surface_control.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_IMPELLER_TOOLKIT_ANDROID_SURFACE_CONTROL_H_
#define FLUTTER_IMPELLER_TOOLKIT_ANDROID_SURFACE_CONTROL_H_
 
#include "flutter/fml/unique_object.h"
#include "impeller/toolkit/android/proc_table.h"
 
namespace impeller::android {
 
//------------------------------------------------------------------------------
/// @brief      A wrapper for ASurfaceControl.
///             https://developer.android.com/ndk/reference/group/native-activity#asurfacecontrol
///
///             Instances of this class represent a node in the hierarchy of
///             surfaces sent to the system compositor for final composition.
///
///             This wrapper is only available on Android API 29 and above.
///
class SurfaceControl {
 public:
  //----------------------------------------------------------------------------
  /// @return     `true` if any surface controls can be created on this
  ///              platform.
  ///
  static bool IsAvailableOnPlatform();
 
  //----------------------------------------------------------------------------
  /// @brief      Creates a new surface control and adds it as a child of the
  ///             given window.
  ///
  /// @param      window      The window
  /// @param[in]  debug_name  A debug name. See it using
  ///                         `adb shell dumpsys SurfaceFlinger` along with
  ///                         other control properties. If no debug name is
  ///                         specified, the value "Impeller Layer" is used.
  ///
  explicit SurfaceControl(ANativeWindow* window,
                          const char* debug_name = nullptr);
 
  //----------------------------------------------------------------------------
  /// @brief      Removes the surface control from the presentation hierarchy
  ///             managed by the system compositor and release the client side
  ///             reference to the control. At this point, it may be collected
  ///             when the compositor is also done using it.
  ///
  ~SurfaceControl();
 
  SurfaceControl(const SurfaceControl&) = delete;
 
  SurfaceControl& operator=(const SurfaceControl&) = delete;
 
  bool IsValid() const;
 
  ASurfaceControl* GetHandle() const;
 
  //----------------------------------------------------------------------------
  /// @brief      Remove the surface control from the hierarchy of nodes
  ///             presented by the system compositor.
  ///
  ///             This is called implicitly when the surface control is
  ///             collected.
  ///
  /// @return     `true` If the control will be removed from the hierarchy of
  ///             nodes presented by the system compositor.
  ///
  bool RemoveFromParent() const;
 
 private:
  struct UniqueASurfaceControlTraits {
    static ASurfaceControl* InvalidValue() { return nullptr; }
 
    static bool IsValid(ASurfaceControl* value) {
      return value != InvalidValue();
    }
 
    static void Free(ASurfaceControl* value) {
      GetProcTable().ASurfaceControl_release(value);
    }
  };
 
  fml::UniqueObject<ASurfaceControl*, UniqueASurfaceControlTraits> control_;
};
 
}  // namespace impeller::android
 
#endif  // FLUTTER_IMPELLER_TOOLKIT_ANDROID_SURFACE_CONTROL_H_