feat: add shadow tokens (#7726)

frontend/appflowy_flutter/packages/appflowy_ui/lib/src/theme/data/builder.dart

@@ -8,6 +8,7 @@ import 'package:appflowy_ui/src/theme/color_scheme/icon/icon_color_theme.dart';
 import 'package:appflowy_ui/src/theme/color_scheme/surface/surface_color_scheme.dart';
 import 'package:appflowy_ui/src/theme/color_scheme/text/text_color_scheme.dart';
 import 'package:appflowy_ui/src/theme/dimensions.dart';
+import 'package:appflowy_ui/src/theme/shadow/shadow.dart';
 import 'package:appflowy_ui/src/theme/spacing/spacing.dart';
 import 'package:flutter/material.dart';
 
@@ -321,4 +322,43 @@ class AppFlowyThemeBuilder {
       xxl: AppFlowySpacingConstant.spacing600,
     );
   }
+
+  AppFlowyShadow buildShadow(
+    Brightness brightness,
+  ) {
+    return switch (brightness) {
+      Brightness.light => AppFlowyShadow(
+          small: [
+            BoxShadow(
+              offset: Offset(0, 2),
+              blurRadius: 16,
+              color: Color(0x1F000000),
+            ),
+          ],
+          medium: [
+            BoxShadow(
+              offset: Offset(0, 4),
+              blurRadius: 32,
+              color: Color(0x1F000000),
+            ),
+          ],
+        ),
+      Brightness.dark => AppFlowyShadow(
+          small: [
+            BoxShadow(
+              offset: Offset(0, 2),
+              blurRadius: 16,
+              color: Color(0x7A000000),
+            ),
+          ],
+          medium: [
+            BoxShadow(
+              offset: Offset(0, 4),
+              blurRadius: 32,
+              color: Color(0x7A000000),
+            ),
+          ],
+        ),
+    };
+  }
 }

frontend/appflowy_flutter/packages/appflowy_ui/lib/src/theme/data/data.dart

@@ -8,6 +8,7 @@ import 'package:appflowy_ui/src/theme/color_scheme/icon/icon_color_theme.dart';
 import 'package:appflowy_ui/src/theme/color_scheme/surface/surface_color_scheme.dart';
 import 'package:appflowy_ui/src/theme/color_scheme/text/text_color_scheme.dart';
 import 'package:appflowy_ui/src/theme/data/builder.dart';
+import 'package:appflowy_ui/src/theme/shadow/shadow.dart';
 import 'package:appflowy_ui/src/theme/spacing/spacing.dart';
 import 'package:appflowy_ui/src/theme/text_style/text_style.dart';
 import 'package:flutter/material.dart';
@@ -35,6 +36,8 @@ abstract class AppFlowyBaseTheme {
 
   AppFlowySpacing get spacing;
 
+  AppFlowyShadow get shadow;
+
   AppFlowyBrandColorScheme get brandColorScheme;
 }
 
@@ -70,6 +73,7 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
     final brandColorScheme = themeBuilder.buildBrandColorScheme(colorScheme);
     final borderRadius = themeBuilder.buildBorderRadius(colorScheme);
     final spacing = themeBuilder.buildSpacing(colorScheme);
+    final shadow = themeBuilder.buildShadow(Brightness.light);
 
     return AppFlowyThemeData(
       colorScheme: colorScheme,
@@ -82,6 +86,7 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
       surfaceColorScheme: surfaceColorScheme,
       borderRadius: borderRadius,
       spacing: spacing,
+      shadow: shadow,
       brandColorScheme: brandColorScheme,
     );
   }
@@ -116,6 +121,7 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
     final brandColorScheme = themeBuilder.buildBrandColorScheme(colorScheme);
     final borderRadius = themeBuilder.buildBorderRadius(colorScheme);
     final spacing = themeBuilder.buildSpacing(colorScheme);
+    final shadow = themeBuilder.buildShadow(Brightness.dark);
 
     return AppFlowyThemeData(
       colorScheme: colorScheme,
@@ -128,6 +134,7 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
       surfaceColorScheme: surfaceColorScheme,
       borderRadius: borderRadius,
       spacing: spacing,
+      shadow: shadow,
       brandColorScheme: brandColorScheme,
     );
   }
@@ -141,6 +148,7 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
     required this.surfaceColorScheme,
     required this.borderRadius,
     required this.spacing,
+    required this.shadow,
     required this.brandColorScheme,
     required this.iconColorTheme,
     required this.backgroundColorScheme,
@@ -175,6 +183,9 @@ class AppFlowyThemeData extends AppFlowyBaseTheme {
   @override
   final AppFlowySpacing spacing;
 
+  @override
+  final AppFlowyShadow shadow;
+
   @override
   final AppFlowyBrandColorScheme brandColorScheme;
 

frontend/appflowy_flutter/packages/appflowy_ui/lib/src/theme/shadow/shadow.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/widgets.dart';
+
+class AppFlowyShadow {
+  AppFlowyShadow({
+    required this.small,
+    required this.medium,
+  });
+
+  final List<BoxShadow> small;
+  final List<BoxShadow> medium;
+}