1/* 2 * Copyright (C) 2011 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#include "config.h" 32#include "JSPopStateEvent.h" 33 34#include "JSHistory.h" 35#include <runtime/JSCJSValueInlines.h> 36 37using namespace JSC; 38 39namespace WebCore { 40 41// Save the state value to the m_state member of a JSPopStateEvent, and return it, for convenience. 42static const JSValue& cacheState(ExecState* exec, JSPopStateEvent* event, const JSValue& state) 43{ 44 event->m_state.set(exec->vm(), event, state); 45 return state; 46} 47 48JSValue JSPopStateEvent::state(ExecState* exec) const 49{ 50 JSValue cachedValue = m_state.get(); 51 if (!cachedValue.isEmpty()) 52 return cachedValue; 53 54 PopStateEvent& event = impl(); 55 56 if (!event.state().hasNoValue()) 57 return cacheState(exec, const_cast<JSPopStateEvent*>(this), event.state().jsValue()); 58 59 History* history = event.history(); 60 if (!history || !event.serializedState()) 61 return cacheState(exec, const_cast<JSPopStateEvent*>(this), jsNull()); 62 63 // There's no cached value from a previous invocation, nor a state value was provided by the 64 // event, but there is a history object, so first we need to see if the state object has been 65 // deserialized through the history object already. 66 // The current history state object might've changed in the meantime, so we need to take care 67 // of using the correct one, and always share the same deserialization with history.state. 68 69 bool isSameState = history->isSameAsCurrentState(event.serializedState().get()); 70 JSValue result; 71 72 if (isSameState) { 73 JSHistory* jsHistory = jsCast<JSHistory*>(toJS(exec, globalObject(), history).asCell()); 74 result = jsHistory->state(exec); 75 } else 76 result = event.serializedState()->deserialize(exec, globalObject(), 0); 77 78 return cacheState(exec, const_cast<JSPopStateEvent*>(this), result); 79} 80 81} // namespace WebCore 82