Wsrtjtyk

I know that the onDataChange download is asynchronous, but the body has UI Thread. And loading images using Glide is also asynchronous. onDataChange is being executed, it comes to the body of the UI Thread, but there the image is loaded in the new thread and, therefore, the image does not have time to load, how the code is executed further.

myRef.addListenerForSingleValueEvent(new ValueEventListener() {

    @Override

    public void onDataChange(DataSnapshot dataSnapshot) {

        for(DataSnapshot ds : dataSnapshot.getChildren()) {

              ...

              if(word.contains("https")){

                  Glide.with(Activity.this)

                  .load(url)

                  .into(imageView);

              }else{

                  Log.d(TAG, "Another");

              }

         }

    }

}

This is Firebase database.

How to wait for the image to load before the cycle "for" goes on?

Put the Glide logic in a method passing dataSnapshot as param. Something like this :

Glide.with(Activity.this)

 .load(url)

 .listener(new RequestListener<String, GlideDrawable>() {

     @Override

     public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {

         return false;

     }



     @Override

     public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {

         imageSend(imageView);

         return false;

     }

 })

 .into(imageView);

If you are using Glide-v4, you can set a listener for loading the image like this:

Glide.with(Activity.this)

        .load(url)

        .listener(new RequestListener<Drawable>() {



            @Override

            public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {

                return false;

            }



            @Override

            public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {

                imageSend(imageView);

                return false;

            }

        })

        .into(imageView);

Try this,

Declare a global variable:

ArrayList<String> list = new ArrayList<>();

add urls to list:

myRef.addListenerForSingleValueEvent(new ValueEventListener() {

@Override

public void onDataChange(DataSnapshot dataSnapshot) {

    for(DataSnapshot childDS : dataSnapshot.getChildren()){

       list.add(childDS.getValue(String.class));

   }

   setImages(list); // this function will be called only after all the URLs are added to the list 

 }

}

Create a new method:

void setImages(ArrayList<String> urlList){

  for(int i = 0; i<urlList.size; i++){

   if(urlList.get(i).contains("https")){

         Glide.with(Activity.this)

         .load(url)

         .into(imageView);

         imageSend(imageView);

    }else{

         Log.d(TAG, "Another");

    }

  }

}