Multiple executions of the same failed target when backgrounding

[mattleibow]

Glide Version: 4.12.0

Integration libraries: n/a

Device/Android Version: Pixel 5 - API 30 emulator

Issue details / Repro steps / Use case background:

If an image fails to load (does not exist) then pausing and resuming the app triggers the load again

Glide load line / GlideModule (if any) / list Adapter code (if any):

package com.example.myapplication;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import com.bumptech.glide.Glide;
import com.bumptech.glide.RequestManager;
import com.bumptech.glide.request.target.CustomViewTarget;
import com.bumptech.glide.request.transition.Transition;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button btn = findViewById(R.id.my_button);
        ImageView img = findViewById(R.id.my_image);

        btn.setOnClickListener(v -> {
            RequestManager glide = Glide.with(img);
            MyCustomViewTarget target = new MyCustomViewTarget(img, glide);
            glide
                .load("bad_file_name.png")
                .into(target);
        });
    }
}

class MyCustomViewTarget extends CustomViewTarget<ImageView, Drawable> {
    private final RequestManager requestManager;
    private int counter;

    public MyCustomViewTarget(@NonNull ImageView view, RequestManager requestManager) {
        super(view);
        this.requestManager = requestManager;
        Log.e("MY_APP", "new MyCustomViewTarget");
    }

    @Override
    protected void onResourceCleared(@Nullable Drawable placeholder) {
    }

    @Override
    public void onLoadFailed(@Nullable Drawable errorDrawable) {
        Log.e("MY_APP", "onLoadFailed: " + counter++);
    }

    @Override
    public void onResourceReady(@NonNull Drawable resource, @Nullable Transition<? super Drawable> transition) {
        Log.e("MY_APP", "onResourceReady");
        this.view.setImageDrawable(resource);
    }
}

Layout XML:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <ImageView
            android:layout_width="200dp"
            android:layout_height="200dp"
            android:id="@+id/my_image" />
        <Button
            android:layout_width="200dp"
            android:layout_height="50dp"
            android:text="Hello"
            android:id="@+id/my_button" />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

https://user-images.githubusercontent.com/1096616/166216185-e2a846e1-ea54-4126-9fa7-6a7f573ef150.mp4

[sjudd]

I think Bug/Feature is exactly the right way to describe this :).

As a general rule Glide's Targets do not complete once. One example where this is more clearly a feature is when Glide restarts failed requests when it thinks the app might have regained connectivity.

You can opt-out of the lifecycle by using the application context for Glide.with, but that's not free because it removes other lifecycle integrations. It also doesn't remove the restart-on-connectivity-change behavior.

I could be convinced either way I guess. Restating failures for loads in normal Android Views seems pretty harmless. But when done for other frameworks or reasons it's easy to see why it's not what people expect.