.py
new file mode 100644
index 0000000000..1e0da9411e
--- /dev/null
+++ b/common/lib/capa/capa/graders/tests.py
@@ -0,0 +1,23 @@
+import unittest
+
+import draganddrop
+
+
+class Test_DragAndDrop(unittest.TestCase):
+
+    def test_1(self):
+        user_input = '{"laice": "bcc", "points": [["0.00", "1.00", "0.00"], ["1.00", "1.00", "0.00"], ["0.00", "0.00", "1.00"]]}'
+        correct_answer = {}
+        self.assertTrue(draganddrop.grade(user_input, correct_answer))
+
+
+def suite():
+
+    testcases = [Test_DragAndDrop]
+    suites = []
+    for testcase in testcases:
+        suites.append(unittest.TestLoader().loadTestsFromTestCase(testcase))
+    return unittest.TestSuite(suites)
+
+if __name__ == "__main__":
+    unittest.TextTestRunner(verbosity=2).run(suite())