Flutter iOS Embedder
FlutterDartProject.mm File Reference
#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterDartProject_Internal.h"
#include <syslog.h>
#import <Metal/Metal.h>
#include <sstream>
#include <string>
#include "flutter/common/constants.h"
#include "flutter/common/task_runners.h"
#include "flutter/fml/mapping.h"
#include "flutter/fml/message_loop.h"
#include "flutter/fml/platform/darwin/scoped_nsobject.h"
#include "flutter/runtime/dart_vm.h"
#include "flutter/shell/common/shell.h"
#include "flutter/shell/common/switches.h"
#import "flutter/shell/platform/darwin/common/command_line.h"
#import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"

Go to the source code of this file.

Macros

#define FML_USED_ON_EMBEDDER
 

Functions

static BOOL DoesHardwareSupportWideGamut ()
 
flutter::Settings FLTDefaultSettingsForBundle (NSBundle *bundle, NSProcessInfo *processInfoOrNil)
 

Variables

const FLUTTER_ASSERT_NOT_ARC uint8_t kPlatformStrongDill []
 
const intptr_t kPlatformStrongDillSize
 
static const char * kApplicationKernelSnapshotFileName = "kernel_blob.bin"
 

Macro Definition Documentation

◆ FML_USED_ON_EMBEDDER

#define FML_USED_ON_EMBEDDER

Definition at line 5 of file FlutterDartProject.mm.

Function Documentation

◆ DoesHardwareSupportWideGamut()

static BOOL DoesHardwareSupportWideGamut ( )
static

Definition at line 38 of file FlutterDartProject.mm.

38  {
39  static BOOL result = NO;
40  static dispatch_once_t once_token = 0;
41  dispatch_once(&once_token, ^{
42  id<MTLDevice> device = MTLCreateSystemDefaultDevice();
43  if (@available(iOS 13.0, *)) {
44  // MTLGPUFamilyApple2 = A9/A10
45  result = [device supportsFamily:MTLGPUFamilyApple2];
46  } else {
47  // A9/A10 on iOS 10+
48  result = [device supportsFeatureSet:MTLFeatureSet_iOS_GPUFamily3_v2];
49  }
50  [device release];
51  });
52  return result;
53 }

Referenced by FLTDefaultSettingsForBundle().

◆ FLTDefaultSettingsForBundle()

flutter::Settings FLTDefaultSettingsForBundle ( NSBundle *  bundle,
NSProcessInfo *  processInfoOrNil 
)

Definition at line 55 of file FlutterDartProject.mm.

55  {
56  auto command_line = flutter::CommandLineFromNSProcessInfo(processInfoOrNil);
57 
58  // Precedence:
59  // 1. Settings from the specified NSBundle (except for enable-impeller).
60  // 2. Settings passed explicitly via command-line arguments.
61  // 3. Settings from the NSBundle with the default bundle ID.
62  // 4. Settings from the main NSBundle and default values.
63 
64  NSBundle* mainBundle = FLTGetApplicationBundle();
65  NSBundle* engineBundle = [NSBundle bundleForClass:[FlutterViewController class]];
66 
67  bool hasExplicitBundle = bundle != nil;
68  if (bundle == nil) {
69  bundle = FLTFrameworkBundleWithIdentifier([FlutterDartProject defaultBundleIdentifier]);
70  }
71 
72  auto settings = flutter::SettingsFromCommandLine(command_line);
73 
74  settings.task_observer_add = [](intptr_t key, const fml::closure& callback) {
75  fml::MessageLoop::GetCurrent().AddTaskObserver(key, callback);
76  };
77 
78  settings.task_observer_remove = [](intptr_t key) {
79  fml::MessageLoop::GetCurrent().RemoveTaskObserver(key);
80  };
81 
82  settings.log_message_callback = [](const std::string& tag, const std::string& message) {
83  // TODO(cbracken): replace this with os_log-based approach.
84  // https://github.com/flutter/flutter/issues/44030
85  std::stringstream stream;
86  if (!tag.empty()) {
87  stream << tag << ": ";
88  }
89  stream << message;
90  std::string log = stream.str();
91  syslog(LOG_ALERT, "%.*s", (int)log.size(), log.c_str());
92  };
93 
94  // The command line arguments may not always be complete. If they aren't, attempt to fill in
95  // defaults.
96 
97  // Flutter ships the ICU data file in the bundle of the engine. Look for it there.
98  if (settings.icu_data_path.empty()) {
99  NSString* icuDataPath = [engineBundle pathForResource:@"icudtl" ofType:@"dat"];
100  if (icuDataPath.length > 0) {
101  settings.icu_data_path = icuDataPath.UTF8String;
102  }
103  }
104 
105  if (flutter::DartVM::IsRunningPrecompiledCode()) {
106  if (hasExplicitBundle) {
107  NSString* executablePath = bundle.executablePath;
108  if ([[NSFileManager defaultManager] fileExistsAtPath:executablePath]) {
109  settings.application_library_path.push_back(executablePath.UTF8String);
110  }
111  }
112 
113  // No application bundle specified. Try a known location from the main bundle's Info.plist.
114  if (settings.application_library_path.empty()) {
115  NSString* libraryName = [mainBundle objectForInfoDictionaryKey:@"FLTLibraryPath"];
116  NSString* libraryPath = [mainBundle pathForResource:libraryName ofType:@""];
117  if (libraryPath.length > 0) {
118  NSString* executablePath = [NSBundle bundleWithPath:libraryPath].executablePath;
119  if (executablePath.length > 0) {
120  settings.application_library_path.push_back(executablePath.UTF8String);
121  }
122  }
123  }
124 
125  // In case the application bundle is still not specified, look for the App.framework in the
126  // Frameworks directory.
127  if (settings.application_library_path.empty()) {
128  NSString* applicationFrameworkPath = [mainBundle pathForResource:@"Frameworks/App.framework"
129  ofType:@""];
130  if (applicationFrameworkPath.length > 0) {
131  NSString* executablePath =
132  [NSBundle bundleWithPath:applicationFrameworkPath].executablePath;
133  if (executablePath.length > 0) {
134  settings.application_library_path.push_back(executablePath.UTF8String);
135  }
136  }
137  }
138  }
139 
140  // Checks to see if the flutter assets directory is already present.
141  if (settings.assets_path.empty()) {
142  NSString* assetsPath = FLTAssetsPathFromBundle(bundle);
143 
144  if (assetsPath.length == 0) {
145  NSLog(@"Failed to find assets path for \"%@\"", bundle);
146  } else {
147  settings.assets_path = assetsPath.UTF8String;
148 
149  // Check if there is an application kernel snapshot in the assets directory we could
150  // potentially use. Looking for the snapshot makes sense only if we have a VM that can use
151  // it.
152  if (!flutter::DartVM::IsRunningPrecompiledCode()) {
153  NSURL* applicationKernelSnapshotURL =
154  [NSURL URLWithString:@(kApplicationKernelSnapshotFileName)
155  relativeToURL:[NSURL fileURLWithPath:assetsPath]];
156  NSError* error;
157  if ([applicationKernelSnapshotURL checkResourceIsReachableAndReturnError:&error]) {
158  settings.application_kernel_asset = applicationKernelSnapshotURL.path.UTF8String;
159  } else {
160  NSLog(@"Failed to find snapshot at %@: %@", applicationKernelSnapshotURL.path, error);
161  }
162  }
163  }
164  }
165 
166  // Domain network configuration
167  // Disabled in https://github.com/flutter/flutter/issues/72723.
168  // Re-enable in https://github.com/flutter/flutter/issues/54448.
169  settings.may_insecurely_connect_to_all_domains = true;
170  settings.domain_network_policy = "";
171 
172  // Whether to enable wide gamut colors.
173 #if TARGET_OS_SIMULATOR
174  // As of Xcode 14.1, the wide gamut surface pixel formats are not supported by
175  // the simulator.
176  settings.enable_wide_gamut = false;
177  // Removes unused function warning.
179 #else
180  NSNumber* nsEnableWideGamut = [mainBundle objectForInfoDictionaryKey:@"FLTEnableWideGamut"];
181  BOOL enableWideGamut =
182  (nsEnableWideGamut ? nsEnableWideGamut.boolValue : YES) && DoesHardwareSupportWideGamut();
183  settings.enable_wide_gamut = enableWideGamut;
184 #endif
185 
186  // TODO(dnfield): We should reverse the order for all these settings so that command line options
187  // are preferred to plist settings. https://github.com/flutter/flutter/issues/124049
188  // Whether to enable Impeller. If the command line explicitly
189  // specified an option for this, ignore what's in the plist.
190  if (!command_line.HasOption("enable-impeller")) {
191  // Next, look in the app bundle.
192  NSNumber* enableImpeller = [bundle objectForInfoDictionaryKey:@"FLTEnableImpeller"];
193  if (enableImpeller == nil) {
194  // If it isn't in the app bundle, look in the main bundle.
195  enableImpeller = [mainBundle objectForInfoDictionaryKey:@"FLTEnableImpeller"];
196  }
197  // Change the default only if the option is present.
198  if (enableImpeller != nil) {
199  settings.enable_impeller = enableImpeller.boolValue;
200  }
201  }
202 
203  settings.warn_on_impeller_opt_out = true;
204 
205  NSNumber* enableTraceSystrace = [mainBundle objectForInfoDictionaryKey:@"FLTTraceSystrace"];
206  // Change the default only if the option is present.
207  if (enableTraceSystrace != nil) {
208  settings.trace_systrace = enableTraceSystrace.boolValue;
209  }
210 
211  NSNumber* enableDartProfiling = [mainBundle objectForInfoDictionaryKey:@"FLTEnableDartProfiling"];
212  // Change the default only if the option is present.
213  if (enableDartProfiling != nil) {
214  settings.enable_dart_profiling = enableDartProfiling.boolValue;
215  }
216 
217  // Leak Dart VM settings, set whether leave or clean up the VM after the last shell shuts down.
218  NSNumber* leakDartVM = [mainBundle objectForInfoDictionaryKey:@"FLTLeakDartVM"];
219  // It will change the default leak_vm value in settings only if the key exists.
220  if (leakDartVM != nil) {
221  settings.leak_vm = leakDartVM.boolValue;
222  }
223 
224 #if FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG
225  // There are no ownership concerns here as all mappings are owned by the
226  // embedder and not the engine.
227  auto make_mapping_callback = [](const uint8_t* mapping, size_t size) {
228  return [mapping, size]() { return std::make_unique<fml::NonOwnedMapping>(mapping, size); };
229  };
230 
231  settings.dart_library_sources_kernel =
232  make_mapping_callback(kPlatformStrongDill, kPlatformStrongDillSize);
233 #endif // FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG
234 
235  // If we even support setting this e.g. from the command line or the plist,
236  // we should let the user override it.
237  // Otherwise, we want to set this to a value that will avoid having the OS
238  // kill us. On most iOS devices, that happens somewhere near half
239  // the available memory.
240  // The VM expects this value to be in megabytes.
241  if (settings.old_gen_heap_size <= 0) {
242  settings.old_gen_heap_size = std::round([NSProcessInfo processInfo].physicalMemory * .48 /
243  flutter::kMegaByteSizeInBytes);
244  }
245 
246  // This is the formula Android uses.
247  // https://android.googlesource.com/platform/frameworks/base/+/39ae5bac216757bc201490f4c7b8c0f63006c6cd/libs/hwui/renderthread/CacheManager.cpp#45
248  CGFloat scale = [UIScreen mainScreen].scale;
249  CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width * scale;
250  CGFloat screenHeight = [UIScreen mainScreen].bounds.size.height * scale;
251  settings.resource_cache_max_bytes_threshold = screenWidth * screenHeight * 12 * 4;
252 
253  // Whether to enable ios embedder api.
254  NSNumber* enable_embedder_api =
255  [mainBundle objectForInfoDictionaryKey:@"FLTEnableIOSEmbedderAPI"];
256  // Change the default only if the option is present.
257  if (enable_embedder_api) {
258  settings.enable_embedder_api = enable_embedder_api.boolValue;
259  }
260 
261  return settings;
262 }

References flutter::CommandLineFromNSProcessInfo(), DoesHardwareSupportWideGamut(), FLTAssetsPathFromBundle(), FLTFrameworkBundleWithIdentifier(), FLTGetApplicationBundle(), kApplicationKernelSnapshotFileName, kPlatformStrongDill, and kPlatformStrongDillSize.

Referenced by FlutterDartProject::initWithPrecompiledDartBundle:.

Variable Documentation

◆ kApplicationKernelSnapshotFileName

const char* kApplicationKernelSnapshotFileName = "kernel_blob.bin"
static

Definition at line 36 of file FlutterDartProject.mm.

Referenced by FLTDefaultSettingsForBundle().

◆ kPlatformStrongDill

const FLUTTER_ASSERT_NOT_ARC uint8_t kPlatformStrongDill[]

◆ kPlatformStrongDillSize

const intptr_t kPlatformStrongDillSize
kApplicationKernelSnapshotFileName
static const char * kApplicationKernelSnapshotFileName
Definition: FlutterDartProject.mm:36
FlutterViewController
Definition: FlutterViewController.h:56
kPlatformStrongDillSize
const intptr_t kPlatformStrongDillSize
DoesHardwareSupportWideGamut
static BOOL DoesHardwareSupportWideGamut()
Definition: FlutterDartProject.mm:38
FLTGetApplicationBundle
NSBundle * FLTGetApplicationBundle()
Definition: FlutterNSBundleUtils.mm:32
flutter::CommandLineFromNSProcessInfo
fml::CommandLine CommandLineFromNSProcessInfo(NSProcessInfo *processInfoOrNil=nil)
Definition: command_line.mm:11
FLTFrameworkBundleWithIdentifier
NSBundle * FLTFrameworkBundleWithIdentifier(NSString *flutterFrameworkBundleID)
Definition: FlutterNSBundleUtils.mm:43
FLTAssetsPathFromBundle
NSString * FLTAssetsPathFromBundle(NSBundle *bundle)
Definition: FlutterNSBundleUtils.mm:61
FlutterDartProject
Definition: FlutterDartProject.mm:264
kPlatformStrongDill
const FLUTTER_ASSERT_NOT_ARC uint8_t kPlatformStrongDill[]