Disable toolbar scroll flag when content it's not enough to fill the screen

ToolbarActivity.java

public class ToolbarActivity extends AppCompatActivity {
  // Set the flags that fit your needs
  private static final int ENABLED_SCROLL_BEHAVIOR = AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS | AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL;
  private static final int DISABLED_SCROLL_BEHAVIOR = 0;
  private static final int SCROLL_DOWN = 1;
  
  //Injected via ButterKnife (http://jakewharton.github.io/butterknife)
  @InjectView(R.id.toolbar)
  Toolbar toolbar;
  @InjectView(R.id.recyclerview)
  RecyclerView recyclerView;
  
  private final View.OnLayoutChangeListener recyclerViewChangeListener = new View.OnLayoutChangeListener() {
    @Override
    public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
      updateToolbarScrollBehavior();
    }
  };
  
  @Override
  public void onResume() {
    super.onResume();
    recyclerView.addOnLayoutChangeListener(recyclerViewChangeListener);
  }
  
  @Override
  public void onPause() {
    super.onPause();
    recyclerView.removeOnLayoutChangeListener(recyclerViewChangeListener);
  }
  
  private void updateToolbarScrollBehavior() {
    applyScrollBehavior(DISABLED_SCROLL_BEHAVIOR);
    if (recyclerView.canScrollVertically(SCROLL_DOWN)) {
        applyScrollBehavior(ENABLED_SCROLL_BEHAVIOR);
    }
  }
  
  private void applyScrollBehavior(int scrollFlags) {
    AppBarLayout.LayoutParams layoutParams = (AppBarLayout.LayoutParams) toolbar.getLayoutParams();
    layoutParams.setScrollFlags(scrollFlags);
    toolbar.setLayoutParams(layoutParams);
  }
}

canScrollVertically use getWith() and getHeight() internally so use LayoutChangeListener to ensure that those values are updated before call updateToolbarScrollBehavior