How to apply an onClick Listener to an imageView within a CardView - android-recyclerview

Question

I'm trying to setup an onClick Listener where that listener already has a button. The purpose is to provide a second way to access an intent (in this case a "ReadActivity" class. An example of this is
Here is my code:
#Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
holder.tv_book_title.setText(mData.get(position).getBookTitle());
holder.tv_book_author.setText("by " + mData.get(position).getBookAuthor());
holder.img_book_thumbnail.setImageResource(mData.get(position).getBookId());
holder.actionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(mContext, ReadActivity.class);
// passing data to the book activity
intent.putExtra("Id", mData.get(position).getPhotoId());
intent.putExtra("Title", mData.get(position).getBookTitle());
intent.putExtra("Author", mData.get(position).getBookAuthor());
intent.putExtra("Description", mData.get(position).getContentUrl());
intent.putExtra("Thumbnail", mData.get(position).getBookId());
// start the activity
mContext.startActivity(intent);
}
});
And this is my cardview_item xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/card_view"
android:layout_width="match_parent"
android:layout_height="#dimen/card_height"
android:layout_gravity="center"
android:layout_marginBottom="#dimen/md_keylines"
android:layout_marginLeft="#dimen/md_keylines"
android:layout_marginRight="#dimen/md_keylines"
android:foreground="?attr/selectableItemBackground">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/book_img_id"
**android:onClick="imageClick"**
android:layout_width="match_parent"
android:layout_height="#dimen/card_image_height"
android:scaleType="centerCrop"
android:contentDescription="#string/todo" />
<TextView
android:id="#+id/book_title_id"
android:layout_width="match_parent"
android:layout_height="#dimen/card_title_height"
android:layout_alignBottom="#+id/book_img_id"
android:layout_marginStart="#dimen/md_keylines"
android:textAppearance="#style/TextAppearance.AppCompat.Title"
android:textColor="#color/white" />
<TextView
android:id="#+id/book_author_id"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/book_img_id"
android:layout_marginLeft="#dimen/md_keylines"
android:layout_marginTop="#dimen/md_keylines"
android:layout_marginBottom="#dimen/md_keylines"
android:layout_marginRight="#dimen/md_keylines"
android:ellipsize="end"
android:singleLine="true"
android:textColor="#color/dark_grey"
android:textSize="#dimen/article_subheading" />
<Button
android:id="#+id/action_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/book_author_id"
style="?android:attr/borderlessButtonStyle"
android:textColor="?attr/colorPrimary"
android:text="#string/read" />
</RelativeLayout>
</android.support.v7.widget.CardView>
In the xml, I tried to set a onClick line, but I'm not sure how to setup the onClick listener. Is there a way to do this without affecting the originial code? Or would it be easier to copy to actionButton.setOnClickListener and just change the holder setting to the thumbnail?

Answer 1

You should not use `android:onClick" attribute for handling click. You better handle it in code so that your Layout and logic not tightly coupled.
You need to use setOnClickListener like at the actionButton. Or you can slightly change your code to handle the click inside your ViewHolder. Change your code like this:
// use View.OnClickListener so that the click listener won't
// be recreated when the View is recycled
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public Button actionButton;
public ImageView img_book_thumbnail;
public ViewHolder(Context context, View itemView) {
super(itemView);
// find actionButton and img_book_thumbnail
...
// Attach a click listener to both of them
actionButton.setOnClickListener(this);
img_book_thumbnail.setOnClickListener(this);
}
// Handles clicked
#Override
public void onClick(View view) {
if(view.getId == R.id.action_button) {
// do something
} else if(view.getId == R.id.book_img_id) {
// do something
}
}
}
Instead of directly handling the click in Adapter, you should delegate the click handling to the parent activity / fragment of the Adapter by using a Listener/Callback mechanism.