Add alwaysUse24HourFormat and textScaleFactor (flutter/engine#4202)

* systems/settings channel split

* merge textScaleFactor and alwaysUse24HourFormat into flutter/settings channel

* add debugOverrideAlwaysUse24HourFormat

* implement textScaleFactor on iOS

* address comments

* remove debugOverrideAlwaysUse24HourFormat

* clang-format

engine/src/flutter/lib/ui/hooks.dart

@@ -32,11 +32,21 @@ void _updateLocale(String languageCode, String countryCode) {
   _invoke(window.onLocaleChanged, window._onLocaleChangedZone);
 }
 
+void _updateUserSettingsData(String json) {
+  final Map<String, dynamic> data = JSON.decode(json);
+  _updateTextScaleFactor(data['textScaleFactor'].toDouble());
+  _updateAlwaysUse24HourFormat(data['alwaysUse24HourFormat']);
+}
+
 void _updateTextScaleFactor(double textScaleFactor) {
   window._textScaleFactor = textScaleFactor;
   _invoke(window.onTextScaleFactorChanged, window._onTextScaleFactorChangedZone);
 }
 
+void _updateAlwaysUse24HourFormat(bool alwaysUse24HourFormat) {
+  window._alwaysUse24HourFormat = alwaysUse24HourFormat;
+}
+
 void _updateSemanticsEnabled(bool enabled) {
   window._semanticsEnabled = enabled;
   _invoke(window.onSemanticsEnabledChanged, window._onSemanticsEnabledChangedZone);

engine/src/flutter/lib/ui/window.dart

@@ -269,6 +269,13 @@ class Window {
   double get textScaleFactor => _textScaleFactor;
   double _textScaleFactor = 1.0;
 
+  /// The setting indicating whether time should always be shown in the 24-hour
+  /// format.
+  /// 
+  /// This option is used by [showTimePicker].
+  bool get alwaysUse24HourFormat => _alwaysUse24HourFormat;
+  bool _alwaysUse24HourFormat = false;
+
   /// A callback that is invoked whenever [textScaleFactor] changes value.
   ///
   /// The framework invokes this callback in the same zone in which the

engine/src/flutter/lib/ui/window/window.cc

@@ -163,15 +163,15 @@ void Window::UpdateLocale(const std::string& language_code,
                   });
 }
 
-void Window::UpdateTextScaleFactor(double text_scale_factor) {
+void Window::UpdateUserSettingsData(const std::string& data) {
   tonic::DartState* dart_state = library_.dart_state().get();
   if (!dart_state)
     return;
   tonic::DartState::Scope scope(dart_state);
 
-  DartInvokeField(library_.value(), "_updateTextScaleFactor",
+  DartInvokeField(library_.value(), "_updateUserSettingsData",
                   {
-                      ToDart(static_cast<double>(text_scale_factor)),
+                      StdStringToDart(data),
                   });
 }
 

engine/src/flutter/lib/ui/window/window.h

@@ -45,7 +45,7 @@ class Window {
   void UpdateWindowMetrics(const ViewportMetrics& metrics);
   void UpdateLocale(const std::string& language_code,
                     const std::string& country_code);
-  void UpdateTextScaleFactor(double text_scale_factor);
+  void UpdateUserSettingsData(const std::string& data);
   void UpdateSemanticsEnabled(bool enabled);
   void DispatchPlatformMessage(fxl::RefPtr<PlatformMessage> message);
   void DispatchPointerDataPacket(const PointerDataPacket& packet);

engine/src/flutter/runtime/runtime_controller.cc

@@ -66,11 +66,11 @@ void RuntimeController::SetLocale(const std::string& language_code,
   GetWindow()->UpdateLocale(language_code_, country_code_);
 }
 
-void RuntimeController::SetTextScaleFactor(double text_scale_factor) {
-  if (text_scale_factor_ == text_scale_factor)
+void RuntimeController::SetUserSettingsData(const std::string& data) {
+  if (user_settings_data_ == data)
     return;
-  text_scale_factor_ = text_scale_factor;
-  GetWindow()->UpdateTextScaleFactor(text_scale_factor_);
+  user_settings_data_ = data;
+  GetWindow()->UpdateUserSettingsData(user_settings_data_);
 }
 
 void RuntimeController::SetSemanticsEnabled(bool enabled) {

engine/src/flutter/runtime/runtime_controller.h

@@ -35,7 +35,7 @@ class RuntimeController : public WindowClient, public IsolateClient {
   void SetViewportMetrics(const ViewportMetrics& metrics);
   void SetLocale(const std::string& language_code,
                  const std::string& country_code);
-  void SetTextScaleFactor(double textScaleFactor);
+  void SetUserSettingsData(const std::string& data);
   void SetSemanticsEnabled(bool enabled);
 
   void BeginFrame(fxl::TimePoint frame_time);
@@ -66,7 +66,7 @@ class RuntimeController : public WindowClient, public IsolateClient {
   RuntimeDelegate* client_;
   std::string language_code_;
   std::string country_code_;
-  double text_scale_factor_ = 1.0;
+  std::string user_settings_data_ = "{}";
   bool semantics_enabled_ = false;
   std::unique_ptr<DartController> dart_controller_;
 

engine/src/flutter/shell/common/engine.cc

@@ -44,7 +44,7 @@ constexpr char kAssetChannel[] = "flutter/assets";
 constexpr char kLifecycleChannel[] = "flutter/lifecycle";
 constexpr char kNavigationChannel[] = "flutter/navigation";
 constexpr char kLocalizationChannel[] = "flutter/localization";
-constexpr char kSystemChannel[] = "flutter/system";
+constexpr char kSettingsChannel[] = "flutter/settings";
 
 bool PathExists(const std::string& path) {
   return access(path.c_str(), R_OK) == 0;
@@ -75,7 +75,7 @@ Engine::Engine(PlatformView* platform_view)
           platform_view->GetVsyncWaiter(),
           this)),
       load_script_error_(tonic::kNoError),
-      text_scale_factor_(1.0),
+      user_settings_data_("{}"),
       activity_running_(false),
       have_surface_(false),
       weak_factory_(this) {}
@@ -337,11 +337,9 @@ void Engine::DispatchPlatformMessage(
   } else if (message->channel() == kLocalizationChannel) {
     if (HandleLocalizationPlatformMessage(message.get()))
       return;
-  } else if (message->channel() == kSystemChannel) {
-    // This only handles textScaleFactor changes: other system messages are
-    // handled by DispatchPlatformMessage below.
-    if (HandleSystemPlatformMessage(message.get()))
-      return;
+  } else if (message->channel() == kSettingsChannel) {
+    HandleSettingsPlatformMessage(message.get());
+    return;
   }
 
   if (runtime_) {
@@ -424,35 +422,15 @@ bool Engine::HandleLocalizationPlatformMessage(
   return true;
 }
 
-bool Engine::HandleSystemPlatformMessage(blink::PlatformMessage* message) {
+void Engine::HandleSettingsPlatformMessage(blink::PlatformMessage* message) {
   const auto& data = message->data();
-  rapidjson::Document document;
-  document.Parse(reinterpret_cast<const char*>(data.data()), data.size());
-
-  if (document.HasParseError() || !document.IsObject())
-    return false;
-
-  auto root = document.GetObject();
-  auto type = root.FindMember("type");
-  if (type == root.MemberEnd() || type->value != "systemSettings")
-    return false;
-
-  // This only handles textScaleFactor changes: other system messages
-  // are handled by DispatchPlatformMessage.
-  auto text_scale_factor = root.FindMember("textScaleFactor");
-  if (text_scale_factor == root.MemberEnd() ||
-      !text_scale_factor->value.IsDouble()) {
-    return false;
-  }
-  text_scale_factor_ = text_scale_factor->value.GetDouble();
+  std::string jsonData(reinterpret_cast<const char*>(data.data()), data.size());
+  user_settings_data_ = jsonData;
   if (runtime_) {
-    runtime_->SetTextScaleFactor(text_scale_factor_);
+    runtime_->SetUserSettingsData(user_settings_data_);
     if (have_surface_)
       ScheduleFrame();
   }
-  // If the only members were "type" and "textScaleFactor", then we're done.
-  // If there are more members, then we need to send it on to other handlers.
-  return root.MemberCount() == 2;
 }
 
 void Engine::DispatchPointerDataPacket(const PointerDataPacket& packet) {
@@ -507,7 +485,7 @@ void Engine::ConfigureRuntime(const std::string& script_uri,
         default_isolate_snapshot_instr, platform_kernel);
     runtime_->SetViewportMetrics(viewport_metrics_);
     runtime_->SetLocale(language_code_, country_code_);
-    runtime_->SetTextScaleFactor(text_scale_factor_);
+    runtime_->SetUserSettingsData(user_settings_data_);
     runtime_->SetSemanticsEnabled(semantics_enabled_);
   }
 }

engine/src/flutter/shell/common/engine.h

@@ -97,7 +97,7 @@ class Engine : public blink::RuntimeDelegate {
   bool HandleNavigationPlatformMessage(
       fxl::RefPtr<blink::PlatformMessage> message);
   bool HandleLocalizationPlatformMessage(blink::PlatformMessage* message);
-  bool HandleSystemPlatformMessage(blink::PlatformMessage* message);
+  void HandleSettingsPlatformMessage(blink::PlatformMessage* message);
 
   void HandleAssetPlatformMessage(fxl::RefPtr<blink::PlatformMessage> message);
   bool GetAssetAsBuffer(const std::string& name, std::vector<uint8_t>* data);
@@ -112,7 +112,7 @@ class Engine : public blink::RuntimeDelegate {
   blink::ViewportMetrics viewport_metrics_;
   std::string language_code_;
   std::string country_code_;
-  double text_scale_factor_;
+  std::string user_settings_data_;
   bool semantics_enabled_ = false;
   // TODO(abarth): Unify these two behind a common interface.
   fxl::RefPtr<blink::ZipAssetStore> asset_store_;

engine/src/flutter/shell/platform/android/io/flutter/view/FlutterView.java

@@ -17,6 +17,7 @@ import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Matrix;
 import android.os.Build;
+import android.text.format.DateFormat;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.TypedValue;
@@ -101,6 +102,7 @@ public class FlutterView extends SurfaceView
     private final BasicMessageChannel<Object> mFlutterKeyEventChannel;
     private final BasicMessageChannel<String> mFlutterLifecycleChannel;
     private final BasicMessageChannel<Object> mFlutterSystemChannel;
+    private final BasicMessageChannel<Object> mFlutterSettingsChannel;
     private final BroadcastReceiver mDiscoveryReceiver;
     private final List<ActivityLifecycleListener> mActivityLifecycleListeners;
     private final List<FirstFrameListener> mFirstFrameListeners;
@@ -173,6 +175,8 @@ public class FlutterView extends SurfaceView
             StringCodec.INSTANCE);
         mFlutterSystemChannel = new BasicMessageChannel<>(this, "flutter/system",
             JSONMessageCodec.INSTANCE);
+        mFlutterSettingsChannel = new BasicMessageChannel<>(this, "flutter/settings",
+            JSONMessageCodec.INSTANCE);
 
         // TODO(plugins): Change PlatformPlugin to accept a Context. Disable the
         // operations that require an Activity when a Context is passed.
@@ -186,7 +190,7 @@ public class FlutterView extends SurfaceView
         mTextInputPlugin = new TextInputPlugin(this);
 
         setLocale(getResources().getConfiguration().locale);
-        setTextScaleFactor(getResources().getConfiguration().fontScale);
+        setUserSettings();
 
         if ((context.getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0) {
             mDiscoveryReceiver = new DiscoveryReceiver();
@@ -284,11 +288,11 @@ public class FlutterView extends SurfaceView
         mFlutterNavigationChannel.invokeMethod("popRoute", null);
     }
 
-    private void setTextScaleFactor(float textScaleFactor) {
+    private void setUserSettings() {
       Map<String, Object> message = new HashMap<>();
-      message.put("type", "systemSettings");
-      message.put("textScaleFactor", textScaleFactor);
-      mFlutterSystemChannel.send(message);
+      message.put("textScaleFactor", getResources().getConfiguration().fontScale);
+      message.put("alwaysUse24HourFormat", DateFormat.is24HourFormat(getContext()));
+      mFlutterSettingsChannel.send(message);
     }
 
     private void setLocale(Locale locale) {
@@ -300,7 +304,7 @@ public class FlutterView extends SurfaceView
     protected void onConfigurationChanged(Configuration newConfig) {
         super.onConfigurationChanged(newConfig);
         setLocale(newConfig.locale);
-        setTextScaleFactor(newConfig.fontScale);
+        setUserSettings();
     }
 
     float getDevicePixelRatio() {

engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -72,6 +72,7 @@ class PlatformMessageResponseDarwin : public blink::PlatformMessageResponse {
   fml::scoped_nsprotocol<FlutterMethodChannel*> _textInputChannel;
   fml::scoped_nsprotocol<FlutterBasicMessageChannel*> _lifecycleChannel;
   fml::scoped_nsprotocol<FlutterBasicMessageChannel*> _systemChannel;
+  fml::scoped_nsprotocol<FlutterBasicMessageChannel*> _settingsChannel;
   fml::scoped_nsprotocol<UIView*> _launchView;
   bool _platformSupportsTouchTypes;
   bool _platformSupportsTouchPressure;
@@ -177,6 +178,11 @@ class PlatformMessageResponseDarwin : public blink::PlatformMessageResponse {
       binaryMessenger:self
                 codec:[FlutterJSONMessageCodec sharedInstance]]);
 
+  _settingsChannel.reset([[FlutterBasicMessageChannel alloc]
+         initWithName:@"flutter/settings"
+      binaryMessenger:self
+                codec:[FlutterJSONMessageCodec sharedInstance]]);
+
   _platformPlugin.reset([[FlutterPlatformPlugin alloc] init]);
   [_platformChannel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
     [_platformPlugin.get() handleMethodCall:call result:result];
@@ -247,6 +253,11 @@ class PlatformMessageResponseDarwin : public blink::PlatformMessageResponse {
              selector:@selector(onMemoryWarning:)
                  name:UIApplicationDidReceiveMemoryWarningNotification
                object:nil];
+
+  [center addObserver:self
+             selector:@selector(onUserSettingsChanged:)
+                 name:UIContentSizeCategoryDidChangeNotification
+               object:nil];
 }
 
 - (void)setInitialRoute:(NSString*)route {
@@ -340,6 +351,7 @@ class PlatformMessageResponseDarwin : public blink::PlatformMessageResponse {
 - (void)viewDidAppear:(BOOL)animated {
   TRACE_EVENT0("flutter", "viewDidAppear");
   [self onLocaleUpdated:nil];
+  [self onUserSettingsChanged:nil];
   [self onVoiceOverChanged:nil];
   [_lifecycleChannel.get() sendMessage:@"AppLifecycleState.resumed"];
 
@@ -693,6 +705,60 @@ static inline blink::PointerData::DeviceKind DeviceKindFromTouchType(UITouch* to
   [_localizationChannel.get() invokeMethod:@"setLocale" arguments:@[ languageCode, countryCode ]];
 }
 
+#pragma mark - Set user settings
+
+- (void)onUserSettingsChanged:(NSNotification*)notification {
+  [_settingsChannel.get() sendMessage:@{
+    @"textScaleFactor" : @([self textScaleFactor]),
+    @"alwaysUse24HourFormat" : @([self isAlwaysUse24HourFormat]),
+  }];
+}
+
+- (CGFloat)textScaleFactor {
+  UIContentSizeCategory category = [UIApplication sharedApplication].preferredContentSizeCategory;
+  // The delta is computed based on the following:
+  // - L (large) is the default 1.0 scale.
+  // - The scale is linear spanning from XS to XXXL.
+  // - XXXL = 1.4 * XS.
+  //
+  // L    = 1.0      = XS + 3 * delta
+  // XXXL = 1.4 * XS = XS + 6 * delta
+  const CGFloat delta = 0.055555;
+  if ([category isEqualToString:UIContentSizeCategoryExtraSmall])
+    return 1.0 - 3 * delta;
+  else if ([category isEqualToString:UIContentSizeCategorySmall])
+    return 1.0 - 2 * delta;
+  else if ([category isEqualToString:UIContentSizeCategoryMedium])
+    return 1.0 - delta;
+  else if ([category isEqualToString:UIContentSizeCategoryLarge])
+    return 1.0;
+  else if ([category isEqualToString:UIContentSizeCategoryExtraLarge])
+    return 1.0 + delta;
+  else if ([category isEqualToString:UIContentSizeCategoryExtraExtraLarge])
+    return 1.0 + 2 * delta;
+  else if ([category isEqualToString:UIContentSizeCategoryExtraExtraExtraLarge])
+    return 1.0 + 3 * delta;
+  else
+    return 1.0;
+}
+
+- (BOOL)isAlwaysUse24HourFormat {
+  // iOS does not report its "24-Hour Time" user setting in the API. Instead, it applies
+  // it automatically to NSDateFormatter when used with [NSLocale currentLocale]. It is
+  // essential that [NSLocale currentLocale] is used. Any custom locale, even the one
+  // that's the same as [NSLocale currentLocale] will ignore the 24-hour option (there
+  // must be some internal field that's not exposed to developers).
+  //
+  // Therefore this option behaves differently across Android and iOS. On Android this
+  // setting is exposed standalone, and can therefore be applied to all locales, whether
+  // the "current system locale" or a custom one. On iOS it only applies to the current
+  // system locale. Widget implementors must take this into account in order to provide
+  // platform-idiomatic behavior in their widgets.
+  NSString* dateFormat =
+      [NSDateFormatter dateFormatFromTemplate:@"j" options:0 locale:[NSLocale currentLocale]];
+  return [dateFormat rangeOfString:@"a"].location == NSNotFound;
+}
+
 #pragma mark - Status Bar touch event handling
 
 // Standard iOS status bar height in pixels.