Add a Transition API and a CrossFade Transition for Compose

Similar to Glide's existing Transitions, but intended for use with
Animatable instead of views. I've started with a simple CrossFade. We
probably should add at least a FadeOnTopOf (or something similar) to
mimic the existing Crossfade support.

integration/compose/api/compose.api

@@ -1,8 +1,33 @@
+public final class com/bumptech/glide/integration/compose/CrossFade : com/bumptech/glide/integration/compose/Transition {
+	public static final field $stable I
+	public static final field OPAQUE_ALPHA I
+	public synthetic fun <init> (Landroidx/compose/animation/core/AnimationSpec;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun getDrawCurrent ()Lkotlin/jvm/functions/Function2;
+	public fun getDrawPlaceholder ()Lkotlin/jvm/functions/Function2;
+	public fun stop (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun transition (Lkotlin/jvm/functions/Function0;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public final class com/bumptech/glide/integration/compose/CrossFade$Factory : com/bumptech/glide/integration/compose/Transition$Factory {
+	public static final field $stable I
+	public static final field Companion Lcom/bumptech/glide/integration/compose/CrossFade$Factory$Companion;
+	public fun <init> ()V
+	public fun <init> (Landroidx/compose/animation/core/AnimationSpec;)V
+	public synthetic fun <init> (Landroidx/compose/animation/core/AnimationSpec;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public fun build ()Lcom/bumptech/glide/integration/compose/Transition;
+	public fun equals (Ljava/lang/Object;)Z
+	public fun hashCode ()I
+}
+
+public final class com/bumptech/glide/integration/compose/CrossFade$Factory$Companion {
+	public final fun getDEFAULT ()Lcom/bumptech/glide/integration/compose/CrossFade$Factory;
+}
+
 public abstract interface annotation class com/bumptech/glide/integration/compose/ExperimentalGlideComposeApi : java/lang/annotation/Annotation {
 }
 
 public final class com/bumptech/glide/integration/compose/GlideImageKt {
-	public static final fun GlideImage (Ljava/lang/Object;Ljava/lang/String;Landroidx/compose/ui/Modifier;Landroidx/compose/ui/Alignment;Landroidx/compose/ui/layout/ContentScale;FLandroidx/compose/ui/graphics/ColorFilter;Lcom/bumptech/glide/integration/compose/Placeholder;Lcom/bumptech/glide/integration/compose/Placeholder;Lkotlin/jvm/functions/Function1;Landroidx/compose/runtime/Composer;II)V
+	public static final fun GlideImage (Ljava/lang/Object;Ljava/lang/String;Landroidx/compose/ui/Modifier;Landroidx/compose/ui/Alignment;Landroidx/compose/ui/layout/ContentScale;FLandroidx/compose/ui/graphics/ColorFilter;Lcom/bumptech/glide/integration/compose/Placeholder;Lcom/bumptech/glide/integration/compose/Placeholder;Lcom/bumptech/glide/integration/compose/Transition$Factory;Lkotlin/jvm/functions/Function1;Landroidx/compose/runtime/Composer;III)V
 	public static final fun GlideSubcomposition (Ljava/lang/Object;Landroidx/compose/ui/Modifier;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function3;Landroidx/compose/runtime/Composer;II)V
 	public static final fun placeholder (I)Lcom/bumptech/glide/integration/compose/Placeholder;
 	public static final fun placeholder (Landroid/graphics/drawable/Drawable;)Lcom/bumptech/glide/integration/compose/Placeholder;
@@ -54,3 +79,14 @@ public final class com/bumptech/glide/integration/compose/RequestState$Success :
 	public fun toString ()Ljava/lang/String;
 }
 
+public abstract interface class com/bumptech/glide/integration/compose/Transition {
+	public abstract fun getDrawCurrent ()Lkotlin/jvm/functions/Function2;
+	public abstract fun getDrawPlaceholder ()Lkotlin/jvm/functions/Function2;
+	public abstract fun stop (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public abstract fun transition (Lkotlin/jvm/functions/Function0;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public abstract interface class com/bumptech/glide/integration/compose/Transition$Factory {
+	public abstract fun build ()Lcom/bumptech/glide/integration/compose/Transition;
+}
+

integration/compose/src/main/java/com/bumptech/glide/integration/compose/GlideImage.kt

@@ -85,6 +85,13 @@ public typealias RequestBuilderTransform<T> = (RequestBuilder<T>) -> RequestBuil
  * opposed to resource id or [Drawable]), this [Placeholder] will not be used unless the `error`
  * [RequestBuilder] also fails. This parameter does not override error [RequestBuilder]s, only error
  * resource ids and/or [Drawable]s.
+ * @param transition An optional [TransitionFactory] that can animate the transition from a
+ * placeholder to a loaded image. The transition will only be called once, when the load transitions
+ * from showing the placeholder to showing the first resource. The transition will persist across
+ * multiple resources if you're using thumbnail, but will not be called for each successive resource
+ * in the request chain. The transition factory will not be called across different requests if
+ * multiple are made. The transition will not be called if you use [placeholder] or [failure] with
+ * the deprecated [Composable] API. See [CrossFade]
  */
 // TODO(judds): the API here is not particularly composeesque, we should consider alternatives
 // to RequestBuilder (though thumbnail() may make that a challenge).
@@ -104,6 +111,7 @@ public fun GlideImage(
   // See http://shortn/_x79pjkMZIH for an internal discussion.
   loading: Placeholder? = null,
   failure: Placeholder? = null,
+  transition: Transition.Factory? = null,
   // TODO(judds): Consider defaulting to load the model here instead of always doing so below.
   requestBuilderTransform: RequestBuilderTransform<Drawable> = { it },
 ) {
@@ -154,6 +162,7 @@ public fun GlideImage(
       contentScale,
       alpha,
       colorFilter,
+      transition,
     )
   }
 }
@@ -482,7 +491,8 @@ private fun ModifierGlideImage(
   alignment: Alignment,
   contentScale: ContentScale,
   alpha: Float,
-  colorFilter: ColorFilter?
+  colorFilter: ColorFilter?,
+  transitionFactory: Transition.Factory?,
 ) {
   Layout(
     {},
@@ -495,6 +505,7 @@ private fun ModifierGlideImage(
         contentScale,
         alpha,
         colorFilter,
+        transitionFactory,
       )
     ) { _, constraints ->
     layout(constraints.minWidth, constraints.minHeight) {}