✨ Add full semantics support (#72)

Author: AlexV525

lib/src/constants/constants.dart

@@ -12,6 +12,5 @@ export 'screens.dart';
 class Constants {
   const Constants._();
 
-  static CameraPickerTextDelegate textDelegate =
-      DefaultCameraPickerTextDelegate();
+  static CameraPickerTextDelegate textDelegate = CameraPickerTextDelegate();
 }

lib/src/delegates/camera_picker_text_delegate.dart

@@ -2,63 +2,105 @@
 /// [Author] Alex (https://github.com/AlexV525)
 /// [Date] 2020/7/16 11:07
 ///
+import 'package:camera/camera.dart' show CameraLensDirection, FlashMode;
 
-/// Text delegate that controls text in widgets.
-/// 控制部件中的文字实现
-abstract class CameraPickerTextDelegate {
+/// Text delegate that controls text in widgets, implemented with Chinese.
+/// 控制部件中的文字实现，中文。
+class CameraPickerTextDelegate {
   /// Confirm string for the confirm button.
   /// 确认按钮的字段
-  String get confirm;
+  String get confirm => '确认';
 
   /// Tips string above the shooting button before shooting.
   /// 拍摄前确认按钮上方的提示文字
-  String get shootingTips;
+  String get shootingTips => '轻触拍照';
 
   /// Load failed string for item.
   /// 资源加载失败时的字段
-  String get loadFailed;
-}
+  String get loadFailed => '加载失败';
 
-/// Default text delegate implements with Chinese.
-/// 中文文字实现
-class DefaultCameraPickerTextDelegate extends CameraPickerTextDelegate {
-  @override
-  String get confirm => '确认';
+  /// Semantics fields.
+  ///
+  /// Fields below are only for semantics usage. For customizable these fields,
+  /// head over to [EnglishCameraPickerTextDelegate] for fields understanding.
+  String get sActionManuallyFocusHint => '手动聚焦';
 
-  @override
-  String get shootingTips => '轻触拍照';
+  String get sActionPreviewHint => '预览';
 
-  @override
-  String get loadFailed => '加载失败';
+  String get sActionRecordHint => '录像';
+
+  String get sActionShootHint => '拍照';
+
+  String get sActionShootingButtonTooltip => '拍照按钮';
+
+  String get sActionStopRecordingHint => '停止录像';
+
+  String get sActionSwitchCameraTooltip => '切换摄像头';
+
+  String get sActionToggleFlashModeTooltip => '切换闪光模式';
+
+  String sCameraLensDirectionLabel(CameraLensDirection value) {
+    final String _direction;
+    switch (value) {
+      case CameraLensDirection.front:
+        _direction = '前置';
+        break;
+      case CameraLensDirection.back:
+        _direction = '后置';
+        break;
+      case CameraLensDirection.external:
+        _direction = '外置';
+        break;
+    }
+    return '当前摄像头: $_direction';
+  }
+
+  String sFlashModeLabel(FlashMode mode) {
+    final String _modeString;
+    switch (mode) {
+      case FlashMode.off:
+        _modeString = '关闭';
+        break;
+      case FlashMode.auto:
+        _modeString = '自动';
+        break;
+      case FlashMode.always:
+        _modeString = '拍照时闪光';
+        break;
+      case FlashMode.torch:
+        _modeString = '始终闪光';
+        break;
+    }
+    return '当前闪光模式: $_modeString';
+  }
 }
 
 /// Default text delegate including recording implements with Chinese.
 /// 中文文字实现（包括摄像）
-class DefaultCameraPickerTextDelegateWithRecording
-    extends DefaultCameraPickerTextDelegate {
+class CameraPickerTextDelegateWithRecording extends CameraPickerTextDelegate {
   @override
   String get shootingTips => '轻触拍照，长按摄像';
 }
 
 /// Default text delegate including only recording implements with Chinese.
 /// 中文文字实现（仅摄像）
-class DefaultCameraPickerTextDelegateWithOnlyRecording
-    extends DefaultCameraPickerTextDelegate {
+class CameraPickerTextDelegateWithOnlyRecording
+    extends CameraPickerTextDelegate {
   @override
   String get shootingTips => '长按摄像';
 }
 
 /// Default text delegate including tap recording implements with Chinese.
 /// 中文文字实现（仅轻触摄像）
-class DefaultCameraPickerTextDelegateWithTapRecording
-    extends DefaultCameraPickerTextDelegate {
+class CameraPickerTextDelegateWithTapRecording
+    extends CameraPickerTextDelegate {
   @override
   String get shootingTips => '轻触摄像';
 }
 
 /// Default text delegate implements with English.
 /// 英文文字实现
-class EnglishCameraPickerTextDelegate implements CameraPickerTextDelegate {
+class EnglishCameraPickerTextDelegate extends CameraPickerTextDelegate {
   @override
   String get confirm => 'Confirm';
 
@@ -67,6 +109,38 @@ class EnglishCameraPickerTextDelegate implements CameraPickerTextDelegate {
 
   @override
   String get loadFailed => 'Load failed';
+
+  @override
+  String get sActionManuallyFocusHint => 'manually focus';
+
+  @override
+  String get sActionPreviewHint => 'preview';
+
+  @override
+  String get sActionRecordHint => 'record';
+
+  @override
+  String get sActionShootHint => 'take picture';
+
+  @override
+  String get sActionShootingButtonTooltip => 'shooting button';
+
+  @override
+  String get sActionStopRecordingHint => 'stop recording';
+
+  @override
+  String get sActionSwitchCameraTooltip => 'switch camera';
+
+  @override
+  String get sActionToggleFlashModeTooltip => 'toggle flashlight';
+
+  @override
+  String sCameraLensDirectionLabel(CameraLensDirection value) =>
+      'Current camera lens direction: ${value.name}';
+
+  @override
+  String sFlashModeLabel(FlashMode mode) =>
+      'Current flashlight mode: ${mode.name}';
 }
 
 /// Default text delegate including recording implements with English.