public class RefreshLayout extends SwipeRefreshLayout implements AbsListView.OnScrollListener {
private int mTouchSlop; //滑動最短距離
private int mDownY; //按下時的Y坐标
private int mLastY; //擡起時的Y坐标
private boolean isLoading = false; //是否處于加載狀态
private ListView mListView; //布局内的ListView執行個體
private View mListViewFooter; //上拉加載腳布局
private OnLoadMoreListener onLoadMoreListener; //上拉加載監聽
public RefreshLayout(Context context) {
this(context, null);
}
public RefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mListViewFooter = LayoutInflater.from(context).inflate(R.layout.view_load_more_footer, null, false);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
//初始化布局内的ListView對象
if (mListView == null) {
getListView();
}
}
/**
* 擷取布局内的ListView對象
*/
private void getListView() {
int childCount = getChildCount();
if (childCount > ) {
View childView = getChildAt();
if (childView instanceof ListView) {
mListView = (ListView) childView;
//設定滾動監聽器給ListView, 使得滾動的情況下也可以自動加載
mListView.setOnScrollListener(this);
}
}
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
mDownY = (int) ev.getRawY();
break;
case MotionEvent.ACTION_MOVE:
mLastY = (int) ev.getRawY();
break;
case MotionEvent.ACTION_UP:
if (canLoadMore()) {
LoadMore();
}
break;
}
return super.dispatchTouchEvent(ev);
}
/**
* 處理加載更多
*/
private void LoadMore() {
if (onLoadMoreListener != null) {
//設定上拉加載時的狀态
setLoading(true);
onLoadMoreListener.onLoadMore();
}
}
/**
* 設定上拉加載時的狀态
*/
public void setLoading(boolean loading) {
isLoading = loading;
if (isLoading) {
mListView.addFooterView(mListViewFooter);
} else {
mListView.removeFooterView(mListViewFooter);
mDownY = ;
mLastY = ;
}
}
/**
* 是否滿足上拉加載條件
*/
private boolean canLoadMore() {
return isBottom() && !isLoading && isPullUp();
}
/**
* ListView是否滑倒最底部
*/
private boolean isBottom() {
if (mListView != null && mListView.getAdapter() != null) {
return mListView.getLastVisiblePosition() == (mListView.getAdapter().getCount() - );
}
return false;
}
/**
* 是否是上拉操作
*/
private boolean isPullUp() {
return mLastY == ? false : (mDownY - mLastY) >= mTouchSlop;
}
@Override
public void onScrollStateChanged(AbsListView absListView, int i) {
}
@Override
public void onScroll(AbsListView absListView, int i, int i1, int i2) {
if (canLoadMore()) {
LoadMore();
}
}
/**
* 上拉加載監聽接口
*/
public interface OnLoadMoreListener {
void onLoadMore();
}
/**
* 設定監聽
*/
public void setOnLoadMoreListener(OnLoadMoreListener listener) {
this.onLoadMoreListener = listener;
}
}