title: TextView not showing text in a particular listener
body: <p>I am trying to have a textview display a message for 5 seconds and then disappear.</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
      public Date start;
      public Date end;
      Handler handle = new Handler();
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          Button startButton = (Button) findViewById(R.id.startButton);
          Button endButton = (Button) findViewById(R.id.stopButton);
          // other variables
          final TextView errTextView = (TextView) findViewById(R.id.errorTextView);
          final DateFormat df = new SimpleDateFormat("MM/dd/yy");
  
          final Thread t = new Thread(new Runnable() {
              @Override
              public void run() {
                  //call function in MainActivity class
                  handle.postDelayed(this, 100);
              }
          });
  
          final Thread errt = new Thread(new Runnable() {
              @Override
              public void run() {
                  errTextView.setText("");
              }
          });
  
          startButton.setOnClickListener(new View.OnClickListener(){
              public void onClick(View v){
  
                      if (start != null)
                          errTextView.setText("Timer Reset");
                          handler.postDelayed(errt, 5000);
                      start = new Date();
                      dateEditText.setText(df.format(start));
                      hoursEditText.setText("");
                      errTextView.setText("");
  
                      handle.post(t);
  
              }
          });
  
  
          endButton.setOnClickListener(new View.OnClickListener(){
              public void onClick(View v){
                  if (start == null) {
                      errTextView.setText("Timer must be started before pressing Stop. Press Start.");
                  }
                  else {
                      start = null;
                  }
                  if(handle != null)
                      handle.removeCallbacksAndMessages(null);
              }
          });
  </code></pre>
  
  <p>If the user presses the start button, start will get the current time and save it. So, if the user presses the start button again, the start button should not be null. If the user presses the twice, the condition should hold, <code>errTextView</code> should display "Timer reset", and the handler should tell the main thread to set <code>errTextView = ""</code> after 5 seconds. <code>errTextView</code> properly shows text in the stop button listener, but not in the start listener. </p>