Develop Reference

Scrolling down and updating a ListView

I want to update my ListView when I scroll my ListView down (on the last Item )
mConnectionList.setOnScrollListener(new AbsListView.OnScrollListener() {
private int mLastFirstVisibleItem;
private boolean isScrollingDown = false;
private int mLastVisibleItem;
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int lastInScreen = firstVisibleItem + visibleItemCount;
Log.e("lastInScreen", "lastInScreen " + lastInScreen);
if (mLastFirstVisibleItem <= firstVisibleItem) {
Log.i("SCROLLING DOWN", "TRUE");
isScrollingDown = false;
}else{
isScrollingDown = true;
}
if (mLastFirstVisibleItem > firstVisibleItem) {
Log.i("SCROLLING DOWN", "FALSE");
isScrollingDown = true;
}
mLastFirstVisibleItem = firstVisibleItem;
mLastVisibleItem = lastInScreen;
}
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
int sizeList = connectionList.size();
Log.e("lastVisible", " last " + mLastVisibleItem + " " + isScrollingDown);
if (!isScrollingDown && mLastVisibleItem == sizeList) {
getConnections();
}
}
});
This cause update my ListView then I scroll down on my listView but when I scroll up (when is on the end of listView ) my ListView is updating

You can implement a custom component:
public class EndlessListView extends ListView implements OnScrollListener {
..
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
...
}
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {}
}
and in onScroll you can implement your update logic:
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
if (getAdapter() == null)
return ;
if (getAdapter().getCount() == 0)
return ;
int l = visibleItemCount + firstVisibleItem;
if (l <= totalItemCount && !isLoading) {
// It is time to add new data. We call the listener
this.addFooterView(footer);
isLoading = true;
listener.loadData();
}
}
You could customize the ListView footer to notify the updating process:
public void setLoadingView(int resId) {
LayoutInflater inflater = (LayoutInflater) super.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
footer = (View) inflater.inflate(resId, null);
this.addFooterView(footer);
}
Hope this will help you.
You can find all the source code in my blog post

Expandable ListView inside swipe refresh layout doesn't work

I am trying to apply swipe refresh in expandable listView, when the list view is scrolled to bottom and I try to scroll up, then it doesn't scroll up, the swipe refresh layout activates, How to solve this problem? any idea.!!!

swipeRefreshLayout.setEnabled(false);
expandableListView.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int topRowVerticalPosition = (expandableListView == null || expandableListView.getChildCount() == 0) ? 0 : expandableListView.getChildAt(0).getTop();
swipeRefreshLayout.setEnabled(firstVisibleItem == 0 && topRowVerticalPosition >= 0);
}
});

ExpandableListView inside SwipeRefreshLayout doesnt scroll properly

The issue I am having is that the expandable list view is able to scroll down properly, but when I try scrolling up on the expandable list view, it starts the refresh. I am able to scroll up on the expandable list when it first swipe down, and then up again. I want to know if it is possible to only refresh the expandable list when they are at the top of the list or to properly scroll up. I know that a list view has a onScrollListener, so is there something similar to expandable lists? Any help or other suggestion are welcome
Thanks

swipeRefreshLayout.setEnabled(false);
expandableListView.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int topRowVerticalPosition = (expandableListView == null || expandableListView.getChildCount() == 0) ? 0 : expandableListView.getChildAt(0).getTop();
swipeRefreshLayout.setEnabled(firstVisibleItem == 0 && topRowVerticalPosition >= 0);
}
});

#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
boolean allow = false;
if(visibleItemCount>0) {
long packedPosition = elvMounters.getExpandableListPosition(firstVisibleItem);
int groupPosition = ExpandableListView.getPackedPositionGroup(packedPosition);
int childPosition = ExpandableListView.getPackedPositionChild(packedPosition);
allow = groupPosition==0 && childPosition==-1 && elv.getChildAt(0).getTop()==0;
}
mSwipeRefreshLayout.setEnabled(allow);
}

Hide Android Toolbar when scrolling

I want to hide my Toolbar if I scroll down in my ListView in a ListFragment (which implements AbsListView.OnScrollListener) and show it again if I scroll upwards. I use this code but there it shows a flickering toolbar:
listView.setOnScrollListener(new AbsListView.OnScrollListener() {
int mLastFirstVisibleItem = 0;
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) { }
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (view.getId() == listView.getId()) {
final int currentFirstVisibleItem = listView.getFirstVisiblePosition();
if (currentFirstVisibleItem > mLastFirstVisibleItem) {
// getSherlockActivity().getSupportActionBar().hide();
((ActionBarActivity)getActivity()).getSupportActionBar().hide();
} else if (currentFirstVisibleItem < mLastFirstVisibleItem) {
// getSherlockActivity().getSupportActionBar().show();
((ActionBarActivity)getActivity()).getSupportActionBar().show();
}
mLastFirstVisibleItem = currentFirstVisibleItem;
}
}
});
EDIT
I found a problem because I already have used the OnScrollListener to detect if the end of the ListView is reached. But how can I avoid the conflict?
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// Leave this empty
}
/**
* Method to detect if scrolled to end of listview
*
* #param listView
* #param scrollState
*/
#Override
public void onScrollStateChanged(AbsListView listView, int scrollState) {
if (scrollState == SCROLL_STATE_IDLE) {
int threshold = 0;
if (listView.getLastVisiblePosition() >= listView.getCount() - 1 - threshold) {
Log.d(TAG, "Scrolled to end of list, load more articles");
currentPage++;
Log.d(TAG, "CurrentPage for EndlessAdapter:" + currentPage);
// Load more articles
loadMoreArticles(currentPage);
}
}
}
Anyone an idea or improvement proposals?

How to know if the user has scrolled to the top or bottom of a listview/scrollview

I am trying to know when the user has scrolled to the top or bottom of the listview and he cannot scroll anymore.
Now i'm using OnScrollListener to know what listview items are visible.
listview.setOnScrollListener(new OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) {
}
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (totalItemCount - visibleItemCount == firstVisibleItem) {
//last item visible
}
if (firstVisibleItem == 0) {
//first item visible
}
}
});

I have found a solution by checking the offset of the first or the last item, when the offset of those items is 0 then we have reached the bottom/top of the listview.
listview.setOnScrollListener(new OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (firstVisibleItem == 0) {
// check if we reached the top or bottom of the list
View v = listview.getChildAt(0);
int offset = (v == null) ? 0 : v.getTop();
if (offset == 0) {
// reached the top:
return;
}
} else if (totalItemCount - visibleItemCount == firstVisibleItem){
View v = listview.getChildAt(totalItemCount-1);
int offset = (v == null) ? 0 : v.getTop();
if (offset == 0) {
// reached the bottom:
return;
}
}
}
});

Try this way
list.setOnScrollListener(new OnScrollListener() {
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
}
int mPosition=0;
int mOffset=0;
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
int position = list.getFirstVisiblePosition();
View v = list.getChildAt(0);
int offset = (v == null) ? 0 : v.getTop();
if (mPosition < position || (mPosition == position && mOffset < offset)){
// Scrolled up
} else {
// Scrolled down
}
}
});

adapter getView method call when scroll listview
check the position when your position is equal to data size list view so you are on last element of list

#Override
public void onScrollChanged()
{
// We take the last son in the scrollview
View view = (View) scrollview.getChildAt(scrollview.getChildCount() - 1);
int diff = (view.getBottom() - (scrollview.getHeight() + scrollview.getScrollY()));
if (diff == 0 )
{
// bottom of the scrollview
}
}

If you are using a custom adapter with your
listview, then use and enjoy this answer:
https://stackoverflow.com/a/55350409/1845404
The adapter's getView method detects when the list has been scrolled to the last item. It also adds correction for the rare times when some earlier position is called even after the adapter has already rendered the last view.