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StatusLayout
LoadingAndRetryManager
StatusLayout实现需要在布局中加入layout，通过动态的view gone visible切换

LoadingAndRetryManager的实现原理是
获取父view，移除内容，换上该显示的layout

   public LoadingAndRetryManager(Object activityOrFragmentOrView, OnLoadingAndRetryListener listener)
    {
        if (listener == null) listener = DEFAULT_LISTENER;
        ViewGroup contentParent = null;
        Context context;
        if (activityOrFragmentOrView instanceof Activity)
        {
            Activity activity = (Activity) activityOrFragmentOrView;
            context = activity;
            contentParent = (ViewGroup) activity.findViewById(android.R.id.content);
        } else if (activityOrFragmentOrView instanceof Fragment)
        {
            Fragment fragment = (Fragment) activityOrFragmentOrView;
            context = fragment.getActivity();
            contentParent = (ViewGroup) (fragment.getView().getParent());
        } else if (activityOrFragmentOrView instanceof View)
        {
            View view = (View) activityOrFragmentOrView;
            contentParent = (ViewGroup) (view.getParent());
            context = view.getContext();
        } else
        {
            throw new IllegalArgumentException("the argument's type must be Fragment or Activity: init(context)");
        }
        int childCount = contentParent.getChildCount();
        //get contentParent
        int index = 0;
        View oldContent;
        if (activityOrFragmentOrView instanceof View)
        {
            oldContent = (View) activityOrFragmentOrView;
            for (int i = 0; i < childCount; i++)
            {
                if (contentParent.getChildAt(i) == oldContent)
                {
                    index = i;
                    break;
                }
            }
        } else
        {
            oldContent = contentParent.getChildAt(0);
        }
        contentParent.removeView(oldContent);
        //setup content layout
        LoadingAndRetryLayout loadingAndRetryLayout = new LoadingAndRetryLayout(context);
        ViewGroup.LayoutParams lp = oldContent.getLayoutParams();
        contentParent.addView(loadingAndRetryLayout, index, lp);
        loadingAndRetryLayout.setContentView(oldContent);
        // setup loading,retry,empty layout
        setupLoadingLayout(listener, loadingAndRetryLayout);
        setupRetryLayout(listener, loadingAndRetryLayout);
        setupEmptyLayout(listener, loadingAndRetryLayout);
        //callback
        listener.setRetryEvent(loadingAndRetryLayout.getRetryView());
        listener.setLoadingEvent(loadingAndRetryLayout.getLoadingView());
        listener.setEmptyEvent(loadingAndRetryLayout.getEmptyView());
        mLoadingAndRetryLayout = loadingAndRetryLayout;
    }