shell/platform/darwin/common/platform_mac.mm

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "flutter/shell/platform/darwin/common/platform_mac.h"

#include <Foundation/Foundation.h>

#include "flutter/common/threads.h"
#include "flutter/fml/trace_event.h"
#include "flutter/runtime/start_up.h"
#include "flutter/shell/common/shell.h"
#include "flutter/shell/common/switches.h"
#include "flutter/shell/common/tracing_controller.h"
#include "flutter/sky/engine/wtf/MakeUnique.h"
#include "lib/fxl/command_line.h"
#include "lib/fxl/strings/string_view.h"
#include "third_party/dart/runtime/include/dart_tools_api.h"

namespace shell {

static fxl::CommandLine InitializedCommandLine() {
  std::vector<std::string> args_vector;

  for (NSString* arg in [NSProcessInfo processInfo].arguments) {
    args_vector.emplace_back(arg.UTF8String);
  }

  return fxl::CommandLineFromIterators(args_vector.begin(), args_vector.end());
}

class EmbedderState {
 public:
  EmbedderState(std::string icu_data_path, std::string application_library_path) {
#if TARGET_OS_IPHONE
    // This calls crashes on MacOS because we haven't run Dart_Initialize yet.
    // See https://github.com/flutter/flutter/issues/4006
    blink::engine_main_enter_ts = Dart_TimelineGetMicros();
#endif
    FXL_DCHECK([NSThread isMainThread])
        << "Embedder initialization must occur on the main platform thread";

    auto command_line = InitializedCommandLine();

    // This is about as early as tracing of any kind can start. Add an instant
    // marker that can be used as a reference for startup.
    TRACE_EVENT_INSTANT0("flutter", "main");

    shell::Shell::InitStandalone(std::move(command_line), icu_data_path, application_library_path);
  }

  ~EmbedderState() {}

 private:
  FXL_DISALLOW_COPY_AND_ASSIGN(EmbedderState);
};

void PlatformMacMain(std::string icu_data_path, std::string application_library_path) {
  static std::unique_ptr<EmbedderState> g_embedder;
  static std::once_flag once_main;

  std::call_once(once_main, [&]() {
    g_embedder = WTF::MakeUnique<EmbedderState>(icu_data_path, application_library_path);
  });
}

static bool FlagsValidForCommandLineLaunch(const std::string& bundle_path,
                                           const std::string& main,
                                           const std::string& packages) {
  if (main.empty() || packages.empty() || bundle_path.empty()) {
    return false;
  }

  // Ensure that the paths exists. This catches cases where the user has
  // successfully launched the application from the tooling but has since moved
  // the source files on disk and is launching again directly.

  NSFileManager* manager = [NSFileManager defaultManager];

  if (![manager fileExistsAtPath:@(main.c_str())]) {
    return false;
  }

  if (![manager fileExistsAtPath:@(packages.c_str())]) {
    return false;
  }

  if (![manager fileExistsAtPath:@(bundle_path.c_str())]) {
    return false;
  }

  return true;
}

static std::string ResolveCommandLineLaunchFlag(const fxl::StringView name) {
  const auto& command_line = shell::Shell::Shared().GetCommandLine();

  std::string command_line_option;
  if (command_line.GetOptionValue(name, &command_line_option)) {
    return command_line_option;
  }

  const char* saved_default =
      [[NSUserDefaults standardUserDefaults] stringForKey:@(name.data())].UTF8String;

  if (saved_default != NULL) {
    return saved_default;
  }

  return "";
}

bool AttemptLaunchFromCommandLineSwitches(Engine* engine) {
  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];

  const auto& command_line = shell::Shell::Shared().GetCommandLine();

  if (command_line.HasOption(FlagForSwitch(Switch::FlutterAssetsDir)) ||
      command_line.HasOption(FlagForSwitch(Switch::MainDartFile)) ||
      command_line.HasOption(FlagForSwitch(Switch::Packages))) {
    // The main dart file, Flutter assets directory and the package root must be
    // specified in one go. We dont want to end up in a situation where we take
    // one value from the command line and the others from user defaults. In
    // case, any new flags are specified, forget about all the old ones.
    [defaults removeObjectForKey:@(FlagForSwitch(Switch::FlutterAssetsDir).data())];
    [defaults removeObjectForKey:@(FlagForSwitch(Switch::MainDartFile).data())];
    [defaults removeObjectForKey:@(FlagForSwitch(Switch::Packages).data())];

    [defaults synchronize];
  }

  std::string bundle_path = ResolveCommandLineLaunchFlag(FlagForSwitch(Switch::FlutterAssetsDir));
  std::string main = ResolveCommandLineLaunchFlag(FlagForSwitch(Switch::MainDartFile));
  std::string packages = ResolveCommandLineLaunchFlag(FlagForSwitch(Switch::Packages));

  if (!FlagsValidForCommandLineLaunch(bundle_path, main, packages)) {
    return false;
  }

  // Save the newly resolved dart main file and the package root to user
  // defaults so that the next time the user launches the application in the
  // simulator without the tooling, the application boots up.
  [defaults setObject:@(bundle_path.c_str())
               forKey:@(FlagForSwitch(Switch::FlutterAssetsDir).data())];
  [defaults setObject:@(main.c_str()) forKey:@(FlagForSwitch(Switch::MainDartFile).data())];
  [defaults setObject:@(packages.c_str()) forKey:@(FlagForSwitch(Switch::Packages).data())];

  [defaults synchronize];

  blink::Threads::UI()->PostTask([ engine = engine->GetWeakPtr(), bundle_path, main, packages ] {
    if (engine)
      engine->RunBundleAndSource(bundle_path, main, packages);
  });

  return true;
}

}  // namespace shell