Mercury-IM/app/src/main/java/org/mercury_im/messenger/ui/chat/ChatInputFragment.java

package org.mercury_im.messenger.ui.chat;

import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;

import android.content.Context;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

import org.mercury_im.messenger.R;

public class ChatInputFragment extends Fragment implements View.OnClickListener {

    private EditText textInput;
    private ImageButton addAttachement;
    private ImageButton buttonSend;

    private ChatInputViewModel mViewModel;

    private OnChatInputActionListener actionListener;

    public static ChatInputFragment newInstance() {
        return new ChatInputFragment();
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_chat, container, false);
        textInput = view.findViewById(R.id.chat_field__text_input);
        addAttachement = view.findViewById(R.id.chat_field__button_attachment);
        buttonSend = view.findViewById(R.id.chat_field__button_send);

        addAttachement.setOnClickListener(this);
        buttonSend.setOnClickListener(this);
        return view;
    }

    @Override2
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mViewModel = ViewModelProviders.of(this).get(ChatInputViewModel.class);
        // observeViewModel(mViewModel);
    }

    private void observeViewModel(ChatInputViewModel viewModel) {
        viewModel.getDraft().observe(ChatInputFragment.this, new Observer<String>() {
            @Override
            public void onChanged(@Nullable String draft) {
                textInput.setText(draft);
            }
        });
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnChatInputActionListener) {
            this.actionListener = (OnChatInputActionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnListFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        this.actionListener = null;
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            // Add media
            case R.id.chat_field__button_attachment:
                if (actionListener != null) {
                    actionListener.onButtonAddAttachementClicked();
                }
                Toast.makeText(getContext(), R.string.not_yet_implemented, Toast.LENGTH_SHORT).show();
                break;

            // Send message
            case R.id.chat_field__button_send:
                if (actionListener != null) {
                    actionListener.onComposingBodySend(textInput.getText().toString());
                }
                textInput.setText(null);
                break;
        }
    }

    public interface OnChatInputActionListener {

        void onButtonAddAttachementClicked();

        void onComposingBodyChanged(String body);

        void onComposingBodySend(String body);
    }
}