fix(#304): 뒤로 가기 시 OnBackPressedCallback을 활용한 CrdtTree 클리어

Co-authored-by: yang1318 <[email protected]>
Co-authored-by: jaehan4707 <[email protected]>

AOS/app/src/main/java/boostcamp/and07/mindsync/ui/mindmap/MindMapFragment.kt

@@ -1,6 +1,10 @@
 package boostcamp.and07.mindsync.ui.mindmap
 
+import android.content.Context
+import android.content.res.Configuration
+import android.os.Bundle
 import android.util.Log
+import androidx.activity.OnBackPressedCallback
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.repeatOnLifecycle
@@ -38,6 +42,18 @@ class MindMapFragment :
     }
     private lateinit var mindMapContainer: MindMapContainer
     private val args: MindMapFragmentArgs by navArgs()
+    private var isBack = false
+
+    override fun onAttach(context: Context) {
+        super.onAttach(context)
+        val callback = object : OnBackPressedCallback(true) {
+            override fun handleOnBackPressed() {
+                isBack = true
+                findNavController().popBackStack()
+            }
+        }
+        requireActivity().onBackPressedDispatcher.addCallback(this, callback)
+    }
 
     override fun initView() {
         setupRootNode()
@@ -165,4 +181,11 @@ class MindMapFragment :
     ) {
         mindMapViewModel.moveNode(tree, target, parent)
     }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        if (isBack) {
+            mindMapViewModel.clearTree()
+        }
+    }
 }

AOS/app/src/main/java/boostcamp/and07/mindsync/ui/mindmap/MindMapViewModel.kt

@@ -30,186 +30,191 @@ import javax.inject.Inject
 
 @HiltViewModel
 class MindMapViewModel
-    @Inject
-    constructor() : ViewModel() {
-        private var boardId: String = ""
-        val crdtTree = CrdtTree(id = IdGenerator.makeRandomNodeId(), tree = Tree())
-        private var _selectedNode = MutableStateFlow<Node?>(null)
-        val selectedNode: StateFlow<Node?> = _selectedNode
-        private val _operation = MutableStateFlow<Operation?>(null)
-        val operation: StateFlow<Operation?> = _operation
-        private val mindMapSocketManager = MindMapSocketManager()
-        private val _socketState = MutableStateFlow(SocketState.DISCONNECT)
-        val socketState: StateFlow<SocketState> = _socketState
-        private val _socketEvent = MutableStateFlow<SocketEvent?>(null)
-        val socketEvent: StateFlow<SocketEvent?> = _socketEvent
-        private val _operationType = MutableStateFlow("")
-        val operationType: StateFlow<String> = _operationType
-
-        init {
-            setSocketState()
-            setSocketEvent()
-        }
+@Inject
+constructor() : ViewModel() {
+    private var boardId: String = ""
+    var crdtTree = CrdtTree(id = IdGenerator.makeRandomNodeId(), tree = Tree())
+    private var _selectedNode = MutableStateFlow<Node?>(null)
+    val selectedNode: StateFlow<Node?> = _selectedNode
+    private val _operation = MutableStateFlow<Operation?>(null)
+    val operation: StateFlow<Operation?> = _operation
+    private val mindMapSocketManager = MindMapSocketManager()
+    private val _socketState = MutableStateFlow(SocketState.DISCONNECT)
+    val socketState: StateFlow<SocketState> = _socketState
+    private val _socketEvent = MutableStateFlow<SocketEvent?>(null)
+    val socketEvent: StateFlow<SocketEvent?> = _socketEvent
+    private val _operationType = MutableStateFlow("")
+    val operationType: StateFlow<String> = _operationType
+
+    init {
+        setSocketState()
+        setSocketEvent()
+    }
 
-        fun setBoard(
-            boardId: String,
-            boardName: String,
-        ) {
-            if (this.boardId != boardId) {
-                this.boardId = boardId
-                joinBoard(boardId, boardName)
-                updateNode(crdtTree.tree.getRootNode().copy(description = boardName))
-            }
+    fun setBoard(
+        boardId: String,
+        boardName: String,
+    ) {
+        if (this.boardId != boardId) {
+            this.boardId = boardId
+            joinBoard(boardId, boardName)
+            updateNode(crdtTree.tree.getRootNode().copy(description = boardName))
         }
+    }
 
-        private fun setSocketState() {
-            viewModelScope.launch {
-                mindMapSocketManager.listenState().collectLatest { state ->
-                    _socketState.value = state
-                }
+    private fun setSocketState() {
+        viewModelScope.launch {
+            mindMapSocketManager.listenState().collectLatest { state ->
+                _socketState.value = state
             }
         }
+    }
+
+    private fun setSocketEvent() {
+        viewModelScope.launch {
+            mindMapSocketManager.listenEvent().collectLatest { event ->
+                _socketEvent.value = event
+                when (event.eventType) {
+                    SocketEventType.OPERATION_FROM_SERVER -> {
+                        when (val operation = event.operation) {
+                            is SerializedOperation -> {
+                                applyOperation(operation)
+                            }
 
-        private fun setSocketEvent() {
-            viewModelScope.launch {
-                mindMapSocketManager.listenEvent().collectLatest { event ->
-                    _socketEvent.value = event
-                    when (event.eventType) {
-                        SocketEventType.OPERATION_FROM_SERVER -> {
-                            when (val operation = event.operation) {
-                                is SerializedOperation -> {
-                                    applyOperation(operation)
-                                }
-
-                                is SerializedCrdtTree -> {
-                                    applyOperation(operation)
-                                }
+                            is SerializedCrdtTree -> {
+                                applyOperation(operation)
                             }
                         }
                     }
                 }
             }
         }
+    }
 
-        fun joinBoard(
-            boardId: String,
-            boardName: String,
-        ) {
-            mindMapSocketManager.joinBoard(boardId, boardName)
-        }
+    fun joinBoard(
+        boardId: String,
+        boardName: String,
+    ) {
+        mindMapSocketManager.joinBoard(boardId, boardName)
+    }
 
-        fun addNode(
-            parent: Node,
-            addNode: RectangleNode,
-        ) {
-            val addOperation =
-                crdtTree.generateOperationAdd(addNode.id, parent.id, addNode.description)
-            crdtTree.applyOperation(addOperation)
-            _operation.value = addOperation
-            requestUpdateMindMap(operation = addOperation)
-        }
+    fun addNode(
+        parent: Node,
+        addNode: RectangleNode,
+    ) {
+        val addOperation =
+            crdtTree.generateOperationAdd(addNode.id, parent.id, addNode.description)
+        crdtTree.applyOperation(addOperation)
+        _operation.value = addOperation
+        requestUpdateMindMap(operation = addOperation)
+    }
 
-        fun removeNode(target: Node) {
-            _selectedNode.value = null
-            val removeOperation = crdtTree.generateOperationDelete(target.id)
-            crdtTree.applyOperation(removeOperation)
-            _operation.value = removeOperation
-            requestUpdateMindMap(operation = removeOperation)
-        }
+    fun removeNode(target: Node) {
+        _selectedNode.value = null
+        val removeOperation = crdtTree.generateOperationDelete(target.id)
+        crdtTree.applyOperation(removeOperation)
+        _operation.value = removeOperation
+        requestUpdateMindMap(operation = removeOperation)
+    }
 
-        fun moveNode(
-            tree: Tree,
-            target: Node,
-            parent: Node,
-        ) {
-            this.crdtTree.tree = tree
-            val moveOperation = crdtTree.generateOperationMove(target.id, parent.id)
-            crdtTree.applyOperation(moveOperation)
-            _operation.value = moveOperation
-            requestUpdateMindMap(operation = moveOperation)
-        }
+    fun moveNode(
+        tree: Tree,
+        target: Node,
+        parent: Node,
+    ) {
+        this.crdtTree.tree = tree
+        val moveOperation = crdtTree.generateOperationMove(target.id, parent.id)
+        crdtTree.applyOperation(moveOperation)
+        _operation.value = moveOperation
+        requestUpdateMindMap(operation = moveOperation)
+    }
 
-        fun setSelectedNode(selectNode: Node?) {
-            _selectedNode.value = selectNode
-        }
+    fun setSelectedNode(selectNode: Node?) {
+        _selectedNode.value = selectNode
+    }
+
+    fun requestUpdateMindMap(operation: Operation) {
+        val serializedOperation =
+            when (operation) {
+                is OperationAdd -> crdtTree.serializeOperationAdd(operation)
 
-        fun requestUpdateMindMap(operation: Operation) {
-            val serializedOperation =
-                when (operation) {
-                    is OperationAdd -> crdtTree.serializeOperationAdd(operation)
+                is OperationDelete -> crdtTree.serializeOperationDelete(operation)
 
-                    is OperationDelete -> crdtTree.serializeOperationDelete(operation)
+                is OperationMove -> crdtTree.serializeOperationMove(operation)
 
-                    is OperationMove -> crdtTree.serializeOperationMove(operation)
+                is OperationUpdate -> crdtTree.serializeOperationUpdate(operation)
+            }
+        mindMapSocketManager.updateMindMap(
+            serializedOperation = serializedOperation,
+            boardId = boardId,
+        )
+    }
 
-                    is OperationUpdate -> crdtTree.serializeOperationUpdate(operation)
+    fun applyOperation(operation: SerializedOperation) {
+        val operation =
+            when (operation.operationType) {
+                OperationType.ADD.command -> crdtTree.deserializeOperationAdd(operation)
+                OperationType.DELETE.command -> crdtTree.deserializeOperationDelete(operation)
+                OperationType.UPDATE.command -> crdtTree.deserializeOperationUpdate(operation)
+                OperationType.MOVE.command -> crdtTree.deserializeOperationMove(operation)
+                else -> {
+                    throw IllegalArgumentException(ExceptionMessage.ERROR_MESSAGE_NOT_DEFINED_OPERATION.message)
                 }
-            mindMapSocketManager.updateMindMap(
-                serializedOperation = serializedOperation,
-                boardId = boardId,
-            )
-        }
+            }
+        crdtTree.applyOperation(operation)
+        _operation.value = operation
+    }
 
-        fun applyOperation(operation: SerializedOperation) {
+    fun applyOperation(operation: SerializedCrdtTree) {
+        operation.operationLogs?.forEach { operationLog ->
             val operation =
-                when (operation.operationType) {
-                    OperationType.ADD.command -> crdtTree.deserializeOperationAdd(operation)
-                    OperationType.DELETE.command -> crdtTree.deserializeOperationDelete(operation)
-                    OperationType.UPDATE.command -> crdtTree.deserializeOperationUpdate(operation)
-                    OperationType.MOVE.command -> crdtTree.deserializeOperationMove(operation)
+                when (operationLog.operation.operationType) {
+                    OperationType.ADD.command -> crdtTree.deserializeOperationAdd(operationLog.operation)
+                    OperationType.DELETE.command -> crdtTree.deserializeOperationDelete(operationLog.operation)
+                    OperationType.UPDATE.command -> crdtTree.deserializeOperationUpdate(operationLog.operation)
+                    OperationType.MOVE.command -> crdtTree.deserializeOperationMove(operationLog.operation)
                     else -> {
                         throw IllegalArgumentException(ExceptionMessage.ERROR_MESSAGE_NOT_DEFINED_OPERATION.message)
                     }
                 }
             crdtTree.applyOperation(operation)
             _operation.value = operation
         }
+    }
 
-        fun applyOperation(operation: SerializedCrdtTree) {
-            operation.operationLogs?.forEach { operationLog ->
-                val operation =
-                    when (operationLog.operation.operationType) {
-                        OperationType.ADD.command -> crdtTree.deserializeOperationAdd(operationLog.operation)
-                        OperationType.DELETE.command -> crdtTree.deserializeOperationDelete(operationLog.operation)
-                        OperationType.UPDATE.command -> crdtTree.deserializeOperationUpdate(operationLog.operation)
-                        OperationType.MOVE.command -> crdtTree.deserializeOperationMove(operationLog.operation)
-                        else -> {
-                            throw IllegalArgumentException(ExceptionMessage.ERROR_MESSAGE_NOT_DEFINED_OPERATION.message)
-                        }
-                    }
-                crdtTree.applyOperation(operation)
-                _operation.value = operation
-            }
-        }
-
-        fun updateNode(updateNode: Node) {
-            val updateOperation =
-                crdtTree.generateOperationUpdate(updateNode.id, updateNode.description)
-            crdtTree.applyOperation(updateOperation)
-            _operation.value = updateOperation
-            requestUpdateMindMap(updateOperation)
-        }
+    fun updateNode(updateNode: Node) {
+        val updateOperation =
+            crdtTree.generateOperationUpdate(updateNode.id, updateNode.description)
+        crdtTree.applyOperation(updateOperation)
+        _operation.value = updateOperation
+        requestUpdateMindMap(updateOperation)
+    }
 
-        fun update(newTree: Tree) {
-            crdtTree.tree = newTree
-        }
+    fun update(newTree: Tree) {
+        crdtTree.tree = newTree
+    }
 
-        fun changeRootXY(
-            windowWidth: Dp,
-            windowHeight: Dp,
-        ) {
-            crdtTree.tree.setRootNode(
-                crdtTree.tree.getRootNode().copy(
-                    path =
-                        crdtTree.tree.getRootNode().path.copy(
-                            centerX = windowWidth,
-                            centerY = windowHeight,
-                        ),
+    fun changeRootXY(
+        windowWidth: Dp,
+        windowHeight: Dp,
+    ) {
+        crdtTree.tree.setRootNode(
+            crdtTree.tree.getRootNode().copy(
+                path =
+                crdtTree.tree.getRootNode().path.copy(
+                    centerX = windowWidth,
+                    centerY = windowHeight,
                 ),
-            )
-        }
+            ),
+        )
+    }
 
-        fun updateOperationType(operationType: String) {
-            _operationType.value = operationType
-        }
+    fun updateOperationType(operationType: String) {
+        _operationType.value = operationType
+    }
+
+    fun clearTree() {
+        crdtTree = CrdtTree(id = "", tree = Tree())
+        _selectedNode.value = null
     }
+}