Endless Gridview

Question

I have looked at lots of implementations of endless lists. One of them is https://github.com/commonsguy/cwac-endless

All of them are using listviews. And all of them are simply adding another row to the list. But when we consider Gridview (like in Google Play Store) and add the loading view as another item in the grid, it looks ugly. How can I achive the same thing in the Play Store?

Answer 1

use a relative layout like this and handle the visiblity in onscroll listener

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <GridView
        android:id="@+id/myGrid"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:columnWidth="60dp"
        android:gravity="center"
        android:horizontalSpacing="10dp"
        android:numColumns="auto_fit"
        android:padding="10dp"
        android:stretchMode="columnWidth"
        android:verticalSpacing="10dp" />

    <View
        android:id="@+id/footer"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:layout_alignBottom="@+id/myGrid"
        android:background="@android:color/white" />

</RelativeLayout

>

Answer 2

Well, to literally use the same technique as is used in EndlessAdapter, you might add N items to the grid, where N is your number of columns.

Another approach is to detect when the user has scrolled near the bottom, then kick off the background work to load in more stuff. I don't have a link handy, but what I've seen uses an OnScrollListener to detect your scroll position as it changes.

Answer 3

i have write a scroll listener and set this scroll listener to my grid view . please correct me if found error.

EG:

final GridView g = (GridView) findViewById(R.id.myGrid);
        g.setAdapter(new ImageAdapter(this));
        EndlessScrollListener scrollListener=new EndlessScrollListener(g,new RefreshList() {

            @Override
            public void onRefresh(int pageNumber) {
                System.out.println("On Refresh invoked..");

            }
        });
        g.setOnScrollListener(scrollListener);

/////////////////////////////////////////////////////////////////////////

import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.GridView;

public class EndlessScrollListener implements OnScrollListener {

    private GridView gridView;
    private boolean isLoading;
    private boolean hasMorePages;
    private int pageNumber=0;
    private RefreshList refreshList;
    private boolean isRefreshing;

    public EndlessScrollListener(GridView gridView,RefreshList refreshList) {
        this.gridView = gridView;
        this.isLoading = false;
        this.hasMorePages = true;
        this.refreshList=refreshList;
    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
        if (gridView.getLastVisiblePosition() + 1 == totalItemCount && !isLoading) {
            isLoading = true;
            if (hasMorePages&&!isRefreshing) {
                isRefreshing=true;
                refreshList.onRefresh(pageNumber);
            }
        } else {
            isLoading = false;
        }

    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {

    }

    public void noMorePages() {
        this.hasMorePages = false;
    }

    public void notifyMorePages(){
        isRefreshing=false;
        pageNumber=pageNumber+1;
    }

    public interface RefreshList {
        public void onRefresh(int pageNumber);
    }
}