fixed duplicate contacts and added "delete" option

app/src/main/java/d/d/meshenger/ContactListActivity.java

@@ -40,6 +40,7 @@
 import android.widget.EditText;
 import android.widget.LinearLayout;
 import android.widget.ListView;
+import android.widget.PopupMenu;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -264,8 +265,26 @@ private void refreshContactList() {
         new Handler(getMainLooper()).post(new Runnable() {
             @Override
             public void run() {
-                contactListView.setAdapter(new ContactListAdapter(ContactListActivity.this, R.layout.contact_item, mainBinder.getContacts()));
+                List<Contact> contacts = mainBinder.getContacts();
+                contactListView.setAdapter(new ContactListAdapter(ContactListActivity.this, R.layout.contact_item, contacts));
                 contactListView.setOnItemClickListener(ContactListActivity.this);
+                contactListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
+                    @Override
+                    public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
+                        PopupMenu menu = new PopupMenu(ContactListActivity.this, view);
+                        menu.getMenu().add("delete");
+                        menu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
+                            @Override
+                            public boolean onMenuItemClick(MenuItem menuItem) {
+                                mainBinder.deleteContact(contacts.get(i));
+                                refreshContactList();
+                                return false;
+                            }
+                        });
+                        menu.show();
+                        return true;
+                    }
+                });
             }
         });
     }

app/src/main/java/d/d/meshenger/ContactSqlHelper.java

@@ -57,19 +57,19 @@ public void close(){
         database.close();
     }
 
-    public void insertContact(Contact c) {
+    public void insertContact(Contact c) throws ContactAlreadyAddedException{
         ContentValues values = new ContentValues(3);
         //values.put(columnID, c.getId());
+        values.put(columnIdentifier, c.getIdentifier());
         values.put(columnIP, c.getAddress());
         values.put(columnName, c.getName());
         values.put(columnPhoto, c.getPhoto());
-        values.put(columnIdentifier, c.getIdentifier());
 
         Cursor cur = database.query(tableName, new String[]{columnID}, columnIdentifier + "=\"" + c.getIdentifier() + "\"", null, "", "", "");
         int length = cur.getCount();
         cur.close();
         if(length > 0){
-            return;
+            throw new ContactAlreadyAddedException();
         }
 
 
@@ -113,4 +113,11 @@ public void onCreate(SQLiteDatabase sqLiteDatabase) {
     public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
 
     }
+
+    class ContactAlreadyAddedException extends Exception{
+        @Override
+        public String getMessage() {
+            return "Contact already added";
+        }
+    }
 }

app/src/main/java/d/d/meshenger/MainService.java

@@ -171,8 +171,10 @@ private void handleClient(Socket client) {
                                             "",
                                             identifier
                                     );
-                                    sqlHelper.insertContact(c);
-                                    contacts.add(c);
+                                    try {
+                                        sqlHelper.insertContact(c);
+                                        contacts.add(c);
+                                    }catch (ContactSqlHelper.ContactAlreadyAddedException e){}
                                     JSONObject response = new JSONObject();
                                     response.put("username", userName);
                                     os.write((response.toString() + "\n").getBytes());
@@ -259,13 +261,23 @@ String generateChallenge() {
         }
 
         void addContact(Contact c, String challenge) {
-            sqlHelper.insertContact(c);
-            contacts.add(c);
-            log("adding contact " + c.getName() + "  " + c.getId());
 
+            try {
+                sqlHelper.insertContact(c);
+                contacts.add(c);
+                log("adding contact " + c.getName() + "  " + c.getId());
+
+            } catch (ContactSqlHelper.ContactAlreadyAddedException e) {
+                Toast.makeText(MainService.this, "Contact already added", 0).show();
+            }
             new Thread(new ConnectRunnable(c, challenge)).start();
         }
 
+        void deleteContact(Contact c){
+            sqlHelper.deleteContact(c);
+            refreshContacts();
+        }
+
         void pingContacts(List<Contact> c, ContactPingListener listener) {
             new Thread(new PingRunnable(c, listener)).start();
         }