scoped_select_object.h

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// Copyright 2024 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#ifndef CORE_FXCRT_WIN_SCOPED_SELECT_OBJECT_H_
#define CORE_FXCRT_WIN_SCOPED_SELECT_OBJECT_H_
 
#include <windows.h>
 
#include "core/fxcrt/check.h"
 
namespace pdfium {
 
// Helper class for deselecting object from DC.
class ScopedSelectObject {
 public:
  ScopedSelectObject(HDC hdc, HGDIOBJ object)
      : hdc_(hdc), oldobj_(SelectObject(hdc, object)) {
    DCHECK(hdc_);
    DCHECK(object);
    DCHECK(oldobj_);
    DCHECK(oldobj_ != HGDI_ERROR);
  }
 
  ScopedSelectObject(const ScopedSelectObject&) = delete;
  ScopedSelectObject& operator=(const ScopedSelectObject&) = delete;
 
  ~ScopedSelectObject() {
    [[maybe_unused]] HGDIOBJ object = SelectObject(hdc_, oldobj_);
    DCHECK((GetObjectType(oldobj_) != OBJ_REGION && object) ||
           (GetObjectType(oldobj_) == OBJ_REGION && object != HGDI_ERROR));
  }
 
 private:
  const HDC hdc_;
  const HGDIOBJ oldobj_;
};
 
}  // namespace pdfium
 
#endif  // CORE_FXCRT_WIN_SCOPED_SELECT_OBJECT_H_