license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 1 | // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 4 | |
| 5 | #ifndef BASE_SCOPED_HANDLE_H__ |
| 6 | #define BASE_SCOPED_HANDLE_H__ |
| 7 | |
| 8 | #include <windows.h> |
| 9 | |
| 10 | #include "base/basictypes.h" |
| 11 | |
| 12 | // Used so we always remember to close the handle. Example: |
| 13 | // ScopedHandle hfile(CreateFile(...)); |
| 14 | // if (!hfile.Get()) |
| 15 | // ...process error |
| 16 | // ReadFile(hfile.Get(), ...); |
| 17 | // |
| 18 | // To sqirrel the handle away somewhere else: |
| 19 | // secret_handle_ = hfile.Take(); |
| 20 | // |
| 21 | // To explicitly close the handle: |
| 22 | // CloseHandle(hfile.Take()); |
| 23 | class ScopedHandle { |
| 24 | public: |
| 25 | ScopedHandle() : handle_(NULL) { |
| 26 | } |
| 27 | |
| 28 | explicit ScopedHandle(HANDLE h) : handle_(NULL) { |
| 29 | Set(h); |
| 30 | } |
| 31 | |
| 32 | ~ScopedHandle() { |
| 33 | Close(); |
| 34 | } |
| 35 | |
| 36 | // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL |
| 37 | // usage for errors. |
| 38 | bool IsValid() const { |
| 39 | return handle_ != NULL; |
| 40 | } |
| 41 | |
| 42 | void Set(HANDLE new_handle) { |
| 43 | Close(); |
| 44 | |
| 45 | // Windows is inconsistent about invalid handles, so we always use NULL |
| 46 | if (handle_ != INVALID_HANDLE_VALUE) |
| 47 | handle_ = new_handle; |
| 48 | } |
| 49 | |
| 50 | HANDLE Get() { |
| 51 | return handle_; |
| 52 | } |
| 53 | |
| 54 | operator HANDLE() { return handle_; } |
| 55 | |
| 56 | HANDLE Take() { |
| 57 | // transfers ownership away from this object |
| 58 | HANDLE h = handle_; |
| 59 | handle_ = NULL; |
| 60 | return h; |
| 61 | } |
| 62 | |
| 63 | private: |
| 64 | void Close() { |
| 65 | if (handle_) { |
| 66 | CloseHandle(handle_); |
| 67 | handle_ = NULL; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | HANDLE handle_; |
| 72 | DISALLOW_EVIL_CONSTRUCTORS(ScopedHandle); |
| 73 | }; |
| 74 | |
| 75 | // Like ScopedHandle, but for HANDLEs returned from FindFile(). |
| 76 | class ScopedFindFileHandle { |
| 77 | public: |
| 78 | explicit ScopedFindFileHandle(HANDLE handle) : handle_(handle) { |
| 79 | // Windows is inconsistent about invalid handles, so we always use NULL |
| 80 | if (handle_ == INVALID_HANDLE_VALUE) |
| 81 | handle_ = NULL; |
| 82 | } |
| 83 | |
| 84 | ~ScopedFindFileHandle() { |
| 85 | if (handle_) |
| 86 | FindClose(handle_); |
| 87 | } |
| 88 | |
| 89 | // Use this instead of comparing to INVALID_HANDLE_VALUE to pick up our NULL |
| 90 | // usage for errors. |
| 91 | bool IsValid() const { return handle_ != NULL; } |
| 92 | |
| 93 | operator HANDLE() { return handle_; } |
| 94 | |
| 95 | private: |
| 96 | HANDLE handle_; |
| 97 | |
| 98 | DISALLOW_EVIL_CONSTRUCTORS(ScopedFindFileHandle); |
| 99 | }; |
| 100 | |
| 101 | // Like ScopedHandle but for HDC. Only use this on HDCs returned from |
| 102 | // CreateCompatibleDC. For an HDC returned by GetDC, use ReleaseDC instead. |
| 103 | class ScopedHDC { |
| 104 | public: |
| 105 | explicit ScopedHDC(HDC h) : hdc_(h) { } |
| 106 | |
| 107 | ~ScopedHDC() { |
| 108 | if (hdc_) |
| 109 | DeleteDC(hdc_); |
| 110 | } |
| 111 | |
| 112 | operator HDC() { return hdc_; } |
| 113 | |
| 114 | private: |
| 115 | HDC hdc_; |
| 116 | DISALLOW_EVIL_CONSTRUCTORS(ScopedHDC); |
| 117 | }; |
| 118 | |
| 119 | // Like ScopedHandle but for HBITMAP. |
| 120 | class ScopedBitmap { |
| 121 | public: |
| 122 | explicit ScopedBitmap(HBITMAP h) : hbitmap_(h) { } |
| 123 | |
| 124 | ~ScopedBitmap() { |
| 125 | if (hbitmap_) |
| 126 | DeleteObject(hbitmap_); |
| 127 | } |
| 128 | |
| 129 | operator HBITMAP() { return hbitmap_; } |
| 130 | |
| 131 | private: |
| 132 | HBITMAP hbitmap_; |
| 133 | DISALLOW_EVIL_CONSTRUCTORS(ScopedBitmap); |
| 134 | }; |
| 135 | |
| 136 | // Like ScopedHandle but for HRGN. |
| 137 | class ScopedHRGN { |
| 138 | public: |
| 139 | explicit ScopedHRGN(HRGN h) : hrgn_(h) { } |
| 140 | |
| 141 | ~ScopedHRGN() { |
| 142 | if (hrgn_) |
| 143 | DeleteObject(hrgn_); |
| 144 | } |
| 145 | |
| 146 | operator HRGN() { return hrgn_; } |
| 147 | |
| 148 | ScopedHRGN& operator=(HRGN hrgn) { |
| 149 | if (hrgn_ && hrgn != hrgn_) |
| 150 | DeleteObject(hrgn_); |
| 151 | hrgn_ = hrgn; |
| 152 | return *this; |
| 153 | } |
| 154 | |
| 155 | private: |
| 156 | HRGN hrgn_; |
| 157 | DISALLOW_EVIL_CONSTRUCTORS(ScopedHRGN); |
| 158 | }; |
| 159 | |
| 160 | // Like ScopedHandle except for HGLOBAL. |
| 161 | template<class T> |
| 162 | class ScopedHGlobal { |
| 163 | public: |
| 164 | explicit ScopedHGlobal(HGLOBAL glob) : glob_(glob) { |
| 165 | data_ = static_cast<T*>(GlobalLock(glob_)); |
| 166 | } |
| 167 | ~ScopedHGlobal() { |
| 168 | GlobalUnlock(glob_); |
| 169 | } |
| 170 | |
| 171 | T* get() { return data_; } |
| 172 | |
| 173 | size_t Size() const { return GlobalSize(glob_); } |
| 174 | |
| 175 | T* operator->() const { |
| 176 | assert(data_ != 0); |
| 177 | return data_; |
| 178 | } |
| 179 | |
| 180 | private: |
| 181 | HGLOBAL glob_; |
| 182 | |
| 183 | T* data_; |
| 184 | |
| 185 | DISALLOW_EVIL_CONSTRUCTORS(ScopedHGlobal); |
| 186 | }; |
| 187 | |
| 188 | #endif // BASE_SCOPED_HANDLE_H__ |
license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 189 | |