Update for Flutter 3.35 (#2313)

## Pre-launch Checklist

- [x] I read the [Effective Dart: Style] _recently_, and have followed
its advice.
- [x] I signed the [CLA].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel
channel on [Discord].

<!-- Links -->
[Effective Dart: Style]:
https://dart.dev/guides/language/effective-dart/style
[CLA]: https://cla.developers.google.com/
[Discord]:
https://github.com/flutter/flutter/blob/master/docs/contributing/Chat.md

Author: domesticmouse

adaptive_app/codelab_rebuild.yaml

@@ -0,0 +1,10 @@
+{
+    "mcpServers": {
+        "dart": {
+            "command": "dart",
+            "args": [
+                "mcp-server"
+            ]
+        }
+    }
+}

adaptive_app/step_03/.gemini/settings.json

@@ -27,11 +27,11 @@ migrate_working_dir/
 **/doc/api/
 **/ios/Flutter/.last_build_id
 .dart_tool/
-.flutter-plugins
 .flutter-plugins-dependencies
 .pub-cache/
 .pub/
 /build/
+/coverage/
 
 # Symbolication related
 app.*.symbols

adaptive_app/step_03/.gitignore

@@ -5,7 +5,10 @@ allprojects {
     }
 }
 
-val newBuildDir: Directory = rootProject.layout.buildDirectory.dir("../../build").get()
+val newBuildDir: Directory =
+    rootProject.layout.buildDirectory
+        .dir("../../build")
+        .get()
 rootProject.layout.buildDirectory.value(newBuildDir)
 
 subprojects {

adaptive_app/step_03/android/build.gradle.kts

@@ -1,11 +1,12 @@
 pluginManagement {
-    val flutterSdkPath = run {
-        val properties = java.util.Properties()
-        file("local.properties").inputStream().use { properties.load(it) }
-        val flutterSdkPath = properties.getProperty("flutter.sdk")
-        require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
-        flutterSdkPath
-    }
+    val flutterSdkPath =
+        run {
+            val properties = java.util.Properties()
+            file("local.properties").inputStream().use { properties.load(it) }
+            val flutterSdkPath = properties.getProperty("flutter.sdk")
+            require(flutterSdkPath != null) { "flutter.sdk not set in local.properties" }
+            flutterSdkPath
+        }
 
     includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")
 
@@ -18,7 +19,7 @@ pluginManagement {
 
 plugins {
     id("dev.flutter.flutter-plugin-loader") version "1.0.0"
-    id("com.android.application") version "8.7.3" apply false
+    id("com.android.application") version "8.9.1" apply false
     id("org.jetbrains.kotlin.android") version "2.1.0" apply false
 }
 

adaptive_app/step_03/android/settings.gradle.kts

@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>12.0</string>
+  <string>13.0</string>
 </dict>
 </plist>

adaptive_app/step_03/ios/Flutter/AppFrameworkInfo.plist

@@ -346,7 +346,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
@@ -472,7 +472,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -523,7 +523,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 13.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;

adaptive_app/step_03/ios/Runner.xcodeproj/project.pbxproj

@@ -14,6 +14,12 @@ struct _MyApplication {
 
 G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
 
+// Called when first Flutter frame received.
+static void first_frame_cb(MyApplication* self, FlView *view)
+{
+  gtk_widget_show(gtk_widget_get_toplevel(GTK_WIDGET(view)));
+}
+
 // Implements GApplication::activate.
 static void my_application_activate(GApplication* application) {
   MyApplication* self = MY_APPLICATION(application);
@@ -48,15 +54,23 @@ static void my_application_activate(GApplication* application) {
   }
 
   gtk_window_set_default_size(window, 1280, 720);
-  gtk_widget_show(GTK_WIDGET(window));
 
   g_autoptr(FlDartProject) project = fl_dart_project_new();
   fl_dart_project_set_dart_entrypoint_arguments(project, self->dart_entrypoint_arguments);
 
   FlView* view = fl_view_new(project);
+  GdkRGBA background_color;
+  // Background defaults to black, override it here if necessary, e.g. #00000000 for transparent.
+  gdk_rgba_parse(&background_color, "#000000");
+  fl_view_set_background_color(view, &background_color);
   gtk_widget_show(GTK_WIDGET(view));
   gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(view));
 
+  // Show the window when Flutter renders.
+  // Requires the view to be realized so we can start rendering.
+  g_signal_connect_swapped(view, "first-frame", G_CALLBACK(first_frame_cb), self);
+  gtk_widget_realize(GTK_WIDGET(view));
+
   fl_register_plugins(FL_PLUGIN_REGISTRY(view));
 
   gtk_widget_grab_focus(GTK_WIDGET(view));

adaptive_app/step_03/linux/runner/my_application.cc

@@ -461,7 +461,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.14;
+				MACOSX_DEPLOYMENT_TARGET = 10.15;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_COMPILATION_MODE = wholemodule;
@@ -543,7 +543,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.14;
+				MACOSX_DEPLOYMENT_TARGET = 10.15;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = macosx;
@@ -593,7 +593,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				MACOSX_DEPLOYMENT_TARGET = 10.14;
+				MACOSX_DEPLOYMENT_TARGET = 10.15;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_COMPILATION_MODE = wholemodule;

adaptive_app/step_03/macos/Runner.xcodeproj/project.pbxproj

@@ -19,7 +19,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ^3.8.1
+  sdk: ^3.9.0-0
 
 # Dependencies specify other packages that your package needs in order to work.
 # To automatically upgrade your package dependencies to the latest versions