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// 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 BASE_WIN_SCOPED_HDC_H_
#define BASE_WIN_SCOPED_HDC_H_
#include <windows.h>
#include "base/basictypes.h"
#include "base/logging.h"
#include "base/win/scoped_handle.h"
namespace base {
namespace win {
// Like ScopedHandle but for HDC. Only use this on HDCs returned from
// GetDC.
class ScopedGetDC {
public:
explicit ScopedGetDC(HWND hwnd)
: hwnd_(hwnd),
hdc_(GetDC(hwnd)) {
if (hwnd_) {
DCHECK(IsWindow(hwnd_));
DCHECK(hdc_);
} else {
// If GetDC(NULL) returns NULL, something really bad has happened, like
// GDI handle exhaustion. In this case Chrome is going to behave badly no
// matter what, so we may as well just force a crash now.
CHECK(hdc_);
}
}
~ScopedGetDC() {
if (hdc_)
ReleaseDC(hwnd_, hdc_);
}
operator HDC() { return hdc_; }
private:
HWND hwnd_;
HDC hdc_;
DISALLOW_COPY_AND_ASSIGN(ScopedGetDC);
};
// Like ScopedHandle but for HDC. Only use this on HDCs returned from
// CreateCompatibleDC, CreateDC and CreateIC.
class CreateDCTraits {
public:
typedef HDC Handle;
static bool CloseHandle(HDC handle) {
return ::DeleteDC(handle) != FALSE;
}
static bool IsHandleValid(HDC handle) {
return handle != NULL;
}
static HDC NullHandle() {
return NULL;
}
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(CreateDCTraits);
};
typedef GenericScopedHandle<CreateDCTraits, VerifierTraits> ScopedCreateDC;
} // namespace win
} // namespace base
#endif // BASE_WIN_SCOPED_HDC_H_
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