Initial commit

2026-08-11 19:46:54 +08:00
commit 8d4535ff00
60 changed files with 2794 additions and 0 deletions
@@ -0,0 +1,85 @@
+package com.example.jnicpp.bowling
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asSharedFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+
+/**
+ * Holds camera/recording UI state so it survives configuration changes and
+ * so the state machine lives outside the Activity. This class knows nothing
+ * about CameraX or ML Kit APIs directly -- [BowlingCameraActivity] and
+ * [CameraXController] report events into it, and the UI observes it back
+ * out. That keeps this class trivially unit-testable (no Android camera
+ * framework involved).
+ */
+class CameraViewModel : ViewModel() {
+
+    sealed interface RecordingState {
+        data object Idle : RecordingState
+        data object Starting : RecordingState
+        data class Recording(val elapsedSeconds: Long) : RecordingState
+    }
+
+    private val _recordingState = MutableStateFlow<RecordingState>(RecordingState.Idle)
+    val recordingState: StateFlow<RecordingState> = _recordingState.asStateFlow()
+
+    private val _permissionsGranted = MutableStateFlow(false)
+    val permissionsGranted: StateFlow<Boolean> = _permissionsGranted.asStateFlow()
+
+    // One-shot user-facing error messages (camera unavailable, detector
+    // failure, storage failure, ...). SharedFlow, not StateFlow, so the same
+    // error doesn't get replayed and re-shown after a config change.
+    private val _errorEvents = MutableSharedFlow<String>(extraBufferCapacity = 4)
+    val errorEvents: SharedFlow<String> = _errorEvents.asSharedFlow()
+
+    private var timerJob: Job? = null
+
+    fun onPermissionsResult(granted: Boolean) {
+        _permissionsGranted.value = granted
+    }
+
+    fun onRecordingStarting() {
+        _recordingState.value = RecordingState.Starting
+    }
+
+    fun onRecordingStarted() {
+        timerJob?.cancel()
+        timerJob = viewModelScope.launch {
+            var seconds = 0L
+            while (isActive) {
+                _recordingState.value = RecordingState.Recording(seconds)
+                delay(1000)
+                seconds++
+            }
+        }
+    }
+
+    fun onRecordingStopped() {
+        timerJob?.cancel()
+        timerJob = null
+        _recordingState.value = RecordingState.Idle
+    }
+
+    fun postError(message: String) {
+        _errorEvents.tryEmit(message)
+        // A failed start/stop shouldn't leave the UI stuck showing a
+        // recording indicator that no longer reflects reality.
+        if (_recordingState.value != RecordingState.Idle) {
+            onRecordingStopped()
+        }
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        timerJob?.cancel()
+    }
+}