| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef FLUTTER_COMMON_CONSTANTS_H_ |
| #define FLUTTER_COMMON_CONSTANTS_H_ |
| |
| namespace flutter { |
| constexpr double kMegaByteSizeInBytes = (1 << 20); |
| |
| // The ID for the implicit view if the implicit view is enabled. |
| // |
| // The implicit view is a compatibility mechanism to help the transition from |
| // the older single-view APIs to the newer multi-view APIs. The two sets of APIs |
| // use different models for view management. The implicit view mechanism allows |
| // single-view APIs to operate a special view as if other views don't exist. |
| // |
| // In the regular multi-view model, all views should be created by |
| // `Shell::AddView` before being used, and removed by `Shell::RemoveView` to |
| // signify that they are gone. If a view is added or removed, the framework |
| // (`PlatformDispatcher`) will be notified. New view IDs are always unique, |
| // never reused. Operating a non-existing view is an error. |
| // |
| // The implicit view is another special view in addition to the "regular views" |
| // as above. The shell starts up having the implicit view, which has a fixed |
| // view ID of `kFlutterImplicitViewId` and is available throughout the lifetime |
| // of the shell. `Shell::AddView` or `RemoveView` must not be called for this |
| // view. Even when the window that shows the view is closed, the framework is |
| // unaware and might continue rendering into or operating this view. |
| // |
| // The single-view APIs, which are APIs that do not specify view IDs, operate |
| // the implicit view. The multi-view APIs can operate all views, including the |
| // implicit view if the target ID is `kFlutterImplicitViewId`, unless specified |
| // otherwise. |
| constexpr int64_t kFlutterImplicitViewId = 0; |
| } // namespace flutter |
| |
| #endif // FLUTTER_COMMON_CONSTANTS_H_ |
