Android - False when make thread

Question

I want: if user already put name and choose game types, user can click button 'OK' but if user doesn't already put name and choose game types, user can't click button 'OK'.

public class UserConfig extends Activity {
Button userConfigBack;
Button userConfigOK;
EditText userNameTextbox;
Spinner gameTypes;
private String gameType;
private String playerName;
private Handler handler;
Thread validation;

@Override
protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.user_config);
     userConfigBack = (Button) findViewById(R.id.user_config_back);
     userConfigOK = (Button) findViewById(R.id.user_config_ok);
     userNameTextbox = (EditText) findViewById(R.id.user_name_textbox);
     gameTypes = (Spinner) findViewById(R.id.game_types);
     gameTimes = (Spinner) findViewById(R.id.game_times);
     userConfigOK.setEnabled(false);
     userConfigOK.setClickable(false);
     setName();
     setGameType();
     handler = new Handler();
     autoValidation();
     OK();

}

public void setName() {
    playerName = userNameTextbox.getText().toString();

     userNameTextbox.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                playerName = userNameTextbox.getText().toString();
                nameLabel.setText(playerName);
            }

            @Override
            public void afterTextChanged(Editable arg0) {

            } 

        });


}

public void setGameType() {
    gameTypes.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> adapterView, View arg1,
                int arg2, long arg3) {

            gameType = (String) gameTypes.getSelectedItem();
            gameTypeLabel.setText(gameType);
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {

        }
    });

}


public void OK() {

    userConfigOK.setOnClickListener( new OnClickListener() {
        @SuppressWarnings("deprecation")
        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            Intent intent = new Intent(UserConfig.this, EnemyConfig1.class);
            startActivity(intent);

        }
    });


}


public void autoValidation() {

    validation = new Thread(new Runnable() {
        @Override
        public void run() {


            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            handler.post(new Runnable() {

                @Override
                public void run() {

                         if(!gameType.equals("")) {
                             if(!playerName.equals("")) {
                                 userConfigOK.setEnabled(true);
                                 userConfigOK.setClickable(true);
                             }

                         }


                }
            });


        } 
    });
    validation.start();

}

}

I create thread inside method AUTOVALIDATION. If editText not null and user already choose game types spinner, user can click button OK. But

userConfigOK.setEnabled(true); 
userConfigOK.setClickable(true);

doesn't work.

Answer 1

You can't change any UI elements from another Thread. Try to use a runOnUiThread this should solve the problem.

You really should read this carefully: http://developer.android.com/guide/components/processes-and-threads.html This will save you al lot of time if you are working with Threads.

And here is an example that helped me a lot: how to use runOnUiThread

Answer 2

add a text watcher to your edittext and then use this if elsestatement:

if(!userNameTextbox.getText().toString().equals("")){
 //do your job
}else{
//Toast some thing
}