Unregistering callbacks for components when the parent fragment view is destroyed

Author: shreelakshmijoshi

DrawableAnimations/app/src/main/java/com/example/android/drawableanimations/ViewBindingDelegates.kt

@@ -16,12 +16,15 @@
 
 package com.example.android.drawableanimations
 
+import android.R
 import android.view.View
+import androidx.constraintlayout.widget.ConstraintLayout
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
 import androidx.viewbinding.ViewBinding
 
+
 /**
  * Retrieves a view binding handle in a Fragment. The field is available only after
  * [Fragment.onViewCreated].
@@ -45,12 +48,18 @@ inline fun <reified BindingT : ViewBinding> Fragment.viewBindings(
             cached = null
         }
     }
-
-    override val value: BindingT
-        get() = cached ?: bind(requireView()).also {
-            viewLifecycleOwner.lifecycle.addObserver(observer)
-            cached = it
-        }
+//    val mConstraintLayout: ConstraintLayout = findViewById(R.id.constraintLayoutParent)
+ //   var layout: View = layoutInflater.inflate(R.layout.activity_list_item, null)
+//    override val value: BindingT
+//        get() = cached ?: bind(requireView()).also {
+//            viewLifecycleOwner.lifecycle.addObserver(observer)
+//            cached = it
+//        }
+override val value: BindingT
+    get() = cached ?: bind(requireView()).also {
+        viewLifecycleOwner.lifecycle.addObserver(observer)
+        cached = it
+    }
 
     override fun isInitialized() = cached != null
 }

DrawableAnimations/app/src/main/java/com/example/android/drawableanimations/demo/animated/AnimatedFragment.kt

@@ -16,11 +16,9 @@
 
 package com.example.android.drawableanimations.demo.animated
 
-import android.content.Context
 import android.graphics.drawable.Drawable
 import android.os.Bundle
 import android.view.View
-import androidx.activity.OnBackPressedCallback
 import androidx.fragment.app.Fragment
 import androidx.vectordrawable.graphics.drawable.Animatable2Compat
 import androidx.vectordrawable.graphics.drawable.AnimatedVectorDrawableCompat
@@ -29,31 +27,21 @@ import com.example.android.drawableanimations.databinding.AnimatedFragmentBindin
 import com.example.android.drawableanimations.viewBindings
 
 class AnimatedFragment : Fragment(R.layout.animated_fragment) {
-
     private val binding by viewBindings(AnimatedFragmentBinding::bind)
-    override fun onAttach(context: Context) {
-        super.onAttach(context)
-        val callback: OnBackPressedCallback = object : OnBackPressedCallback(
-            true 
-        ) {
-            override fun handleOnBackPressed() {
-               binding.stop.performClick()
-               activity?.supportFragmentManager?.popBackStack()
-            }
-        }
-        requireActivity().onBackPressedDispatcher.addCallback(
-            this,  
-            callback
-        )
-    }
 
+    override fun onDestroyView() {
+        super.onDestroyView()
+        (binding.icon.drawable as? AnimatedVectorDrawableCompat)?.clearAnimationCallbacks()
+    }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+
         val icon = AnimatedVectorDrawableCompat.create(
             requireContext(),
             R.drawable.ic_hourglass_animated
         )!!
-        icon.registerAnimationCallback(object: Animatable2Compat.AnimationCallback() {
+
+        icon.registerAnimationCallback(object : Animatable2Compat.AnimationCallback() {
             override fun onAnimationStart(drawable: Drawable?) {
                 binding.start.isEnabled = false
                 binding.stop.isEnabled = true
@@ -69,3 +57,4 @@ class AnimatedFragment : Fragment(R.layout.animated_fragment) {
         binding.stop.setOnClickListener { icon.stop() }
     }
 }
+

DrawableAnimations/app/src/main/java/com/example/android/drawableanimations/demo/seekable/SeekableFragment.kt

@@ -20,6 +20,7 @@ import android.os.Bundle
 import android.view.View
 import android.widget.SeekBar
 import androidx.fragment.app.Fragment
+import androidx.vectordrawable.graphics.drawable.AnimatedVectorDrawableCompat
 import androidx.vectordrawable.graphics.drawable.SeekableAnimatedVectorDrawable
 import com.example.android.drawableanimations.R
 import com.example.android.drawableanimations.databinding.SeekableFragmentBinding
@@ -29,6 +30,11 @@ class SeekableFragment : Fragment(R.layout.seekable_fragment) {
 
     private val binding by viewBindings(SeekableFragmentBinding::bind)
 
+    override fun onDestroyView() {
+        super.onDestroyView()
+        (binding.icon.drawable as? AnimatedVectorDrawableCompat)?.clearAnimationCallbacks()
+    }
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         // You can use the same XML format of <animated-vector> to inflate a
         // SeekableAnimatedVectorDrawable.