XListView.java

package net.yasite.view;

import net.yasite.test.R;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;


public class XListView extends ListView implements OnScrollListener
{
	private float mLastY = -1; // save event y
	private Scroller mScroller; // used for scroll back
	private OnScrollListener mScrollListener; // user's scroll listener

	// the interface to trigger refresh and load more.
	private OnXListViewListener mListViewListener;

	// -- header view
	private XListViewHeader mHeaderView;
	// header view content, use it to calculate the Header's height. And hide it
	// when disable pull refresh.
	private RelativeLayout mHeaderViewContent;
	private TextView mHeaderTimeView;
	private int mHeaderViewHeight; // header view's height
	private boolean mEnablePullRefresh = true;
	private boolean mPullRefreshing = false; // is refreashing.

	// -- footer view
	private XListViewFooter mFooterView;
	private RelativeLayout mFooterViewContent;
	private int mPullLoadState;
	private boolean mPullLoading;
	private boolean mIsFooterReady = false;

	// total list items, used to detect is at the bottom of listview.
	// private int mTotalItemCount;

	// for mScroller, scroll back from header or footer.
	private int mScrollBack;
	private final static int SCROLLBACK_HEADER = 0;
	// private final static int SCROLLBACK_FOOTER = 1;

	private final static int SCROLL_DURATION = 400; // scroll back duration
	// private final static int PULL_LOAD_MORE_DELTA = 50; // when pull up >=
	// 50px
	// at bottom, trigger
	// load more.
	private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
													// feature.
	/** FooterView可以显示 */
	public static final int FOOTER_SHOW = 0x01;
	/** FooterView可以隐藏 */
	public static final int FOOTER_HIDE = 0x02;
	/** FooterView保持显示，但不可点击 */
	public static final int FOOTER_RETAIN = 0x03;
	/** FooterView保持显示，可点击 */
	public static final int FOOTER_WAIT = 0x04;

	/**
	 * @param context
	 */
	public XListView(Context context)
	{
		super(context);
		this.initWithContext(context);
	}

	public XListView(Context context, AttributeSet attrs)
	{
		super(context, attrs);
		this.initWithContext(context);
	}

	public XListView(Context context, AttributeSet attrs, int defStyle)
	{
		super(context, attrs, defStyle);
		this.initWithContext(context);
	}

	private void initWithContext(Context context)
	{
		mScroller = new Scroller(context, new DecelerateInterpolator());
		// XListView need the scroll event, and it will dispatch the event to
		// user's listener (as a proxy).
		super.setOnScrollListener(this);

		// init header view
		mHeaderView = new XListViewHeader(context);
		mHeaderViewContent = (RelativeLayout) mHeaderView.findViewById(R.id.xlistview_header_content);
		mHeaderTimeView = (TextView) mHeaderView.findViewById(R.id.xlistview_header_time);
		this.addHeaderView(mHeaderView);

		// init footer view
		mFooterView = new XListViewFooter(context);
		mFooterViewContent = (RelativeLayout) mFooterView.findViewById(R.id.xlistview_footer_content);

		// init header height
		mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(mOnGlobalLayoutListener);
	}
	
	OnGlobalLayoutListener mOnGlobalLayoutListener = new OnGlobalLayoutListener() {
		
		@Override
		public void onGlobalLayout() {
			mHeaderView.getViewTreeObserver().removeGlobalOnLayoutListener(mOnGlobalLayoutListener);
			mHeaderViewHeight = mHeaderViewContent.getHeight();
		}
	};

	@Override
	public void setAdapter(ListAdapter adapter)
	{
		if (adapter != null)
			// make sure XListViewFooter is the last footer view, and only add
			// once.
			if (mIsFooterReady)
			{
				mIsFooterReady = false;
				this.addFooterView(mFooterView);
			}
		super.setAdapter(adapter);
	}
	
	public void setFooterReady(boolean mIsFooterReady)
	{
		this.mIsFooterReady = mIsFooterReady;
	}

	/**
	 * 为列表设置适配数据集
	 * 
	 * @param adapter
	 *            The ListAdapter which is responsible for maintaining the data
	 *            backing this list and for producing a view to represent an
	 *            item in that data set.
	 * @param isAnimation
	 *            是否为动画模式显示
	 * @see #setAdapter(ListAdapter)
	 */
	public void setAdapter(BaseAdapter adapter, boolean isAnimation)
	{
		if (isAnimation)
		{
//			SwingBottomInAnimationAdapter swingBottomInAnimationAdapter = new SwingBottomInAnimationAdapter(adapter);
//			swingBottomInAnimationAdapter.setListView(this);
//			this.setAdapter(swingBottomInAnimationAdapter);
			return;
		}
		this.setAdapter(adapter);
	}

	/**
	 * enable or disable pull down refresh feature.
	 * 
	 * @param enable
	 */
	public void setPullRefreshEnable(boolean enable)
	{
		mEnablePullRefresh = enable;
		if (!mEnablePullRefresh){
			// disable, hide the content
			mHeaderViewContent.setVisibility(View.INVISIBLE);
		}else{
			mHeaderViewContent.setVisibility(View.VISIBLE);
		}
	}

	/**
	 * enable or disable pull up load more feature.
	 * 
	 * @param enable
	 */
	public void setPullLoadEnable(int enableState)
	{
		mPullLoadState = enableState;
		switch (mPullLoadState)
		{
		case FOOTER_SHOW:
			mFooterViewContent.setVisibility(View.VISIBLE);
			mPullLoading = false;
			mFooterView.setState(XListViewFooter.STATE_NORMAL);
			// both "pull up" and "click" will invoke load more.
			mFooterView.setOnClickListener(new OnClickListener()
			{
				@Override
				public void onClick(View v)
				{
					startLoadMore();
				}
			});
			break;
		case FOOTER_HIDE:
			mFooterViewContent.setVisibility(View.GONE);
			mFooterView.setOnClickListener(null);
			break;
		case FOOTER_RETAIN:
			mFooterViewContent.setVisibility(View.VISIBLE);
			mFooterView.setState(XListViewFooter.STATE_NOTDATA);
			mFooterView.setOnClickListener(null);
			break;
		case FOOTER_WAIT:
			mFooterViewContent.setVisibility(View.VISIBLE);
			mPullLoading = false;
			mFooterView.setState(XListViewFooter.STATE_WAIT);
			// both "pull up" and "click" will invoke load more.
			mFooterView.setOnClickListener(new OnClickListener()
			{
				@Override
				public void onClick(View v)
				{
					startLoadMore();
				}
			});
			break;
		}
	}

	public int getPullLoadState()
	{
		return mPullLoadState;
	}
	
	public View getFooterView()
	{
		return mFooterView;
	}

	/**
	 * stop refresh, reset header view.
	 */
	public void stopRefresh()
	{
		if (mPullRefreshing)
		{
			mPullRefreshing = false;
			this.resetHeaderHeight();
		}
	}

	/**
	 * stop load more, reset footer view.
	 */
	public void stopLoadMore()
	{
		if (mPullLoading)
		{
			mPullLoading = false;
			mFooterView.setState(XListViewFooter.STATE_NORMAL);
		}
	}

	/**
	 * set last refresh time
	 * 
	 * @param time
	 */
	public void setRefreshTime(String time)
	{
		mHeaderTimeView.setText(time);
	}

	private void invokeOnScrolling()
	{
		if (mScrollListener instanceof OnXScrollListener)
		{
			OnXScrollListener l = (OnXScrollListener) mScrollListener;
			l.onXScrolling(this);
		}
	}

	private void updateHeaderHeight(float delta)
	{
		mHeaderView.setVisiableHeight((int) delta + mHeaderView.getVisiableHeight());
		if (mEnablePullRefresh && !mPullRefreshing)
			// 未处于刷新状态，更新箭头
			if (mHeaderView.getVisiableHeight() > mHeaderViewHeight)
				mHeaderView.setState(XListViewHeader.STATE_READY);
			else
				mHeaderView.setState(XListViewHeader.STATE_NORMAL);
		this.setSelection(0); // scroll to top each time
	}

	/**
	 * reset header view's height.
	 */
	private void resetHeaderHeight()
	{
		int height = mHeaderView.getVisiableHeight();
		if (height == 0) // not visible.
			return;
		// refreshing and header isn't shown fully. do nothing.
		if (mPullRefreshing && height <= mHeaderViewHeight)
			return;
		int finalHeight = 0; // default: scroll back to dismiss header.
		// is refreshing, just scroll back to show all the header.
		if (mPullRefreshing && height > mHeaderViewHeight)
			finalHeight = mHeaderViewHeight;
		mScrollBack = SCROLLBACK_HEADER;
		mScroller.startScroll(0, height, 0, finalHeight - height, SCROLL_DURATION);
		// trigger computeScroll
		this.invalidate();
	}

	private void startLoadMore()
	{
		if (mListViewListener != null && !mPullLoading){
			mFooterView.setState(XListViewFooter.STATE_LOADING);
			mListViewListener.onLoadMore();
			mPullLoading = true;
		}
	}

	/**
	 * 一开始刷新
	 */
	public void refresh(OnXListViewListener mListViewListener)
	{
		this.updateHeaderHeight(mHeaderViewContent.getLayoutParams().height);
		this.invokeOnScrolling();
		mPullRefreshing = true;
		mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
		if (mListViewListener != null)
			mListViewListener.onRefresh();
		this.resetHeaderHeight();
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev)
	{
		if (mLastY == -1)
			mLastY = ev.getRawY();
		switch (ev.getAction())
		{
		case MotionEvent.ACTION_DOWN:
			mLastY = ev.getRawY();
			break;
		case MotionEvent.ACTION_MOVE:
			final float deltaY = ev.getRawY() - mLastY;
			mLastY = ev.getRawY();
			if (this.getFirstVisiblePosition() == 0 && (mHeaderView.getVisiableHeight() > 0 || deltaY > 0))
			{
				// the first item is showing, header has shown or pull down.
				this.updateHeaderHeight(deltaY / OFFSET_RADIO);
				this.invokeOnScrolling();
			}
			break;
		default:
			mLastY = -1; // reset
			if (this.getFirstVisiblePosition() == 0)
			{
				// invoke refresh
				if (mEnablePullRefresh && mHeaderView.getVisiableHeight() > mHeaderViewHeight)
				{
					mPullRefreshing = true;
					mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
					if (mListViewListener != null)
						mListViewListener.onRefresh();
				}
				this.resetHeaderHeight();
			}
			break;
		}
		return super.onTouchEvent(ev);
	}

	@Override
	public void computeScroll()
	{
		if (mScroller.computeScrollOffset())
		{
			if (mScrollBack == SCROLLBACK_HEADER)
			{
				mHeaderView.setVisiableHeight(mScroller.getCurrY());
			} else
			{
				mFooterView.setBottomMargin(mScroller.getCurrY());
			}
			this.postInvalidate();
			this.invokeOnScrolling();
		}
		super.computeScroll();
	}

	@Override
	public void setOnScrollListener(OnScrollListener l)
	{
		mScrollListener = l;
	}

	@Override
	public void onScrollStateChanged(AbsListView view, int scrollState)
	{
//		if (App.ISAUTOLOADERMORE)
//		{
			switch (scrollState)
			{
			case OnScrollListener.SCROLL_STATE_IDLE:
				if ((view.getLastVisiblePosition() == (view.getCount() - 1)) 
						&& (mPullLoadState == FOOTER_SHOW || mPullLoadState == FOOTER_WAIT))
					this.startLoadMore();
				break;
			}
//		}
		if (mScrollListener != null)
			mScrollListener.onScrollStateChanged(view, scrollState);
	}

	@Override
	public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
	{
		// send to user's listener
		// mTotalItemCount = totalItemCount;
		if (mScrollListener != null)
			mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
	}

	public void setXListViewListener(OnXListViewListener l)
	{
		mListViewListener = l;
	}

	/**
	 * you can listen ListView.OnScrollListener or this one. it will invoke
	 * onXScrolling when header/footer scroll back.
	 */
	public interface OnXScrollListener extends OnScrollListener
	{
		public void onXScrolling(View view);
	}

	/**
	 * implements this interface to get refresh/load more event.
	 */
	public interface OnXListViewListener
	{
		public void onRefresh();

		public void onLoadMore();
	}
}