Intercept Picasso network calls.

app/build.gradle

@@ -5,14 +5,14 @@ apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion 29
     defaultConfig {
         applicationId "com.nekodev.paulina.sadowska.progressiveloadingdemo"
         minSdkVersion 17
-        targetSdkVersion 28
+        targetSdkVersion 29
         versionCode 1
-        versionName "1.0"
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        versionName "2.0"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
         release {
@@ -25,18 +25,28 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'com.android.support:appcompat-v7:28.0.0'
-    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
 
-    implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
-    implementation 'io.reactivex.rxjava2:rxjava:2.2.2'
+    // <editor-fold desc="Rx">
+    implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
+    implementation 'io.reactivex.rxjava2:rxjava:2.2.6'
     implementation 'io.reactivex.rxjava2:rxkotlin:2.2.0'
+    // </editor-fold>
 
+    // <editor-fold desc="Picasso">
     implementation 'com.squareup.picasso:picasso:2.71828'
-    implementation 'com.android.support:exifinterface:28.0.0'
-    //force picasso to use newer support lib version
+    implementation 'com.jakewharton.picasso:picasso2-okhttp3-downloader:1.0.2'
+    // </editor-fold>
 
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    // <editor-fold desc="Stetho">
+    implementation 'com.facebook.stetho:stetho:1.5.1'
+    implementation 'com.facebook.stetho:stetho-okhttp3:1.5.1' // for OkHttp library
+    // </editor-fold>
+
+    // <editor-fold desc="Test">
+    testImplementation 'junit:junit:4.13'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    // </editor-fold>
 }

app/src/main/java/com/nekodev/paulina/sadowska/progressiveloadingdemo/ImageLoadingApplication.kt

@@ -1,14 +1,35 @@
 package com.nekodev.paulina.sadowska.progressiveloadingdemo
 
 import android.app.Application
+import com.facebook.stetho.Stetho
+import com.facebook.stetho.okhttp3.StethoInterceptor
+import com.squareup.picasso.OkHttp3Downloader
 import com.squareup.picasso.Picasso
 import io.reactivex.plugins.RxJavaPlugins
+import okhttp3.OkHttpClient
+import java.util.concurrent.TimeUnit
+
 
 class ImageLoadingApplication : Application() {
 
     override fun onCreate() {
         super.onCreate()
+
         RxJavaPlugins.setErrorHandler(RxJavaErrorHandler())
-        Picasso.get().isLoggingEnabled = true
+
+        // open chrome://inspect/#devices on Chrome browse, then click on "inspect" link.
+        Stetho.initializeWithDefaults(this)
+
+        val client = OkHttpClient.Builder()
+                .connectTimeout(30, TimeUnit.SECONDS)
+                .addNetworkInterceptor(StethoInterceptor()) // add network interceptor
+                .build()
+
+        val instance = Picasso.Builder(this)
+                .downloader(OkHttp3Downloader(client))  // custom downloader
+                .loggingEnabled(true)
+                .build()
+
+        Picasso.setSingletonInstance(instance)
     }
 }

app/src/main/java/com/nekodev/paulina/sadowska/progressiveloadingdemo/ImageViewModel.kt

@@ -1,6 +1,7 @@
 package com.nekodev.paulina.sadowska.progressiveloadingdemo
 
-import android.arch.lifecycle.MutableLiveData
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.ImageFetcher
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.data.BitmapResult
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.data.BitmapWithQuality
@@ -17,29 +18,41 @@ class ImageViewModel {
     private val disposable = CompositeDisposable()
     private val fetcher = ImageFetcher(Picasso.get())
 
-    val bitmapResult = MutableLiveData<BitmapResult>()
+    private val _bitmapResult = MutableLiveData<BitmapResult>()
+
+    val bitmapResult: LiveData<BitmapResult>
+        get() = _bitmapResult
 
     fun loadImages(qualities: List<Int>) {
-        bitmapResult.value = BitmapResult.loading()
-        disposable.add(fetcher.loadProgressively(BASE_IMAGE_URL, qualities)
-                .filter { getCurrentQuality() < it.quality }
-                .subscribeBy(
-                        onNext = { applyImage(it) },
-                        onComplete = { postErrorIfNotSufficientQuality() }
-                ))
+        _bitmapResult.value = BitmapResult.loading()
+
+        disposable.add(
+                fetcher.loadProgressively(BASE_IMAGE_URL, qualities)
+                        .doOnSubscribe { resetImageView() }
+                        .filter { getCurrentQuality() < it.quality }
+                        .subscribeBy(
+                                onNext = { applyImage(it) },
+                                onComplete = {
+                                    postErrorIfNotSufficientQuality()
+                                }
+                        ))
+    }
+
+    private fun resetImageView() {
+        _bitmapResult.value = BitmapResult.loading()
     }
 
     private fun getCurrentQuality(): Int {
         return bitmapResult.value?.quality ?: -1
     }
 
     private fun applyImage(bitmap: BitmapWithQuality) {
-        bitmapResult.value = BitmapResult.success(bitmap)
+        _bitmapResult.value = BitmapResult.success(bitmap)
     }
-    
+
     private fun postErrorIfNotSufficientQuality() {
         if (getCurrentQuality() < 0) {
-            bitmapResult.value = BitmapResult.error()
+            _bitmapResult.value = BitmapResult.error()
         }
     }
 

app/src/main/java/com/nekodev/paulina/sadowska/progressiveloadingdemo/MainActivity.kt

@@ -1,10 +1,10 @@
 package com.nekodev.paulina.sadowska.progressiveloadingdemo
 
-import android.arch.lifecycle.Observer
 import android.graphics.Bitmap
 import android.os.Bundle
-import android.support.v7.app.AppCompatActivity
 import android.view.View
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.Observer
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.data.BitmapResult
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.data.ResponseState
 import kotlinx.android.synthetic.main.activity_main.*
@@ -17,15 +17,16 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
-        viewModel.bitmapResult.observe(this, Observer<BitmapResult> { it -> process(it) })
-        viewModel.loadImages(listOf(3000, 10, 300))
+        viewModel.bitmapResult.observe(this, Observer<BitmapResult> { process(it) })
+        btn_load_image.setOnClickListener { viewModel.loadImages(listOf(3000, 10, 300)) }
     }
 
     private fun process(result: BitmapResult?) {
         result?.let {
             when (it.state) {
                 ResponseState.LOADING -> {
                     showProgress()
+                    hideError()
                 }
                 ResponseState.ERROR -> {
                     hideProgress()
@@ -41,12 +42,17 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    private fun hideError() {
+        errorText.visibility = View.GONE
+    }
+
     private fun showImage(bitmap: Bitmap) {
         imageView.setImageBitmap(bitmap)
     }
 
     private fun showProgress() {
         loader.visibility = View.VISIBLE
+        imageView.setImageBitmap(null)
     }
 
     private fun hideProgress() {

app/src/main/java/com/nekodev/paulina/sadowska/progressiveloadingdemo/fetcher/ImageFetcher.kt

@@ -10,6 +10,8 @@ import io.reactivex.Single
  */
 class ImageFetcher(private val picasso: Picasso) {
 
+    private val pet = 237
+
     fun loadProgressively(baseUrl: String, qualities: List<Int>): Observable<BitmapWithQuality> {
         return qualities
                 .map { quality -> Pair(createUrl(baseUrl, quality), quality) }
@@ -36,6 +38,6 @@ class ImageFetcher(private val picasso: Picasso) {
                 .onErrorResumeNext(Observable.empty<BitmapWithQuality>())
     }
 
-    private fun createUrl(url: String, size: Int): String = "$url/$size/$size?image=0" //?image=0 added so image wont be random
+    private fun createUrl(url: String, size: Int): String = "$url/id/${pet}/$size/$size"
 }
 

app/src/main/java/com/nekodev/paulina/sadowska/progressiveloadingdemo/fetcher/ImageFetcherSingleSubscribe.kt

@@ -1,6 +1,8 @@
 package com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher
 
 import com.nekodev.paulina.sadowska.progressiveloadingdemo.fetcher.data.BitmapWithQuality
+import com.squareup.picasso.MemoryPolicy
+import com.squareup.picasso.NetworkPolicy
 import com.squareup.picasso.Picasso
 import com.squareup.picasso.Target
 import io.reactivex.SingleEmitter
@@ -22,6 +24,8 @@ class ImageFetcherSingleSubscribe(private val picasso: Picasso,
 
         runningTargets.add(target)
         picasso.load(url)
+                .memoryPolicy(MemoryPolicy.NO_CACHE, MemoryPolicy.NO_STORE)     // avoiding cache to force reload
+                .networkPolicy(NetworkPolicy.NO_CACHE, NetworkPolicy.NO_STORE)  // avoiding cache to force reload
                 .into(target)
     }
 

app/src/main/res/layout/activity_main.xml

@@ -1,28 +1,55 @@
 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<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">
 
+    <Button
+        android:id="@+id/btn_load_image"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="Load Image"
+        app:layout_constraintBottom_toTopOf="@+id/imageView"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
     <ProgressBar
         android:id="@+id/loader"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:layout_gravity="center" />
+        android:layout_gravity="center"
+        android:visibility="gone"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:visibility="visible" />
 
     <ImageView
         android:id="@+id/imageView"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/btn_load_image" />
 
     <TextView
         android:id="@+id/errorText"
-        android:layout_width="wrap_content"
+        android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
         android:text="@string/error_while_fetching_image"
+        android:textAlignment="center"
         android:textSize="18sp"
-        android:visibility="gone" />
+        android:visibility="gone"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:visibility="visible" />
 
-</FrameLayout>
+</androidx.constraintlayout.widget.ConstraintLayout>

build.gradle

@@ -1,13 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.3.0'
+    ext.kotlin_version = '1.3.61'
     repositories {
         google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:3.5.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong

gradle.properties

@@ -6,6 +6,8 @@
 # http://www.gradle.org/docs/current/userguide/build_environment.html
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
+android.enableJetifier=true
+android.useAndroidX=true
 org.gradle.jvmargs=-Xmx1536m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Sun Nov 11 14:52:24 CET 2018
+#Mon Jan 13 19:53:30 BRST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip