1 /* 2 * Copyright (C) 2013 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef CallbackPromiseAdapter_h 32 #define CallbackPromiseAdapter_h 33 34 #include "bindings/v8/ScriptPromiseResolverWithContext.h" 35 #include "public/platform/WebCallbacks.h" 36 37 namespace WebCore { 38 39 // This class provides an easy way to convert from a Script-exposed 40 // class (i.e. a class that has a toV8() overload) that uses Promises 41 // to a WebKit API class that uses WebCallbacks. You can define 42 // separate Success and Error classes, but this example just uses one 43 // object for both. 44 // 45 // To use: 46 // 47 // class MyClass ... { 48 // typedef blink::WebMyClass WebType; 49 // static PassRefPtr<MyClass> from(ScriptPromiseResolverWithContext* resolver, 50 // blink::WebMyClass* webInstance) { 51 // // convert/create as appropriate, but often it's just: 52 // return MyClass::create(adoptPtr(webInstance)); 53 // 54 // // Since promise resolving is done as an async task, it's not 55 // // guaranteed that the script context has seen the promise resolve 56 // // immediately after calling onSuccess/onError. You can use the 57 // // ScriptPromise from the resolver to schedule a task that executes 58 // // after resolving: 59 // ScriptState::Scope scope(resolver->scriptState()); 60 // resolver->promise().then(...); 61 // } 62 // 63 // Now when calling into a WebKit API that requires a WebCallbacks<blink::WebMyClass, blink::WebMyClass>*: 64 // 65 // // call signature: callSomeMethod(WebCallbacks<MyClass, MyClass>* callbacks) 66 // webObject->callSomeMethod(new CallbackPromiseAdapter<MyClass, MyClass>(resolver, scriptExecutionContext)); 67 // 68 // Note that this class does not manage its own lifetime. In this 69 // example that ownership of the WebCallbacks instance is being passed 70 // in and it is up to the callee to free the WebCallbacks instace. 71 template<typename S, typename T> 72 class CallbackPromiseAdapter FINAL : public blink::WebCallbacks<typename S::WebType, typename T::WebType> { 73 public: 74 CallbackPromiseAdapter(PassRefPtr<ScriptPromiseResolverWithContext> resolver) 75 : m_resolver(resolver) 76 { 77 } 78 virtual ~CallbackPromiseAdapter() { } 79 80 virtual void onSuccess(typename S::WebType* result) OVERRIDE 81 { 82 m_resolver->resolve(S::from(m_resolver.get(), result)); 83 } 84 virtual void onError(typename T::WebType* error) OVERRIDE 85 { 86 m_resolver->reject(T::from(m_resolver.get(), error)); 87 } 88 private: 89 RefPtr<ScriptPromiseResolverWithContext> m_resolver; 90 WTF_MAKE_NONCOPYABLE(CallbackPromiseAdapter); 91 }; 92 93 } // namespace WebCore 94 95 #endif 96
