How to handle the onclick map button in a gridview? Best practice

Question

I am trying to find the best solution for handling the event OnClickthat is generated by the button of my card (see the figure below) within GridView.

So, as you can see, I have a regular one GridViewwith cells made from my custom Map.

I just initialize GridViewand its adapter:

mGrid = (GridView) findViewById(R.id.grid);
mAdapter = new ImageTopicsAdapter(..blah blah blah..);
mGrid.setAdapter(mAdapter);

As you probably know, I can easily handle the events OnClickgenerated GridView. But it will only work if I click on the map:

mGrid.setOnItemClickListener(..blah blah blah..);

I want to create something similar to this (see the code below), so I can easily "implement" my Activityto handle the button of my OnClickevent card :

mGrid.setOnItemButtonClickListener(..blah blah blah..);

What is the best way (clean \ easy \ elegant)?

. . :)

Answer 1

, , . @Dimitar G. @Konstantin Kiriushyn. , .

1). CardView Compound View, : LinearLayout + ImageView + TextView + Button.

public class TopicCardView extends LinearLayout {

   private ImageView mImage;
   private Button mButtonMenu;
   private TextView mTitle;

   public TopicCardView (Context context) {
      initializeViews(context);
   }

   private void initializeViews(Context context) {
      LayoutInflater inflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
      inflater.inflate(R.layout.topic_card_view, this);
   }

   private void setTitle(...) {
      ...
   }

   private void setImage(...) {
      ...
   }

   private void setMenuClickListener(...) {
      ...
   }

   // and so on...
}

2) createListOfGridCardsFromDB(...) Activity\Fragment. (LinkedList) CardView ( \ CardView s).

3) LinkedList CardView GridViewAdapter.

. , , .. Adapter.

Answer 2

, . ( ):

• , ArrayAdapter

  • , ( )
  • ( )

  • context ApplicationActivity , - , ,

    private final MyAdapter extends ArrayAdapter implements View.OnClickListener {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // inflate your card then get a reference to your button
            View card = ....;
            card.findViewById(R.id.YOUR_BUTTON_ID).setOnClickListener(this);
            return card;
        }
    
        @Override
        public void onClick(View view) {
            ApplicationActivity activity = (ApplicationActivity) view.getContext();
            if (activity != null && !activity.isFinishing()) {
                applicationActivity.onCardButtonClick();
            }
        }
    }
    
    // in your ApplicationActivity
    public final class ApplicationActivity extends Activity {
        ...
    
        public void onCardButtonClick() {
            // deal with your click
        }
    }
    

textbook ( ..), , .

.

View ( ), . , .

BTW. , " " ( , ), (-)/p >

, , , . , , , :

public final MyAdapter extends ArrayAdapter {
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // inflate your card then get a reference to your button
        View card = ....;
        card.findViewById(R.id.YOUR_BUTTON_ID).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                ApplicationActivity activity = (ApplicationActivity) view.getContext();
                if (activity != null && !activity.isFinishing() && !activity.isDestroyed()) {
                    applicationActivity.onCardButtonClick();
                }
            }
        });
        return card;
    }
}

-

, . :

public class ApplicationActivity extends Activity {
    ....

    public void onCardButtonClick(Cell cell) {
        // do whatever you want with the model/view
    }
}

// ViewModel instances are used in your adapter
public final class ViewModel {
    public final String description;
    public final String title;

    public ViewModel(String title, String description) {
        this.title = title != null ? title.trim() : "";
        this.description = description != null ? description.trim() : "";
    }
}

public final class Cell extends LinearLayout {
    private View button;
    private ViewModel model;

    // ViewModel is data model and is the list of items in your adapter
    public void update(ViewModel model) {
        this.model = model;
        // update your card with your model
    }

    public ViewModel getModel() {
        return model;
    }

    @Override
    protected void onAttachedToWindow() {
        button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener {
            @Override
            public void onClick(View view) {
                ApplicationActivity activity = (ApplicationActivity) view.getContext();
                if (model != null && activity != null && !activity.isFinishing() && !activity.isDestroyed() {
                    activity.onCardButtonClick(Cell.this);
                }
            }
        });
    }
}

// then your adapter `getView()` needs to inflate/create your compound view and return it
public final MyAdapter extends ArrayAdapter {
    private final List<ViewModel> items;

    public MyAdapter() {
        // update your models from outside or create on the fly, etc.
        this.items = ...;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {        
            // inflate - say it is a layout file 'cell.xml'
            convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.cell);
        }

        ((Cell) convertView).update(items.get(position));
        return convertView;
    }
}

Answer 3

. , setOnOptionsClickListener ( OnOptionsClickListener), , .

, Activity/Fragment

public interface OnOptionsClickListener {
      void onOptionsClicked(View view, PictureItem item);
}


mAdapter= new MyGridAdapter();
mAdapter.setOnOptionsClickListener(new OnOptionsClickListener() {
       public void onClick(View view, PictureItem item) {
            //process click
       }
});

public void setOnOptionsClickListener(OnOptionsClickListener l) {
    mOnOptionsClickListener = l;
}

findViewById(R.id.btn_options).setOnClickListener(new OnClickListener(){
    public void OnClick(View view) {
        mOnOptionsClickListener.onOptionsClicked(view, currentPictureItem);
    }
});

.. , OnClick() (, currentPictureItem, URL- ). OnClickListener.

Edit So here is the explanation. Adapterserves for viewing GridViewfor View-provider. It creates views and sets up the base state. Therefore, during initialization of views, all clicks must be set to Adapter. Moreover, we do not want to have messy Activitywith a nested Adapter, but we want Adapter to be a separate class. For this reason, you usually need to create an additional interface in order to have access to the object currentItemto retrieve data.