Add crossfade between subsequent image results in AsyncImage

coil-compose-core/src/commonMain/kotlin/coil3/compose/AsyncImagePainter.kt

@@ -276,8 +276,11 @@ class AsyncImagePainter internal constructor(
 
         return request.newBuilder()
             .target(
-                onStart = { placeholder ->
-                    val painter = placeholder?.asPainter(request.context, filterQuality)
+                onStart = { placeholder, crossfadeBetweenImages ->
+                    var painter = placeholder?.asPainter(request.context, filterQuality)
+                    if (crossfadeBetweenImages && painter == null && this.painter != null) {
+                        painter = this.painter
+                    }
                     updateState(State.Loading(painter))
                 },
             )

coil-core/api/android/coil-core.api

@@ -692,8 +692,8 @@ public final class coil3/request/ImageRequest$Builder {
 	public final fun size (Lcoil3/size/Size;)Lcoil3/request/ImageRequest$Builder;
 	public final fun size (Lcoil3/size/SizeResolver;)Lcoil3/request/ImageRequest$Builder;
 	public final fun target (Lcoil3/target/Target;)Lcoil3/request/ImageRequest$Builder;
-	public final fun target (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lcoil3/request/ImageRequest$Builder;
-	public static synthetic fun target$default (Lcoil3/request/ImageRequest$Builder;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcoil3/request/ImageRequest$Builder;
+	public final fun target (Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lcoil3/request/ImageRequest$Builder;
+	public static synthetic fun target$default (Lcoil3/request/ImageRequest$Builder;Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcoil3/request/ImageRequest$Builder;
 }
 
 public final class coil3/request/ImageRequest$Defaults {
@@ -764,12 +764,16 @@ public final class coil3/request/ImageRequestsKt {
 	public static final fun allowConversionToBitmap (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
 	public static final fun crossfade (Lcoil3/ImageLoader$Builder;Z)Lcoil3/ImageLoader$Builder;
 	public static final fun crossfade (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
+	public static final fun crossfadeBetweenImages (Lcoil3/ImageLoader$Builder;Z)Lcoil3/ImageLoader$Builder;
+	public static final fun crossfadeBetweenImages (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/request/ImageRequest;)Z
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/request/Options;)Z
 	public static final fun getAllowConversionToBitmap (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getAllowConversionToBitmap (Lcoil3/request/ImageRequest;)Z
 	public static final fun getAllowConversionToBitmap (Lcoil3/request/Options;)Z
+	public static final fun getCrossfadeBetweenImages (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
+	public static final fun getCrossfadeBetweenImages (Lcoil3/request/ImageRequest;)Z
 	public static final fun getMaxBitmapSize (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getMaxBitmapSize (Lcoil3/request/ImageRequest;)Lcoil3/size/Size;
 	public static final fun getMaxBitmapSize (Lcoil3/request/Options;)Lcoil3/size/Size;
@@ -1019,12 +1023,13 @@ public abstract class coil3/target/GenericViewTarget : androidx/lifecycle/Defaul
 	public abstract fun getDrawable ()Landroid/graphics/drawable/Drawable;
 	public fun onError (Lcoil3/Image;)V
 	public fun onStart (Landroidx/lifecycle/LifecycleOwner;)V
-	public fun onStart (Lcoil3/Image;)V
+	public fun onStart (Lcoil3/Image;Z)V
 	public fun onStop (Landroidx/lifecycle/LifecycleOwner;)V
 	public fun onSuccess (Lcoil3/Image;)V
 	public abstract fun setDrawable (Landroid/graphics/drawable/Drawable;)V
 	protected final fun updateAnimation ()V
-	protected final fun updateImage (Lcoil3/Image;)V
+	protected final fun updateImage (Lcoil3/Image;Z)V
+	public static synthetic fun updateImage$default (Lcoil3/target/GenericViewTarget;Lcoil3/Image;ZILjava/lang/Object;)V
 }
 
 public class coil3/target/ImageViewTarget : coil3/target/GenericViewTarget {
@@ -1040,7 +1045,8 @@ public class coil3/target/ImageViewTarget : coil3/target/GenericViewTarget {
 
 public abstract interface class coil3/target/Target {
 	public fun onError (Lcoil3/Image;)V
-	public fun onStart (Lcoil3/Image;)V
+	public fun onStart (Lcoil3/Image;Z)V
+	public static synthetic fun onStart$default (Lcoil3/target/Target;Lcoil3/Image;ZILjava/lang/Object;)V
 	public fun onSuccess (Lcoil3/Image;)V
 }
 

coil-core/api/coil-core.klib.api

@@ -250,7 +250,7 @@ abstract interface coil3.request/Disposable { // coil3.request/Disposable|null[0
 
 abstract interface coil3.target/Target { // coil3.target/Target|null[0]
     open fun onError(coil3/Image?) // coil3.target/Target.onError|onError(coil3.Image?){}[0]
-    open fun onStart(coil3/Image?) // coil3.target/Target.onStart|onStart(coil3.Image?){}[0]
+    open fun onStart(coil3/Image?, kotlin/Boolean = ...) // coil3.target/Target.onStart|onStart(coil3.Image?;kotlin.Boolean){}[0]
     open fun onSuccess(coil3/Image) // coil3.target/Target.onSuccess|onSuccess(coil3.Image){}[0]
 }
 
@@ -644,7 +644,7 @@ final class coil3.request/ImageRequest { // coil3.request/ImageRequest|null[0]
         final fun target(coil3.target/Target?): coil3.request/ImageRequest.Builder // coil3.request/ImageRequest.Builder.target|target(coil3.target.Target?){}[0]
         final inline fun <#A2: reified kotlin/Any> fetcherFactory(coil3.fetch/Fetcher.Factory<#A2>): coil3.request/ImageRequest.Builder // coil3.request/ImageRequest.Builder.fetcherFactory|fetcherFactory(coil3.fetch.Fetcher.Factory<0:0>){0§<kotlin.Any>}[0]
         final inline fun listener(crossinline kotlin/Function1<coil3.request/ImageRequest, kotlin/Unit> = ..., crossinline kotlin/Function1<coil3.request/ImageRequest, kotlin/Unit> = ..., crossinline kotlin/Function2<coil3.request/ImageRequest, coil3.request/ErrorResult, kotlin/Unit> = ..., crossinline kotlin/Function2<coil3.request/ImageRequest, coil3.request/SuccessResult, kotlin/Unit> = ...): coil3.request/ImageRequest.Builder // coil3.request/ImageRequest.Builder.listener|listener(kotlin.Function1<coil3.request.ImageRequest,kotlin.Unit>;kotlin.Function1<coil3.request.ImageRequest,kotlin.Unit>;kotlin.Function2<coil3.request.ImageRequest,coil3.request.ErrorResult,kotlin.Unit>;kotlin.Function2<coil3.request.ImageRequest,coil3.request.SuccessResult,kotlin.Unit>){}[0]
-        final inline fun target(crossinline kotlin/Function1<coil3/Image?, kotlin/Unit> = ..., crossinline kotlin/Function1<coil3/Image?, kotlin/Unit> = ..., crossinline kotlin/Function1<coil3/Image, kotlin/Unit> = ...): coil3.request/ImageRequest.Builder // coil3.request/ImageRequest.Builder.target|target(kotlin.Function1<coil3.Image?,kotlin.Unit>;kotlin.Function1<coil3.Image?,kotlin.Unit>;kotlin.Function1<coil3.Image,kotlin.Unit>){}[0]
+        final inline fun target(crossinline kotlin/Function2<coil3/Image?, kotlin/Boolean, kotlin/Unit> = ..., crossinline kotlin/Function1<coil3/Image?, kotlin/Unit> = ..., crossinline kotlin/Function1<coil3/Image, kotlin/Unit> = ...): coil3.request/ImageRequest.Builder // coil3.request/ImageRequest.Builder.target|target(kotlin.Function2<coil3.Image?,kotlin.Boolean,kotlin.Unit>;kotlin.Function1<coil3.Image?,kotlin.Unit>;kotlin.Function1<coil3.Image,kotlin.Unit>){}[0]
     }
 
     final class Defaults { // coil3.request/ImageRequest.Defaults|null[0]
@@ -1010,6 +1010,10 @@ final val coil3.request/allowConversionToBitmap // coil3.request/allowConversion
     final fun (coil3.request/ImageRequest).<get-allowConversionToBitmap>(): kotlin/Boolean // coil3.request/allowConversionToBitmap.<get-allowConversionToBitmap>|<get-allowConversionToBitmap>@coil3.request.ImageRequest(){}[0]
 final val coil3.request/allowConversionToBitmap // coil3.request/allowConversionToBitmap|@coil3.request.Options{}allowConversionToBitmap[0]
     final fun (coil3.request/Options).<get-allowConversionToBitmap>(): kotlin/Boolean // coil3.request/allowConversionToBitmap.<get-allowConversionToBitmap>|<get-allowConversionToBitmap>@coil3.request.Options(){}[0]
+final val coil3.request/crossfadeBetweenImages // coil3.request/crossfadeBetweenImages|@coil3.Extras.Key.Companion{}crossfadeBetweenImages[0]
+    final fun (coil3/Extras.Key.Companion).<get-crossfadeBetweenImages>(): coil3/Extras.Key<kotlin/Boolean> // coil3.request/crossfadeBetweenImages.<get-crossfadeBetweenImages>|<get-crossfadeBetweenImages>@coil3.Extras.Key.Companion(){}[0]
+final val coil3.request/crossfadeBetweenImages // coil3.request/crossfadeBetweenImages|@coil3.request.ImageRequest{}crossfadeBetweenImages[0]
+    final fun (coil3.request/ImageRequest).<get-crossfadeBetweenImages>(): kotlin/Boolean // coil3.request/crossfadeBetweenImages.<get-crossfadeBetweenImages>|<get-crossfadeBetweenImages>@coil3.request.ImageRequest(){}[0]
 final val coil3.request/crossfadeMillis // coil3.request/crossfadeMillis|@coil3.request.ImageRequest{}crossfadeMillis[0]
     final fun (coil3.request/ImageRequest).<get-crossfadeMillis>(): kotlin/Int // coil3.request/crossfadeMillis.<get-crossfadeMillis>|<get-crossfadeMillis>@coil3.request.ImageRequest(){}[0]
 final val coil3.request/maxBitmapSize // coil3.request/maxBitmapSize|@coil3.Extras.Key.Companion{}maxBitmapSize[0]
@@ -1035,6 +1039,7 @@ final fun (coil3.request/ImageRequest.Builder).coil3.request/addLastModifiedToFi
 final fun (coil3.request/ImageRequest.Builder).coil3.request/allowConversionToBitmap(kotlin/Boolean): coil3.request/ImageRequest.Builder // coil3.request/allowConversionToBitmap|allowConversionToBitmap@coil3.request.ImageRequest.Builder(kotlin.Boolean){}[0]
 final fun (coil3.request/ImageRequest.Builder).coil3.request/crossfade(kotlin/Boolean): coil3.request/ImageRequest.Builder // coil3.request/crossfade|crossfade@coil3.request.ImageRequest.Builder(kotlin.Boolean){}[0]
 final fun (coil3.request/ImageRequest.Builder).coil3.request/crossfade(kotlin/Int): coil3.request/ImageRequest.Builder // coil3.request/crossfade|crossfade@coil3.request.ImageRequest.Builder(kotlin.Int){}[0]
+final fun (coil3.request/ImageRequest.Builder).coil3.request/crossfadeBetweenImages(kotlin/Boolean): coil3.request/ImageRequest.Builder // coil3.request/crossfadeBetweenImages|crossfadeBetweenImages@coil3.request.ImageRequest.Builder(kotlin.Boolean){}[0]
 final fun (coil3.request/ImageRequest.Builder).coil3.request/maxBitmapSize(coil3.size/Size): coil3.request/ImageRequest.Builder // coil3.request/maxBitmapSize|maxBitmapSize@coil3.request.ImageRequest.Builder(coil3.size.Size){}[0]
 final fun (coil3.request/ImageRequest.Builder).coil3.request/transformations(kotlin.collections/List<coil3.transform/Transformation>): coil3.request/ImageRequest.Builder // coil3.request/transformations|transformations@coil3.request.ImageRequest.Builder(kotlin.collections.List<coil3.transform.Transformation>){}[0]
 final fun (coil3.request/ImageRequest.Builder).coil3.request/transformations(kotlin/Array<out coil3.transform/Transformation>...): coil3.request/ImageRequest.Builder // coil3.request/transformations|transformations@coil3.request.ImageRequest.Builder(kotlin.Array<out|coil3.transform.Transformation>...){}[0]
@@ -1047,6 +1052,7 @@ final fun (coil3/ImageLoader.Builder).coil3.request/addLastModifiedToFileCacheKe
 final fun (coil3/ImageLoader.Builder).coil3.request/allowConversionToBitmap(kotlin/Boolean): coil3/ImageLoader.Builder // coil3.request/allowConversionToBitmap|allowConversionToBitmap@coil3.ImageLoader.Builder(kotlin.Boolean){}[0]
 final fun (coil3/ImageLoader.Builder).coil3.request/crossfade(kotlin/Boolean): coil3/ImageLoader.Builder // coil3.request/crossfade|crossfade@coil3.ImageLoader.Builder(kotlin.Boolean){}[0]
 final fun (coil3/ImageLoader.Builder).coil3.request/crossfade(kotlin/Int): coil3/ImageLoader.Builder // coil3.request/crossfade|crossfade@coil3.ImageLoader.Builder(kotlin.Int){}[0]
+final fun (coil3/ImageLoader.Builder).coil3.request/crossfadeBetweenImages(kotlin/Boolean): coil3/ImageLoader.Builder // coil3.request/crossfadeBetweenImages|crossfadeBetweenImages@coil3.ImageLoader.Builder(kotlin.Boolean){}[0]
 final fun (coil3/ImageLoader.Builder).coil3.request/maxBitmapSize(coil3.size/Size): coil3/ImageLoader.Builder // coil3.request/maxBitmapSize|maxBitmapSize@coil3.ImageLoader.Builder(coil3.size.Size){}[0]
 final fun (coil3/ImageLoader.Builder).coil3/serviceLoaderEnabled(kotlin/Boolean): coil3/ImageLoader.Builder // coil3/serviceLoaderEnabled|serviceLoaderEnabled@coil3.ImageLoader.Builder(kotlin.Boolean){}[0]
 final fun (kotlin/String).coil3/toUri(kotlin/String = ...): coil3/Uri // coil3/toUri|toUri@kotlin.String(kotlin.String){}[0]

coil-core/api/jvm/coil-core.api

@@ -609,8 +609,8 @@ public final class coil3/request/ImageRequest$Builder {
 	public final fun size (Lcoil3/size/Size;)Lcoil3/request/ImageRequest$Builder;
 	public final fun size (Lcoil3/size/SizeResolver;)Lcoil3/request/ImageRequest$Builder;
 	public final fun target (Lcoil3/target/Target;)Lcoil3/request/ImageRequest$Builder;
-	public final fun target (Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lcoil3/request/ImageRequest$Builder;
-	public static synthetic fun target$default (Lcoil3/request/ImageRequest$Builder;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcoil3/request/ImageRequest$Builder;
+	public final fun target (Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;)Lcoil3/request/ImageRequest$Builder;
+	public static synthetic fun target$default (Lcoil3/request/ImageRequest$Builder;Lkotlin/jvm/functions/Function2;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcoil3/request/ImageRequest$Builder;
 }
 
 public final class coil3/request/ImageRequest$Defaults {
@@ -681,12 +681,16 @@ public final class coil3/request/ImageRequestsKt {
 	public static final fun allowConversionToBitmap (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
 	public static final fun crossfade (Lcoil3/ImageLoader$Builder;Z)Lcoil3/ImageLoader$Builder;
 	public static final fun crossfade (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
+	public static final fun crossfadeBetweenImages (Lcoil3/ImageLoader$Builder;Z)Lcoil3/ImageLoader$Builder;
+	public static final fun crossfadeBetweenImages (Lcoil3/request/ImageRequest$Builder;Z)Lcoil3/request/ImageRequest$Builder;
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/request/ImageRequest;)Z
 	public static final fun getAddLastModifiedToFileCacheKey (Lcoil3/request/Options;)Z
 	public static final fun getAllowConversionToBitmap (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getAllowConversionToBitmap (Lcoil3/request/ImageRequest;)Z
 	public static final fun getAllowConversionToBitmap (Lcoil3/request/Options;)Z
+	public static final fun getCrossfadeBetweenImages (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
+	public static final fun getCrossfadeBetweenImages (Lcoil3/request/ImageRequest;)Z
 	public static final fun getMaxBitmapSize (Lcoil3/Extras$Key$Companion;)Lcoil3/Extras$Key;
 	public static final fun getMaxBitmapSize (Lcoil3/request/ImageRequest;)Lcoil3/size/Size;
 	public static final fun getMaxBitmapSize (Lcoil3/request/Options;)Lcoil3/size/Size;
@@ -843,7 +847,8 @@ public final class coil3/size/SizeResolverKt {
 
 public abstract interface class coil3/target/Target {
 	public fun onError (Lcoil3/Image;)V
-	public fun onStart (Lcoil3/Image;)V
+	public fun onStart (Lcoil3/Image;Z)V
+	public static synthetic fun onStart$default (Lcoil3/target/Target;Lcoil3/Image;ZILjava/lang/Object;)V
 	public fun onSuccess (Lcoil3/Image;)V
 }
 

coil-core/src/androidInstrumentedTest/kotlin/coil3/RealImageLoaderAndroidTest.kt

@@ -231,7 +231,7 @@ class RealImageLoaderAndroidTest {
                 .error(error)
                 .fallback(fallback)
                 .target(
-                    onStart = { throw IllegalStateException() },
+                    onStart = { _, _ -> throw IllegalStateException() },
                     onError = { drawable ->
                         check(drawable === fallback)
                         hasCalledTargetOnError = true
@@ -271,9 +271,9 @@ class RealImageLoaderAndroidTest {
                 .allowHardware(true)
                 .coroutineContext(EmptyCoroutineContext)
                 .target(
-                    onStart = {
+                    onStart = { placeholder, _ ->
                         // The drawable in the memory cache should be returned here.
-                        assertEquals(bitmap, (it as BitmapImage).bitmap)
+                        assertEquals(bitmap, (placeholder as BitmapImage).bitmap)
                     },
                     onSuccess = {
                         // The same drawable should be returned since the drawable is valid for this request.

coil-core/src/androidMain/kotlin/coil3/target/GenericViewTarget.kt

@@ -26,7 +26,7 @@ abstract class GenericViewTarget<T : View> : ViewTarget<T>, TransitionTarget, De
      */
     abstract override var drawable: Drawable?
 
-    override fun onStart(placeholder: Image?) = updateImage(placeholder)
+    override fun onStart(placeholder: Image?, crossfadeBetweenImages: Boolean) = updateImage(placeholder, crossfadeBetweenImages)
 
     override fun onError(error: Image?) = updateImage(error)
 
@@ -43,8 +43,12 @@ abstract class GenericViewTarget<T : View> : ViewTarget<T>, TransitionTarget, De
     }
 
     /** Replace the [ImageView]'s current image with [image]. */
-    protected fun updateImage(image: Image?) {
-        val drawable = image?.asDrawable(view.resources)
+    protected fun updateImage(image: Image?, crossfadeBetweenImages: Boolean = false) {
+        var drawable = image?.asDrawable(view.resources)
+        if (drawable == null && crossfadeBetweenImages) {
+            drawable = this.drawable
+        }
+
         (this.drawable as? Animatable)?.stop()
         this.drawable = drawable
         updateAnimation()

coil-core/src/androidUnitTest/kotlin/coil3/transition/CrossfadeTransitionTest.kt

@@ -105,13 +105,13 @@ class CrossfadeTransitionTest : RobolectricTest() {
 
     private inline fun createTransitionTarget(
         imageView: ImageView = ImageView(context),
-        crossinline onStart: (placeholder: Image?) -> Unit = { fail() },
+        crossinline onStart: (placeholder: Image?, crossfadeBetweenImages: Boolean) -> Unit = { _, _ -> fail() },
         crossinline onError: (error: Image?) -> Unit = { fail() },
-        crossinline onSuccess: (result: Image) -> Unit = { fail() }
+        crossinline onSuccess: (result: Image) -> Unit = { fail() },
     ) = object : TransitionTarget {
         override val view = imageView
         override val drawable: Drawable? get() = imageView.drawable
-        override fun onStart(placeholder: Image?) = onStart(placeholder)
+        override fun onStart(placeholder: Image?, crossfadeBetweenImages: Boolean) = onStart(placeholder, crossfadeBetweenImages)
         override fun onError(error: Image?) = onError(error)
         override fun onSuccess(result: Image) = onSuccess(result)
     }

coil-core/src/commonMain/kotlin/coil3/RealImageLoader.kt

@@ -19,6 +19,7 @@ import coil3.request.NullRequestData
 import coil3.request.NullRequestDataException
 import coil3.request.RequestService
 import coil3.request.SuccessResult
+import coil3.request.crossfadeBetweenImages
 import coil3.target.Target
 import coil3.util.ErrorResult
 import coil3.util.FetcherServiceLoaderTarget
@@ -119,7 +120,10 @@ internal class RealImageLoader(
 
             // Set the placeholder on the target.
             val cachedPlaceholder = request.placeholderMemoryCacheKey?.let { memoryCache?.get(it)?.image }
-            request.target?.onStart(placeholder = cachedPlaceholder ?: request.placeholder())
+            request.target?.onStart(
+                placeholder = cachedPlaceholder ?: request.placeholder(),
+                crossfadeBetweenImages = request.crossfadeBetweenImages,
+            )
             eventListener.onStart(request)
             request.listener?.onStart(request)