77 lines
1.7 KiB
C
77 lines
1.7 KiB
C
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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_WIN_SCOPED_HDC_H_
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#define BASE_WIN_SCOPED_HDC_H_
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#include <windows.h>
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#include "base/basictypes.h"
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#include "base/logging.h"
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#include "base/win/scoped_handle.h"
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namespace base {
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namespace win {
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// Like ScopedHandle but for HDC. Only use this on HDCs returned from
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// GetDC.
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class ScopedGetDC {
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public:
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explicit ScopedGetDC(HWND hwnd)
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: hwnd_(hwnd),
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hdc_(GetDC(hwnd)) {
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if (hwnd_) {
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DCHECK(IsWindow(hwnd_));
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DCHECK(hdc_);
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} else {
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// If GetDC(NULL) returns NULL, something really bad has happened, like
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// GDI handle exhaustion. In this case Chrome is going to behave badly no
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// matter what, so we may as well just force a crash now.
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CHECK(hdc_);
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}
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}
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~ScopedGetDC() {
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if (hdc_)
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ReleaseDC(hwnd_, hdc_);
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}
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operator HDC() { return hdc_; }
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private:
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HWND hwnd_;
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HDC hdc_;
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DISALLOW_COPY_AND_ASSIGN(ScopedGetDC);
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};
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// Like ScopedHandle but for HDC. Only use this on HDCs returned from
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// CreateCompatibleDC, CreateDC and CreateIC.
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class CreateDCTraits {
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public:
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typedef HDC Handle;
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static bool CloseHandle(HDC handle) {
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return ::DeleteDC(handle) != FALSE;
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}
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static bool IsHandleValid(HDC handle) {
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return handle != NULL;
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}
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static HDC NullHandle() {
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return NULL;
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}
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private:
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DISALLOW_IMPLICIT_CONSTRUCTORS(CreateDCTraits);
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};
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typedef GenericScopedHandle<CreateDCTraits, VerifierTraits> ScopedCreateDC;
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} // namespace win
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} // namespace base
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#endif // BASE_WIN_SCOPED_HDC_H_
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