Android 页面多状态布局管理的开发

public class StatusView extends FrameLayout {
  ......
  /**
   * 在 Activity 中的初始化方法，默认页面的根布局使用多状态布局
   */
  public static StatusView init(Activity activity) {
    View contentView = ((ViewGroup) activity.findViewById(android.R.id.content)).getChildAt(0);
    return init(contentView);
  }

  /**
   * 在 Activity 中的初始化方法
   * @param viewId  使用多状态布局的 ViewId
   */
  public static StatusView init(Activity activity, @IdRes int viewId) {
    View rootView = ((ViewGroup) activity.findViewById(android.R.id.content)).getChildAt(0);
    View contentView = rootView.findViewById(viewId);
    return init(contentView);
  }

  /**
   * 在Fragment中的初始化方法
   * @param viewId  使用多状态布局的 ViewId
   */
  public static StatusView init(Fragment fragment, @IdRes int viewId) {
    View rootView = fragment.getView();
    View contentView = null;
    if (rootView != null) {
      contentView = rootView.findViewById(viewId);
    }
    return init(contentView);
  }

  /**
   * 用 StatusView 替换要使用多状态布局的 View
   */
  private static StatusView init(View contentView) {
    if (contentView == null) {
      throw new RuntimeException("ContentView can not be null!");
    }
    ViewGroup parent = (ViewGroup) contentView.getParent();
    if (parent == null) {
      throw new RuntimeException("ContentView must have a parent view!");
    }
    ViewGroup.LayoutParams lp = contentView.getLayoutParams();
    int index = parent.indexOfChild(contentView);
    parent.removeView(contentView);
    StatusView statusView = new StatusView(contentView.getContext());
    statusView.addView(contentView);
    statusView.setContentView(contentView);
    parent.addView(statusView, index, lp);
    return statusView;
  }
  ......
}

@Override
protected void onFinishInflate() {
  super.onFinishInflate();
  if (getChildCount() == 1) {
    View view = getChildAt(0);
    setContentView(view);
  }
}

private void switchStatusView(View statusView) {
  if (statusView == currentView) {
    return;
  }
  removeView(currentView);
  currentView = statusView;
  addView(currentView);
}

private View generateStatusView(@LayoutRes int layoutId) {
    View statusView = viewArray.get(layoutId);
    if (statusView == null) {
      statusView = inflate(layoutId);
      viewArray.put(layoutId, statusView);
      configStatusView(layoutId, statusView);
    }
    return statusView;
  }

// 添加指定索引对应的状态布局
statusView.setStatusView(int index, @LayoutRes int layoutId)
// 为指定索引的状态布局设置初次显示的监听事件，用来进行状态布局的相关初始化
statusView.setOnStatusViewConvertListener(int index, StatusViewConvertListener listener)
// 显示指定索引的状态布局
statusView.showStatusView(int index)