xListview

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 IXListViewListener 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 boolean mEnablePullLoad;

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.

 

/**

 * @param context

 */

public XListView(Context context) {

super(context);

initWithContext(context);

}

 

public XListView(Context context, AttributeSet attrs) {

super(context, attrs);

initWithContext(context);

}

 

public XListView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

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);

addHeaderView(mHeaderView);

 

// init footer view

mFooterView = new XListViewFooter(context);

 

// init header height

mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(

new OnGlobalLayoutListener() {

@Override

public void onGlobalLayout() {

mHeaderViewHeight = mHeaderViewContent.getHeight();

getViewTreeObserver()

.removeGlobalOnLayoutListener(this);

}

});

}

 

@Override

public void setAdapter(ListAdapter adapter) {

// make sure XListViewFooter is the last footer view, and only add once.

if (mIsFooterReady == false) {

mIsFooterReady = true;

addFooterView(mFooterView);

}

super.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(boolean enable) {

mEnablePullLoad = enable;

if (!mEnablePullLoad) {

mFooterView.hide();

mFooterView.setOnClickListener(null);

//make sure "pull up" don't show a line in bottom when listview with one page

setFooterDividersEnabled(false);

} else {

mPullLoading = false;

mFooterView.show();

mFooterView.setState(XListViewFooter.STATE_NORMAL);

//make sure "pull up" don't show a line in bottom when listview with one page  

setFooterDividersEnabled(true);

// both "pull up" and "click" will invoke load more.

mFooterView.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

startLoadMore();

}

});

}

}

 

/**

 * stop refresh, reset header view.

 */

public void stopRefresh() {

if (mPullRefreshing == true) {

mPullRefreshing = false;

resetHeaderHeight();

}

}

 

/**

 * stop load more, reset footer view.

 */

public void stopLoadMore() {

if (mPullLoading == true) {

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);

}

}

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

invalidate();

}

 

private void updateFooterHeight(float delta) {

int height = mFooterView.getBottomMargin() + (int) delta;

if (mEnablePullLoad && !mPullLoading) {

if (height > PULL_LOAD_MORE_DELTA) { // height enough to invoke load

// more.

mFooterView.setState(XListViewFooter.STATE_READY);

} else {

mFooterView.setState(XListViewFooter.STATE_NORMAL);

}

}

mFooterView.setBottomMargin(height);

 

// setSelection(mTotalItemCount - 1); // scroll to bottom

}

 

private void resetFooterHeight() {

int bottomMargin = mFooterView.getBottomMargin();

if (bottomMargin > 0) {

mScrollBack = SCROLLBACK_FOOTER;

mScroller.startScroll(0, bottomMargin, 0, -bottomMargin,

SCROLL_DURATION);

invalidate();

}

}

 

private void startLoadMore() {

mPullLoading = true;

mFooterView.setState(XListViewFooter.STATE_LOADING);

if (mListViewListener != null) {

mListViewListener.onLoadMore();

}

}

 

@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 (getFirstVisiblePosition() == 0

&& (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {

// the first item is showing, header has shown or pull down.

updateHeaderHeight(deltaY / OFFSET_RADIO);

invokeOnScrolling();

} else if (getLastVisiblePosition() == mTotalItemCount - 1

&& (mFooterView.getBottomMargin() > 0 || deltaY < 0)) {

// last item, already pulled up or want to pull up.

updateFooterHeight(-deltaY / OFFSET_RADIO);

}

break;

default:

mLastY = -1; // reset

if (getFirstVisiblePosition() == 0) {

// invoke refresh

if (mEnablePullRefresh

&& mHeaderView.getVisiableHeight() > mHeaderViewHeight) {

mPullRefreshing = true;

mHeaderView.setState(XListViewHeader.STATE_REFRESHING);

if (mListViewListener != null) {

mListViewListener.onRefresh();

}

}

resetHeaderHeight();

} else if (getLastVisiblePosition() == mTotalItemCount - 1) {

// invoke load more.

if (mEnablePullLoad

    && mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA

    && !mPullLoading) {

startLoadMore();

}

resetFooterHeight();

}

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());

}

postInvalidate();

invokeOnScrolling();

}

super.computeScroll();

}

 

@Override

public void setOnScrollListener(OnScrollListener l) {

mScrollListener = l;

}

 

@Override

public void onScrollStateChanged(AbsListView view, int scrollState) {

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(IXListViewListener 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 IXListViewListener {

public void onRefresh();

 

public void onLoadMore();

}

}

转载于:https://www.cnblogs.com/xiaxinxin/p/8909079.html