customize main widget to allow for customization

this includes two test commands to move items up and down the initiative
with < and >

npytabletracker/ui.py

@@ -5,8 +5,43 @@ from npytabletracker.cmd import ManagementActionController
 from npytabletracker.data import TableState
 
 
+class CharacterList(npyscreen.MultiLineAction):
+    """Display characters' initiative order and allow for operations on them."""
+
+    def __init__(self, *args, **keywords):
+        """Set up some extra handlers when selecting characters in the list."""
+        super(CharacterList, self).__init__(*args, **keywords)
+        self.add_handlers({
+            ">": self.when_init_move_down,
+            "<": self.when_init_move_up
+        })
+
+    def when_init_move_down(self, *args, **keywords):
+        """Move the selected character down one spot in the initiative table."""
+        if self.cursor_line < len(self.parent.value.characters) - 1:
+            chars = self.parent.value.characters
+            pos = self.cursor_line
+            chars[pos], chars[pos+1] = chars[pos+1], chars[pos]
+            self.parent.update_list()
+            self.cursor_line += 1
+
+    def when_init_move_up(self, *args, **keywords):
+        """Move the selected character up one spot in the initiative table."""
+        if self.cursor_line - 1 >= 0:
+            chars = self.parent.value.characters
+            pos = self.cursor_line
+            chars[pos], chars[pos-1] = chars[pos-1], chars[pos]
+            self.parent.update_list()
+            self.cursor_line -= 1
+
+
 class TableTrackerDisplay(npyscreen.FormMuttActiveTraditional):
     """Create the high level form, which is organized like mutt/irssi."""
 
     ACTION_CONTROLLER = ManagementActionController
     DATA_CONTROLER = TableState
+    MAIN_WIDGET_CLASS = CharacterList
+
+    def update_list(self):
+        """Update data in the window and represent it."""
+        self.wMain.display()