public class GlobalAdapter implements Gloading.Adapter {
    @Override
    public View getView(Gloading.Holder holder, View convertView, int status) {
        GlobalLoadingStatusView loadingStatusView = null;
        //reuse the old view, if possible
        if (convertView != null && convertView instanceof GlobalLoadingStatusView) {
            loadingStatusView = (GlobalLoadingStatusView) convertView;
        }
        if (loadingStatusView == null) {
            loadingStatusView = new GlobalLoadingStatusView(holder.getContext(), holder.getRetryTask());
        }
        loadingStatusView.setStatus(status);
        return loadingStatusView;
    }
    
    class GlobalLoadingStatusView extends RelativeLayout {

        public GlobalLoadingStatusView(Context context, Runnable retryTask) {
            super(context);
            //init view ...
        }
        
        public void setStatus(int status) {
            //change ui by different status...
        }
    }
}

Gloading.initDefault(new GlobalAdapter());

//Gloading wrapped whole activity, wrapper view: android.R.id.content
Gloading.Holder holder = Gloading.getDefault().wrap(activity);

//with load failed retry task
Gloading.Holder holder = Gloading.getDefault().wrap(activity).withRetry(retryTask);

//Gloading will create a FrameLayout to wrap it
Gloading.Holder holder = Gloading.getDefault().wrap(view);

//with load failed retry task
Gloading.Holder holder = Gloading.getDefault().wrap(view).withRetry(retryTask);

//Gloading will create a FrameLayout to cover it
Gloading.Holder holder = Gloading.getDefault().cover(view);

//with load failed retry task
Gloading.Holder holder = Gloading.getDefault().cover(view).withRetry(retryTask);

//show loading status view by holder
holder.showLoading() 

//show load success status view by holder (frequently, hide gloading)
holder.showLoadSuccess()

//show load failed status view by holder (frequently, needs retry task)
holder.showFailed()

//show empty status view by holder. (load completed, but data is empty)
holder.showEmpty()

public abstract class BaseActivity extends Activity {

    protected Gloading.Holder mHolder;

    /**
     * make a Gloading.Holder wrap with current activity by default
     * override this method in subclass to do special initialization
     */
    protected void initLoadingStatusViewIfNeed() {
        if (mHolder == null) {
            //bind status view to activity root view by default
            mHolder = Gloading.getDefault().wrap(this).withRetry(new Runnable() {
                @Override
                public void run() {
                    onLoadRetry();
                }
            });
        }
    }

    protected void onLoadRetry() {
        // override this method in subclass to do retry task
    }

    public void showLoading() {
        initLoadingStatusViewIfNeed();
        mHolder.showLoading();
    }

    public void showLoadSuccess() {
        initLoadingStatusViewIfNeed();
        mHolder.showLoadSuccess();
    }

    public void showLoadFailed() {
        initLoadingStatusViewIfNeed();
        mHolder.showLoadFailed();
    }

    public void showEmpty() {
        initLoadingStatusViewIfNeed();
        mHolder.showEmpty();
    }

}

public class GlobalFailedActivity extends BaseActivity {
    private ImageView imageView;
    private String picUrl;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //do sth init...
        loadData();
    }

    private void loadData() {
        showLoading();
        loadDataAndCallback(new Callback() {
        	public void success(Data data) {
        		if (isEmpty(data)) {
        			showEmpty();
        		} else {
        			//do sth with data...
        			showLoadSuccess();
        		}
        	}
        	public void failed() {
        		//do sth...
        		showLoadFailed();
        	}
        });
    }

    @Override
    protected void onLoadRetry() {
        loadData();
    }
    
    //other codes...
}

//debug mode. if set true, logs will print into logcat
Gloading.debug(trueOrFalse);