Smooth transition when changing image on SimpleDraweeView

I have a SimpleDraweeView that is processing an image request through a controller:

Postprocessor redMeshPostprocessor = new BasePostprocessor() {
                @Override
                public String getName() {
                    return "redMeshPostprocessor";
                }

                @Override
                public CloseableReference<Bitmap> process(
                        Bitmap sourceBitmap,
                        PlatformBitmapFactory bitmapFactory) {
                    //custom processing on the bitmap and returning it

                }
            };

            ImageRequest request = ImageRequestBuilder.newBuilderWithSource(Uri.parse(coverImage))
                    .setPostprocessor(redMeshPostprocessor)
                    .build();

            PipelineDraweeController controller = (PipelineDraweeController)
                    Fresco.newDraweeControllerBuilder()
                            .setImageRequest(request)
                            .setOldController(iv_cover.getController())
                            // other setters as you need
                            .build();
            iv_cover.setController(controller);

Then later on, I want to change the image on the SimpleDraweeView by simply saying: iv_cover.setImageURI(Uri.parse(url));

Problem is that when loading the second image, there’s a split second where the SimpleDraweeView is showing the placeholder. How to avoid that? Want the transition between the 2 images to be gapless and smooth. Thanks!

[ziad-halabi9]

@massimocarli Thank you for your response. Say I have an image already cached and I want to request it but with bigger size to replace it. So what I do is I get the first cached bitmap, resize it, blur it and display it on SimpleDraweeView. In the meantime I request the image with bigger size, and when I receive it, I want to place it on the same SimpleDraweeView with a fade in animation. So I want the transition between the 2 images to be gapless, hence without showing a placeholder.

[oprisnik]

See #1328 and linked issues there.