System chrome platform service updates

sky/services/platform/ios/system_chrome_impl.h

@@ -22,10 +22,18 @@ class SystemChromeImpl : public SystemChrome {
       uint32_t device_orientation_mask,
       const SetPreferredOrientationsCallback& callback) override;
 
+  void SetApplicationSwitcherDescription(
+      ApplicationSwitcherDescriptionPtr description,
+      const SetApplicationSwitcherDescriptionCallback& callback) override;
+
   void SetEnabledSystemUIOverlays(
       uint32_t overlays,
       const SetEnabledSystemUIOverlaysCallback& callback) override;
 
+  void SetSystemUIOverlayStyle(
+      SystemUIOverlayStyle style,
+      const SetSystemUIOverlayStyleCallback& callback) override;
+
  private:
   mojo::StrongBinding<SystemChrome> binding_;
 
@@ -34,6 +42,8 @@ class SystemChromeImpl : public SystemChrome {
 
 extern const char* const kOrientationUpdateNotificationName;
 extern const char* const kOrientationUpdateNotificationKey;
+extern const char* const kOverlayStyleUpdateNotificationName;
+extern const char* const kOverlayStyleUpdateNotificationKey;
 
 }  // namespace platform
 }  // namespace flutter

sky/services/platform/ios/system_chrome_impl.mm

@@ -4,6 +4,7 @@
 
 #include "sky/services/platform/ios/system_chrome_impl.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
+#include <UIKit/UIApplication.h>
 #include <UIKit/UIKit.h>
 
 namespace flutter {
@@ -59,8 +60,15 @@ static constexpr bool IsSet(uint32_t mask, T orientation) {
   callback.Run(true);
 }
 
+void SystemChromeImpl::SetApplicationSwitcherDescription(
+    ApplicationSwitcherDescriptionPtr description,
+    const SetApplicationSwitcherDescriptionCallback& callback) {
+  // No counterpart on iOS but is a benign operation. So no asserts.
+  callback.Run(true);
+}
+
 void SystemChromeImpl::SetEnabledSystemUIOverlays(
-    uint32_t overlays,
+    uint32_t overlay_mask,
     const SetEnabledSystemUIOverlaysCallback& callback) {
   // Checks if the top status bar should be visible. This platform ignores all
   // other overlays
@@ -71,15 +79,56 @@ static constexpr bool IsSet(uint32_t mask, T orientation) {
   // to be able to modify this on the fly. The key used is
   // UIViewControllerBasedStatusBarAppearance
   [UIApplication sharedApplication].statusBarHidden =
-      !IsSet(overlays, SystemUIOverlay::Top);
+      !IsSet(overlay_mask, SystemUIOverlay::Top);
+
+  callback.Run(true);
+}
+
+void SystemChromeImpl::SetSystemUIOverlayStyle(
+    SystemUIOverlayStyle style,
+    const SetSystemUIOverlayStyleCallback& callback) {
+  base::mac::ScopedNSAutoreleasePool pool;
+
+  UIStatusBarStyle statusBarStyle;
+  switch (style) {
+    case SystemUIOverlayStyle::Light:
+      statusBarStyle = UIStatusBarStyleLightContent;
+      break;
+    case SystemUIOverlayStyle::Dark:
+      statusBarStyle = UIStatusBarStyleDefault;
+      break;
+  }
+
+  NSNumber* infoValue = [[NSBundle mainBundle]
+      objectForInfoDictionaryKey:@"UIViewControllerBasedStatusBarAppearance"];
+  Boolean delegateToViewController =
+      (infoValue == nil || [infoValue boolValue]);
+
+  if (delegateToViewController) {
+    // This notification is respected by the iOS embedder
+    [[NSNotificationCenter defaultCenter]
+        postNotificationName:@(kOverlayStyleUpdateNotificationName)
+                      object:nil
+                    userInfo:@{
+                      @(kOverlayStyleUpdateNotificationKey) : @(statusBarStyle)
+                    }];
+  } else {
+    // Note: -[UIApplication setStatusBarStyle] is deprecated in iOS9
+    // in favor of delegating to the view controller
+    [[UIApplication sharedApplication] setStatusBarStyle:statusBarStyle];
+  }
 
   callback.Run(true);
 }
 
 const char* const kOrientationUpdateNotificationName =
-    "SystemChromeOrientationNotificationName";
+    "io.flutter.SystemChromeOrientationNotificationName";
 const char* const kOrientationUpdateNotificationKey =
-    "SystemChromeOrientationNotificationName";
+    "io.flutter.SystemChromeOrientationNotificationKey";
+const char* const kOverlayStyleUpdateNotificationName =
+    "io.flutter.SystemChromeOverlayNotificationName";
+const char* const kOverlayStyleUpdateNotificationKey =
+    "io.flutter.SystemChromeOverlayNotificationKey";
 
 }  // namespace platform
 }  // namespace flutter

sky/services/platform/src/org/domokit/platform/SystemChromeImpl.java

@@ -6,9 +6,11 @@
 
 import android.app.Activity;
 import android.content.pm.ActivityInfo;
+import android.os.Build;
 import android.view.View;
 
 import org.chromium.mojo.system.MojoException;
+import org.chromium.mojom.flutter.platform.ApplicationSwitcherDescription;
 import org.chromium.mojom.flutter.platform.DeviceOrientation;
 import org.chromium.mojom.flutter.platform.SystemChrome;
 import org.chromium.mojom.flutter.platform.SystemUiOverlay;
@@ -54,6 +56,31 @@ public void setPreferredOrientations(int deviceOrientationMask,
         callback.call(true);
     }
 
+    @Override
+    public void setApplicationSwitcherDescription(
+        ApplicationSwitcherDescription description,
+        SetApplicationSwitcherDescriptionResponse callback) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            callback.call(true);
+            return;
+        }
+
+        int color = description.primaryColor;
+        if (color != 0) { // 0 means color isn't set, use system default
+            color = color | 0xFF000000; // color must be opaque if set
+        }
+
+        mActivity.setTaskDescription(
+            new android.app.ActivityManager.TaskDescription(
+                description.label,
+                null,
+                color
+            )
+        );
+
+        callback.call(true);
+    }
+
     @Override
     public void setEnabledSystemUiOverlays(int overlays,
                                            SetEnabledSystemUiOverlaysResponse callback) {
@@ -71,4 +98,12 @@ public void setEnabledSystemUiOverlays(int overlays,
         mActivity.getWindow().getDecorView().setSystemUiVisibility(flags);
         callback.call(true);
     }
+
+    @Override
+    public void setSystemUiOverlayStyle(int style, SetSystemUiOverlayStyleResponse callback) {
+        // You can change the navigation bar color (including translucent colors)
+        // in Android, but you can't change the color of the navigation buttons,
+        // so LIGHT vs DARK effectively isn't supported in Android.
+        callback.call(true);
+    }
 }

sky/services/platform/system_chrome.mojom

@@ -39,29 +39,66 @@ enum SystemUIOverlay {
   Bottom = 2,
 };
 
+/// Specifies a preference for the style of the system overlays. Certain
+/// platforms may not respect this preference.
+enum SystemUIOverlayStyle {
+  /// System overlays should be drawn with a light color. Intended for
+  /// applications with a dark background.
+  Light = 1,
+
+  /// System overlays should be drawn with a dark color. Intended for
+  /// applications with a light background.
+  Dark  = 2,
+};
+
+/// Specifies a description of the application that is pertinent to the
+/// embedder's application switcher (a.k.a. "recent tasks") user interface.
+struct ApplicationSwitcherDescription {
+  /// A label and description of the current state of the application.
+  string? label;
+
+  /// The application's primary color.
+  uint32 primaryColor;
+};
+
 /// Controls specific aspects of the embedder interface.
 [ServiceName="flutter::platform::SystemChrome"]
 interface SystemChrome {
   /// Specifies the set of orientations the application interface can
   /// be displayed in.
   ///
-  /// The value 0 is synonymous with having all options enabled.
   /// Arguments:
-  ///      device_orientation_mask: A mask of `DeviceOrientation` enum values.
+  ///   device_orientation_mask: A mask of `DeviceOrientation` enum values.
+  ///       A value of 0 is synonymous with having all options enabled.
   ///
   /// Return Value:
   ///   boolean indicating if the orientation mask is valid and the changes
   ///   could be conveyed successfully to the embedder.
   SetPreferredOrientations(uint32 device_orientation_mask) => (bool success);
 
+  /// Specifies the description of the application within the embedder's
+  /// application switcher (a.k.a. "recent tasks") user interface.
+  ///
+  /// Arguments:
+  ///   description: The description of the current state of the application.
+  ///
+  /// Return value:
+  ///   boolean indicating if the preference was conveyed successfully to the
+  ///   embedder.
+  ///
+  /// Platform Specific Notes:
+  ///   If application switcher metadata cannot be manually set on the platform,
+  ///   specifying such metadata is a no-op and always return true.
+  SetApplicationSwitcherDescription(ApplicationSwitcherDescription description) => (bool success);
 
   /// Specifies the set of overlays visible on the embedder when the
   /// application is running. The embedder may choose to ignore unsupported
   /// overlays
   ///
   /// Arguments:
-  ///   style: A mask of `SystemUIOverlay` enum values that denotes the overlays
-  ///          to show.
+  ///   overlay_mask: A mask of `SystemUIOverlay` enum values that denotes the
+  ///       overlays to show. A value of 0 is synonymous with showing no
+  ///       overlays.
   ///
   /// Return Value:
   ///   boolean indicating if the preference was conveyed successfully to the
@@ -70,5 +107,20 @@ interface SystemChrome {
   /// Platform Specific Notes:
   ///   If the overlay is unsupported on the platform, enabling or disabling
   ///   that overlay is a no-op and always return true.
-  SetEnabledSystemUIOverlays(uint32 overlays) => (bool success);
+  SetEnabledSystemUIOverlays(uint32 overlay_mask) => (bool success);
+
+  /// Specifies the style of the overlays that are visible on the embedder when
+  /// the applicatiomn is running.
+  ///
+  /// Arguments:
+  ///   style: A `SystemUIOverlayStyle` enum value that denotes the style
+  ///
+  /// Return value:
+  ///   boolean indicating if the preference was conveyed successfully to the
+  ///   embedder.
+  ///
+  /// Platform Specific Notes:
+  ///   If overlay style is unsupported on the platform, specifying a style is
+  ///   a no-op and always return true.
+  SetSystemUIOverlayStyle(SystemUIOverlayStyle style) => (bool success);
 };

sky/shell/platform/ios/framework/Source/FlutterViewController.mm

@@ -43,6 +43,7 @@ void FlutterInit(int argc, const char* argv[]) {
 @implementation FlutterViewController {
   base::scoped_nsprotocol<FlutterDartProject*> _dartProject;
   UIInterfaceOrientationMask _orientationPreferences;
+  UIStatusBarStyle _statusBarStyle;
   base::scoped_nsprotocol<FlutterDynamicServiceLoader*> _dynamicServiceLoader;
   sky::ViewportMetricsPtr _viewportMetrics;
   sky::shell::TouchMapper _touchMapper;
@@ -87,6 +88,7 @@ - (void)performCommonViewControllerInitialization {
   _initialized = YES;
 
   _orientationPreferences = UIInterfaceOrientationMaskAll;
+  _statusBarStyle = UIStatusBarStyleDefault;
   _dynamicServiceLoader.reset([[FlutterDynamicServiceLoader alloc] init]);
   _viewportMetrics = sky::ViewportMetrics::New();
   _shellView =
@@ -116,6 +118,11 @@ - (void)setupNotificationCenterObservers {
                  name:@(flutter::platform::kOrientationUpdateNotificationName)
                object:nil];
 
+  [center addObserver:self
+             selector:@selector(onPreferredStatusBarStyleUpdated:)
+                 name:@(flutter::platform::kOverlayStyleUpdateNotificationName)
+               object:nil];
+
   [center addObserver:self
              selector:@selector(applicationBecameActive:)
                  name:UIApplicationDidBecomeActiveNotification
@@ -450,15 +457,38 @@ - (void)viewWillDisappear:(BOOL)animated {
   [super viewWillDisappear:animated];
 }
 
-- (UIStatusBarStyle)preferredStatusBarStyle {
-  return UIStatusBarStyleLightContent;
-}
-
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [super dealloc];
 }
 
+#pragma mark - Status bar style
+
+- (UIStatusBarStyle)preferredStatusBarStyle {
+  return _statusBarStyle;
+}
+
+- (void)onPreferredStatusBarStyleUpdated:(NSNotification*)notification {
+  // Notifications may not be on the iOS UI thread
+  dispatch_async(dispatch_get_main_queue(), ^{
+    NSDictionary* info = notification.userInfo;
+
+    NSNumber* update =
+        info[@(flutter::platform::kOverlayStyleUpdateNotificationKey)];
+
+    if (update == nil) {
+      return;
+    }
+
+    NSInteger style = update.integerValue;
+
+    if (style != _statusBarStyle) {
+      _statusBarStyle = static_cast<UIStatusBarStyle>(style);
+      [self setNeedsStatusBarAppearanceUpdate];
+    }
+  });
+}
+
 #pragma mark - Application Messages
 
 - (void)sendString:(NSString*)message withMessageName:(NSString*)messageName {
@@ -497,14 +527,16 @@ - (void)removeMessageListener:(NSObject<FlutterMessageListener>*)listener {
   _appMessageReceiver.SetMessageListener(messageName.UTF8String, nil);
 }
 
-- (void)addAsyncMessageListener:(NSObject<FlutterAsyncMessageListener>*)listener {
+- (void)addAsyncMessageListener:
+    (NSObject<FlutterAsyncMessageListener>*)listener {
   NSAssert(listener, @"The listener must not be null");
   NSString* messageName = listener.messageName;
   NSAssert(messageName, @"The messageName must not be null");
   _appMessageReceiver.SetAsyncMessageListener(messageName.UTF8String, listener);
 }
 
-- (void)removeAsyncMessageListener:(NSObject<FlutterAsyncMessageListener>*)listener {
+- (void)removeAsyncMessageListener:
+    (NSObject<FlutterAsyncMessageListener>*)listener {
   NSAssert(listener, @"The listener must not be null");
   NSString* messageName = listener.messageName;
   NSAssert(messageName, @"The messageName must not be null");