实现缩放功能：增加缩放功能检索和设置方法，更新UI以支持缩放调整，增强缩放比例的状态管理。

android/app/src/main/kotlin/com/dronex/rec/recording/RecordingCameraController.kt

@@ -2,6 +2,7 @@ package com.dronex.rec.recording
 
 import android.content.Context
 import android.util.Log
+import androidx.camera.core.Camera
 import androidx.camera.core.CameraSelector
 import androidx.camera.core.Preview
 import androidx.camera.lifecycle.ProcessCameraProvider
@@ -24,8 +25,10 @@ class RecordingCameraController(
     private var cameraProvider: ProcessCameraProvider? = null
     private var preview: Preview? = null
     private var videoCapture: VideoCapture<Recorder>? = null
+    private var camera: Camera? = null
     private var activeRecording: Recording? = null
     private var boundLifecycleOwner: LifecycleOwner? = null
+    private var currentZoomRatio: Float = 1f
 
     var status: RecordingStatus = RecordingStatus(RecordingState.IDLE)
         private set
@@ -61,12 +64,14 @@ class RecordingCameraController(
                         videoCapture = VideoCapture.withOutput(recorder)
 
                         provider.unbindAll()
-                        provider.bindToLifecycle(
+                        camera =
-                                lifecycleOwner,
+                                provider.bindToLifecycle(
-                                CameraSelector.DEFAULT_BACK_CAMERA,
+                                        lifecycleOwner,
-                                preview,
+                                        CameraSelector.DEFAULT_BACK_CAMERA,
-                                videoCapture,
+                                        preview,
-                        )
+                                        videoCapture,
+                                )
+                        applyCurrentZoom()
 
                         updateStatus(RecordingStatus(RecordingState.PREVIEWING))
                         onReady(true)
@@ -108,12 +113,14 @@ class RecordingCameraController(
         try {
             boundLifecycleOwner = lifecycleOwner
             provider.unbindAll()
-            provider.bindToLifecycle(
+            camera =
-                    lifecycleOwner,
+                    provider.bindToLifecycle(
-                    CameraSelector.DEFAULT_BACK_CAMERA,
+                            lifecycleOwner,
-                    preview,
+                            CameraSelector.DEFAULT_BACK_CAMERA,
-                    videoCapture,
+                            preview,
-            )
+                            videoCapture,
+                    )
+            applyCurrentZoom()
             onReady(true)
         } catch (error: Exception) {
             Log.e(TAG, "rebindForRecording failed", error)
@@ -221,6 +228,52 @@ class RecordingCameraController(
         activeRecording = null
     }
 
+    fun zoomCapabilitiesMap(): Map<String, Any> {
+        val zoomState = camera?.cameraInfo?.zoomState?.value
+        val minZoom = zoomState?.minZoomRatio ?: 1f
+        val maxZoom = zoomState?.maxZoomRatio ?: 3f
+        val zoom = (zoomState?.zoomRatio ?: currentZoomRatio).coerceIn(minZoom, maxZoom)
+        currentZoomRatio = zoom
+        return mapOf(
+                "zoomRatio" to zoom.toDouble(),
+                "minZoomRatio" to minZoom.toDouble(),
+                "maxZoomRatio" to maxZoom.toDouble(),
+        )
+    }
+
+    fun setZoomRatio(
+            ratio: Double,
+            onComplete: (Boolean, Map<String, Any>, String?) -> Unit,
+    ) {
+        val boundCamera = camera
+        if (boundCamera == null) {
+            val clamped = ratio.toFloat().coerceAtLeast(1f)
+            currentZoomRatio = clamped
+            onComplete(true, zoomCapabilitiesMap(), null)
+            return
+        }
+
+        val zoomState = boundCamera.cameraInfo.zoomState.value
+        val minZoom = zoomState?.minZoomRatio ?: 1f
+        val maxZoom = zoomState?.maxZoomRatio ?: clampedMaxZoom()
+        val nextZoom = ratio.toFloat().coerceIn(minZoom, maxZoom)
+        currentZoomRatio = nextZoom
+
+        val future = boundCamera.cameraControl.setZoomRatio(nextZoom)
+        future.addListener(
+                {
+                    try {
+                        future.get()
+                        onComplete(true, zoomCapabilitiesMap(), null)
+                    } catch (error: Exception) {
+                        Log.e(TAG, "setZoomRatio failed", error)
+                        onComplete(false, zoomCapabilitiesMap(), error.message)
+                    }
+                },
+                mainExecutor,
+        )
+    }
+
     fun unbind() {
         activeRecording?.stop()
         activeRecording = null
@@ -228,7 +281,9 @@ class RecordingCameraController(
         cameraProvider = null
         preview = null
         videoCapture = null
+        camera = null
         boundLifecycleOwner = null
+        currentZoomRatio = 1f
         updateStatus(RecordingStatus(RecordingState.IDLE))
     }
 
@@ -242,6 +297,19 @@ class RecordingCameraController(
         statusListener?.invoke(next)
     }
 
+    private fun applyCurrentZoom() {
+        val boundCamera = camera ?: return
+        val zoomState = boundCamera.cameraInfo.zoomState.value
+        val minZoom = zoomState?.minZoomRatio ?: 1f
+        val maxZoom = zoomState?.maxZoomRatio ?: clampedMaxZoom()
+        currentZoomRatio = currentZoomRatio.coerceIn(minZoom, maxZoom)
+        boundCamera.cameraControl.setZoomRatio(currentZoomRatio)
+    }
+
+    private fun clampedMaxZoom(): Float {
+        return camera?.cameraInfo?.zoomState?.value?.maxZoomRatio ?: 3f
+    }
+
     companion object {
         private const val TAG = "RecordingCamera"
     }

android/app/src/main/kotlin/com/dronex/rec/recording/RecordingPlatformHandler.kt

@@ -50,6 +50,11 @@ class RecordingPlatformHandler(
                 startRecording(withAudio, enableDnd, displayName, result)
             }
             "stopRecording" -> stopRecording(result)
+            "getZoomCapabilities" -> result.success(controller.zoomCapabilitiesMap())
+            "setZoomRatio" -> {
+                val ratio = call.argument<Double>("zoomRatio") ?: 1.0
+                setZoomRatio(ratio, result)
+            }
             "disposePreview" -> {
                 controller.unbind()
                 result.success(null)
@@ -172,6 +177,18 @@ class RecordingPlatformHandler(
         }
     }
 
+    private fun setZoomRatio(ratio: Double, result: MethodChannel.Result) {
+        controller.setZoomRatio(ratio) { success, capabilities, message ->
+            mainHandler.post {
+                if (success) {
+                    result.success(capabilities)
+                } else {
+                    result.error("ZOOM_FAILED", message ?: "Failed to set camera zoom", null)
+                }
+            }
+        }
+    }
+
     private fun deliverStopResult(result: MethodChannel.Result, path: String?) {
         val gallerySaved = path != null && controller.status.state != RecordingState.ERROR
         val payload =

ios/Runner/RecordingPlugin.swift

@@ -116,6 +116,7 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
   private var recordingStartedAt: Date?
   private var elapsedTimer: Timer?
   private var pendingStopResult: FlutterResult?
+  private var currentZoomRatio: CGFloat = 1.0
 
   private(set) var status = RecordingStatus(state: .idle) {
     didSet {
@@ -291,6 +292,7 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
       self.session.commitConfiguration()
       self.videoInput = nil
       self.audioInput = nil
+      self.currentZoomRatio = 1.0
       self.configured = false
       self.updateStatus(RecordingStatus(state: .idle))
 
@@ -312,6 +314,52 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
     return status.toMap()
   }
 
+  func zoomCapabilities(result: @escaping FlutterResult) {
+    sessionQueue.async { [weak self] in
+      guard let self else { return }
+      let capabilities = self.currentZoomCapabilitiesMap()
+      DispatchQueue.main.async {
+        result(capabilities)
+      }
+    }
+  }
+
+  func setZoomRatio(_ ratio: CGFloat, result: @escaping FlutterResult) {
+    sessionQueue.async { [weak self] in
+      guard let self else { return }
+      guard let device = self.videoInput?.device else {
+        self.currentZoomRatio = max(1.0, ratio)
+        let capabilities = self.currentZoomCapabilitiesMap()
+        DispatchQueue.main.async {
+          result(capabilities)
+        }
+        return
+      }
+
+      do {
+        let nextZoom = self.clampedZoomRatio(ratio, for: device)
+        try device.lockForConfiguration()
+        device.videoZoomFactor = nextZoom
+        device.unlockForConfiguration()
+        self.currentZoomRatio = nextZoom
+        let capabilities = self.currentZoomCapabilitiesMap()
+        DispatchQueue.main.async {
+          result(capabilities)
+        }
+      } catch {
+        DispatchQueue.main.async {
+          result(
+            FlutterError(
+              code: "ZOOM_FAILED",
+              message: error.localizedDescription,
+              details: nil
+            )
+          )
+        }
+      }
+    }
+  }
+
   func fileOutput(
     _ output: AVCaptureFileOutput,
     didFinishRecordingTo outputFileURL: URL,
@@ -465,9 +513,43 @@ private final class RecordingCameraController: NSObject, AVCaptureFileOutputReco
     session.commitConfiguration()
 
     configured = true
+    try applyCurrentZoom()
     try configureAudioInput(enabled: withAudio)
   }
 
+  private func currentZoomCapabilitiesMap() -> [String: Any] {
+    guard let device = videoInput?.device else {
+      return [
+        "zoomRatio": Double(currentZoomRatio),
+        "minZoomRatio": 1.0,
+        "maxZoomRatio": 3.0,
+      ]
+    }
+
+    let minZoom = device.minAvailableVideoZoomFactor
+    let maxZoom = device.maxAvailableVideoZoomFactor
+    let zoom = clampedZoomRatio(device.videoZoomFactor, for: device)
+    currentZoomRatio = zoom
+    return [
+      "zoomRatio": Double(zoom),
+      "minZoomRatio": Double(minZoom),
+      "maxZoomRatio": Double(maxZoom),
+    ]
+  }
+
+  private func applyCurrentZoom() throws {
+    guard let device = videoInput?.device else { return }
+    let nextZoom = clampedZoomRatio(currentZoomRatio, for: device)
+    try device.lockForConfiguration()
+    device.videoZoomFactor = nextZoom
+    device.unlockForConfiguration()
+    currentZoomRatio = nextZoom
+  }
+
+  private func clampedZoomRatio(_ ratio: CGFloat, for device: AVCaptureDevice) -> CGFloat {
+    min(max(ratio, device.minAvailableVideoZoomFactor), device.maxAvailableVideoZoomFactor)
+  }
+
   private func configureAudioInput(enabled: Bool) throws {
     session.beginConfiguration()
     defer { session.commitConfiguration() }
@@ -587,6 +669,12 @@ final class RecordingPlugin: NSObject, FlutterPlugin, FlutterStreamHandler {
       controller.startRecording(withAudio: withAudio, displayName: displayName, result: result)
     case "stopRecording":
       controller.stopRecording(result: result)
+    case "getZoomCapabilities":
+      controller.zoomCapabilities(result: result)
+    case "setZoomRatio":
+      let args = call.arguments as? [String: Any]
+      let ratio = args?["zoomRatio"] as? Double ?? 1.0
+      controller.setZoomRatio(CGFloat(ratio), result: result)
     case "disposePreview":
       controller.disposePreview(result: result)
     case "getStatus":

lib/features/recording/model/model_recording_session.dart

@@ -11,6 +11,9 @@ class RecordingSessionState {
     this.isBatteryOptimizedIgnored = true,
     this.notificationsGranted = true,
     this.isMicrophoneGranted = false,
+    this.zoomRatio = 1.0,
+    this.minZoomRatio = 1.0,
+    this.maxZoomRatio = 3.0,
     this.lastOutputPath,
     this.lastSavedDisplayName,
     this.errorMessage,
@@ -26,6 +29,9 @@ class RecordingSessionState {
   final bool isBatteryOptimizedIgnored;
   final bool notificationsGranted;
   final bool isMicrophoneGranted;
+  final double zoomRatio;
+  final double minZoomRatio;
+  final double maxZoomRatio;
   final String? lastOutputPath;
   final String? lastSavedDisplayName;
   final String? errorMessage;
@@ -51,6 +57,9 @@ class RecordingSessionState {
     bool? isBatteryOptimizedIgnored,
     bool? notificationsGranted,
     bool? isMicrophoneGranted,
+    double? zoomRatio,
+    double? minZoomRatio,
+    double? maxZoomRatio,
     String? lastOutputPath,
     String? lastSavedDisplayName,
     String? errorMessage,
@@ -69,6 +78,9 @@ class RecordingSessionState {
           isBatteryOptimizedIgnored ?? this.isBatteryOptimizedIgnored,
       notificationsGranted: notificationsGranted ?? this.notificationsGranted,
       isMicrophoneGranted: isMicrophoneGranted ?? this.isMicrophoneGranted,
+      zoomRatio: zoomRatio ?? this.zoomRatio,
+      minZoomRatio: minZoomRatio ?? this.minZoomRatio,
+      maxZoomRatio: maxZoomRatio ?? this.maxZoomRatio,
       lastOutputPath: lastOutputPath ?? this.lastOutputPath,
       lastSavedDisplayName: clearLastSaved
           ? null

lib/features/recording/pages/page_record.dart

@@ -357,10 +357,7 @@ class _PreviewLoadingLayer extends ConsumerWidget {
 }
 
 class _RecordingHudLayer extends ConsumerWidget {
-  const _RecordingHudLayer({
+  const _RecordingHudLayer({required this.onStart, required this.onStop});
-    required this.onStart,
-    required this.onStop,
-  });
 
   final Future<void> Function() onStart;
   final Future<void> Function() onStop;
@@ -378,6 +375,9 @@ class _RecordingHudLayer extends ConsumerWidget {
           m.session.isRecording,
           m.session.isStartingRecording,
           m.session.isTouchLocked,
+          m.session.zoomRatio,
+          m.session.minZoomRatio,
+          m.session.maxZoomRatio,
           m.hasValidClipboardInfo,
           m.clipboardRecordingModel.address.trim(),
         ),
@@ -392,6 +392,9 @@ class _RecordingHudLayer extends ConsumerWidget {
       isRecording,
       isStartingRecording,
       isTouchLocked,
+      zoomRatio,
+      minZoomRatio,
+      maxZoomRatio,
       showClipboardHint,
       clipboardAddress,
     ) = hudState;
@@ -406,6 +409,9 @@ class _RecordingHudLayer extends ConsumerWidget {
       isRecording: isRecording,
       isStartingRecording: isStartingRecording,
       isTouchLocked: isTouchLocked,
+      zoomRatio: zoomRatio,
+      minZoomRatio: minZoomRatio,
+      maxZoomRatio: maxZoomRatio,
       showClipboardHint: showClipboardHint,
       clipboardAddress: clipboardAddress,
       onStart: onStart,
@@ -419,9 +425,15 @@ class _RecordingHudLayer extends ConsumerWidget {
         await viewModel.refreshBatteryOptimization();
       },
       onToggleTouchLock: () {
-        final locked = ref.read(recordingViewModelProvider).session.isTouchLocked;
+        final locked = ref
+            .read(recordingViewModelProvider)
+            .session
+            .isTouchLocked;
         viewModel.setTouchLocked(!locked);
       },
+      onZoomSelected: (ratio) async {
+        await viewModel.setZoomRatio(ratio);
+      },
     );
   }
 }

lib/features/recording/platform/recording_platform.dart

@@ -81,6 +81,21 @@ class RecordingPlatform {
     return RecordingStatus.fromMap(result ?? const {});
   }
 
+  static Future<RecordingZoomCapabilities> getZoomCapabilities() async {
+    final result = await _channel.invokeMapMethod<String, dynamic>(
+      'getZoomCapabilities',
+    );
+    return RecordingZoomCapabilities.fromMap(result);
+  }
+
+  static Future<RecordingZoomCapabilities> setZoomRatio(double ratio) async {
+    final result = await _channel.invokeMapMethod<String, dynamic>(
+      'setZoomRatio',
+      <String, dynamic>{'zoomRatio': ratio},
+    );
+    return RecordingZoomCapabilities.fromMap(result);
+  }
+
   static Future<RecordingStartResult> startRecording({
     bool withAudio = true,
     bool enableDoNotDisturb = true,
@@ -156,6 +171,29 @@ class RecordingPlatform {
   }
 }
 
+class RecordingZoomCapabilities {
+  const RecordingZoomCapabilities({
+    required this.zoomRatio,
+    required this.minZoomRatio,
+    required this.maxZoomRatio,
+  });
+
+  final double zoomRatio;
+  final double minZoomRatio;
+  final double maxZoomRatio;
+
+  factory RecordingZoomCapabilities.fromMap(Map<String, dynamic>? map) {
+    final minZoomRatio = (map?['minZoomRatio'] as num?)?.toDouble() ?? 1.0;
+    final maxZoomRatio = (map?['maxZoomRatio'] as num?)?.toDouble() ?? 3.0;
+    final zoomRatio = (map?['zoomRatio'] as num?)?.toDouble() ?? minZoomRatio;
+    return RecordingZoomCapabilities(
+      zoomRatio: zoomRatio.clamp(minZoomRatio, maxZoomRatio).toDouble(),
+      minZoomRatio: minZoomRatio,
+      maxZoomRatio: maxZoomRatio,
+    );
+  }
+}
+
 class RecordingStartResult {
   const RecordingStartResult({this.outputPath, required this.status});
 

lib/features/recording/view-model/view_model_recording.dart

@@ -193,6 +193,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
     await _listenStatus();
     try {
       final status = await _initializePreviewWithRetry();
+      await _refreshZoomCapabilities();
       _updateSession(
         (s) => s.copyWith(
           status: status,
@@ -239,6 +240,7 @@ class RecordingViewModel extends Notifier<RecordingModel> {
     );
     try {
       final status = await _initializePreviewWithRetry();
+      await _refreshZoomCapabilities();
       _updateSession(
         (s) => s.copyWith(
           status: status,
@@ -309,6 +311,47 @@ class RecordingViewModel extends Notifier<RecordingModel> {
     return status?.isGranted == true || status?.isLimited == true;
   }
 
+  /// 读取相机支持的倍距范围并同步当前倍距。
+  Future<void> _refreshZoomCapabilities() async {
+    try {
+      final zoom = await RecordingPlatform.getZoomCapabilities();
+      _updateSession(
+        (s) => s.copyWith(
+          zoomRatio: zoom.zoomRatio,
+          minZoomRatio: zoom.minZoomRatio,
+          maxZoomRatio: zoom.maxZoomRatio,
+          errorMessage: null,
+        ),
+      );
+    } on PlatformException catch (error) {
+      AppLogger.debug('读取相机倍距能力失败', error: error);
+    }
+  }
+
+  /// 设置相机倍距，原生层会返回设备实际应用后的倍距范围与当前值。
+  Future<void> setZoomRatio(double ratio) async {
+    final session = state.session;
+    final clamped = ratio
+        .clamp(session.minZoomRatio, session.maxZoomRatio)
+        .toDouble();
+
+    try {
+      final zoom = await RecordingPlatform.setZoomRatio(clamped);
+      _updateSession(
+        (s) => s.copyWith(
+          zoomRatio: zoom.zoomRatio,
+          minZoomRatio: zoom.minZoomRatio,
+          maxZoomRatio: zoom.maxZoomRatio,
+          errorMessage: null,
+        ),
+      );
+    } on PlatformException catch (error) {
+      _updateSession(
+        (s) => s.copyWith(errorMessage: error.message ?? '相机倍距设置失败'),
+      );
+    }
+  }
+
   /// 开始录制，可选开启勿扰模式。
   Future<void> startRecording({bool enableDoNotDisturb = true}) async {
     final session = state.session;

lib/features/recording/widgets/widget_record_header.dart

@@ -170,7 +170,7 @@ class _HeaderPasteActions extends StatelessWidget {
     return Row(
       mainAxisAlignment: MainAxisAlignment.end,
       children: [
-        // _HeaderActionButton(label: 'mock', onPressed: onMockCopy),
+        _HeaderActionButton(label: 'mock', onPressed: onMockCopy),
         _HeaderActionButton(
           label: '粘贴选手信息',
           onPressed: () => onPasteEventInfo(),

lib/features/recording/widgets/widget_recording_hud.dart

@@ -21,11 +21,15 @@ class RecordingHudWidget extends StatelessWidget {
     required this.isTouchLocked,
     this.showClipboardHint = false,
     this.clipboardAddress = '',
+    required this.zoomRatio,
+    required this.minZoomRatio,
+    required this.maxZoomRatio,
     required this.onStart,
     required this.onStop,
     required this.onOpenDnd,
     required this.onOpenBattery,
     required this.onToggleTouchLock,
+    required this.onZoomSelected,
   });
 
   final String? errorMessage;
@@ -38,16 +42,21 @@ class RecordingHudWidget extends StatelessWidget {
   final bool isTouchLocked;
   final bool showClipboardHint;
   final String clipboardAddress;
+  final double zoomRatio;
+  final double minZoomRatio;
+  final double maxZoomRatio;
   final Future<void> Function() onStart;
   final Future<void> Function() onStop;
   final VoidCallback onOpenDnd;
   final VoidCallback onOpenBattery;
   final VoidCallback onToggleTouchLock;
+  final ValueChanged<double> onZoomSelected;
 
   static double get _recordButtonSize => 70.r;
   static double get _recordButtonBottom => 63.r;
   static double get _overlayInfoLeft => 13.r;
   static double get _overlayInfoBottom => 10.r;
+  static const List<double> _zoomPresets = [1.0, 2.0, 3.0];
 
   @override
   Widget build(BuildContext context) {
@@ -133,6 +142,17 @@ class RecordingHudWidget extends StatelessWidget {
               ),
             ),
           ),
+        Positioned(
+          right: 16.r,
+          bottom: _recordButtonBottom + _recordButtonSize + 14.h,
+          child: _ZoomPresetControl(
+            zoomRatio: zoomRatio,
+            minZoomRatio: minZoomRatio,
+            maxZoomRatio: maxZoomRatio,
+            presets: _zoomPresets,
+            onSelected: onZoomSelected,
+          ),
+        ),
         Positioned(
           left: 0,
           right: 0,
@@ -171,3 +191,94 @@ class RecordingHudWidget extends StatelessWidget {
     );
   }
 }
+
+class _ZoomPresetControl extends StatelessWidget {
+  const _ZoomPresetControl({
+    required this.zoomRatio,
+    required this.minZoomRatio,
+    required this.maxZoomRatio,
+    required this.presets,
+    required this.onSelected,
+  });
+
+  final double zoomRatio;
+  final double minZoomRatio;
+  final double maxZoomRatio;
+  final List<double> presets;
+  final ValueChanged<double> onSelected;
+
+  @override
+  Widget build(BuildContext context) {
+    final availablePresets = presets
+        .where((preset) => preset >= minZoomRatio && preset <= maxZoomRatio)
+        .toList(growable: false);
+
+    if (availablePresets.isEmpty) {
+      return const SizedBox.shrink();
+    }
+
+    return DecoratedBox(
+      decoration: BoxDecoration(
+        color: Colors.black.withValues(alpha: 0.46),
+        borderRadius: BorderRadius.circular(18.r),
+        border: Border.all(color: Colors.white.withValues(alpha: 0.18)),
+      ),
+      child: Padding(
+        padding: EdgeInsets.all(3.r),
+        child: Row(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            for (final preset in availablePresets)
+              _ZoomPresetButton(
+                ratio: preset,
+                selected: (zoomRatio - preset).abs() < 0.05,
+                onSelected: onSelected,
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _ZoomPresetButton extends StatelessWidget {
+  const _ZoomPresetButton({
+    required this.ratio,
+    required this.selected,
+    required this.onSelected,
+  });
+
+  final double ratio;
+  final bool selected;
+  final ValueChanged<double> onSelected;
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: EdgeInsets.symmetric(horizontal: 1.r),
+      child: TextButton(
+        onPressed: selected ? null : () => onSelected(ratio),
+        style: TextButton.styleFrom(
+          minimumSize: Size(38.r, 32.r),
+          padding: EdgeInsets.zero,
+          tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+          foregroundColor: selected ? Colors.black : Colors.white,
+          disabledForegroundColor: Colors.black,
+          backgroundColor: selected ? Colors.white : Colors.transparent,
+          disabledBackgroundColor: Colors.white,
+          shape: RoundedRectangleBorder(
+            borderRadius: BorderRadius.circular(15.r),
+          ),
+        ),
+        child: Text(
+          '${ratio.toStringAsFixed(0)}x',
+          style: TextStyle(
+            fontSize: 13.sp,
+            fontWeight: FontWeight.w700,
+            letterSpacing: 0,
+          ),
+        ),
+      ),
+    );
+  }
+}

test/features/recording/view_model_recording_test.dart

@@ -2,6 +2,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:permission_handler/permission_handler.dart';
+import 'package:recording_tool/features/recording/platform/recording_channel_names.dart';
 import 'package:recording_tool/features/recording/view-model/view_model_recording.dart';
 
 void main() {
@@ -24,6 +25,11 @@ void main() {
   tearDown(() {
     TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
         .setMockMethodCallHandler(SystemChannels.platform, null);
+    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+        .setMockMethodCallHandler(
+          const MethodChannel(RecordingChannelNames.method),
+          null,
+        );
   });
 
   group('RecordingViewModel', () {
@@ -36,9 +42,89 @@ void main() {
       expect(model.clipboardRecordingModel.title, defaultClipboardTitle);
       expect(model.session.isPreviewReady, isFalse);
       expect(model.session.isRecording, isFalse);
+      expect(model.session.zoomRatio, 1.0);
+      expect(model.session.minZoomRatio, 1.0);
+      expect(model.session.maxZoomRatio, 3.0);
     });
   });
 
+  group('RecordingViewModel.setZoomRatio', () {
+    test('updates zoom ratio from native response', () async {
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(
+            const MethodChannel(RecordingChannelNames.method),
+            (call) async {
+              expect(call.method, 'setZoomRatio');
+              expect(call.arguments, <String, dynamic>{'zoomRatio': 2.0});
+              return <String, dynamic>{
+                'zoomRatio': 2.0,
+                'minZoomRatio': 1.0,
+                'maxZoomRatio': 3.0,
+              };
+            },
+          );
+      final container = ProviderContainer();
+      addTearDown(container.dispose);
+
+      await container.read(recordingViewModelProvider.notifier).setZoomRatio(2);
+
+      final session = container.read(recordingViewModelProvider).session;
+      expect(session.zoomRatio, 2.0);
+      expect(session.minZoomRatio, 1.0);
+      expect(session.maxZoomRatio, 3.0);
+      expect(session.errorMessage, isNull);
+    });
+
+    test('clamps requested zoom ratio before invoking native', () async {
+      final calls = <MethodCall>[];
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+          .setMockMethodCallHandler(
+            const MethodChannel(RecordingChannelNames.method),
+            (call) async {
+              calls.add(call);
+              return <String, dynamic>{
+                'zoomRatio': 1.0,
+                'minZoomRatio': 1.0,
+                'maxZoomRatio': 1.0,
+              };
+            },
+          );
+      final container = ProviderContainer();
+      addTearDown(container.dispose);
+
+      await container.read(recordingViewModelProvider.notifier).setZoomRatio(4);
+
+      expect(calls.single.arguments, <String, dynamic>{'zoomRatio': 3.0});
+      expect(container.read(recordingViewModelProvider).session.zoomRatio, 1.0);
+    });
+
+    test(
+      'keeps previous zoom ratio and stores error when native fails',
+      () async {
+        TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
+            .setMockMethodCallHandler(
+              const MethodChannel(RecordingChannelNames.method),
+              (call) async {
+                throw PlatformException(
+                  code: 'ZOOM_FAILED',
+                  message: 'Zoom is unavailable',
+                );
+              },
+            );
+        final container = ProviderContainer();
+        addTearDown(container.dispose);
+
+        await container
+            .read(recordingViewModelProvider.notifier)
+            .setZoomRatio(2);
+
+        final session = container.read(recordingViewModelProvider).session;
+        expect(session.zoomRatio, 1.0);
+        expect(session.errorMessage, 'Zoom is unavailable');
+      },
+    );
+  });
+
   group('recordingGalleryPermissionsForHost', () {
     test('requests only add-only photo permission on iOS', () {
       final permissions = recordingGalleryPermissionsForHost(

test/features/recording/widget_recording_hud_test.dart

@@ -0,0 +1,80 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_screenutil/flutter_screenutil.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:recording_tool/features/recording/widgets/widget_recording_hud.dart';
+
+void main() {
+  Future<void> pumpHud(
+    WidgetTester tester, {
+    double zoomRatio = 1.0,
+    double minZoomRatio = 1.0,
+    double maxZoomRatio = 3.0,
+    ValueChanged<double>? onZoomSelected,
+  }) async {
+    await tester.pumpWidget(
+      ScreenUtilInit(
+        designSize: const Size(375, 812),
+        builder: (context, _) {
+          return MaterialApp(
+            home: Scaffold(
+              backgroundColor: Colors.black,
+              body: RecordingHudWidget(
+                hasDndAccess: true,
+                isBatteryOptimizedIgnored: true,
+                notificationsGranted: true,
+                isRecording: false,
+                isStartingRecording: false,
+                isTouchLocked: false,
+                zoomRatio: zoomRatio,
+                minZoomRatio: minZoomRatio,
+                maxZoomRatio: maxZoomRatio,
+                onStart: () async {},
+                onStop: () async {},
+                onOpenDnd: () {},
+                onOpenBattery: () {},
+                onToggleTouchLock: () {},
+                onZoomSelected: onZoomSelected ?? (_) {},
+              ),
+            ),
+          );
+        },
+      ),
+    );
+    await tester.pump();
+  }
+
+  testWidgets('shows preset zoom buttons', (tester) async {
+    await pumpHud(tester);
+
+    expect(find.text('1x'), findsOneWidget);
+    expect(find.text('2x'), findsOneWidget);
+    expect(find.text('3x'), findsOneWidget);
+  });
+
+  testWidgets('marks current zoom ratio as selected', (tester) async {
+    await pumpHud(tester, zoomRatio: 2.0);
+
+    final selectedButton = tester.widget<TextButton>(
+      find.ancestor(of: find.text('2x'), matching: find.byType(TextButton)),
+    );
+    expect(selectedButton.enabled, isFalse);
+  });
+
+  testWidgets('does not expose presets beyond max zoom ratio', (tester) async {
+    await pumpHud(tester, maxZoomRatio: 2.0);
+
+    expect(find.text('1x'), findsOneWidget);
+    expect(find.text('2x'), findsOneWidget);
+    expect(find.text('3x'), findsNothing);
+  });
+
+  testWidgets('tapping zoom preset reports selected ratio', (tester) async {
+    double? selected;
+    await pumpHud(tester, onZoomSelected: (ratio) => selected = ratio);
+
+    await tester.tap(find.text('2x'));
+    await tester.pump();
+
+    expect(selected, 2.0);
+  });
+}