Implement a Click Listener with RecyclerView and DataBinding

ChaMinZi · Jun 7, 2021 · 7fcd74e · 7fcd74e
1 parent 85b2b5a
commit 7fcd74e
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Showing 3 changed files with 26 additions and 6 deletions.
diff --git a/...p/src/main/java/com/example/android/trackmysleepquality/sleeptracker/SleepNightAdapter.kt b/...p/src/main/java/com/example/android/trackmysleepquality/sleeptracker/SleepNightAdapter.kt
@@ -10,8 +10,9 @@ import com.example.android.trackmysleepquality.convertDurationToFormatted
 import com.example.android.trackmysleepquality.convertNumericQualityToString
 import com.example.android.trackmysleepquality.database.SleepNight
 import com.example.android.trackmysleepquality.databinding.ListItemSleepNightBinding
+import com.example.android.trackmysleepquality.generated.callback.OnClickListener
 
-class SleepNightAdapter : ListAdapter<SleepNight,
+class SleepNightAdapter(private val clickListener:SleepNightListener) : ListAdapter<SleepNight,
         SleepNightAdapter.ViewHolder>(SleepNightDiffCallback()) {
 
     // ViewHolder 만 변경해서 다른 로직으로 바꿀 수 있게 캡슐화 됨
@@ -20,8 +21,7 @@ class SleepNightAdapter : ListAdapter<SleepNight,
     }
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
-        val item = getItem(position)
-        holder.bind(item)
+        holder.bind(getItem(position)!!, clickListener)
     }
 
     /**
@@ -30,8 +30,9 @@ class SleepNightAdapter : ListAdapter<SleepNight,
     class ViewHolder private constructor(val binding: ListItemSleepNightBinding) : RecyclerView.ViewHolder(binding.root) {
 
         // RecyclerView는 여러 타입의 ViewHolder를 지원할 수 있기 때문에 캡슐화
-        fun bind(item: SleepNight) {
+        fun bind(item: SleepNight, clickListener: SleepNightListener) {
             binding.sleep = item
+            binding.clickListener = clickListener
             binding.executePendingBindings()
         }
 
@@ -58,4 +59,15 @@ class SleepNightDiffCallback : DiffUtil.ItemCallback<SleepNight>() {
     override fun areContentsTheSame(oldItem: SleepNight, newItem: SleepNight): Boolean {
         return oldItem == newItem
     }
+}
+
+/**
+ * click 을 감지하고 클릭과 관련되어 처리해야 데이터를 fragment 에 전달합니다.
+ * click event 가 발생할 때마다 이를 fragment 에 알리는 아래의 Callback method 는 ViewHolder 가 가지고 있을 것입니다.
+ *
+ * nightId만 있어도 Database 에서 원하는 데이터에 접근할 수 있기 때문에
+ * SleepNight 객체 참조를 가지고 있을 필요는 없습니다. 따라서 sleep night id 만 파라미터로 넘겨줍니다.
+ **/
+class SleepNightListener(val clickListener: (sleepId: Long) -> Unit) {
+    fun onClick(night: SleepNight) = clickListener(night.nightId)
 }
diff --git a/...rc/main/java/com/example/android/trackmysleepquality/sleeptracker/SleepTrackerFragment.kt b/...rc/main/java/com/example/android/trackmysleepquality/sleeptracker/SleepTrackerFragment.kt
@@ -4,6 +4,7 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.Toast
 import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
@@ -50,7 +51,9 @@ class SleepTrackerFragment : Fragment() {
         binding.sleepList.layoutManager = manager
 
         // recyclerView setting
-        val adapter = SleepNightAdapter()
+        val adapter = SleepNightAdapter(SleepNightListener { nightId ->
+            Toast.makeText(context, "$nightId", Toast.LENGTH_LONG).show()
+        })
         binding.sleepList.adapter = adapter
 
         sleepTrackerViewModel.nights.observe(viewLifecycleOwner, Observer {

diff --git a/TrackmySleepQuality/app/src/main/res/layout/list_item_sleep_night.xml b/TrackmySleepQuality/app/src/main/res/layout/list_item_sleep_night.xml
@@ -7,11 +7,16 @@
         <variable
             name="sleep"
             type="com.example.android.trackmysleepquality.database.SleepNight" />
+
+        <variable
+            name="clickListener"
+            type="com.example.android.trackmysleepquality.sleeptracker.SleepNightListener" />
     </data>
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="match_parent"
-        android:layout_height="wrap_content">
+        android:layout_height="wrap_content"
+        android:onClick="@{() -> clickListener.onClick(sleep)}">
 
         <ImageView
             android:id="@+id/quality_image"