From 625c6a87073857dc2f53488c657c241cbad1a0cb Mon Sep 17 00:00:00 2001
From: Seifer <alexey.shikov@gmail.com>
Date: Mon, 27 Jan 2020 17:21:54 +0200
Subject: [PATCH] Make smooth animation of different image scale type

This fixes the case when source ImageView scale type is centerCrop or other.
So the trasnition works smooth now from centerCrop to fitCenter.
---
 .../viewer/view/TransitionImageAnimator.kt    | 26 +++++++++++++------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/imageviewer/src/main/java/com/stfalcon/imageviewer/viewer/view/TransitionImageAnimator.kt b/imageviewer/src/main/java/com/stfalcon/imageviewer/viewer/view/TransitionImageAnimator.kt
index d5e66c9..00dae7d 100644
--- a/imageviewer/src/main/java/com/stfalcon/imageviewer/viewer/view/TransitionImageAnimator.kt
+++ b/imageviewer/src/main/java/com/stfalcon/imageviewer/viewer/view/TransitionImageAnimator.kt
@@ -21,9 +21,7 @@ import android.view.ViewGroup
 import android.view.animation.DecelerateInterpolator
 import android.widget.FrameLayout
 import android.widget.ImageView
-import androidx.transition.AutoTransition
-import androidx.transition.Transition
-import androidx.transition.TransitionManager
+import androidx.transition.*
 import com.stfalcon.imageviewer.common.extensions.*
 
 internal class TransitionImageAnimator(
@@ -91,6 +89,7 @@ internal class TransitionImageAnimator(
 
             internalImageContainer.makeViewMatchParent()
             internalImage.makeViewMatchParent()
+            internalImage.scaleType = ImageView.ScaleType.FIT_CENTER
 
             internalRoot.applyMargin(
                 containerPadding[0],
@@ -126,6 +125,8 @@ internal class TransitionImageAnimator(
                 }
             }
 
+            internalImage.scaleType = it.scaleType
+
             resetRootTranslation()
         }
     }
@@ -144,9 +145,18 @@ internal class TransitionImageAnimator(
             .start()
     }
 
-    private fun createTransition(onTransitionEnd: (() -> Unit)? = null): Transition =
-        AutoTransition()
-            .setDuration(transitionDuration)
-            .setInterpolator(DecelerateInterpolator())
-            .addListener(onTransitionEnd = { onTransitionEnd?.invoke() })
+    private fun createTransition(onTransitionEnd: (() -> Unit)? = null): Transition  {
+        var transition =
+                TransitionSet ()
+                        .setOrdering(TransitionSet.ORDERING_TOGETHER)
+                        .addTransition(ChangeBounds())
+                        .addTransition(ChangeTransform())
+                        .addTransition(ChangeClipBounds())
+                        .addTransition(ChangeImageTransform())
+
+        return transition
+                .setDuration(transitionDuration)
+                .setInterpolator(DecelerateInterpolator())
+                .addListener(onTransitionEnd = { onTransitionEnd?.invoke() })
+    }
 }
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