package com.yuyh.stickyheader.view;
import android.content.Context;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.View;
import android.view.animation.AlphaAnimation;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.RelativeLayout;
public class StickyHeaderListView extends RelativeLayout {
// TODO: Handle listViews with fast scroll
// TODO: See if there are methods to dispatch to mListView
private static final int FADE_DELAY = 1000;
private static final int FADE_DURATION = 2000;
private InternalListView mListView;
private StickyHeaderAdapter mAdapter;
private RelativeLayout mHeader;
private View mHeaderConvertView;
private AbsListView.OnScrollListener mExternalOnScrollListener;
public StickyHeaderListView(Context context) {
this(context, null);
}
public StickyHeaderListView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}
private void init(Context context, AttributeSet attrs) {
mListView = new InternalListView(getContext(), attrs);
LayoutParams listParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
listParams.addRule(ALIGN_PARENT_TOP);
mListView.setLayoutParams(listParams);
mListView.setOnScrollListener(new HeaderListViewOnScrollListener());
mListView.setVerticalScrollBarEnabled(true);
mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (mAdapter != null) {
mAdapter.onItemClick(parent, view, position, id);
}
}
});
addView(mListView);
mHeader = new RelativeLayout(getContext());
LayoutParams headerParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
headerParams.addRule(ALIGN_PARENT_TOP);
mHeader.setLayoutParams(headerParams);
mHeader.setGravity(Gravity.BOTTOM);
addView(mHeader);
}
public void setAdapter(StickyHeaderAdapter adapter) {
mAdapter = adapter;
mListView.setAdapter(adapter);
}
public void setOnScrollListener(AbsListView.OnScrollListener l) {
mExternalOnScrollListener = l;
}
private class HeaderListViewOnScrollListener implements AbsListView.OnScrollListener {
private int previousFirstVisibleItem = -1;
private int direction = 0;
private int actualSection = 0;
private boolean scrollingStart = false;
private boolean doneMeasuring = false;
private int lastResetSection = -1;
private int nextH;
private int prevH;
private View previous;
private View next;
private AlphaAnimation fadeOut = new AlphaAnimation(1f, 0f);
private boolean noHeaderUpToHeader = false;
private boolean didScroll = false;
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (mExternalOnScrollListener != null) {
mExternalOnScrollListener.onScrollStateChanged(view, scrollState);
}
didScroll = true;
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (mExternalOnScrollListener != null) {
mExternalOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
}
if (!didScroll) {
return;
}
firstVisibleItem -= mListView.getHeaderViewsCount();
if (firstVisibleItem < 0) {
mHeader.removeAllViews();
return;
}
if (visibleItemCount > 0 && firstVisibleItem == 0 && mHeader.getChildAt(0) == null) {
addSectionHeader(0);
lastResetSection = 0;
}
int realFirstVisibleItem = getRealFirstVisibleItem(firstVisibleItem, visibleItemCount);
if (totalItemCount > 0 && previousFirstVisibleItem != realFirstVisibleItem) {
direction = realFirstVisibleItem - previousFirstVisibleItem;
actualSection = mAdapter.getSection(realFirstVisibleItem);
boolean currIsHeader = mAdapter.isSectionHeader(realFirstVisibleItem);
boolean prevHasHeader = mAdapter.hasSectionHeaderView(actualSection - 1);
boolean nextHasHeader = mAdapter.hasSectionHeaderView(actualSection + 1);
boolean currHasHeader = mAdapter.hasSectionHeaderView(actualSection);
boolean currIsLast = mAdapter.getRowInSection(realFirstVisibleItem) == mAdapter.rowCounts(actualSection) - 1;
boolean prevHasRows = mAdapter.rowCounts(actualSection - 1) > 0;
boolean currIsFirst = mAdapter.getRowInSection(realFirstVisibleItem) == 0;
boolean needScrolling = currIsFirst && !currHasHeader && prevHasHeader && realFirstVisibleItem != firstVisibleItem;
boolean needNoHeaderUpToHeader = currIsLast && currHasHeader && !nextHasHeader && realFirstVisibleItem == firstVisibleItem && Math.abs(mListView.getChildAt(0).getTop()) >= mListView.getChildAt(0).getHeight() / 2;
noHeaderUpToHeader = false;
if (currIsHeader && !prevHasHeader && firstVisibleItem >= 0) {
resetHeader(direction < 0 ? actualSection - 1 : actualSection);
} else if ((currIsHeader && firstVisibleItem > 0) || needScrolling) {
if (!prevHasRows) {
resetHeader(actualSection - 1);
}
startScrolling();
} else if (needNoHeaderUpToHeader) {
noHeaderUpToHeader = true;
} else if (lastResetSection != actualSection) {
resetHeader(actualSection);
}
previousFirstVisibleItem = realFirstVisibleItem;
}
if (scrollingStart) {
int scrolled = realFirstVisibleItem >= firstVisibleItem ? mListView.getChildAt(realFirstVisibleItem - firstVisibleItem).getTop() : 0;
if (!doneMeasuring) {
setMeasurements(realFirstVisibleItem, firstVisibleItem);
}
int headerH = doneMeasuring ? (prevH - nextH) * direction * Math.abs(scrolled) / (direction < 0 ? nextH : prevH) + (direction > 0 ? nextH : prevH) : 0;
mHeader.scrollTo(0, -Math.min(0, scrolled - headerH));
if (doneMeasuring && headerH != mHeader.getLayoutParams().height) {
LayoutParams p = (LayoutParams) (direction < 0 ? next.getLayoutParams() : previous.getLayoutParams());
p.topMargin = headerH - p.height;
mHeader.getLayoutParams().height = headerH;
mHeader.requestLayout();
}
}
if (noHeaderUpToHeader) {
if (lastResetSection != actualSection) {
addSectionHeader(actualSection);
lastResetSection = actualSection + 1;
}
mHeader.scrollTo(0, mHeader.getLayoutParams().height - (mListView.getChildAt(0).getHeight() + mListView.getChildAt(0).getTop()));
}
}
private void startScrolling() {
scrollingStart = true;
doneMeasuring = false;
lastResetSection = -1;
}
private void resetHeader(int section) {
scrollingStart = false;
addSectionHeader(section);
mHeader.requestLayout();
lastResetSection = section;
}
private void setMeasurements(int realFirstVisibleItem, int firstVisibleItem) {
if (direction > 0) {
nextH = realFirstVisibleItem >= firstVisibleItem ? mListView.getChildAt(realFirstVisibleItem - firstVisibleItem).getMeasuredHeight() : 0;
}
previous = mHeader.getChildAt(0);
prevH = previous != null ? previous.getMeasuredHeight() : mHeader.getHeight();
if (direction < 0) {
if (lastResetSection != actualSection - 1) {
addSectionHeader(Math.max(0, actualSection - 1));
next = mHeader.getChildAt(0);
}
nextH = mHeader.getChildCount() > 0 ? mHeader.getChildAt(0).getMeasuredHeight() : 0;
mHeader.scrollTo(0, prevH);
}
doneMeasuring = previous != null && prevH > 0 && nextH > 0;
}
private void addSectionHeader(int actualSection) {
View previousHeader = mHeader.getChildAt(0);
if (previousHeader != null) {
mHeader.removeViewAt(0);
}
if (mAdapter.hasSectionHeaderView(actualSection)) {
mHeaderConvertView = mAdapter.getSectionHeaderView(actualSection, mHeaderConvertView, mHeader);
mHeaderConvertView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
mHeaderConvertView.measure(MeasureSpec.makeMeasureSpec(mHeader.getWidth(), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
mHeader.getLayoutParams().height = mHeaderConvertView.getMeasuredHeight();
mHeaderConvertView.scrollTo(0, 0);
mHeader.scrollTo(0, 0);
mHeader.addView(mHeaderConvertView, 0);
} else {
mHeader.getLayoutParams().height = 0;
mHeader.scrollTo(0, 0);
}
}
private int getRealFirstVisibleItem(int firstVisibleItem, int visibleItemCount) {
if (visibleItemCount == 0) {
return -1;
}
int relativeIndex = 0, totalHeight = mListView.getChildAt(0).getTop();
for (relativeIndex = 0; relativeIndex < visibleItemCount && totalHeight < mHeader.getHeight(); relativeIndex++) {
totalHeight += mListView.getChildAt(relativeIndex).getHeight();
}
int realFVI = Math.max(firstVisibleItem, firstVisibleItem + relativeIndex - 1);
return realFVI;
}
}
public ListView getListView() {
return mListView;
}
public void addHeaderView(View v) {
mListView.addHeaderView(v);
}
private float dpToPx(float dp) {
return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, getContext().getResources().getDisplayMetrics());
}
protected class InternalListView extends ListView {
public InternalListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected int computeVerticalScrollExtent() {
return super.computeVerticalScrollExtent();
}
@Override
protected int computeVerticalScrollOffset() {
return super.computeVerticalScrollOffset();
}
@Override
protected int computeVerticalScrollRange() {
return super.computeVerticalScrollRange();
}
}
}
