added some basic network protocol definitions

README.md

@@ -1,3 +1,53 @@
 # Connect Four
 
 A simple version of the popular game "connect four" written in Java.
+
+## API docs
+### SOCKET API
+#### Basic structure
+A command consists of a json encoded string of type object which starts with ```<message>``` and ends with ```</message>```.
+It contains:
+- id     (int):   some number, the response will contain the same number
+- header (int):   the actual command to execute
+- data   (mixed): data that has to be passed with the command
+
+A response consists of a json encoded string of type object which starts with ```<message>``` and ends with ```</message>```.
+It contains:
+- id     (int):   id of the command
+- header (int):   return code of the command (see later)
+- data   (midex): returned data of the command
+
+#### Return codes
+The return codes are mostly identical with the HTTP standard codes.
+However there are some additional ones as well:
+
+#### Enums
+Some enumeration types
+- PlateType
+    - 0: X
+    - 1: O
+
+#### Commands
+- Confirm game start
+    - command: 1
+    - requestdata:
+        - type: null
+    - responsedata:
+        - type: object
+        - def:
+            - 'player'
+                - type: PlateType
+                - desc: the plate type the client will use
+- Insert a plate
+    - command: 100
+    - requestdata:
+        - type: int
+        - decs: index of column to insert plate
+    - replydata:
+        - type: string
+        - def:
+            - 'ok': plate was inserted
+            - 'err': plate was not inserted (either index out of range or clumn full)
+            - 'X': insertion resulted in the winning of PlateType X
+            - 'O': insertion resulted in the winning of PlateType O
+            

src/de/itsblue/ConnectFour/GameBoard.java

@@ -284,7 +284,7 @@ public class GameBoard extends JPanel {
     }
 
     /**
-     * Override paint function to rescale all caontainers on every repaint
+     * Override paint function to rescale all containers on every repaint
      */
     @Override
     public void paint(Graphics g) {