AdapterPost.java

package com.codewithharry.firebase.adapters;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.text.format.DateFormat;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.PopupMenu;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.recyclerview.widget.RecyclerView;

import com.codewithharry.firebase.AddPostActivity;
import com.codewithharry.firebase.PostDetailsActivity;
import com.codewithharry.firebase.R;
import com.codewithharry.firebase.TheirProfileActivity;
import com.codewithharry.firebase.models.ModelPost;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.squareup.picasso.Picasso;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.Locale;

public class AdapterPost extends RecyclerView.Adapter<AdapterPost.MyHolder> {

    Context context;
    ArrayList<ModelPost> postList;

    String myUid;
    boolean mProcessLike = false;
    private final DatabaseReference likesRef; //for likes database node
    private final DatabaseReference postsRef; //reference of posts

    public AdapterPost(Context context, ArrayList<ModelPost> postList) {
        this.context = context;
        this.postList = postList;

        myUid = FirebaseAuth.getInstance().getCurrentUser().getUid();
        likesRef = FirebaseDatabase.getInstance().getReference().child("Likes");
        postsRef = FirebaseDatabase.getInstance().getReference().child("Posts");
    }

    @NonNull
    @Override
    public MyHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {

        //inflate layout row_posts.xml
        View view = LayoutInflater.from(context).inflate(R.layout.row_posts, viewGroup, false);
        return new MyHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyHolder holder, int position) {
        //get data
        final String uid = postList.get(position).getUid();
        String uEmail = postList.get(position).getuEmail();
        String uName = postList.get(position).getuName();
        String uDp = postList.get(position).getuDp();
        final String pId = postList.get(position).getpId();
        String pTitle = postList.get(position).getpTitle();
        String pDescription = postList.get(position).getpDescr();
        final String pImage = postList.get(position).getpImage();
        String pTimeStamp = postList.get(position).getpTime();
        String pLikes = postList.get(position).getpLikes();
        String pComments = postList.get(position).getpComments();
        //contains total number of likes for the post

        //convert timeStamp to dd/mm/yyyy hh:mm am/pm
        Calendar calendar = Calendar.getInstance(Locale.getDefault());
        calendar.setTimeInMillis(Long.parseLong(pTimeStamp));
        String pTime = DateFormat.format("dd/MM/yyyy hh:mm aa", calendar).toString();

        //set data
        holder.uNameTv.setText(uName);
        holder.pTimeTv.setText(pTime);
        holder.pTitleTv.setText(pTitle);
        holder.pDescriptionTv.setText(pDescription);
        holder.pLikesTv.setText(pLikes + " Likes");
        holder.pCommentsTv.setText(pComments + " Comments");
        //set likes for post
        setLikes(holder, pId);

        //set user dp
        try {
            Picasso.get().load(uDp).placeholder(R.drawable.ic_default_image_white).into(holder.uPictureIv);
        } catch (Exception e) {

        }

        //set post image
        //if there is no image then hide image view
        if (pImage.equals("noImage")) {
            //hide imageview
            holder.pImageIv.setVisibility(View.GONE);

        } else {
            //show imageview
            holder.pImageIv.setVisibility(View.VISIBLE);

            try {
                Picasso.get().load(pImage).into(holder.pImageIv);
            } catch (Exception e) {

            }

        }

        //handle button clicks
        holder.moreBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showMoreOptions(holder.moreBtn, uid, myUid, pId, pImage);
            }
        });

        holder.likeBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //get total number of likes for the post, whose like button is clicked
                //if currently signed in user has not liked it before
                //increase value by 1, otherwise decrease value by 1
                int pLikes = Integer.parseInt(postList.get(position).getpLikes());
                mProcessLike = true;
                //get id of the post clicked
                String postIde = postList.get(position).getpId();
                likesRef.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot snapshot) {
                        if (mProcessLike) {
                            if (snapshot.child(postIde).hasChild(myUid)) {
                                //already liked, so remove like
                                postsRef.child(postIde).child("pLikes").setValue("" + (pLikes - 1));
                                likesRef.child(postIde).child(myUid).removeValue();
                                mProcessLike = false;
                            } else {
                                //not liked, like
                                postsRef.child(postIde).child("pLikes").setValue("" + (pLikes + 1));
                                likesRef.child(postIde).child(myUid).setValue("Liked"); //set any value
                                mProcessLike = false;
                            }
                        }
                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError error) {

                    }
                });
            }
        });

        holder.commentBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //start postDetailActivity
                Intent intent = new Intent(context, PostDetailsActivity.class);
                intent.putExtra("postId", pId);
                context.startActivity(intent);
            }
        });

        holder.shareBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //will implement later
                Toast.makeText(context, "Share", Toast.LENGTH_SHORT).show();
            }
        });

        holder.profileLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                /*Click to go to TheirProfileActivity with UID,
                this UID is clicked of the clicked user
                * which will be used to show user specific data/posts*/
                Intent intent = new Intent(context, TheirProfileActivity.class);
                intent.putExtra("uid", uid);
                context.startActivity(intent);
            }
        });


    }

    //
//    @Override
//    public void onBindViewHolder(@NonNull MyHolder myHolder, int i) {
//    }

    private void setLikes(MyHolder holder, String postKey) {
        likesRef.addValueEventListener(new ValueEventListener() {
            @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR1)
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                if (snapshot.child(postKey).hasChild(myUid)) {
                    //user has liked this post
                    /*To indicate that the post is liked by this(SignedIn) user
                     * Change drawable left icon of like button
                     * Change text of like button fro "Like" to "Liked"*/
                    holder.likeBtn.setCompoundDrawablesRelativeWithIntrinsicBounds(R.drawable.ic_liked, 0, 0, 0);
                    holder.likeBtn.setText("Liked");
                } else {
                    //user has not liked this post
                    /*To indicate that the post is not liked by this(SignedIn) user
                     * Change drawable left icon of like button
                     * Change text of like button fro "Liked" to "Like"*/
                    holder.likeBtn.setCompoundDrawablesRelativeWithIntrinsicBounds(R.drawable.ic_like_black, 0, 0, 0);
                    holder.likeBtn.setText("Like");
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

    private void showMoreOptions(ImageButton moreBtn, String uid, String myUid, String pId, String pImage) {
        //creating pop up menu currently having option Delete, we wil add more options later
        PopupMenu popupMenu = null;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
            popupMenu = new PopupMenu(context, moreBtn, Gravity.END);
        }

        //show delete option in only post(s) of currently signed in user
        if (uid.equals(myUid)) {
            //add items in menu
            popupMenu.getMenu().add(Menu.NONE, 0, 0, "Delete");
            popupMenu.getMenu().add(Menu.NONE, 1, 0, "Edit");
        }
        popupMenu.getMenu().add(Menu.NONE, 2, 0, "View Details");

        //item click listener
        popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem menuItem) {
                int id = menuItem.getItemId();
                if (id == 0) {
                    //delete option is clicked
                    beginDelete(pId, pImage);
                } else if (id == 1) {
                    //Edit is clicked
                    //start AddPostActivity with key "editPost" and the id of the post clicked
                    Intent intent = new Intent(context, AddPostActivity.class);
                    intent.putExtra("key", "editPost");
                    intent.putExtra("editPostId", pId);
                    context.startActivity(intent);
                } else if (id == 2) {
                    //start postdetailactivity
                    Intent intent = new Intent(context, PostDetailsActivity.class);
                    intent.putExtra("postId", pId);
                    context.startActivity(intent);
                }
                return false;
            }
        });
        //show menu
        popupMenu.show();
    }

    private void beginDelete(String pId, String pImage) {
        //post can be with or without image

        if (pImage.equals("noImage")) {
            //post is without image
            deleteWithoutImage(pId);
        } else {
            //post is with image
            deleteWithImage(pId, pImage);
        }
    }

    private void deleteWithImage(String pId, String pImage) {
        //progress bar
        ProgressDialog pd = new ProgressDialog(context);
        pd.setMessage("Deleting post..");

        /*Steps:
         * Delete image using url
         * Delete from database using post id*/

        StorageReference picRef = FirebaseStorage.getInstance().getReferenceFromUrl(pImage);
        picRef.delete()
                .addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void unused) {
                        //image deleted, now delete database
                        Query fquery = FirebaseDatabase.getInstance().getReference("Posts")
                                .orderByChild("pId").equalTo(pId);
                        fquery.addValueEventListener(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot snapshot) {
                                for (DataSnapshot ds : snapshot.getChildren()) {
                                    ds.getRef().removeValue();
                                    //remove values from firebase where pId matches
                                }
                                //deleted
                                Toast.makeText(context, "Deleted successfully", Toast.LENGTH_SHORT).show();
                                pd.dismiss();
                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError error) {

                            }
                        });
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        //failed, can't go further
                        pd.dismiss();
                        Toast.makeText(context, "" + e.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });
    }

    private void deleteWithoutImage(String pId) {
        ProgressDialog pd = new ProgressDialog(context);
        pd.setMessage("Deleting post..");

        Query fquery = FirebaseDatabase.getInstance().getReference("Posts")
                .orderByChild("pId").equalTo(pId);
        fquery.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {
                for (DataSnapshot ds : snapshot.getChildren()) {
                    ds.getRef().removeValue();
                    //remove values from firebase where pId matches
                }
                //deleted
                Toast.makeText(context, "Deleted successfully", Toast.LENGTH_SHORT).show();
                pd.dismiss();
            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
    }

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

    //view holder class
    class MyHolder extends RecyclerView.ViewHolder {

        //views from row_post.xml
        ImageView uPictureIv, pImageIv;
        TextView uNameTv, pTimeTv, pTitleTv, pDescriptionTv, pLikesTv, pCommentsTv;
        ImageButton moreBtn;
        Button likeBtn, commentBtn, shareBtn;
        LinearLayout profileLayout;

        public MyHolder(@NonNull View itemView) {
            super(itemView);

            //init views
            uPictureIv = itemView.findViewById(R.id.uPictureIv);
            pImageIv = itemView.findViewById(R.id.pImageIv);
            uNameTv = itemView.findViewById(R.id.uNameTv);
            pTimeTv = itemView.findViewById(R.id.pTimeTv);
            pTitleTv = itemView.findViewById(R.id.pTitleTv);
            pDescriptionTv = itemView.findViewById(R.id.pDescriptionTv);
            pLikesTv = itemView.findViewById(R.id.pLikesTv);
            pCommentsTv = itemView.findViewById(R.id.pCommentsTv);
            moreBtn = itemView.findViewById(R.id.moreBtn);
            commentBtn = itemView.findViewById(R.id.commentBtn);
            shareBtn = itemView.findViewById(R.id.shareBtn);
            likeBtn = itemView.findViewById(R.id.likeBtn);
            profileLayout = itemView.findViewById(R.id.profileLayout);
        }
    }
}