content: package me.alexrs.circlebutton.demo;
  
  import android.app.Activity;
  import android.graphics.Color;
  import android.os.Bundle;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.View;
  import android.widget.Toast;
  
  import me.alexrs.circularbutton.lib.CircularButton;
  
  
  public class MainActivity extends Activity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          final CircularButton button = (CircularButton) findViewById(R.id.button);
  
          //Here is shown how you can change the color of the button and shadow.
          button.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  Toast.makeText(getBaseContext(), "CLICK!", Toast.LENGTH_SHORT).show();
                  if (button.getButtonColor() == Color.WHITE) {
                      button.setButtonColor(Color.BLACK);
                      button.setShadowColor(Color.BLUE);
                  } else {
                      button.setButtonColor(Color.WHITE);
                      button.setShadowColor(Color.GRAY);
                  }
              }
          });
      }
  
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.main, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
          if (id == R.id.action_settings) {
              return true;
          }
          return super.onOptionsItemSelected(item);
      }
  }
  