Retain the image loader through configuration change

Make PreviewViewModel own an image loader instance.
This required ImagePreviewImageLoader to:
 * receive a CoroutineScope instance instead of a Lifecycle as ViewModel
   does not offer an associated Lifecycle;
 * make ImagePreviewImageLoader#loadImage to receive a caller's
   Lifecycle to avoid potential memory (Activity) leak.
With ImagePreviewImageLoader now receiving a scope, the dispatcher
argument is dropped as a scope can be configured with a proper
dispatcher.
As ChooserActivity is no longer responsible for the image loader
instantiation, to facilitate testing, a method hook to create an image
loader is replaced with a method hook to create a preview view model and
all the associated plumbing is done for the tests.

Plus some kfmt complience changes.
ImagePreviewImageLoader (and ImagePreviewImageLoaderTest) is moved into
contentpreview package as it's accessed only from within this package.

Fix: 282029067
Test: manual testing with an injected debug logging
Change-Id: I5dcdee2599714a2c51c3e1b63f5c727e43b26f6a

5 files changed, 118 insertions, 47 deletions

diff --git a/java/tests/src/com/android/intentresolver/ChooserWrapperActivity.java b/java/tests/src/com/android/intentresolver/ChooserWrapperActivity.java
index 82ba8d4d..fa934f87 100644
--- a/java/tests/src/com/android/intentresolver/ChooserWrapperActivity.java
+++ b/java/tests/src/com/android/intentresolver/ChooserWrapperActivity.java
@@ -32,10 +32,11 @@ import android.net.Uri;
 import android.os.Bundle;
 import android.os.UserHandle;
 
+import androidx.lifecycle.ViewModelProvider;
+
 import com.android.intentresolver.AbstractMultiProfilePagerAdapter.CrossProfileIntentsChecker;
 import com.android.intentresolver.chooser.DisplayResolveInfo;
 import com.android.intentresolver.chooser.TargetInfo;
-import com.android.intentresolver.contentpreview.ImageLoader;
 import com.android.intentresolver.flags.FeatureFlagRepository;
 import com.android.intentresolver.grid.ChooserGridAdapter;
 import com.android.intentresolver.shortcuts.ShortcutLoader;
@@ -194,10 +195,10 @@ public class ChooserWrapperActivity
     }
 
     @Override
-    protected ImageLoader createPreviewImageLoader() {
-        return sOverrides.imageLoader == null
-                ? super.createPreviewImageLoader()
-                : sOverrides.imageLoader;
+    protected ViewModelProvider.Factory createPreviewViewModelFactory() {
+        return TestContentPreviewViewModel.Companion.wrap(
+                super.createPreviewViewModelFactory(),
+                sOverrides.imageLoader);
     }
 
     @Override
diff --git a/java/tests/src/com/android/intentresolver/TestContentPreviewViewModel.kt b/java/tests/src/com/android/intentresolver/TestContentPreviewViewModel.kt
new file mode 100644
index 00000000..d239f612
--- /dev/null
+++ b/java/tests/src/com/android/intentresolver/TestContentPreviewViewModel.kt
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.intentresolver
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewmodel.CreationExtras
+import com.android.intentresolver.contentpreview.BasePreviewViewModel
+import com.android.intentresolver.contentpreview.ImageLoader
+import com.android.intentresolver.contentpreview.PreviewDataProvider
+
+/** A test content preview model that supports image loader override. */
+class TestContentPreviewViewModel(
+    private val viewModel: BasePreviewViewModel,
+    private val imageLoader: ImageLoader? = null,
+) : BasePreviewViewModel() {
+    override fun createOrReuseProvider(
+        chooserRequest: ChooserRequestParameters
+    ): PreviewDataProvider = viewModel.createOrReuseProvider(chooserRequest)
+
+    override fun createOrReuseImageLoader(): ImageLoader =
+        imageLoader ?: viewModel.createOrReuseImageLoader()
+
+    companion object {
+        fun wrap(
+            factory: ViewModelProvider.Factory,
+            imageLoader: ImageLoader?,
+        ): ViewModelProvider.Factory =
+            object : ViewModelProvider.Factory {
+                @Suppress("UNCHECKED_CAST")
+                override fun <T : ViewModel> create(
+                    modelClass: Class<T>,
+                    extras: CreationExtras
+                ): T {
+                    return TestContentPreviewViewModel(
+                        factory.create(modelClass, extras) as BasePreviewViewModel,
+                        imageLoader,
+                    ) as T
+                }
+            }
+    }
+}
diff --git a/java/tests/src/com/android/intentresolver/TestPreviewImageLoader.kt b/java/tests/src/com/android/intentresolver/TestPreviewImageLoader.kt
index 74a253b8..bf87ed8a 100644
--- a/java/tests/src/com/android/intentresolver/TestPreviewImageLoader.kt
+++ b/java/tests/src/com/android/intentresolver/TestPreviewImageLoader.kt
@@ -18,13 +18,12 @@ package com.android.intentresolver
 
 import android.graphics.Bitmap
 import android.net.Uri
+import androidx.lifecycle.Lifecycle
 import com.android.intentresolver.contentpreview.ImageLoader
 import java.util.function.Consumer
 
-internal class TestPreviewImageLoader(
-    private val bitmaps: Map<Uri, Bitmap>
-) : ImageLoader {
-    override fun loadImage(uri: Uri, callback: Consumer<Bitmap?>) {
+internal class TestPreviewImageLoader(private val bitmaps: Map<Uri, Bitmap>) : ImageLoader {
+    override fun loadImage(callerLifecycle: Lifecycle, uri: Uri, callback: Consumer<Bitmap?>) {
         callback.accept(bitmaps[uri])
     }
 
diff --git a/java/tests/src/com/android/intentresolver/contentpreview/ChooserContentPreviewUiTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/ChooserContentPreviewUiTest.kt
index 0bcd8423..c62f36ce 100644
--- a/java/tests/src/com/android/intentresolver/contentpreview/ChooserContentPreviewUiTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/ChooserContentPreviewUiTest.kt
@@ -39,7 +39,11 @@ class ChooserContentPreviewUiTest {
     private val headlineGenerator = mock<HeadlineGenerator>()
     private val imageLoader =
         object : ImageLoader {
-            override fun loadImage(uri: Uri, callback: Consumer<Bitmap?>) {
+            override fun loadImage(
+                callerLifecycle: Lifecycle,
+                uri: Uri,
+                callback: Consumer<Bitmap?>,
+            ) {
                 callback.accept(null)
             }
             override fun prePopulate(uris: List<Uri>) = Unit
diff --git a/java/tests/src/com/android/intentresolver/ImagePreviewImageLoaderTest.kt b/java/tests/src/com/android/intentresolver/contentpreview/ImagePreviewImageLoaderTest.kt
index 3c399cc4..184401a0 100644
--- a/java/tests/src/com/android/intentresolver/ImagePreviewImageLoaderTest.kt
+++ b/java/tests/src/com/android/intentresolver/contentpreview/ImagePreviewImageLoaderTest.kt
@@ -14,15 +14,19 @@
  * limitations under the License.
  */
 
-package com.android.intentresolver
+package com.android.intentresolver.contentpreview
 
 import android.content.ContentResolver
-import android.content.Context
-import android.content.res.Resources
 import android.graphics.Bitmap
 import android.net.Uri
 import android.util.Size
 import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.coroutineScope
+import com.android.intentresolver.TestLifecycleOwner
+import com.android.intentresolver.any
+import com.android.intentresolver.anyOrNull
+import com.android.intentresolver.mock
+import com.android.intentresolver.whenever
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineStart.UNDISPATCHED
 import kotlinx.coroutines.Dispatchers
@@ -30,6 +34,7 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.async
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.plus
 import kotlinx.coroutines.test.StandardTestDispatcher
 import kotlinx.coroutines.test.TestCoroutineScheduler
 import kotlinx.coroutines.test.UnconfinedTestDispatcher
@@ -49,28 +54,26 @@ class ImagePreviewImageLoaderTest {
     private val uriOne = Uri.parse("content://org.package.app/image-1.png")
     private val uriTwo = Uri.parse("content://org.package.app/image-2.png")
     private val bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888)
-    private val contentResolver = mock<ContentResolver> {
-        whenever(loadThumbnail(any(), any(), anyOrNull())).thenReturn(bitmap)
-    }
-    private val resources = mock<Resources> {
-        whenever(getDimensionPixelSize(R.dimen.chooser_preview_image_max_dimen))
-            .thenReturn(imageSize.width)
-    }
-    private val context = mock<Context> {
-        whenever(this.resources).thenReturn(this@ImagePreviewImageLoaderTest.resources)
-        whenever(this.contentResolver).thenReturn(this@ImagePreviewImageLoaderTest.contentResolver)
-    }
-    private val scheduler = TestCoroutineScheduler()
+    private val contentResolver =
+        mock<ContentResolver> {
+            whenever(loadThumbnail(any(), any(), anyOrNull())).thenReturn(bitmap)
+        }
     private val lifecycleOwner = TestLifecycleOwner()
-    private val dispatcher = UnconfinedTestDispatcher(scheduler)
-    private val testSubject = ImagePreviewImageLoader(
-        context, lifecycleOwner.lifecycle, 1, dispatcher
-    )
+    private val dispatcher = UnconfinedTestDispatcher()
+    private lateinit var testSubject: ImagePreviewImageLoader
 
     @Before
     fun setup() {
         Dispatchers.setMain(dispatcher)
         lifecycleOwner.state = Lifecycle.State.CREATED
+        // create test subject after we've updated the lifecycle dispatcher
+        testSubject =
+            ImagePreviewImageLoader(
+                lifecycleOwner.lifecycle.coroutineScope + dispatcher,
+                imageSize.width,
+                contentResolver,
+                1,
+            )
     }
 
     @After
@@ -110,14 +113,16 @@ class ImagePreviewImageLoaderTest {
     fun invoke_overlappedRequests_Deduplicate() = runTest {
         val scheduler = TestCoroutineScheduler()
         val dispatcher = StandardTestDispatcher(scheduler)
-        val testSubject = ImagePreviewImageLoader(context, lifecycleOwner.lifecycle, 1, dispatcher)
+        val testSubject =
+            ImagePreviewImageLoader(
+                lifecycleOwner.lifecycle.coroutineScope + dispatcher,
+                imageSize.width,
+                contentResolver,
+                1,
+            )
         coroutineScope {
-            launch(start = UNDISPATCHED) {
-                testSubject(uriOne, false)
-            }
-            launch(start = UNDISPATCHED) {
-                testSubject(uriOne, false)
-            }
+            launch(start = UNDISPATCHED) { testSubject(uriOne, false) }
+            launch(start = UNDISPATCHED) { testSubject(uriOne, false) }
             scheduler.advanceUntilIdle()
         }
 
@@ -154,11 +159,15 @@ class ImagePreviewImageLoaderTest {
     fun invoke_imageLoaderScopeClosedMidflight_throwsCancellationException() = runTest {
         val scheduler = TestCoroutineScheduler()
         val dispatcher = StandardTestDispatcher(scheduler)
-        val testSubject = ImagePreviewImageLoader(context, lifecycleOwner.lifecycle, 1, dispatcher)
+        val testSubject =
+            ImagePreviewImageLoader(
+                lifecycleOwner.lifecycle.coroutineScope + dispatcher,
+                imageSize.width,
+                contentResolver,
+                1
+            )
         coroutineScope {
-            val deferred = async(start = UNDISPATCHED) {
-                testSubject(uriOne, false)
-            }
+            val deferred = async(start = UNDISPATCHED) { testSubject(uriOne, false) }
             lifecycleOwner.state = Lifecycle.State.DESTROYED
             scheduler.advanceUntilIdle()
             deferred.await()
@@ -169,14 +178,16 @@ class ImagePreviewImageLoaderTest {
     fun invoke_multipleCallsWithDifferentCacheInstructions_cachingPrevails() = runTest {
         val scheduler = TestCoroutineScheduler()
         val dispatcher = StandardTestDispatcher(scheduler)
-        val testSubject = ImagePreviewImageLoader(context, lifecycleOwner.lifecycle, 1, dispatcher)
+        val testSubject =
+            ImagePreviewImageLoader(
+                lifecycleOwner.lifecycle.coroutineScope + dispatcher,
+                imageSize.width,
+                contentResolver,
+                1
+            )
         coroutineScope {
-            launch(start = UNDISPATCHED) {
-                testSubject(uriOne, false)
-            }
-            launch(start = UNDISPATCHED) {
-                testSubject(uriOne, true)
-            }
+            launch(start = UNDISPATCHED) { testSubject(uriOne, false) }
+            launch(start = UNDISPATCHED) { testSubject(uriOne, true) }
             scheduler.advanceUntilIdle()
         }
         testSubject(uriOne, true)