Feature: Configure dark and tinted mode icons for iOS 18+ (#569)

* Add support for iOS dark and tinted icons

* Fix location of Contents.json file

* Fix location of Contents.json file

* Fix generation of Contents.json file

* Prevent ios-marketing idiom from getting dark and tinted variants

* Split Contents.json types in legacy and new variants

* Add tests

* Add ability to desaturate tinted iOS images

* Add documentation and template file for iOS dark and tinted icons

README.md

@@ -116,6 +116,9 @@ foreground of the Android 13+ themed icon. For more information see [Android Ada
   - `icon/path/here.png`: This will generate a new launcher icons for the platform with the name you specify, without removing the old default existing Flutter launcher icon.
 - `image_path_ios`: The location of the icon image file specific for iOS platform (optional - if not defined then the image_path is used)
 - `remove_alpha_ios`: Removes alpha channel for IOS icons
+- `image_path_ios_dark_transparent`: The location of the dark mode icon image file specific for iOS 18+ platform. *Note: Apple recommends this icon to be transparent. For more information see [Apple Human Interface Guidelines for App Icons](https://developer.apple.com/design/human-interface-guidelines/app-icons#iOS-iPadOS)*
+- `image_path_ios_tinted_grayscale`: The location of the tinted mode icon image file specific for iOS 18+ platform. *Note: This icon should be an grayscale image. Use `desaturate_tinted_to_grayscale_ios: true` to automatically desaturate the image provided here.*
+- `desaturate_tinted_to_grayscale_ios`: Automatically desaturates tinted mode icon image to grayscale, *defaults to false*
 - `background_color_ios`: The color (in the format "#RRGGBB") to be used as the background when removing the alpha channel. It is used only when the `remove_alpha_ios` property is set to true. (optional - if not defined then `#ffffff` is used)
 
 ### Web

bin/generate.dart

@@ -96,6 +96,9 @@ flutter_launcher_icons:
   ios: true
   # image_path_ios: "assets/icon/icon.png"
   remove_alpha_channel_ios: true
+  # image_path_ios_dark_transparent: "assets/icon/icon_dark.png"
+  # image_path_ios_tinted_grayscale: "assets/icon/icon_tinted.png"
+  # desaturate_tinted_to_grayscale_ios: true
 
   web:
     generate: true

lib/config/config.dart

@@ -25,11 +25,14 @@ class Config {
     this.ios = false,
     this.imagePathAndroid,
     this.imagePathIOS,
+    this.imagePathIOSDarkTransparent,
+    this.imagePathIOSTintedGrayscale,
     this.adaptiveIconForeground,
     this.adaptiveIconBackground,
     this.adaptiveIconMonochrome,
     this.minSdkAndroid = constants.androidDefaultAndroidMinSDK,
     this.removeAlphaIOS = false,
+    this.desaturateTintedToGrayscaleIOS = false,
     this.backgroundColorIOS = '#ffffff',
     this.webConfig,
     this.windowsConfig,
@@ -117,6 +120,14 @@ class Config {
   @JsonKey(name: 'image_path_ios')
   final String? imagePathIOS;
 
+  /// IOS image_path_ios_dark_transparent
+  @JsonKey(name: 'image_path_ios_dark_transparent')
+  final String? imagePathIOSDarkTransparent;
+
+  /// IOS image_path_ios_tinted_grayscale
+  @JsonKey(name: 'image_path_ios_tinted_grayscale')
+  final String? imagePathIOSTintedGrayscale;
+
   /// android adaptive_icon_foreground image
   @JsonKey(name: 'adaptive_icon_foreground')
   final String? adaptiveIconForeground;
@@ -137,6 +148,10 @@ class Config {
   @JsonKey(name: 'remove_alpha_ios')
   final bool removeAlphaIOS;
 
+  /// IOS desaturate_tinted_to_grayscale
+  @JsonKey(name: 'desaturate_tinted_to_grayscale_ios')
+  final bool desaturateTintedToGrayscaleIOS;
+
   /// IOS background_color_ios
   @JsonKey(name: 'background_color_ios')
   final String backgroundColorIOS;