fix: diff fragment lifecycle and viewLifecycleOwner (#15, #13)

hi-dhl · Jan 25, 2021 · 77ee11b · 77ee11b
1 parent eabfbf4
commit 77ee11b
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Showing 5 changed files with 84 additions and 27 deletions.
diff --git a/binding/src/main/java/androidx/lifecycle/BindingLifecycleObserver.kt b/binding/src/main/java/androidx/lifecycle/BindingLifecycleObserver.kt
@@ -0,0 +1,31 @@
+package androidx.lifecycle
+
+/**
+ * <pre>
+ *     author: dhl
+ *     date  : 2021/1/25
+ *     desc  :
+ * </pre>
+ */
+
+open class BindingLifecycleObserver : FullLifecycleObserver {
+
+    override fun onCreate(owner: LifecycleOwner) {
+    }
+
+    override fun onStart(owner: LifecycleOwner) {
+    }
+
+    override fun onResume(owner: LifecycleOwner) {
+    }
+
+    override fun onPause(owner: LifecycleOwner) {
+    }
+
+    override fun onStop(owner: LifecycleOwner) {
+    }
+
+    override fun onDestroy(owner: LifecycleOwner) {
+    }
+
+}
diff --git a/binding/src/main/java/com/hi/dhl/binding/base/ActivityDelegate.kt b/binding/src/main/java/com/hi/dhl/binding/base/ActivityDelegate.kt
@@ -7,8 +7,7 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.fragment.app.FragmentActivity
 import androidx.viewbinding.ViewBinding
 import com.hi.dhl.binding.LifecycleFragment
-import com.hi.dhl.binding.addObserver
-import com.hi.dhl.binding.registerActivityLifecycleCallbacks
+import com.hi.dhl.binding.observerWhenDestroyed
 import kotlin.properties.ReadOnlyProperty
 
 /**
@@ -28,10 +27,10 @@ abstract class ActivityDelegate<T : ViewBinding>(
 
     init {
         when (activity) {
-            is ComponentActivity -> activity.lifecycle.addObserver { destroyed() }
+            is ComponentActivity -> activity.lifecycle.observerWhenDestroyed { destroyed() }
             else -> {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-                    activity.registerActivityLifecycleCallbacks { destroyed() }
+                    activity.observerWhenDestroyed { destroyed() }
                 }
             }
         }

diff --git a/binding/src/main/java/com/hi/dhl/binding/base/DialogDelegate.kt b/binding/src/main/java/com/hi/dhl/binding/base/DialogDelegate.kt
@@ -3,7 +3,7 @@ package com.hi.dhl.binding.base
 import android.app.Dialog
 import androidx.lifecycle.Lifecycle
 import androidx.viewbinding.ViewBinding
-import com.hi.dhl.binding.addObserver
+import com.hi.dhl.binding.observerWhenDestroyed
 import kotlin.properties.ReadOnlyProperty
 
 /**
@@ -20,7 +20,7 @@ abstract class DialogDelegate<T : ViewBinding>(
     protected var viewBinding: T? = null
 
     init {
-        lifecycle?.addObserver { destroyed() }
+        lifecycle?.observerWhenDestroyed { destroyed() }
     }
 
     fun destroyed() {

diff --git a/binding/src/main/java/com/hi/dhl/binding/base/FragmentDelegate.kt b/binding/src/main/java/com/hi/dhl/binding/base/FragmentDelegate.kt
@@ -2,7 +2,8 @@ package com.hi.dhl.binding.base
 
 import androidx.fragment.app.Fragment
 import androidx.viewbinding.ViewBinding
-import com.hi.dhl.binding.addObserver
+import com.hi.dhl.binding.observerWhenCreated
+import com.hi.dhl.binding.observerWhenDestroyed
 import kotlin.properties.ReadOnlyProperty
 
 /**
@@ -19,7 +20,21 @@ abstract class FragmentDelegate<T : ViewBinding>(
     protected var viewBinding: T? = null
 
     init {
-        fragment.lifecycle.addObserver { destroyed() }
+
+        /**
+         * 感谢 architecture-components-samples 提供的思路
+         *
+         * 最原始的处理的方案 监听 Fragment 的生命周期，会存在 Fragment 和 Fragment 中的 View 生命周期不一致问题
+         * 详情查看 [issue][https://github.com/hi-dhl/Binding/issues/15]
+         */
+        fragment.lifecycle.observerWhenCreated {
+            fragment.viewLifecycleOwnerLiveData.observe(fragment) { viewOwner ->
+                viewOwner.lifecycle.observerWhenDestroyed {
+                    destroyed()
+                }
+            }
+        }
+
     }
 
     private fun destroyed() {

diff --git a/binding/src/main/java/com/hi/dhl/binding/ext/LifecycleExt.kt b/binding/src/main/java/com/hi/dhl/binding/ext/LifecycleExt.kt
@@ -6,8 +6,8 @@ import android.app.Application
 import android.app.Fragment
 import android.os.Build
 import android.os.Bundle
+import androidx.lifecycle.BindingLifecycleObserver
 import androidx.lifecycle.Lifecycle
-import androidx.lifecycle.LifecycleEventObserver
 import androidx.lifecycle.LifecycleOwner
 
 /**
@@ -18,32 +18,42 @@ import androidx.lifecycle.LifecycleOwner
  * </pre>
  */
 
-fun Lifecycle.addObserver(destroyed: () -> Unit) {
-    addObserver(LifecycleObserver(this, destroyed))
+fun Lifecycle.observerWhenDestroyed(destroyed: () -> Unit) {
+    addObserver(LifecycleObserver(lifecycle = this, destroyed = destroyed))
 }
 
-class LifecycleObserver(var lifecycle: Lifecycle?, val destroyed: () -> Unit) :
-    LifecycleEventObserver {
-    override fun onStateChanged(source: LifecycleOwner, event: Lifecycle.Event) {
-        val lifecycleState = source.lifecycle.currentState
-        if (lifecycleState == Lifecycle.State.DESTROYED) {
-            destroyed()
-            lifecycle?.apply {
-                removeObserver(this@LifecycleObserver)
-                lifecycle = null
-            }
-        }
+fun Lifecycle.observerWhenCreated(create: () -> Unit) {
+    addObserver(LifecycleObserver(lifecycle = this, create = create))
+}
+
+class LifecycleObserver(
+    var lifecycle: Lifecycle?,
+    var destroyed: (() -> Unit)? = null,
+    var create: (() -> Unit)? = null
+) : BindingLifecycleObserver() {
+
+    override fun onCreate(owner: LifecycleOwner) {
+        create?.invoke()
     }
 
+    override fun onDestroy(owner: LifecycleOwner) {
+        destroyed?.invoke()
+        lifecycle?.apply {
+            removeObserver(this@LifecycleObserver)
+            lifecycle = null
+        }
+        create = null
+        destroyed = null
+    }
 }
 
-fun Activity.registerActivityLifecycleCallbacks(destroyed: () -> Unit) {
+fun Activity.observerWhenDestroyed(destroyed: () -> Unit) {
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
         registerActivityLifecycleCallbacks(LifecycleCallbacks(destroyed))
     }
 }
 
-class LifecycleCallbacks(val destroyed: () -> Unit) :
+class LifecycleCallbacks(var destroyed: (() -> Unit)? = null) :
     Application.ActivityLifecycleCallbacks {
     override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
     }
@@ -64,15 +74,16 @@ class LifecycleCallbacks(val destroyed: () -> Unit) :
     }
 
     override fun onActivityDestroyed(activity: Activity) {
-        destroyed()
+        destroyed?.invoke()
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
             activity.unregisterActivityLifecycleCallbacks(this)
         }
+        destroyed = null
     }
 }
 
 class LifecycleFragment : Fragment {
-    lateinit var destroyed: () -> Unit
+    var destroyed: (() -> Unit)? = null
 
     constructor()
 
@@ -83,6 +94,7 @@ class LifecycleFragment : Fragment {
 
     override fun onDestroy() {
         super.onDestroy()
-        destroyed()
+        destroyed?.invoke()
+        destroyed = null
     }
 }