| // Copyright 2015 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 WebFrameImplBase_h |
| #define WebFrameImplBase_h |
| |
| #include "platform/heap/Handle.h" |
| #include "web/WebExport.h" |
| #include "wtf/text/AtomicString.h" |
| |
| namespace blink { |
| |
| class Frame; |
| class FrameHost; |
| class FrameOwner; |
| |
| // WebFrameImplBase exists to avoid the diamond inheritance problem: |
| // - The public interfaces WebLocalFrame/WebRemoteFrame extend WebFrame. |
| // - WebLocalFrameImpl implements WebLocalFrame and WebRemoteFrameImpl |
| // implements WebRemoteFrame. |
| // - The private implementations should share some functionality, but cannot |
| // inherit from a common base class inheriting WebFrame. This would result in |
| // WebFrame beind inherited from two different base classes. |
| // |
| // To get around this, only the private implementations have WebFrameImplBase as |
| // a base class. WebFrame exposes a virtual accessor to retrieve the underlying |
| // implementation as an instance of the base class, but has no inheritance |
| // relationship with it. The cost is a virtual indirection, but this is nicer |
| // than the previous manual dispatch emulating real virtual dispatch. |
| class WEB_EXPORT WebFrameImplBase |
| : public GarbageCollectedFinalized<WebFrameImplBase> { |
| public: |
| virtual ~WebFrameImplBase(); |
| |
| virtual void initializeCoreFrame(FrameHost*, |
| FrameOwner*, |
| const AtomicString& name, |
| const AtomicString& uniqueName) = 0; |
| // TODO(dcheng): Rename this to coreFrame()? This probably also shouldn't be |
| // const... |
| virtual Frame* frame() const = 0; |
| |
| DECLARE_VIRTUAL_TRACE(); |
| }; |
| |
| } // namespace blink |
| |
| #endif // WebFrameImplBase_h |