HorizontalScrollView OnClick method throws errors

Question

In my XML file I have layout for my fragment which contains HorizontalScrollView like this:

<HorizontalScrollView
    android:id="@+id/srollview_seasons_gallery
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="left">
</HorizontalScrollView>

In separate XML file called season_list_item I've made a schema how single item should look like:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/season_image"
        android:layout_marginLeft="7dp"
        android:layout_marginRight="7dp"
        android:onClick="seasonItemClicked"/>

</RelativeLayout>

I add items dynamically with my java code like this:

for (int i=0; i<seasonsSize; i++) {
    View vi = ((LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.season_list_item, null);
    ImageView seasonImage = (ImageView) vi.findViewById(R.id.season_image);
    //seasonImage.setId(i);  
    String imgUrl = response.body().getEmbedded().getSeasons().get(i).getImage().getMedium();
    Picasso.with(getContext()).load(imgUrl).into(seasonImage);
    seasonsLinearLayout.addView(vi);
}
seasonsScrollView.addView(seasonsLinearLayout);

And when I execute my onClick method:

public void seasonItemClicked(View view) {
    }

I get error

java.lang.IllegalStateException: Could not find method seasonItemClicked(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatImageView with id 'season_image'

Uncommenting this line //seasonImage.setId(i); gives me error

android.content.res.Resources$NotFoundException: Unable to find resource ID #0x0`

Pictures are added to layout correctly, just like I want them to. But I cannot achieve to make them clickable. I also find seasonImage.setId(i) important in my case since I need number of the picture that was clicked for further actions.

Could you help me out how this should be approached?

Answer 1

The problem is android:onClick which call your method seasonItemClicked(). As many views you have with this attribute, they will all call this same method, but with the same ID android:id="@+id/season_image".
The setId method could be very annoying because you have to set an unique id. There is some method to generate it, so, for each image, you have to generate an unique ID, and if you set it dynamically, don't set it by xml.

However, assuming that your number of images can be variable, I'd prefer to add the click listener programmatically in the for-loop. That way, they will be related to the imageview clicked. As follows:

for (int i=0; i<seasonsSize; i++) {
    ...
    ImageView seasonImage = (ImageView) vi.findViewById(R.id.season_image);
    seasonImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
             // perform your actions, be aware that 'view' here, is the image clicked
        }
    }
    ...
    seasonsLinearLayout.addView(vi);
}

And just remove the android:onclick attribute:

<ImageView
    ...
    android:id="@+id/season_image"
    android:layout_marginLeft="7dp"
    android:layout_marginRight="7dp"/>

Answer 2

You are assigning conflicting ids, ids that are already assigned to other resources. The best way to generate ids for programmatically created views is to use View.generateViewId or reserve them in the res/values/ids.xml file.