增强变焦功能

lib/features/recording/widgets/widget_recording_hud.dart

@@ -56,7 +56,7 @@ class RecordingHudWidget extends StatelessWidget {
   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];
+  static const List<double> _zoomPresets = [0.6, 1.0];
 
   @override
   Widget build(BuildContext context) {
@@ -146,6 +146,7 @@ class RecordingHudWidget extends StatelessWidget {
           right: 16.r,
           bottom: _recordButtonBottom + _recordButtonSize + 14.h,
           child: _ZoomPresetControl(
+            isRecording: isRecording,
             zoomRatio: zoomRatio,
             minZoomRatio: minZoomRatio,
             maxZoomRatio: maxZoomRatio,
@@ -194,6 +195,7 @@ class RecordingHudWidget extends StatelessWidget {
 
 class _ZoomPresetControl extends StatelessWidget {
   const _ZoomPresetControl({
+    required this.isRecording,
     required this.zoomRatio,
     required this.minZoomRatio,
     required this.maxZoomRatio,
@@ -201,6 +203,7 @@ class _ZoomPresetControl extends StatelessWidget {
     required this.onSelected,
   });
 
+  final bool isRecording;
   final double zoomRatio;
   final double minZoomRatio;
   final double maxZoomRatio;
@@ -210,7 +213,7 @@ class _ZoomPresetControl extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final availablePresets = presets
-        .where((preset) => preset >= minZoomRatio && preset <= maxZoomRatio)
+        .where(_isPresetAvailable)
         .toList(growable: false);
 
     if (availablePresets.isEmpty) {
@@ -230,8 +233,10 @@ class _ZoomPresetControl extends StatelessWidget {
           children: [
             for (final preset in availablePresets)
               _ZoomPresetButton(
-                ratio: preset,
-                selected: (zoomRatio - preset).abs() < 0.05,
+                displayRatio: preset,
+                requestRatio: _requestRatioFor(preset),
+                selected: _isPresetSelected(preset),
+                enabled: !_wouldSwitchPhysicalCamera(preset),
                 onSelected: onSelected,
               ),
           ],
@@ -239,17 +244,51 @@ class _ZoomPresetControl extends StatelessWidget {
       ),
     );
   }
+
+  bool _isPresetAvailable(double preset) {
+    if (preset < 1.0) {
+      return minZoomRatio <= preset && maxZoomRatio >= preset;
+    }
+    return preset >= minZoomRatio && preset <= maxZoomRatio;
+  }
+
+  bool _isPresetSelected(double preset) {
+    if (preset < 1.0) {
+      return zoomRatio < 1.0;
+    }
+    return (zoomRatio - preset).abs() < 0.05;
+  }
+
+  double _requestRatioFor(double preset) {
+    if (preset < 1.0) {
+      return minZoomRatio <= 0.5 ? 0.5 : preset;
+    }
+    return preset;
+  }
+
+  bool _wouldSwitchPhysicalCamera(double preset) {
+    if (!isRecording) {
+      return false;
+    }
+    final currentIsUltraWide = zoomRatio < 1.0;
+    final targetIsUltraWide = preset < 1.0;
+    return currentIsUltraWide != targetIsUltraWide;
+  }
 }
 
 class _ZoomPresetButton extends StatelessWidget {
   const _ZoomPresetButton({
-    required this.ratio,
+    required this.displayRatio,
+    required this.requestRatio,
     required this.selected,
+    required this.enabled,
     required this.onSelected,
   });
 
-  final double ratio;
+  final double displayRatio;
+  final double requestRatio;
   final bool selected;
+  final bool enabled;
   final ValueChanged<double> onSelected;
 
   @override
@@ -257,7 +296,7 @@ class _ZoomPresetButton extends StatelessWidget {
     return Padding(
       padding: EdgeInsets.symmetric(horizontal: 1.r),
       child: TextButton(
-        onPressed: selected ? null : () => onSelected(ratio),
+        onPressed: selected || !enabled ? null : () => onSelected(requestRatio),
         style: TextButton.styleFrom(
           minimumSize: Size(38.r, 32.r),
           padding: EdgeInsets.zero,
@@ -271,7 +310,7 @@ class _ZoomPresetButton extends StatelessWidget {
           ),
         ),
         child: Text(
-          '${ratio.toStringAsFixed(0)}x',
+          '${_formatZoomRatio(displayRatio)}x',
           style: TextStyle(
             fontSize: 13.sp,
             fontWeight: FontWeight.w700,
@@ -281,4 +320,11 @@ class _ZoomPresetButton extends StatelessWidget {
       ),
     );
   }
+
+  String _formatZoomRatio(double ratio) {
+    if (ratio == ratio.roundToDouble()) {
+      return ratio.toStringAsFixed(0);
+    }
+    return ratio.toStringAsFixed(1);
+  }
 }