1 /* 2 * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved. 3 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/) 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 15 * its contributors may be used to endorse or promote products derived 16 * from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 21 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #ifndef HistoryController_h 31 #define HistoryController_h 32 33 #include "core/history/HistoryItem.h" 34 #include "core/loader/FrameLoaderTypes.h" 35 #include "wtf/HashMap.h" 36 #include "wtf/Noncopyable.h" 37 #include "wtf/RefPtr.h" 38 #include "wtf/text/WTFString.h" 39 40 namespace WebCore { 41 42 class Frame; 43 class HistoryEntry; 44 class Page; 45 46 47 // A guide to history state in Blink: 48 // 49 // HistoryController: Owned by Page, is the entry point for interacting with history. 50 // Handles most of the operations to modify history state, navigate to an existing 51 // back/forward entry, etc. 52 // HistoryEntry: Represents a single entry in the back/forward list, encapsulating 53 // all frames in the page it represents. It provides access to each frame's 54 // state via lookups by frame id or frame name. 55 // HistoryNode: Represents a single frame in a HistoryEntry. Owned by a HistoryEntry. HistoryNodes 56 // form a tree that mirrors the FrameTree in the corresponding page. HistoryNodes represent 57 // the structure of the page, but don't hold any per-frame state except a list of child frames. 58 // HistoryItem (lives in a separate file): The state for a given frame. Can persist across 59 // navigations. HistoryItem is reference counted, and each HistoryNode holds a reference 60 // to its single corresponding HistoryItem. Can be referenced by multiple HistoryNodes and 61 // can therefore exist in multiple HistoryEntry instances. 62 // 63 // Suppose we have the following page, foo.com, which embeds foo.com/a in an iframe: 64 // 65 // HistoryEntry 0: 66 // HistoryNode 0_0 (HistoryItem A (url: foo.com)) 67 // HistoryNode 0_1: (HistoryItem B (url: foo.com/a)) 68 // 69 // Now we navigation the top frame to bar.com, which embeds bar.com/b and bar.com/c in iframes, 70 // and bar.com/b in turn embeds bar.com/d. We will create a new HistoryEntry with a tree 71 // containing 4 new HistoryNodes. The state will be: 72 // 73 // HistoryEntry 1: 74 // HistoryNode 1_0 (HistoryItem C (url: bar.com)) 75 // HistoryNode 1_1: (HistoryItem D (url: bar.com/b)) 76 // HistoryNode 1_3: (HistoryItem F (url: bar.com/d)) 77 // HistoryNode 1_2: (HistoryItem E (url: bar.com/c)) 78 // 79 // 80 // Finally, we navigate the first subframe from bar.com/b to bar.com/e, which embeds bar.com/f. 81 // We will create a new HistoryEntry and new HistoryNode for each frame. Any frame that 82 // navigates (bar.com/e and its child, bar.com/f) will receive a new HistoryItem. However, 83 // 2 frames were not navigated (bar.com and bar.com/c), so those two frames will reuse the 84 // existing HistoryItem: 85 // 86 // HistoryEntry 2: 87 // HistoryNode 2_0 (HistoryItem C (url: bar.com)) *REUSED* 88 // HistoryNode 2_1: (HistoryItem G (url: bar.com/e)) 89 // HistoryNode 2_3: (HistoryItem H (url: bar.com/f)) 90 // HistoryNode 2_2: (HistoryItem E (url: bar.com/c)) *REUSED* 91 // 92 93 class HistoryNode { 94 public: 95 static PassOwnPtr<HistoryNode> create(HistoryEntry*, HistoryItem*); 96 ~HistoryNode() { } 97 98 HistoryNode* addChild(PassRefPtr<HistoryItem>); 99 PassOwnPtr<HistoryNode> cloneAndReplace(HistoryEntry*, HistoryItem* newItem, bool clipAtTarget, Frame* targetFrame, Frame* currentFrame); 100 HistoryItem* value() { return m_value.get(); } 101 void updateValue(PassRefPtr<HistoryItem> item) { m_value = item; } 102 const Vector<OwnPtr<HistoryNode> >& children() const { return m_children; } 103 void removeChildren(); 104 105 private: 106 HistoryNode(HistoryEntry*, HistoryItem*); 107 108 HistoryEntry* m_entry; 109 Vector<OwnPtr<HistoryNode> > m_children; 110 RefPtr<HistoryItem> m_value; 111 }; 112 113 class HistoryEntry { 114 public: 115 static PassOwnPtr<HistoryEntry> create(HistoryItem* root); 116 PassOwnPtr<HistoryEntry> cloneAndReplace(HistoryItem* newItem, bool clipAtTarget, Frame* targetFrame, Page*); 117 118 HistoryNode* historyNodeForFrame(Frame*); 119 HistoryItem* itemForFrame(Frame*); 120 HistoryItem* root() const { return m_root->value(); } 121 HistoryNode* rootHistoryNode() const { return m_root.get(); } 122 123 private: 124 friend class HistoryNode; 125 126 HistoryEntry() { } 127 explicit HistoryEntry(HistoryItem* root); 128 129 OwnPtr<HistoryNode> m_root; 130 HashMap<uint64_t, HistoryNode*> m_framesToItems; 131 HashMap<String, HistoryNode*> m_uniqueNamesToItems; 132 }; 133 134 class HistoryController { 135 WTF_MAKE_NONCOPYABLE(HistoryController); 136 public: 137 explicit HistoryController(Page*); 138 ~HistoryController(); 139 140 // Should only be called by embedder. To request a back/forward 141 // navigation, call FrameLoaderClient::navigateBackForward(). 142 void goToItem(HistoryItem*); 143 144 void updateBackForwardListForFragmentScroll(Frame*, HistoryItem*); 145 void updateForCommit(Frame*, HistoryItem*); 146 147 PassRefPtr<HistoryItem> currentItemForExport(); 148 PassRefPtr<HistoryItem> previousItemForExport(); 149 PassRefPtr<HistoryItem> provisionalItemForExport(); 150 HistoryItem* itemForNewChildFrame(Frame*) const; 151 void removeChildrenForRedirect(Frame*); 152 153 bool inSameDocumentLoad() const { return !m_sameDocumentLoadsInProgress.isEmpty() && m_differentDocumentLoadsInProgress.isEmpty(); } 154 155 void setDefersLoading(bool); 156 157 private: 158 void goToEntry(PassOwnPtr<HistoryEntry>); 159 void recursiveGoToEntry(Frame*); 160 161 void updateForInitialLoadInChildFrame(Frame*, HistoryItem*); 162 void createNewBackForwardItem(Frame*, HistoryItem*, bool doClip); 163 164 Page* m_page; 165 166 OwnPtr<HistoryEntry> m_currentEntry; 167 OwnPtr<HistoryEntry> m_previousEntry; 168 OwnPtr<HistoryEntry> m_provisionalEntry; 169 170 typedef HashMap<Frame*, RefPtr<HistoryItem> > HistoryFrameLoadSet; 171 HistoryFrameLoadSet m_sameDocumentLoadsInProgress; 172 HistoryFrameLoadSet m_differentDocumentLoadsInProgress; 173 174 bool m_defersLoading; 175 RefPtr<HistoryItem> m_deferredItem; 176 }; 177 178 } // namespace WebCore 179 180 #endif // HistoryController_h 181
