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Diffstat (limited to '')
-rw-r--r-- | hal/WindowIdentifier.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/hal/WindowIdentifier.h b/hal/WindowIdentifier.h new file mode 100644 index 0000000000..11c5140f61 --- /dev/null +++ b/hal/WindowIdentifier.h @@ -0,0 +1,106 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set sw=2 ts=8 et ft=cpp : */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_hal_WindowIdentifier_h +#define mozilla_hal_WindowIdentifier_h + +#include "mozilla/Types.h" +#include "nsCOMPtr.h" +#include "nsTArray.h" + +class nsPIDOMWindowInner; + +namespace mozilla { +namespace hal { + +/** + * This class serves two purposes. + * + * First, this class wraps a pointer to a window. + * + * Second, WindowIdentifier lets us uniquely identify a window across + * processes. A window exposes an ID which is unique only within its + * process. Thus to identify a window, we need to know the ID of the + * process which contains it. But the scope of a process's ID is its + * parent; that is, two processes with different parents might have + * the same ID. + * + * So to identify a window, we need its ID plus the IDs of all the + * processes in the path from the window's process to the root + * process. We throw in the IDs of the intermediate windows (a + * content window is contained in a window at each level of the + * process tree) for good measures. + * + * You can access this list of IDs by calling AsArray(). + */ +class WindowIdentifier { + public: + /** + * Create an empty WindowIdentifier. Calls to any of this object's + * public methods will assert -- an empty WindowIdentifier may be + * used only as a placeholder to code which promises not to touch + * the object. + */ + WindowIdentifier(); + + /** + * Wrap the given window in a WindowIdentifier. These two + * constructors automatically grab the window's ID and append it to + * the array of IDs. + * + * Note that these constructors allow an implicit conversion to a + * WindowIdentifier. + */ + explicit WindowIdentifier(nsPIDOMWindowInner* window); + + /** + * Create a new WindowIdentifier with the given id array and window. + * This automatically grabs the window's ID and appends it to the + * array. + */ + WindowIdentifier(nsTArray<uint64_t>&& id, nsPIDOMWindowInner* window); + + /** + * Get the list of window and process IDs we contain. + */ + typedef nsTArray<uint64_t> IDArrayType; + const IDArrayType& AsArray() const; + + /** + * Append the ID of the ContentChild singleton to our array of + * window/process IDs. + */ + void AppendProcessID(); + + /** + * Does this WindowIdentifier identify both a window and the process + * containing that window? If so, we say it has traveled through + * IPC. + */ + bool HasTraveledThroughIPC() const; + + /** + * Get the window this object wraps. + */ + nsPIDOMWindowInner* GetWindow() const; + + private: + /** + * Get the ID of the window object we wrap. + */ + uint64_t GetWindowID() const; + + AutoTArray<uint64_t, 3> mID; + nsCOMPtr<nsPIDOMWindowInner> mWindow; +#ifdef DEBUG + bool mIsEmpty = false; +#endif +}; + +} // namespace hal +} // namespace mozilla + +#endif // mozilla_hal_WindowIdentifier_h |