feat(FeedDetailActivity): 댓글 하이라이팅 기능 구현

android/2023-emmsale/app/src/main/java/com/emmsale/presentation/common/layoutManager/CenterSmoothScroller.kt

@@ -0,0 +1,19 @@
+package com.emmsale.presentation.common.layoutManager
+
+import android.content.Context
+import androidx.recyclerview.widget.LinearSmoothScroller
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+
+class CenterSmoothScroller @Inject constructor(
+    @ApplicationContext context: Context,
+) : LinearSmoothScroller(context) {
+
+    override fun calculateDtToFit(
+        viewStart: Int,
+        viewEnd: Int,
+        boxStart: Int,
+        boxEnd: Int,
+        snapPreference: Int,
+    ): Int = (boxStart + (boxEnd - boxStart) / 2) - (viewStart + (viewEnd - viewStart) / 2)
+}

android/2023-emmsale/app/src/main/java/com/emmsale/presentation/common/layoutManager/EndSmoothScroller.kt

@@ -0,0 +1,13 @@
+package com.emmsale.presentation.common.layoutManager
+
+import android.content.Context
+import androidx.recyclerview.widget.LinearSmoothScroller
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+
+class EndSmoothScroller @Inject constructor(
+    @ApplicationContext context: Context,
+) : LinearSmoothScroller(context) {
+
+    override fun getVerticalSnapPreference(): Int = SNAP_TO_END
+}

android/2023-emmsale/app/src/main/java/com/emmsale/presentation/ui/feedDetail/FeedDetailActivity.kt

@@ -5,14 +5,15 @@ import android.content.Intent
 import android.os.Bundle
 import androidx.activity.viewModels
 import androidx.lifecycle.lifecycleScope
-import androidx.recyclerview.widget.LinearSmoothScroller
 import com.emmsale.R
 import com.emmsale.data.model.Comment
 import com.emmsale.databinding.ActivityFeedDetailBinding
 import com.emmsale.presentation.base.NetworkActivity
 import com.emmsale.presentation.common.extension.hideKeyboard
 import com.emmsale.presentation.common.extension.showKeyboard
 import com.emmsale.presentation.common.extension.showSnackBar
+import com.emmsale.presentation.common.layoutManager.CenterSmoothScroller
+import com.emmsale.presentation.common.layoutManager.EndSmoothScroller
 import com.emmsale.presentation.common.recyclerView.DividerItemDecoration
 import com.emmsale.presentation.common.views.InfoDialog
 import com.emmsale.presentation.common.views.WarningDialog
@@ -26,6 +27,7 @@ import com.emmsale.presentation.ui.profile.ProfileActivity
 import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
+import javax.inject.Inject
 
 @AndroidEntryPoint
 class FeedDetailActivity :
@@ -37,6 +39,12 @@ class FeedDetailActivity :
 
     override val viewModel: FeedDetailViewModel by viewModels()
 
+    @Inject
+    lateinit var centerSmoothScroller: CenterSmoothScroller
+
+    @Inject
+    lateinit var endSmoothScroller: EndSmoothScroller
+
     private val bottomMenuDialog: BottomMenuDialog by lazy { BottomMenuDialog(this) }
 
     private val feedAndCommentsAdapter = FeedAndCommentsAdapter(
@@ -71,9 +79,21 @@ class FeedDetailActivity :
 
     private fun BottomMenuDialog.addCommentUpdateButton(commentId: Long) {
         addMenuItemBelow(context.getString(R.string.all_update_button_label)) {
-            viewModel.startEditComment(commentId)
             binding.stiwCommentUpdate.requestFocusOnEditText()
             showKeyboard()
+            viewModel.startEditComment(commentId)
+            startToEditComment(commentId)
+        }
+    }
+
+    private fun startToEditComment(commentId: Long) {
+        val position = getCommentPosition(commentId) + 1 // 게시글을 포함한 멀티 뷰 타입 리사이클러 뷰라서 1을 더함
+
+        lifecycleScope.launch {
+            delay(KEYBOARD_SHOW_WAITING_TIME)
+            binding.rvFeedAndComments
+                .layoutManager
+                ?.startSmoothScroll(endSmoothScroller.apply { targetPosition = position })
         }
     }
 
@@ -212,17 +232,39 @@ class FeedDetailActivity :
     private fun observeFeedDetail() {
         viewModel.feedDetailUiState.observe(this) {
             val feedAndComments = listOf(it.feedUiState) + it.commentsUiState.commentUiStates
-            feedAndCommentsAdapter.submitList(feedAndComments) {
-                if (highlightCommentId == INVALID_COMMENT_ID || isNotRealFirstFetch()) return@submitList
-                viewModel.highlightComment(highlightCommentId)
-                viewModel.isAlreadyFirstFetched = true
-            }
+            feedAndCommentsAdapter.submitList(feedAndComments) { handleHighlightComment() }
         }
     }
 
-    private fun isNotRealFirstFetch(): Boolean =
+    private fun handleHighlightComment() {
+        if (highlightCommentId == INVALID_COMMENT_ID || isNotRealFirstEnter()) return
+
+        viewModel.isAlreadyFirstFetched = true
+        viewModel.highlightCommentOnFirstEnter(highlightCommentId)
+        highlightCommentOnFirstEnter()
+    }
+
+    private fun isNotRealFirstEnter(): Boolean =
         viewModel.isAlreadyFirstFetched || viewModel.commentUiStates.isEmpty()
 
+    private fun highlightCommentOnFirstEnter() {
+        val position =
+            getCommentPosition(highlightCommentId) + 1 // 게시글을 포함한 멀티 뷰 타입 리사이클러 뷰라서 1을 더함
+
+        binding.rvFeedAndComments.scrollToPosition(position)
+        lifecycleScope.launch {
+            delay(100L) // 버그 때문에
+            binding.rvFeedAndComments
+                .layoutManager
+                ?.startSmoothScroll(centerSmoothScroller.apply { targetPosition = position })
+        }
+    }
+
+    private fun getCommentPosition(commentId: Long): Int = viewModel.commentUiStates
+        .indexOfFirst { commentUiState ->
+            commentUiState.comment.id == commentId
+        }
+
     private fun observeUiEvent() {
         viewModel.uiEvent.observe(this, ::handleUiEvent)
     }
@@ -274,8 +316,6 @@ class FeedDetailActivity :
                 binding.btiwCommentPost.clearText()
                 scrollToLastPosition()
             }
-
-            is FeedDetailUiEvent.CommentHighlight -> highlightComment(uiEvent.commentId)
         }
     }
 
@@ -284,26 +324,10 @@ class FeedDetailActivity :
         binding.rvFeedAndComments.smoothScrollToPosition(commentsCount)
     }
 
-    private fun highlightComment(commentId: Long) {
-        val position = viewModel.commentUiStates
-            .indexOfFirst {
-                it.comment.id == commentId
-            }
-
-        binding.rvFeedAndComments.scrollToPosition(position + 1)
-        lifecycleScope.launch {
-            delay(200L)
-            binding.rvFeedAndComments.layoutManager?.startSmoothScroll(
-                object : LinearSmoothScroller(this@FeedDetailActivity) {
-                    override fun getVerticalSnapPreference(): Int = SNAP_TO_START
-                }.apply { targetPosition = position + 1 },
-            )
-        }
-    }
-
     companion object {
         private const val KEY_HIGHLIGHT_COMMENT_ID = "KEY_HIGHLIGHT_COMMENT_ID"
         private const val INVALID_COMMENT_ID: Long = -1
+        private const val KEYBOARD_SHOW_WAITING_TIME = 300L
 
         fun startActivity(
             context: Context,

android/2023-emmsale/app/src/main/java/com/emmsale/presentation/ui/feedDetail/FeedDetailViewModel.kt

@@ -28,6 +28,7 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import javax.inject.Inject
 import kotlin.properties.Delegates
@@ -69,6 +70,8 @@ class FeedDetailViewModel @Inject constructor(
     private val _canSubmitComment = NotNullMutableLiveData(true)
     val canSubmitComment: NotNullLiveData<Boolean> = _canSubmitComment
 
+    private var unhighlightJob: Job? = null
+
     private val _uiEvent = SingleLiveEvent<FeedDetailUiEvent>()
     val uiEvent: LiveData<FeedDetailUiEvent> = _uiEvent
 
@@ -198,12 +201,21 @@ class FeedDetailViewModel @Inject constructor(
 
     fun startEditComment(commentId: Long) {
         _editingCommentId.value = commentId
-        highlightComment(commentId)
+        unhighlightJob?.cancel()
+        _feedDetailUiState.value = _feedDetailUiState.value.highlightComment(commentId)
     }
 
     fun cancelEditComment() {
         _editingCommentId.value = null
-        unhighlightComment()
+        _feedDetailUiState.value = _feedDetailUiState.value.unhighlightComment()
+    }
+
+    fun highlightCommentOnFirstEnter(commentId: Long) {
+        _feedDetailUiState.value = _feedDetailUiState.value.highlightComment(commentId)
+        unhighlightJob = viewModelScope.launch {
+            delay(COMMENT_HIGHLIGHTING_DURATION_ON_FIRST_ENTER)
+            _feedDetailUiState.value = _feedDetailUiState.value.unhighlightComment()
+        }
     }
 
     fun reportComment(commentId: Long): Job = command(
@@ -223,20 +235,13 @@ class FeedDetailViewModel @Inject constructor(
         },
     )
 
-    fun highlightComment(commentId: Long) {
-        _feedDetailUiState.value = _feedDetailUiState.value.highlightComment(commentId)
-        _uiEvent.value = FeedDetailUiEvent.CommentHighlight(commentId)
-    }
-
-    private fun unhighlightComment() {
-        _feedDetailUiState.value = _feedDetailUiState.value.unhighlightComment()
-    }
-
     companion object {
         const val KEY_FEED_ID: String = "KEY_FEED_ID"
         private const val DEFAULT_FEED_ID: Long = -1
 
         private const val DELETED_FEED_FETCH_ERROR_CODE = 403
         private const val REPORT_DUPLICATE_ERROR_CODE = 400
+
+        private const val COMMENT_HIGHLIGHTING_DURATION_ON_FIRST_ENTER = 2000L
     }
 }

android/2023-emmsale/app/src/main/java/com/emmsale/presentation/ui/feedDetail/uiState/FeedDetailUiEvent.kt

@@ -11,5 +11,4 @@ sealed interface FeedDetailUiEvent {
     object CommentReportFail : FeedDetailUiEvent
     object CommentReportComplete : FeedDetailUiEvent
     object CommentPostComplete : FeedDetailUiEvent
-    data class CommentHighlight(val commentId: Long) : FeedDetailUiEvent
 }