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Diffstat (limited to 'ipc/chromium/src/base/scoped_handle_win.h')
-rw-r--r-- | ipc/chromium/src/base/scoped_handle_win.h | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/scoped_handle_win.h b/ipc/chromium/src/base/scoped_handle_win.h new file mode 100644 index 000000000..d4d8fccc4 --- /dev/null +++ b/ipc/chromium/src/base/scoped_handle_win.h @@ -0,0 +1,219 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 2006-2008 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_SCOPED_HANDLE_WIN_H_ +#define BASE_SCOPED_HANDLE_WIN_H_ + +#include <windows.h> + +#include "base/basictypes.h" +#include "base/logging.h" + +// Used so we always remember to close the handle. +// The class interface matches that of ScopedStdioHandle in addition to an +// IsValid() method since invalid handles on windows can be either NULL or +// INVALID_HANDLE_VALUE (-1). +// +// Example: +// ScopedHandle hfile(CreateFile(...)); +// if (!hfile.Get()) +// ...process error +// ReadFile(hfile.Get(), ...); +// +// To sqirrel the handle away somewhere else: +// secret_handle_ = hfile.Take(); +// +// To explicitly close the handle: +// hfile.Close(); +class ScopedHandle { + public: + ScopedHandle() : handle_(NULL) { + } + + explicit ScopedHandle(HANDLE h) : handle_(NULL) { + Set(h); + } + + ~ScopedHandle() { + Close(); + } + + // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL + // usage for errors. + bool IsValid() const { + return handle_ != NULL; + } + + void Set(HANDLE new_handle) { + Close(); + + // Windows is inconsistent about invalid handles, so we always use NULL + if (new_handle != INVALID_HANDLE_VALUE) + handle_ = new_handle; + } + + HANDLE Get() { + return handle_; + } + + operator HANDLE() { return handle_; } + + HANDLE Take() { + // transfers ownership away from this object + HANDLE h = handle_; + handle_ = NULL; + return h; + } + + void Close() { + if (handle_) { + if (!::CloseHandle(handle_)) { + NOTREACHED(); + } + handle_ = NULL; + } + } + + private: + HANDLE handle_; + DISALLOW_EVIL_CONSTRUCTORS(ScopedHandle); +}; + +// Like ScopedHandle, but for HANDLEs returned from FindFile(). +class ScopedFindFileHandle { + public: + explicit ScopedFindFileHandle(HANDLE handle) : handle_(handle) { + // Windows is inconsistent about invalid handles, so we always use NULL + if (handle_ == INVALID_HANDLE_VALUE) + handle_ = NULL; + } + + ~ScopedFindFileHandle() { + if (handle_) + FindClose(handle_); + } + + // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL + // usage for errors. + bool IsValid() const { return handle_ != NULL; } + + operator HANDLE() { return handle_; } + + private: + HANDLE handle_; + + DISALLOW_EVIL_CONSTRUCTORS(ScopedFindFileHandle); +}; + +// Like ScopedHandle but for HDC. Only use this on HDCs returned from +// CreateCompatibleDC. For an HDC returned by GetDC, use ReleaseDC instead. +class ScopedHDC { + public: + ScopedHDC() : hdc_(NULL) { } + explicit ScopedHDC(HDC h) : hdc_(h) { } + + ~ScopedHDC() { + Close(); + } + + HDC Get() { + return hdc_; + } + + void Set(HDC h) { + Close(); + hdc_ = h; + } + + operator HDC() { return hdc_; } + + private: + void Close() { +#ifdef NOGDI + assert(false); +#else + if (hdc_) + DeleteDC(hdc_); +#endif // NOGDI + } + + HDC hdc_; + DISALLOW_EVIL_CONSTRUCTORS(ScopedHDC); +}; + +// Like ScopedHandle but for GDI objects. +template<class T> +class ScopedGDIObject { + public: + ScopedGDIObject() : object_(NULL) {} + explicit ScopedGDIObject(T object) : object_(object) {} + + ~ScopedGDIObject() { + Close(); + } + + T Get() { + return object_; + } + + void Set(T object) { + if (object_ && object != object_) + Close(); + object_ = object; + } + + ScopedGDIObject& operator=(T object) { + Set(object); + return *this; + } + + operator T() { return object_; } + + private: + void Close() { + if (object_) + DeleteObject(object_); + } + + T object_; + DISALLOW_COPY_AND_ASSIGN(ScopedGDIObject); +}; + +// Typedefs for some common use cases. +typedef ScopedGDIObject<HBITMAP> ScopedBitmap; +typedef ScopedGDIObject<HRGN> ScopedHRGN; +typedef ScopedGDIObject<HFONT> ScopedHFONT; + + +// Like ScopedHandle except for HGLOBAL. +template<class T> +class ScopedHGlobal { + public: + explicit ScopedHGlobal(HGLOBAL glob) : glob_(glob) { + data_ = static_cast<T*>(GlobalLock(glob_)); + } + ~ScopedHGlobal() { + GlobalUnlock(glob_); + } + + T* get() { return data_; } + + size_t Size() const { return GlobalSize(glob_); } + + T* operator->() const { + assert(data_ != 0); + return data_; + } + + private: + HGLOBAL glob_; + + T* data_; + + DISALLOW_EVIL_CONSTRUCTORS(ScopedHGlobal); +}; + +#endif // BASE_SCOPED_HANDLE_WIN_H_ |