Updating textview on activity once data in adapter class is changed

Question

I am having textview txtQuantity in my dashboard activity. I wrote separate class for custom adapter which will contain sold products.

 protected void onCrea         


        

Answer 1

By providing a simple callback.

For this to work write a simple interface in your adapter

public interface OnDataChangeListener{
    public void onDataChanged(int size);
}

and add a setter for the listener (also in the adapter)

OnDataChangeListener mOnDataChangeListener;
public void setOnDataChangeListener(OnDataChangeListener onDataChangeListener){
    mOnDataChangeListener = onDataChangeListener;
}

now add additional code to the following block in the adapter

private void doButtonOneClickActions(TextView txtQuantity, int rowNumber) {
    ...
    if(mOnDataChangeListener != null){
        mOnDataChangeListener.onDataChanged(data.size());
    }
}

in your dashboard activity you then need to register the listener

protected void onCreate(Bundle savedInstanceState) {
    ...
    adapter.setOnDataChangeListener(new Sold_item_adaptor.OnDataChangeListener(){
        public void onDataChanged(int size){
            //do whatever here
        }
    });
}

That's about it ;).