Added functionality to display partial images instead of placeholder …

…if in cache

Reviewed By: kartavya-ramnani

Differential Revision: D58424402

fbshipit-source-id: de4434e90c7c785ca7317b36033ac9b308652644

vito/core-impl/src/main/java/com/facebook/fresco/vito/core/impl/KFrescoController.kt

@@ -174,16 +174,24 @@ class KFrescoController(
 
       // Check if the image is in cache
       val cachedImage = vitoImagePipeline.getCachedImage(imageRequest)
-      if (drawable.setActualImage(imageRequest, cachedImage)) {
+
+      val isIntermediateImage =
+          config.useIntermediateImagesAsPlaceholder() &&
+              cachedImage?.get()?.qualityInfo?.isOfFullQuality != true
+      val hasImage = drawable.setActualImage(imageRequest, cachedImage, isIntermediateImage)
+      if (hasImage && !isIntermediateImage) {
+        // Immediately return since we have the full image
         return true
       }
 
-      // The image is not in cache -> Set up layers visible until the image is available
-      drawable.placeholderLayer.setPlaceholder(imageRequest.resources, options)
-      drawable.listenerManager.onPlaceholderSet(
-          imageId, imageRequest, drawable.placeholderLayer.getDataModel().maybeGetDrawable())
+      if (!hasImage) {
+        // The image is not in cache -> Set up layers visible until the image is available
+        drawable.placeholderLayer.setPlaceholder(imageRequest.resources, options)
+        drawable.listenerManager.onPlaceholderSet(
+            imageId, imageRequest, drawable.placeholderLayer.getDataModel().maybeGetDrawable())
 
-      drawable.setupProgressLayer(imageRequest.resources, options)
+        drawable.setupProgressLayer(imageRequest.resources, options)
+      }
 
       // Fetch the image
       lightweightBackgroundThreadExecutor.execute {
@@ -243,7 +251,8 @@ class KFrescoController(
    */
   private fun KFrescoVitoDrawable.setActualImage(
       imageRequest: VitoImageRequest,
-      imageReference: CloseableReference<CloseableImage>?
+      imageReference: CloseableReference<CloseableImage>?,
+      isIntermediateImage: Boolean = false,
   ): Boolean {
     traceSection("KFrescoController#setActualImage") {
       try {
@@ -258,13 +267,17 @@ class KFrescoController(
             // TODO(T105148151): trigger listeners
             invalidateSelf()
             val imageInfo = image.imageInfo
-            listenerManager.onFinalImageSet(
-                imageId,
-                imageRequest,
-                ImageOrigin.MEMORY_BITMAP_SHORTCUT,
-                imageInfo,
-                obtainExtras(null, imageReference),
-                actualImageDrawable)
+            if (isIntermediateImage) {
+              listenerManager.onIntermediateImageSet(imageId, imageRequest, imageInfo)
+            } else {
+              listenerManager.onFinalImageSet(
+                  imageId,
+                  imageRequest,
+                  ImageOrigin.MEMORY_BITMAP_SHORTCUT,
+                  imageInfo,
+                  obtainExtras(null, imageReference),
+                  actualImageDrawable)
+            }
             debugOverlayHandler?.update(this)
             return true
           }

vito/core-java-impl/src/main/java/com/facebook/fresco/vito/core/impl/FrescoController2Impl.kt

@@ -4,6 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
+
 package com.facebook.fresco.vito.core.impl
 
 import android.graphics.Bitmap
@@ -185,26 +186,37 @@ open class FrescoController2Impl(
 
     // Check if the image is in cache
     val cachedImage = mImagePipeline.getCachedImage(imageRequest)
+    var needsPlaceholderDrawable = true
     try {
       if (CloseableReference.isValid(cachedImage)) {
         frescoDrawable.imageOrigin = ImageOrigin.MEMORY_BITMAP_SHORTCUT
+        val isIntermediateImage =
+            mConfig.useIntermediateImagesAsPlaceholder() &&
+                cachedImage?.get()?.qualityInfo?.isOfFullQuality != true
         // Immediately display the actual image.
-        setActualImage(frescoDrawable, imageRequest, cachedImage, true, null)
+        setActualImage(frescoDrawable, imageRequest, cachedImage, true, null, isIntermediateImage)
         frescoDrawable.setFetchSubmitted(true)
         mDebugOverlayFactory.update(frescoDrawable, extras)
-        return true
+        if (!isIntermediateImage) {
+          return true
+        } else {
+          // We are displaying an intermediate image and can skip setting up the placeholder
+          needsPlaceholderDrawable = false
+        }
       }
     } finally {
       CloseableReference.closeSafely(cachedImage)
     }
 
-    // The image is not in cache -> Set up layers visible until the image is available
-    frescoDrawable.setProgressDrawable(
-        mHierarcher.buildProgressDrawable(imageRequest.resources, imageRequest.imageOptions))
-    // Immediately show the progress image and set progress to 0
-    frescoDrawable.setProgress(0f)
-    frescoDrawable.showProgressImmediately()
-    setUpPlaceholder(frescoDrawable, imageRequest, imageId)
+    if (!needsPlaceholderDrawable) {
+      // The image is not in cache -> Set up layers visible until the image is available
+      frescoDrawable.setProgressDrawable(
+          mHierarcher.buildProgressDrawable(imageRequest.resources, imageRequest.imageOptions))
+      // Immediately show the progress image and set progress to 0
+      frescoDrawable.setProgress(0f)
+      frescoDrawable.showProgressImmediately()
+      setUpPlaceholder(frescoDrawable, imageRequest, imageId)
+    }
 
     // Fetch the image
     val fetchRunnable = Runnable {
@@ -286,8 +298,9 @@ open class FrescoController2Impl(
       drawable: FrescoDrawable2Impl,
       imageRequest: VitoImageRequest,
       image: CloseableReference<CloseableImage>?,
-      isImmediate: Boolean,
-      dataSource: DataSource<CloseableReference<CloseableImage>>?
+      displayImmediately: Boolean,
+      dataSource: DataSource<CloseableReference<CloseableImage>>?,
+      isIntermediateImage: Boolean = false,
   ) {
     val actualImageWrapperDrawable = drawable.actualImageWrapper
     mHierarcher.setupActualImageWrapper(
@@ -297,7 +310,7 @@ open class FrescoController2Impl(
             imageRequest.resources, imageRequest.imageOptions, image!!)
     actualImageWrapperDrawable.setCurrent(actualDrawable ?: NopDrawable)
     drawable.setImage(actualImageWrapperDrawable, image)
-    if (isImmediate || imageRequest.imageOptions.fadeDurationMs <= 0) {
+    if (displayImmediately || imageRequest.imageOptions.fadeDurationMs <= 0) {
       drawable.showImageImmediately()
     } else {
       drawable.fadeInImage(imageRequest.imageOptions.fadeDurationMs)
@@ -307,13 +320,13 @@ open class FrescoController2Impl(
     }
     val extras = obtainExtras(dataSource, image, drawable)
     val imageInfo = image.get().imageInfo
-    if (notifyFinalResult(dataSource)) {
+    if (!isIntermediateImage && notifyFinalResult(dataSource)) {
       drawable.internalListener.onFinalImageSet(
           drawable.imageId, imageRequest, drawable.imageOrigin, imageInfo, extras, actualDrawable)
     } else {
       drawable.internalListener.onIntermediateImageSet(drawable.imageId, imageRequest, imageInfo)
     }
-    drawable.imagePerfListener.onImageSuccess(drawable, isImmediate)
+    drawable.imagePerfListener.onImageSuccess(drawable, displayImmediately)
     var progress = 1f
     if (dataSource != null && !dataSource.isFinished) {
       progress = dataSource.progress

vito/core/src/main/java/com/facebook/fresco/vito/core/DefaultFrescoVitoConfig.kt

@@ -38,6 +38,8 @@ constructor(override val prefetchConfig: PrefetchConfig = DefaultPrefetchConfig(
 
   override fun handleImageResultInBackground(): Boolean = false
 
+  override fun useIntermediateImagesAsPlaceholder(): Boolean = false
+
   open class DefaultPrefetchConfig : PrefetchConfig {
     override fun prefetchInOnPrepare(): Boolean = true
 

vito/core/src/main/java/com/facebook/fresco/vito/core/FrescoVitoConfig.kt

@@ -33,4 +33,6 @@ interface FrescoVitoConfig {
   fun enableWindowWideColorGamut(): Boolean
 
   fun handleImageResultInBackground(): Boolean
+
+  fun useIntermediateImagesAsPlaceholder(): Boolean
 }