APagingFragment.java

package org.aisen.android.ui.fragment;

import android.os.Bundle;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.ListView;

import org.aisen.android.R;
import org.aisen.android.common.context.GlobalContext;
import org.aisen.android.common.utils.ActivityHelper;
import org.aisen.android.common.utils.Logger;
import org.aisen.android.common.utils.ViewUtils;
import org.aisen.android.network.biz.IResult;
import org.aisen.android.network.task.TaskException;
import org.aisen.android.support.paging.IPaging;
import org.aisen.android.ui.fragment.adapter.IPagingAdapter;
import org.aisen.android.ui.fragment.itemview.AFooterItemView;
import org.aisen.android.ui.fragment.itemview.AHeaderItemViewCreator;
import org.aisen.android.ui.fragment.itemview.BasicFooterView;
import org.aisen.android.ui.fragment.itemview.IITemView;
import org.aisen.android.ui.fragment.itemview.IItemViewCreator;
import org.aisen.android.ui.fragment.itemview.OnFooterViewListener;
import org.aisen.android.ui.widget.AsToolbar;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

/**
 * 基于APagingFragment，可以扩展支持BaseAdapter的UI控件，并处理上、下拉的交互逻辑<br/>
 *
 * 1、维护Adapter<br/>
 * 2、维护分页线程<br/>
 * 3、处理UI界面的上、下拉<br/>
 * 4、新增FooterView，用于ListView等界面的自动加载更多<br/>
 * 5、当读取缓存数据并配置positionKey时，可以自动滑动到上次最后阅读位置<br/>
 *
 * @param <T>
 * @param <Ts>
 * @param <V>
 */
public abstract class APagingFragment<T extends Serializable, Ts extends Serializable, Header extends Serializable, V extends ViewGroup>
															extends ABaseFragment
															implements AsToolbar.OnToolbarDoubleClick, OnFooterViewListener, AFooterItemView.OnFooterViewCallback {

	private static final String TAG = "AFragment-Paging";

	public static final String PAGING_TASK_ID = "org.aisen.android.PAGING_TASK";
	
	private static final String SAVED_DATAS = "org.aisen.android.ui.Datas";
	private static final String SAVED_PAGING = "org.aisen.android.ui.Paging";
    private static final String SAVED_CONFIG = "org.aisen.android.ui.Config";

	private IPaging mPaging;// 分页器

	private IPagingAdapter<T> mAdapter;
	
	private APagingTask pagingTask;// 分页线程
	
	RefreshConfig refreshConfig;// 刷新方面的配置

	IItemViewCreator<T> mFooterItemViewCreator;
	AFooterItemView<T> mFooterItemView;// FooterView，滑动到底部时，自动加载更多数据

	AHeaderItemViewCreator<Header> mHeaderItemViewCreator;

	public enum RefreshMode {
		/**
		 * 重设数据
		 */
		reset,
		/**
		 * 上拉，加载更多
		 */
		update,
		/**
		 * 下拉，刷新最新
		 */
		refresh
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		if (savedInstanceState == null) {
			refreshConfig = new RefreshConfig();
		}
		else {
			refreshConfig = (RefreshConfig) savedInstanceState.getSerializable(SAVED_CONFIG);
		}

		ArrayList<T> datas = savedInstanceState == null ? new ArrayList<T>()
                                                        : (ArrayList<T>) savedInstanceState.getSerializable(SAVED_DATAS);
		mAdapter = newAdapter(datas);

		if (savedInstanceState != null && savedInstanceState.getSerializable(SAVED_PAGING) != null) {
            mPaging = (IPaging) savedInstanceState.getSerializable(SAVED_PAGING);
		} else {
            mPaging = newPaging();
		}
	}

    @Override
    public void onSaveInstanceState(Bundle outState) {
        // 将分页信息保存起来
        if (mPaging != null)
            outState.putSerializable(SAVED_PAGING, mPaging);
		if (refreshConfig != null)
			outState.putSerializable(SAVED_CONFIG, refreshConfig);

        onSaveDatas(outState);

        super.onSaveInstanceState(outState);
    }

    /**
     * 数据量比较大的时候，子类可以不保存，会阻塞
     *
     * @param outState
     */
    protected void onSaveDatas(Bundle outState) {
        // 将数据保存起来
        if (getAdapter() != null && getAdapter().getDatas().size() != 0)
            outState.putSerializable(SAVED_DATAS, getAdapter().getDatas());
    }
	
	@Override
	void _layoutInit(LayoutInflater inflater, Bundle savedInstanceSate) {
		super._layoutInit(inflater, savedInstanceSate);

		setupRefreshConfig(refreshConfig);

		setupRefreshView(savedInstanceSate);

		setupRefreshViewWithConfig(refreshConfig);

		bindAdapter(getAdapter());
	}
	
	public IPagingAdapter getAdapter() {
		return mAdapter;
	}

	public ArrayList<T> getAdapterItems() {
		return mAdapter.getDatas();
	}
	
    public void onPullDownToRefresh() {
		requestData(RefreshMode.refresh);
	}

    public void onPullUpToRefresh() {
		requestData(RefreshMode.update);
	}
	
	@Override
    public boolean isContentEmpty() {
		return getAdapter() == null || getAdapter().getDatas().size() == 0;
	}

	// 子类不再允许重写这个类
	@Override
	final protected void onTaskStateChanged(ABaseTaskState state, TaskException exception) {
		// super.onTaskStateChanged(state, tag);
	}

	/**
	 * 子类需要根据不同的刷新模式，来刷新自己的UI
	 *
	 * @param state
	 * @param exception
	 * @param mode
	 */
	protected void onTaskStateChanged(ABaseTaskState state, TaskException exception, RefreshMode mode) {
		super.onTaskStateChanged(state, exception);

		onTaskStateChanged(mFooterItemView, state, exception, mode);

		if (state == ABaseTaskState.success) {
			if (isContentEmpty()) {
				if (emptyLayout != null && !TextUtils.isEmpty(refreshConfig.emptyHint))
					ViewUtils.setTextViewValue(emptyLayout, R.id.txtLoadEmpty, refreshConfig.emptyHint);
			}
		}
		else if (state == ABaseTaskState.falid) {
			if (isContentEmpty()) {
				if (loadFailureLayout != null && !TextUtils.isEmpty(exception.getMessage()))
					ViewUtils.setTextViewValue(loadFailureLayout, R.id.txtLoadFailed, exception.getMessage());
			}
		}
		else if (state == ABaseTaskState.finished) {
			onRefreshViewFinished(mode);
		}
	}

	public void setAdapterItems(ArrayList<T> items) {
		mAdapter.getDatas().clear();
		mAdapter.getDatas().addAll(items);
	}

    /**
     * 子类配置
     *
     * @param config
     */
    protected void setupRefreshConfig(RefreshConfig config) {
		config.emptyHint = getString(R.string.comm_content_empty);
    }

    /**
     * 设置分页
     *
     * @return <tt>null</tt> 不分页
     */
    protected IPaging<T, Ts> newPaging() {
        return null;
    }

    abstract public IItemViewCreator<T> configItemViewCreator();

	/**
	 * 根据RefreshMode拉取数据
	 * 
	 * @param mode
	 */
	abstract public void requestData(RefreshMode mode);
	
	/**
	 * 列表控件
	 * 
	 * @return
	 */
	abstract public V getRefreshView();

	/**
	 * 配置Adapter
	 *
	 * @param datas
	 * @return
	 */
	abstract protected IPagingAdapter<T> newAdapter(ArrayList<T> datas);

	/**
	 * 绑定Adapter到RefreshView
	 *
	 * @param adapter
	 */
	abstract protected void bindAdapter(IPagingAdapter adapter);
	
	/**
	 * 设置列表控件状态为刷新状态
	 * 
	 * @return true:某些控件，设置它的刷新状态，它会自己自动回调Callback去刷新数据，true即这种情况
	 */
	public boolean setRefreshViewToLoading() {
		return false;
	}
	
	/**
	 * 根据Config刷新RefreshView
	 */
	protected void setupRefreshViewWithConfig(RefreshConfig config) {

	}

	/**
	 * 设置列表控件状态为刷新结束
	 */
	public void onRefreshViewFinished(RefreshMode mode) {

	}

    /**
     * 初始化RefreshView
     *
     */
    protected void setupRefreshView(Bundle savedInstanceSate) {
		if (refreshConfig != null && refreshConfig.footerMoreEnable) {
			mFooterItemViewCreator = configFooterViewCreator();
			View convertView = mFooterItemViewCreator.newContentView(getActivity().getLayoutInflater(), null, IPagingAdapter.TYPE_FOOTER);
			mFooterItemView = (AFooterItemView<T>) mFooterItemViewCreator.newItemView(convertView, IPagingAdapter.TYPE_FOOTER);
		}

		mHeaderItemViewCreator = configHeaderViewCreator();

		if (mFooterItemView != null) {
			addFooterViewToRefreshView(mFooterItemView);
		}
		if (mHeaderItemViewCreator != null) {
			addHeaderViewToRefreshView(mHeaderItemViewCreator);
		}
    }

	/**
	 * 当前页面是否正在加载刷新
	 *
	 * @return
	 */
	public boolean isRefreshing() {
		return pagingTask != null;
	}
	
    @Override
    public boolean onToolbarDoubleClick() {
        return false;
    }

    public static class RefreshConfig implements Serializable {

		private static final long serialVersionUID = 6244426943442129360L;

		public boolean pagingEnd = false;// 分页是否结束
		
		public String positionKey = null;// 最后阅读坐标的Key，null-不保存，针对缓存数据有效
		
        public boolean displayWhenScrolling = true;// 滚动的时候加载图片

		public int releaseDelay = 5 * 1000;// 当配置了releaseItemIds参数时，离开页面后自动释放资源

		public int[] releaseItemIds = null;// 离开页面时，释放图片的控件，针对ItemView

		public String emptyHint = "数据为空";// 如果EmptyLayout中有R.id.txtLoadEmpty这个控件，将这个提示绑定显示

		public boolean footerMoreEnable = true;// FooterView加载更多
		
	}

	/*********************************************开始数据刷新方法************************************************/

	@Override
	public void requestData() {
		// 如果没有Loading视图，且数据为空，就显示FootView加载状态
		RefreshMode mode = RefreshMode.reset;
		if (getAdapter().getDatas().size() == 0 && loadingLayout == null)
			mode = RefreshMode.update;

		requestData(mode);
	}

	@Override
	public void requestDataOutofdate() {
		putLastReadPosition(0);
		putLastReadTop(0);

		requestDataSetRefreshing();
	}

	/**
	 * 设置刷新控件为刷新状态且刷新数据
	 *
	 */
	public void requestDataSetRefreshing() {
		// 如果没有正在刷新，设置刷新控件，且子类没有自动刷新
		if (!isRefreshing() && !setRefreshViewToLoading())
			requestData(RefreshMode.reset);
	}

	public void requestDataDelaySetRefreshing(long delay) {
		Runnable requestDelayRunnable = new Runnable() {

			@Override
			public void run() {
				Logger.d(TAG, "延迟刷新，开始刷新, " + toString());

				requestDataSetRefreshing();
			}

		};

		runUIRunnable(requestDelayRunnable, delay);
	}

	/**
	 * 分页线程，根据{@link IPaging}构造的分页参数列表调用接口
	 *
	 * @author wangdan
	 *
	 * @param <Params>
	 * @param <Progress>
	 * @param <Result>
	 */
	public abstract class APagingTask<Params, Progress, Result extends Serializable> extends ABaseTask<Params, Progress, Result> {

		final protected RefreshMode mode;

		public APagingTask(RefreshMode mode) {
			super(PAGING_TASK_ID);
			this.mode = mode;
			pagingTask = this;

			if (mode == RefreshMode.reset && mPaging != null)
				mPaging = newPaging();
		}

		@Override
		protected void onPrepare() {
			super.onPrepare();

			Logger.d(TAG, toString() + "-" + ABaseTaskState.prepare + " - " + mode);
			onTaskStateChanged(ABaseTaskState.prepare, null, mode);
		}

		@Override
		public Result workInBackground(Params... params) throws TaskException {
			String previousPage = null;
			String nextPage = null;

			if (mPaging != null) {
				previousPage = mPaging.getPreviousPage();
				nextPage = mPaging.getNextPage();
			}

			return workInBackground(mode, previousPage, nextPage, params);
		}

		@SuppressWarnings("unchecked")
		@Override
		protected void onSuccess(Result result) {
			if (result == null || getActivity() == null) {
				super.onSuccess(result);
				return;
			}

			bindAdapter(getAdapter());

			List<T> resultList;
			if (result instanceof List)
				resultList = (List<T>) result;
			else {
				resultList = parseResult(result);
				if (resultList == null)
					resultList = new ArrayList<T>();
			}

			// 如果子类没有处理新获取的数据刷新UI，默认替换所有数据
			if (!handleResult(mode, resultList))
				if (mode == RefreshMode.reset)
					setAdapterItems(new ArrayList<T>());

			// append数据
			if (mode == RefreshMode.reset || mode == RefreshMode.refresh)
				IPagingAdapter.Utils.addItemsAtFrontAndRefresh(getAdapter(), resultList);
			else if (mode == RefreshMode.update)
				IPagingAdapter.Utils.addItemsAndRefresh(getAdapter(), resultList);

			// 处理分页数据
			if (mPaging != null) {
				if (getAdapter() != null && getAdapter().getDatas().size() != 0)
					mPaging.processData(result, (T) getAdapter().getDatas().get(0),
							(T) getAdapter().getDatas().get(getAdapter().getDatas().size() - 1));
				else
					mPaging.processData(result, null, null);
			}

			// 如果是重置数据，重置canLoadMore
			if (mode == RefreshMode.reset)
				refreshConfig.pagingEnd = false;
			// 如果数据少于这个值，默认加载完了
			if (mode == RefreshMode.update || mode == RefreshMode.reset)
				refreshConfig.pagingEnd = resultList.size() == 0;

			// 如果是缓存数据，且已经过期
			if (result instanceof IResult) {
				// 这里增加一个自动刷新设置功能
				IResult iResult = (IResult) result;

				if (iResult.fromCache() && !iResult.outofdate())
					toLastReadPosition();

				if (mode == RefreshMode.reset || mode == RefreshMode.update) {
					if (iResult.endPaging())
						refreshConfig.pagingEnd = true;
					else
						refreshConfig.pagingEnd = false;
				}
			}

			if (mode == RefreshMode.reset && getTaskCount(getTaskId()) > 1)
				getAdapter().notifyDataSetChanged();

			setupRefreshViewWithConfig(refreshConfig);

			Logger.d(TAG, toString() + "-" + ABaseTaskState.success + " - " + mode);
			onTaskStateChanged(ABaseTaskState.success, null, mode);

			super.onSuccess(result);
		}

		@Override
		protected void onFailure(TaskException exception) {
			super.onFailure(exception);

			Logger.d(TAG, toString() + "-" + ABaseTaskState.falid + " - " + mode + "-" + exception.getMessage());
			onTaskStateChanged(ABaseTaskState.falid, exception, mode);
		}

		@Override
		protected void onCancelled() {
			super.onCancelled();

			Logger.d(TAG, toString() + "-" + ABaseTaskState.canceled + " - " + mode);
			onTaskStateChanged(ABaseTaskState.canceled, null, mode);
		}

		@Override
		protected void onFinished() {
			super.onFinished();

			Logger.d(TAG, toString() + "-" + ABaseTaskState.finished + " - " + mode);
			onTaskStateChanged(ABaseTaskState.finished, null, mode);

			pagingTask = null;
		}

		/**
		 * 每次调用接口，获取新的数据时调用这个方法
		 *
		 * @param mode
		 *            当次拉取数据的类型
		 * @param datas
		 *            当次拉取的数据
		 * @return <tt>false</tt> 如果mode={@link RefreshMode#reset}
		 *         默认清空adapter中的数据
		 */
		protected boolean handleResult(RefreshMode mode, List<T> datas) {
			return false;
		}

		/**
		 * 将Ts转换成List(T)
		 *
		 * @param result
		 *            List(T)
		 * @return
		 */
		abstract protected List<T> parseResult(Result result);

		/**
		 * 异步执行方法
		 *
		 * @param mode 刷新模式
		 * @param previousPage 上一页页码
		 * @param nextPage 下一页页码
		 * @param params task参数
		 * @return
		 * @throws TaskException
		 */
		abstract protected Result workInBackground(RefreshMode mode, String previousPage, String nextPage, Params... params) throws TaskException;

	}

	/*********************************************结束数据刷新方法************************************************/

	/*********************************************开始FooterView************************************************/

	protected AHeaderItemViewCreator<Header> configHeaderViewCreator() {
		return null;
	}

	protected IItemViewCreator<T> configFooterViewCreator() {
		return new IItemViewCreator<T>() {

			@Override
			public View newContentView(LayoutInflater inflater, ViewGroup parent, int viewType) {
				return inflater.inflate(BasicFooterView.LAYOUT_RES, parent, false);
			}

			@Override
			public IITemView<T> newItemView(View convertView, int viewType) {
				return new BasicFooterView<>(getActivity(), convertView, APagingFragment.this);
			}

		};
	}

	abstract protected void addFooterViewToRefreshView(AFooterItemView<?> footerItemView);

	abstract protected void addHeaderViewToRefreshView(AHeaderItemViewCreator<?> headerItemViewCreator);

	/**
	 * 设置FooterView为加载状态，
	 *
	 */
	@Override
	public void setFooterViewToRefreshing() {
		if (mFooterItemView != null) {
			mFooterItemView.setFooterViewToRefreshing();
		}
	}

	/**
	 * 当Task的状态发生改变时，刷新FooterView
	 *
	 * @param state
	 * @param exception
	 * @param mode
	 */
	@Override
	public void onTaskStateChanged(AFooterItemView<?> footerItemView, ABaseTaskState state, TaskException exception, RefreshMode mode) {
		if (refreshConfig == null || !refreshConfig.footerMoreEnable || mFooterItemView == null)
			return;

		if (mFooterItemView != null) {
			mFooterItemView.onTaskStateChanged(footerItemView, state, exception, mode);
		}
	}

	private boolean refreshViewScrolling = false;// 正在滚动
	protected void onScrollStateChanged(int scrollState) {
		// 滑动的时候，不加载图片
		if (!refreshConfig.displayWhenScrolling) {
			if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) {
				refreshViewScrolling = true;
			}
			else if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
				refreshViewScrolling = true;
			}
			else if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
				refreshViewScrolling = false;
			}
		}

		if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE && // 停止滚动
				!refreshConfig.pagingEnd && // 分页未加载完
				refreshConfig.footerMoreEnable && // 自动加载更多
				mFooterItemView != null // 配置了FooterView
				) {
			int childCount = getRefreshView().getChildCount();
			if (childCount > 0 && getRefreshView().getChildAt(childCount - 1) == mFooterItemView.getConvertView()) {
				setFooterViewToRefreshing();
			}
		}

		// 保存最后浏览位置
		if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) {
			if (!TextUtils.isEmpty(refreshConfig.positionKey) && getRefreshView() != null) {
				putLastReadPosition(getFirstVisiblePosition());

				putLastReadTop(getRefreshView().getChildAt(0).getTop());
			}
		}
	}

	@Override
	public boolean canLoadMore() {
		return refreshConfig == null || !refreshConfig.pagingEnd;
	}

	@Override
	public void onLoadMore() {
		if (canLoadMore()) {
			onPullUpToRefresh();
		}
	}

	protected void onScroll(int firstVisibleItem, int visibleItemCount, int totalItemCount) {

	}

	@Override
	public boolean canDisplay() {
		if (refreshConfig.displayWhenScrolling)
			return true;

		return !refreshViewScrolling;
	}

	/*********************************************结束FooterView************************************************/

	/*********************************************开始阅读位置历史************************************************/

	protected void toLastReadPosition() {
		if (getRefreshView() == null || TextUtils.isEmpty(refreshConfig.positionKey))
			return;

		if (getRefreshView() instanceof ListView) {
			runUIRunnable(new Runnable() {

				@Override
				public void run() {
					ListView listView = (ListView) getRefreshView();
					listView.setSelectionFromTop(getLastReadPosition(), getLastReadTop() + listView.getPaddingTop());
				}
			});
		}
	}

	protected int getLastReadPosition() {
		return ActivityHelper.getIntShareData(GlobalContext.getInstance(), refreshConfig.positionKey + "Position", 0);
	}

	protected void putLastReadPosition(int position) {
		if (!TextUtils.isEmpty(refreshConfig.positionKey))
			ActivityHelper.putIntShareData(GlobalContext.getInstance(), refreshConfig.positionKey + "Position", position);
	}

	protected int getLastReadTop() {
		return ActivityHelper.getIntShareData(GlobalContext.getInstance(), refreshConfig.positionKey + "Top", 0);
	}

	protected void putLastReadTop(int top) {
		if (!TextUtils.isEmpty(refreshConfig.positionKey))
			ActivityHelper.putIntShareData(GlobalContext.getInstance(), refreshConfig.positionKey + "Top", top);
	}

	protected int getFirstVisiblePosition() {
		return 0;
	}

	final protected IPaging getPaging() {
		return mPaging;
	}

	/*********************************************结束阅读位置历史************************************************/


	// 重构需要实现的方法
	public void refreshUI() {

	}

	public void releaseImageViewByIds() {

	}

}