vlatkozelka vlatkozelka - 1 month ago 23
Android Question

Android: GridLayout size and View.GONE behaviour

I want to make a

GridLayout
that when one of it's children's
Visibility
is set to
GONE
, it is replaced by the next child.
enter image description here

This is no assignment I drew that myself to better explain.

I can get the layout working as in number of columns and width and all. Just the default
GONE
behaviour of
GridLayout
makes the child just disappear instead of being replaced as if it wasn't there in the first place, like other layouts work.

I did try a lot of stuff, I tried searching SO and google, but I can't seem to work this out. And this would be the most convenient layout for the app I'm working on.Is there anyway to do this in layout without having to do this programmatically?Or maybe a combination of both?

Answer

The solution would be to use RecyclerView along with GridLayoutManager. The key is to notify adapter about the changes to deleted items by using notifyItemRemoved. There is lots of room for customization in RecyclerViews, such as nice animations for disappearing items, rearrangement of remaining items on the screen, item decorations and etc. You can apply all these customization and additional logic around deletion of the items as needed for your particular problem.

Activity

public class MainActivity extends AppCompatActivity {
    RecyclerView recyclerView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        List<String> dataSet = getSampleDataSet();
        recyclerView = (RecyclerView) findViewById(R.id.grid);
        recyclerView.setAdapter(new MyAdapter(dataSet));
        recyclerView.setLayoutManager(new GridLayoutManager(getApplicationContext(), 2));
    }

    private List<String> getSampleDataSet() {
        List strings = new ArrayList();
        strings.add("one");
        strings.add("two");
        strings.add("three");
        strings.add("four");
        strings.add("five");
        strings.add("six");

        return strings;
    }
}

Adapter

public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
    List<String> dataSet;



    public MyAdapter(List<String> dataSet) {
        this.dataSet = dataSet;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        TextView tileView = (TextView) LayoutInflater.from(parent.getContext()).inflate(R.layout.grid_item, parent, false);
        MyViewHolder myViewHolder = new MyViewHolder(tileView);

        return myViewHolder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        holder.view.setText(dataSet.get(position));

        holder.view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                dataSet.remove(position);
                notifyItemRemoved(position); // this notifies the adapter about item being removed
            }
        });

    }

    @Override
    public int getItemCount() {
        return dataSet.size();
    }
}


class MyViewHolder extends RecyclerView.ViewHolder {
    TextView view;

    public MyViewHolder(TextView itemView) {
        super(itemView);
        view = itemView;
    }
}

Activity Layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/grid"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</RelativeLayout>

Grid Item

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gridItem"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="@color/colorPrimary"
    android:textColor="@android:color/white"
    android:gravity="center"
    android:text="Tile"/>

Results Before: Before

After click on 4. On an actual device, you will be able to see a nice framework animation for this action.

After