content: package com.alexjlockwood.example.delight;
  
  import android.os.Bundle;
  import android.support.v7.app.AppCompatActivity;
  import android.widget.ImageView;
  
  import butterknife.BindView;
  import butterknife.ButterKnife;
  import butterknife.OnClick;
  
  public class PathMorphActivity extends AppCompatActivity {
  
    @BindView(R.id.drawer) ImageView drawerView;
    @BindView(R.id.crosstick) ImageView crossTickView;
    @BindView(R.id.plusminus) ImageView plusMinusView;
    @BindView(R.id.arrowoverflow) ImageView arrowoverflowView;
    private boolean isChecked;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_pathmorph);
      ButterKnife.bind(this);
    }
  
    @OnClick(R.id.rootview)
    void onClick() {
      isChecked = !isChecked;
      final int[] stateSet = {android.R.attr.state_checked * (isChecked ? 1 : -1)};
      drawerView.setImageState(stateSet, true);
      crossTickView.setImageState(stateSet, true);
      plusMinusView.setImageState(stateSet, true);
      arrowoverflowView.setImageState(stateSet, true);
    }
  }
  