added DataStore.getCurrentTask() and TaskRef class

DataStore.py

@@ -1,6 +1,14 @@
 
 import sqlite3
 import os
+from datetime import datetime
+
+HISTORY_DT_FMT = '%Y-%m-%d %H:%M:%S'
+
+class TaskRef:
+    def __init__(self, taskid, dt):
+        self.taskid = taskid
+        self.dt = dt
 
 class DataStore:
     def __init__(self, dbfile):
@@ -41,3 +49,18 @@ CREATE TABLE history (
         c.close()
         conn.close()
 
+    def getCurrentTask(self):
+        c = self.conn.cursor()
+        c.execute('''
+SELECT taskid, datetime
+FROM history
+WHERE id = 0
+''')
+        ct = None
+        for row in c:
+            taskid = row[0]
+            dt = datetime.strptime(row[1], HISTORY_DT_FMT)
+            ct = TaskRef(taskid, dt)
+        c.close()
+        self.conn.commit()
+        return ct