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.

Author: sjudd

integration/compose/api/compose.api

@@ -1,8 +1,21 @@
+public final class com/bumptech/glide/integration/compose/CrossFade : com/bumptech/glide/integration/compose/Transition$Factory {
+	public static final field $stable I
+	public static final field Companion Lcom/bumptech/glide/integration/compose/CrossFade$Companion;
+	public fun <init> (Landroidx/compose/animation/core/AnimationSpec;)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$Companion : com/bumptech/glide/integration/compose/Transition$Factory {
+	public fun build ()Lcom/bumptech/glide/integration/compose/Transition;
+}
+
 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$Factory;Lkotlin/jvm/functions/Function1;Landroidx/compose/runtime/Composer;III)V
 	public static final fun GlideSubcomposition (Ljava/lang/Object;Landroidx/compose/ui/Modifier;Lkotlin/jvm/functions/Function1;Lkotlin/jvm/functions/Function3;Landroidx/compose/runtime/Composer;II)V
 	public static final fun placeholder (I)Lcom/bumptech/glide/integration/compose/Placeholder;
 	public static final fun placeholder (Landroid/graphics/drawable/Drawable;)Lcom/bumptech/glide/integration/compose/Placeholder;
@@ -54,3 +67,14 @@ public final class com/bumptech/glide/integration/compose/RequestState$Success :
 	public fun toString ()Ljava/lang/String;
 }
 
+public abstract interface class com/bumptech/glide/integration/compose/Transition {
+	public abstract fun getDrawCurrent ()Lkotlin/jvm/functions/Function5;
+	public abstract fun getDrawPlaceholder ()Lkotlin/jvm/functions/Function5;
+	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

@@ -1,7 +1,5 @@
 package com.bumptech.glide.integration.compose
 
-import android.graphics.drawable.BitmapDrawable
-import android.graphics.drawable.ColorDrawable
 import android.graphics.drawable.Drawable
 import androidx.annotation.DrawableRes
 import androidx.compose.foundation.Image
@@ -15,8 +13,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.ColorFilter
 import androidx.compose.ui.graphics.DefaultAlpha
-import androidx.compose.ui.graphics.asImageBitmap
-import androidx.compose.ui.graphics.painter.BitmapPainter
 import androidx.compose.ui.graphics.painter.ColorPainter
 import androidx.compose.ui.graphics.painter.Painter
 import androidx.compose.ui.layout.ContentScale
@@ -26,10 +22,7 @@ import androidx.compose.ui.platform.LocalInspectionMode
 import com.bumptech.glide.Glide
 import com.bumptech.glide.RequestBuilder
 import com.bumptech.glide.RequestManager
-import com.bumptech.glide.integration.ktx.InternalGlideApi
 import com.bumptech.glide.load.DataSource
-import com.google.accompanist.drawablepainter.DrawablePainter
-import com.google.accompanist.drawablepainter.rememberDrawablePainter
 
 /** Mutates and returns the given [RequestBuilder] to apply relevant options. */
 public typealias RequestBuilderTransform<T> = (RequestBuilder<T>) -> RequestBuilder<T>
@@ -77,6 +70,13 @@ 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 [Transition.Factory] 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).
@@ -95,6 +95,7 @@ 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 },
 ) {
@@ -144,6 +145,7 @@ public fun GlideImage(
           contentScale,
           alpha,
           colorFilter,
+          transition,
         )
     )
   }
@@ -173,12 +175,6 @@ internal class GlideSubcompositionScopeImpl(
   override val painter: Painter
     get() = drawable?.toPainter() ?: ColorPainter(Color.Transparent)
 
-  private fun Drawable.toPainter(): Painter =
-    when (this) {
-      is BitmapDrawable -> BitmapPainter(bitmap.asImageBitmap())
-      is ColorDrawable -> ColorPainter(Color(color))
-      else -> DrawablePainter(mutate())
-    }
 }
 
 /**
@@ -253,7 +249,6 @@ public sealed class RequestState {
  * load never starting, or in an unreasonably large amount of memory being used. Loading overly
  * large images in memory can also impact scrolling performance.
  */
-@OptIn(InternalGlideApi::class)
 @ExperimentalGlideComposeApi
 @Composable
 public fun GlideSubcomposition(
@@ -325,7 +320,7 @@ private fun PreviewResourceOrDrawable(
         throw IllegalArgumentException("Composables should go through the production codepath")
     }
   Image(
-    painter = rememberDrawablePainter(drawable),
+    painter = remember(drawable) { drawable.toPainter() },
     modifier = modifier,
     contentDescription = contentDescription,
   )