// Copyright (c) 2012 The Chromium 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 UI_GL_SCOPED_MAKE_CURRENT_H_
#define UI_GL_SCOPED_MAKE_CURRENT_H_

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/optional.h"
#include "ui/gl/gl_export.h"

namespace gl {
class GLContext;
class GLSurface;
}

namespace ui {

// ScopedMakeCurrent makes given context current with the given surface. If this
// fails, Succeeded() returns false. It also restores the previous context on
// destruction and asserts that this succeeds. Users can optionally use
// Restore() to check if restoring the previous context succeeds. This prevents
// the assert during destruction.
class GL_EXPORT ScopedMakeCurrent {
 public:
  ScopedMakeCurrent(gl::GLContext* context, gl::GLSurface* surface);
  ~ScopedMakeCurrent();

  bool Succeeded() const;

  bool Restore() WARN_UNUSED_RESULT;

 private:
  scoped_refptr<gl::GLContext> previous_context_;
  scoped_refptr<gl::GLSurface> previous_surface_;
  scoped_refptr<gl::GLContext> context_;
  scoped_refptr<gl::GLSurface> surface_;
  bool succeeded_ = false;
  bool restored_ = false;

  DISALLOW_COPY_AND_ASSIGN(ScopedMakeCurrent);
};

// This behaves similarly to ScopedMakeCurrent, except that it releases the
// current context on creation and restores it on destruction.
class GL_EXPORT ScopedReleaseCurrent {
 public:
  ScopedReleaseCurrent();
  ~ScopedReleaseCurrent();

  bool Restore() WARN_UNUSED_RESULT;

 private:
  scoped_refptr<gl::GLContext> previous_context_;
  scoped_refptr<gl::GLSurface> previous_surface_;
  bool restored_ = false;

  DISALLOW_COPY_AND_ASSIGN(ScopedReleaseCurrent);
};

}  // namespace ui

#endif  // UI_GL_SCOPED_MAKE_CURRENT_H_