CODEWITHSUNDEEP
androidxamarinxamarin.android
a.toraby
a.toraby

Reputation: 3391

How to handle an event that is trigged by a button from inside of a listadapter item?

Suppose we have a list with several items. Each item has several fragments and a label within. When a user clicks on each label I need to change the text of the button1 that is out of the list view. How can I receive that label click event from inside of the list item and change a view that is out of the list view and list adapter.

enter image description here

I know how to handle internal events of the list view adapter inside the adapter. It's as simple as assigning the event handlers in GetView() method but they are not available out of the list.
Thanks for any help

Upvotes: 1

Views: 1708

Answers (2)

dlohani
dlohani

Reputation: 2591

I do not know the proper way, but one way to do would be to implement the label item's OnClickListener() in the adapter, pass the reference of Button 1 to your adapter while creating an adapter, and then manipulate button 1 from OnClickListener().

public class MyAdapter extends BaseAdapter {
    private Activity activity;
    private ArrayList data;
    private Button button1;

    /*************  CustomAdapter Constructor *****************/
    public MyAdapter(Activity activity, ArrayList data, Button button1) {
        this.data = data;
        this.button1 = button1;
        this.activity = activity;
        inflater = (LayoutInflater) this.activity.
                getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    public int getCount() {
        if (data.size()<=0)
            return 1;
        return data.size();
    }
    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public static class ViewHolder{
        public TextView label1;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View vi = convertView;
        ViewHolder holder;
        if (convertView==null) {
            vi = inflater.inflate(R.layout.list_item, null);
            holder = new ViewHolder();
            holder.label1 = (TextView)vi.findViewById(R.id.tvLabel1);
            holder.label1.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    this.button1.setText("Label 1 clicked");
                }
            });
            vi.setTag(holder);
        } else {
            holder = (ViewHolder)vi.getTag();
        }

        // show  the data in the list view
        return vi;
    }
}

Suppose you have a button 1 in MainActivity outside list view, so when you create adapter in MainActivity on your MainActivity's onCreate method do following:

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

    // define and initialize your data
    Button button1 = (Button)findViewById(R.id.button1);
    MyAdapter adapter  = new MyAdapter(this, data, button1);
    ...
}

Upvotes: 2

a.toraby
a.toraby

Reputation: 3391

Solved

I created a custom event and EventAgrs. When user clicks the label I invoke this event and in the main activity I handle the event and change the text of buton1. It was easier than I thought. In GetView() I assign the click event to the label_Click() event handler.

GetView(){
.
.
    label.Click += label_Click();
.
.
}

In label_Click() I invoke the custom event that I have implemented before:

private void label_Click()(object sender, EventArgs e)
{
    LabelClickedEvent.Invoke(sender, new LabelClickEventArgs("aaa", "bbb"));
}

In the list Adapter I declared this custom event: (For more information please look at this guide)

public event LabelClickedEventHandler LabelClickedEvent;
public delegate void LabelClickedEventHandler(object, sender,LabelClickEventArgs args);
public class LabelClickEventArgs : EventArgs
{
   public string param1 { get; set; }
   public string param2 { get; set; }
   public LabelClickEventArgs(string param1 , string param2 )
   {
       this.param1 = param1 ;
       this.param2 = param2 ;
   }
}

In the main activity I simply assigned the event to my event handler and did whatever is needed.

listAdapter.LabelClickedEvent += listAdapter_LabelClickedEvent;
.
.


void listAdapter_LabelClickedEvent(object sender, TheListAdapter.LabelClickEventArgs args)
{
sendButton.Text = args.param1;
}

Hope it helps someone.

Upvotes: 3

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