android_context.h

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// 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_SHELL_PLATFORM_ANDROID_CONTEXT_ANDROID_CONTEXT_H_
#define FLUTTER_SHELL_PLATFORM_ANDROID_CONTEXT_ANDROID_CONTEXT_H_
 
#include "common/settings.h"
#include "flutter/fml/macros.h"
#include "flutter/fml/task_runner.h"
#include "flutter/impeller/renderer/context.h"
#include "third_party/skia/include/gpu/GrDirectContext.h"
 
namespace flutter {
 
//------------------------------------------------------------------------------
/// @brief      Holds state that is shared across Android surfaces.
///
class AndroidContext {
 public:
  explicit AndroidContext(AndroidRenderingAPI rendering_api);
 
  virtual ~AndroidContext();
 
  AndroidRenderingAPI RenderingApi() const;
 
  virtual bool IsValid() const;
 
  //----------------------------------------------------------------------------
  /// @brief      Setter for the Skia context to be used by subsequent
  ///             AndroidSurfaces.
  /// @details    This is useful to reduce memory consumption when creating
  ///             multiple AndroidSurfaces for the same AndroidContext.
  ///
  ///             The first AndroidSurface should set this for the
  ///             AndroidContext if the AndroidContext does not yet have a
  ///             Skia context to share via GetMainSkiaContext.
  ///
  void SetMainSkiaContext(const sk_sp<GrDirectContext>& main_context);
 
  //----------------------------------------------------------------------------
  /// @brief      Accessor for the Skia context associated with AndroidSurfaces
  ///             and the raster thread.
  /// @details    This context is created lazily by the AndroidSurface based
  ///             on their respective rendering backend and set on this
  ///             AndroidContext to share via SetMainSkiaContext.
  /// @returns    `nullptr` when no Skia context has been set yet by its
  ///             AndroidSurface via SetMainSkiaContext.
  /// @attention  The software context doesn't have a Skia context, so this
  ///             value will be nullptr.
  ///
  sk_sp<GrDirectContext> GetMainSkiaContext() const;
 
  //----------------------------------------------------------------------------
  /// @brief      Accessor for the Impeller context associated with
  ///             AndroidSurfaces and the raster thread.
  ///
  std::shared_ptr<impeller::Context> GetImpellerContext() const;
 
 protected:
  /// Intended to be called from a subclass constructor after setup work for the
  /// context has completed.
  void SetImpellerContext(const std::shared_ptr<impeller::Context>& context);
 
 private:
  const AndroidRenderingAPI rendering_api_;
 
  // This is the Skia context used for on-screen rendering.
  sk_sp<GrDirectContext> main_context_;
 
  std::shared_ptr<impeller::Context> impeller_context_;
 
  FML_DISALLOW_COPY_AND_ASSIGN(AndroidContext);
};
 
}  // namespace flutter
 
#endif  // FLUTTER_SHELL_PLATFORM_ANDROID_CONTEXT_ANDROID_CONTEXT_H_