Android: Make monochrome icon optional

platform/android/export/export_plugin.cpp

@@ -214,6 +214,18 @@ static const char *MISMATCHED_VERSIONS_MESSAGE = "Android build version mismatch
 
 static const char *GDEXTENSION_LIBS_PATH = "libs/gdextensionlibs.json";
 
+// This template string must always match the content of 'platform/android/java/lib/res/mipmap-anydpi-v26/icon.xml'.
+static const String ICON_XML_TEMPLATE =
+		"<?xml version=\"1.0\" encoding=\"utf-8\"?>\n"
+		"<adaptive-icon xmlns:android=\"http://schemas.android.com/apk/res/android\">\n"
+		"    <background android:drawable=\"@mipmap/icon_background\"/>\n"
+		"    <foreground android:drawable=\"@mipmap/icon_foreground\"/>\n"
+		"%s" // Placeholder for the optional monochrome tag.
+		"</adaptive-icon>";
+
+static const String ICON_XML_PATH = "res/mipmap-anydpi-v26/icon.xml";
+static const String THEMED_ICON_XML_PATH = "res/mipmap-anydpi-v26/themed_icon.xml";
+
 static const int icon_densities_count = 6;
 static const char *launcher_icon_option = PNAME("launcher_icons/main_192x192");
 static const char *launcher_adaptive_icon_foreground_option = PNAME("launcher_icons/adaptive_foreground_432x432");
@@ -1689,7 +1701,7 @@ void EditorExportPlatformAndroid::load_icon_refs(const Ref<EditorExportPreset> &
 	path = static_cast<String>(p_preset->get(launcher_adaptive_icon_monochrome_option)).strip_edges();
 	if (!path.is_empty()) {
 		print_verbose("Loading adaptive monochrome icon from " + path);
-		ImageLoader::load_image(path, background);
+		ImageLoader::load_image(path, monochrome);
 	}
 }
 
@@ -1700,6 +1712,8 @@ void EditorExportPlatformAndroid::_copy_icons_to_gradle_project(const Ref<Editor
 		const Ref<Image> &p_monochrome) {
 	String gradle_build_dir = ExportTemplateManager::get_android_build_directory(p_preset);
 
+	String monochrome_tag = "";
+
 	// Prepare images to be resized for the icons. If some image ends up being uninitialized,
 	// the default image from the export template will be used.
 
@@ -1733,8 +1747,12 @@ void EditorExportPlatformAndroid::_copy_icons_to_gradle_project(const Ref<Editor
 			_process_launcher_icons(launcher_adaptive_icon_monochromes[i].export_path, p_monochrome,
 					launcher_adaptive_icon_monochromes[i].dimensions, data);
 			store_file_at_path(gradle_build_dir.path_join(launcher_adaptive_icon_monochromes[i].export_path), data);
+			monochrome_tag = "    <monochrome android:drawable=\"@mipmap/icon_monochrome\"/>\n";
 		}
 	}
+
+	// Finalize the icon.xml by formatting the template with the optional monochrome tag.
+	store_string_at_path(gradle_build_dir.path_join(ICON_XML_PATH), vformat(ICON_XML_TEMPLATE, monochrome_tag));
 }
 
 Vector<EditorExportPlatformAndroid::ABI> EditorExportPlatformAndroid::get_enabled_abis(const Ref<EditorExportPreset> &p_preset) {
@@ -3398,6 +3416,11 @@ Error EditorExportPlatformAndroid::export_project_helper(const Ref<EditorExportP
 	String apk_expansion_pkey = p_preset->get("apk_expansion/public_key");
 
 	Vector<ABI> invalid_abis(enabled_abis);
+
+	//To temporarily store icon xml data.
+	Vector<uint8_t> themed_icon_xml_data;
+	int icon_xml_compression_method = -1;
+
 	while (ret == UNZ_OK) {
 		//get filename
 		unz_file_info info;
@@ -3427,6 +3450,20 @@ Error EditorExportPlatformAndroid::export_project_helper(const Ref<EditorExportP
 			_fix_resources(p_preset, data);
 		}
 
+		if (file == THEMED_ICON_XML_PATH) {
+			// Store themed_icon.xml data.
+			themed_icon_xml_data = data;
+			skip = true;
+		}
+
+		if (file == ICON_XML_PATH) {
+			if (monochrome.is_valid() && !monochrome->is_empty()) {
+				// Defer processing of icon.xml until after themed_icon.xml is read.
+				icon_xml_compression_method = info.compression_method;
+				skip = true;
+			}
+		}
+
 		if (file.ends_with(".png") && file.contains("mipmap")) {
 			for (int i = 0; i < icon_densities_count; ++i) {
 				if (main_image.is_valid() && !main_image->is_empty()) {
@@ -3496,6 +3533,28 @@ Error EditorExportPlatformAndroid::export_project_helper(const Ref<EditorExportP
 		ret = unzGoToNextFile(pkg);
 	}
 
+	// Process deferred icon.xml and replace it's data with themed_icon.xml.
+	if (monochrome.is_valid() && !monochrome->is_empty()) {
+		print_line("ADDING: " + ICON_XML_PATH + " (replacing with themed_icon.xml data)");
+
+		const bool uncompressed = icon_xml_compression_method == 0;
+		zip_fileinfo zipfi = get_zip_fileinfo();
+
+		zipOpenNewFileInZip(unaligned_apk,
+				ICON_XML_PATH.utf8().get_data(),
+				&zipfi,
+				nullptr,
+				0,
+				nullptr,
+				0,
+				nullptr,
+				uncompressed ? 0 : Z_DEFLATED,
+				Z_DEFAULT_COMPRESSION);
+
+		zipWriteInFileInZip(unaligned_apk, themed_icon_xml_data.ptr(), themed_icon_xml_data.size());
+		zipCloseFileInZip(unaligned_apk);
+	}
+
 	if (!invalid_abis.is_empty()) {
 		add_message(EXPORT_MESSAGE_ERROR, TTR("Export"), vformat(TTR("Missing libraries in the export template for the selected architectures: %s. Please build a template with all required libraries, or uncheck the missing architectures in the export preset."), join_abis(invalid_abis, ", ", false)));
 		CLEANUP_AND_RETURN(ERR_FILE_NOT_FOUND);

platform/android/java/lib/res/mipmap-anydpi-v26/icon.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!--
+WARNING: The content of this file must always match the constant 'platform/android/export/export_plugin.cpp#ICON_XML_TEMPLATE'.
+-->
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
     <background android:drawable="@mipmap/icon_background"/>
     <foreground android:drawable="@mipmap/icon_foreground"/>
-    <monochrome android:drawable="@mipmap/icon_monochrome"/>
 </adaptive-icon>

platform/android/java/lib/res/mipmap-anydpi-v26/themed_icon.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+This file is created to work alongside the icon.xml file.
+If the user provides a Monochrome icon in the export settings, its data will be used to overwrite the icon.xml file.
+We needed to create this file to get a reference for icon_monochrome.
+-->
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@mipmap/icon_background"/>
+    <foreground android:drawable="@mipmap/icon_foreground"/>
+    <monochrome android:drawable="@mipmap/icon_monochrome"/>
+</adaptive-icon>