update: move pictures, remove initial flutter code

app/linux/main.cc

-#include "my_application.h"
-
-int main(int argc, char** argv) {
-  g_autoptr(MyApplication) app = my_application_new();
-  return g_application_run(G_APPLICATION(app), argc, argv);
-}

app/linux/my_application.cc

-#include "my_application.h"
-
-#include <flutter_linux/flutter_linux.h>
-#ifdef GDK_WINDOWING_X11
-#include <gdk/gdkx.h>
-#endif
-
-#include "flutter/generated_plugin_registrant.h"
-
-struct _MyApplication {
-  GtkApplication parent_instance;
-  char** dart_entrypoint_arguments;
-};
-
-G_DEFINE_TYPE(MyApplication, my_application, GTK_TYPE_APPLICATION)
-
-// Implements GApplication::activate.
-static void my_application_activate(GApplication* application) {
-  MyApplication* self = MY_APPLICATION(application);
-  GtkWindow* window =
-      GTK_WINDOW(gtk_application_window_new(GTK_APPLICATION(application)));
-
-  // Use a header bar when running in GNOME as this is the common style used
-  // by applications and is the setup most users will be using (e.g. Ubuntu
-  // desktop).
-  // If running on X and not using GNOME then just use a traditional title bar
-  // in case the window manager does more exotic layout, e.g. tiling.
-  // If running on Wayland assume the header bar will work (may need changing
-  // if future cases occur).
-  gboolean use_header_bar = TRUE;
-#ifdef GDK_WINDOWING_X11
-  GdkScreen* screen = gtk_window_get_screen(window);
-  if (GDK_IS_X11_SCREEN(screen)) {
-    const gchar* wm_name = gdk_x11_screen_get_window_manager_name(screen);
-    if (g_strcmp0(wm_name, "GNOME Shell") != 0) {
-      use_header_bar = FALSE;
-    }
-  }
-#endif
-  if (use_header_bar) {
-    GtkHeaderBar* header_bar = GTK_HEADER_BAR(gtk_header_bar_new());
-    gtk_widget_show(GTK_WIDGET(header_bar));
-    gtk_header_bar_set_title(header_bar, "ice_map");
-    gtk_header_bar_set_show_close_button(header_bar, TRUE);
-    gtk_window_set_titlebar(window, GTK_WIDGET(header_bar));
-  } else {
-    gtk_window_set_title(window, "ice_map");
-  }
-
-  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);
-  gtk_widget_show(GTK_WIDGET(view));
-  gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(view));
-
-  fl_register_plugins(FL_PLUGIN_REGISTRY(view));
-
-  gtk_widget_grab_focus(GTK_WIDGET(view));
-}
-
-// Implements GApplication::local_command_line.
-static gboolean my_application_local_command_line(GApplication* application, gchar*** arguments, int* exit_status) {
-  MyApplication* self = MY_APPLICATION(application);
-  // Strip out the first argument as it is the binary name.
-  self->dart_entrypoint_arguments = g_strdupv(*arguments + 1);
-
-  g_autoptr(GError) error = nullptr;
-  if (!g_application_register(application, nullptr, &error)) {
-     g_warning("Failed to register: %s", error->message);
-     *exit_status = 1;
-     return TRUE;
-  }
-
-  g_application_activate(application);
-  *exit_status = 0;
-
-  return TRUE;
-}
-
-// Implements GObject::dispose.
-static void my_application_dispose(GObject* object) {
-  MyApplication* self = MY_APPLICATION(object);
-  g_clear_pointer(&self->dart_entrypoint_arguments, g_strfreev);
-  G_OBJECT_CLASS(my_application_parent_class)->dispose(object);
-}
-
-static void my_application_class_init(MyApplicationClass* klass) {
-  G_APPLICATION_CLASS(klass)->activate = my_application_activate;
-  G_APPLICATION_CLASS(klass)->local_command_line = my_application_local_command_line;
-  G_OBJECT_CLASS(klass)->dispose = my_application_dispose;
-}
-
-static void my_application_init(MyApplication* self) {}
-
-MyApplication* my_application_new() {
-  return MY_APPLICATION(g_object_new(my_application_get_type(),
-                                     "application-id", APPLICATION_ID,
-                                     "flags", G_APPLICATION_NON_UNIQUE,
-                                     nullptr));
-}

app/linux/my_application.h

-#ifndef FLUTTER_MY_APPLICATION_H_
-#define FLUTTER_MY_APPLICATION_H_
-
-#include <gtk/gtk.h>
-
-G_DECLARE_FINAL_TYPE(MyApplication, my_application, MY, APPLICATION,
-                     GtkApplication)
-
-/**
- * my_application_new:
- *
- * Creates a new Flutter-based application.
- *
- * Returns: a new #MyApplication.
- */
-MyApplication* my_application_new();
-
-#endif  // FLUTTER_MY_APPLICATION_H_

app/macos/.gitignore

-# Flutter-related
-**/Flutter/ephemeral/
-**/Pods/
-
-# Xcode-related
-**/dgph
-**/xcuserdata/

app/macos/Flutter/Flutter-Debug.xcconfig

-#include "ephemeral/Flutter-Generated.xcconfig"

app/macos/Flutter/Flutter-Release.xcconfig

-#include "ephemeral/Flutter-Generated.xcconfig"

app/macos/Flutter/GeneratedPluginRegistrant.swift

-//
-//  Generated file. Do not edit.
-//
-
-import FlutterMacOS
-import Foundation
-
-
-func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
-}

app/macos/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>IDEDidComputeMac32BitWarning</key>
-	<true/>
-</dict>
-</plist>

app/macos/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

-<?xml version="1.0" encoding="UTF-8"?>
-<Scheme
-   LastUpgradeVersion = "1430"
-   version = "1.3">
-   <BuildAction
-      parallelizeBuildables = "YES"
-      buildImplicitDependencies = "YES">
-      <BuildActionEntries>
-         <BuildActionEntry
-            buildForTesting = "YES"
-            buildForRunning = "YES"
-            buildForProfiling = "YES"
-            buildForArchiving = "YES"
-            buildForAnalyzing = "YES">
-            <BuildableReference
-               BuildableIdentifier = "primary"
-               BlueprintIdentifier = "33CC10EC2044A3C60003C045"
-               BuildableName = "ice_map.app"
-               BlueprintName = "Runner"
-               ReferencedContainer = "container:Runner.xcodeproj">
-            </BuildableReference>
-         </BuildActionEntry>
-      </BuildActionEntries>
-   </BuildAction>
-   <TestAction
-      buildConfiguration = "Debug"
-      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
-      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "33CC10EC2044A3C60003C045"
-            BuildableName = "ice_map.app"
-            BlueprintName = "Runner"
-            ReferencedContainer = "container:Runner.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <Testables>
-         <TestableReference
-            skipped = "NO"
-            parallelizable = "YES">
-            <BuildableReference
-               BuildableIdentifier = "primary"
-               BlueprintIdentifier = "331C80D4294CF70F00263BE5"
-               BuildableName = "RunnerTests.xctest"
-               BlueprintName = "RunnerTests"
-               ReferencedContainer = "container:Runner.xcodeproj">
-            </BuildableReference>
-         </TestableReference>
-      </Testables>
-   </TestAction>
-   <LaunchAction
-      buildConfiguration = "Debug"
-      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
-      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      launchStyle = "0"
-      useCustomWorkingDirectory = "NO"
-      ignoresPersistentStateOnLaunch = "NO"
-      debugDocumentVersioning = "YES"
-      debugServiceExtension = "internal"
-      allowLocationSimulation = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "33CC10EC2044A3C60003C045"
-            BuildableName = "ice_map.app"
-            BlueprintName = "Runner"
-            ReferencedContainer = "container:Runner.xcodeproj">
-         </BuildableReference>
-      </BuildableProductRunnable>
-   </LaunchAction>
-   <ProfileAction
-      buildConfiguration = "Profile"
-      shouldUseLaunchSchemeArgsEnv = "YES"
-      savedToolIdentifier = ""
-      useCustomWorkingDirectory = "NO"
-      debugDocumentVersioning = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "33CC10EC2044A3C60003C045"
-            BuildableName = "ice_map.app"
-            BlueprintName = "Runner"
-            ReferencedContainer = "container:Runner.xcodeproj">
-         </BuildableReference>
-      </BuildableProductRunnable>
-   </ProfileAction>
-   <AnalyzeAction
-      buildConfiguration = "Debug">
-   </AnalyzeAction>
-   <ArchiveAction
-      buildConfiguration = "Release"
-      revealArchiveInOrganizer = "YES">
-   </ArchiveAction>
-</Scheme>

app/macos/Runner.xcworkspace/contents.xcworkspacedata

-<?xml version="1.0" encoding="UTF-8"?>
-<Workspace
-   version = "1.0">
-   <FileRef
-      location = "group:Runner.xcodeproj">
-   </FileRef>
-</Workspace>

app/macos/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>IDEDidComputeMac32BitWarning</key>
-	<true/>
-</dict>
-</plist>

app/macos/Runner/AppDelegate.swift

-import Cocoa
-import FlutterMacOS
-
-@NSApplicationMain
-class AppDelegate: FlutterAppDelegate {
-  override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
-    return true
-  }
-}

app/macos/Runner/Assets.xcassets/AppIcon.appiconset/Contents.json

-{
-  "images" : [
-    {
-      "size" : "16x16",
-      "idiom" : "mac",
-      "filename" : "app_icon_16.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "16x16",
-      "idiom" : "mac",
-      "filename" : "app_icon_32.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "32x32",
-      "idiom" : "mac",
-      "filename" : "app_icon_32.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "32x32",
-      "idiom" : "mac",
-      "filename" : "app_icon_64.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "128x128",
-      "idiom" : "mac",
-      "filename" : "app_icon_128.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "128x128",
-      "idiom" : "mac",
-      "filename" : "app_icon_256.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "256x256",
-      "idiom" : "mac",
-      "filename" : "app_icon_256.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "256x256",
-      "idiom" : "mac",
-      "filename" : "app_icon_512.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "512x512",
-      "idiom" : "mac",
-      "filename" : "app_icon_512.png",
-      "scale" : "1x"
-    },
-    {
-      "size" : "512x512",
-      "idiom" : "mac",
-      "filename" : "app_icon_1024.png",
-      "scale" : "2x"
-    }
-  ],
-  "info" : {
-    "version" : 1,
-    "author" : "xcode"
-  }
-}