| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef HTMLImport_h |
| #define HTMLImport_h |
| |
| #include "core/html/imports/HTMLImportState.h" |
| #include "platform/heap/Handle.h" |
| #include "wtf/Allocator.h" |
| #include "wtf/TreeNode.h" |
| |
| namespace blink { |
| |
| class Document; |
| class HTMLImportLoader; |
| |
| // |
| // # Basic Data Structure and Algorithms of HTML Imports implemenation. |
| // |
| // ## The Import Tree |
| // |
| // HTML Imports form a tree: |
| // |
| // * The root of the tree is HTMLImportTreeRoot. |
| // |
| // * The HTMLImportTreeRoot is owned HTMLImportsController, which is owned by |
| // the master document as a DocumentSupplement. |
| // |
| // * The non-root nodes are HTMLImportChild. They are all owned by |
| // HTMLImporTreeRoot. LinkStyle is wired into HTMLImportChild by implementing |
| // HTMLImportChildClient interface |
| // |
| // * Both HTMLImportTreeRoot and HTMLImportChild are derived from HTMLImport |
| // superclass that models the tree data structure using WTF::TreeNode and |
| // provides a set of virtual functions. |
| // |
| // HTMLImportsController also owns all loaders in the tree and manages their |
| // lifetime through it. One assumption is that the tree is append-only and |
| // nodes are never inserted in the middle of the tree nor removed. |
| // |
| // Full diagram is here: |
| // https://docs.google.com/drawings/d/1jFQrO0IupWrlykTNzQ3Nv2SdiBiSz4UE9-V3-vDgBb0/ |
| // |
| // # Import Sharing and HTMLImportLoader |
| // |
| // The HTML Imports spec calls for de-dup mechanism to share already loaded |
| // imports. To implement this, the actual loading machinery is split out from |
| // HTMLImportChild to HTMLImportLoader, and each loader shares HTMLImportLoader |
| // with other loader if the URL is same. Check around |
| // HTMLImportsController::findLink() for more detail. |
| // |
| // HTMLImportLoader can be shared by multiple imports. |
| // |
| // HTMLImportChild (1)-->(*) HTMLImportLoader |
| // |
| // |
| // # Script Blocking |
| // |
| // - An import blocks the HTML parser of its own imported document from running |
| // <script> until all of its children are loaded. Note that dynamically added |
| // import won't block the parser. |
| // |
| // - An import under loading also blocks imported documents that follow from |
| // being created. This is because an import can include another import that |
| // has same URLs of following ones. In such case, the preceding import should |
| // be loaded and following ones should be de-duped. |
| // |
| |
| // The superclass of HTMLImportTreeRoot and HTMLImportChild |
| // This represents the import tree data structure. |
| class HTMLImport : public GarbageCollectedFinalized<HTMLImport>, |
| public TreeNode<HTMLImport> { |
| public: |
| enum SyncMode { Sync = 0, Async = 1 }; |
| |
| virtual ~HTMLImport() {} |
| |
| // FIXME: Consider returning HTMLImportTreeRoot. |
| HTMLImport* root(); |
| bool precedes(HTMLImport*); |
| bool isRoot() const { return !parent(); } |
| bool isSync() const { return SyncMode(m_sync) == Sync; } |
| bool formsCycle() const; |
| const HTMLImportState& state() const { return m_state; } |
| |
| void appendImport(HTMLImport*); |
| |
| virtual Document* document() const = 0; |
| virtual bool hasFinishedLoading() const = 0; |
| virtual HTMLImportLoader* loader() const { return nullptr; } |
| virtual void stateWillChange() {} |
| virtual void stateDidChange(); |
| |
| DEFINE_INLINE_VIRTUAL_TRACE() {} |
| |
| protected: |
| // Stating from most conservative state. |
| // It will be corrected through state update flow. |
| explicit HTMLImport(SyncMode sync) : m_sync(sync) {} |
| |
| static void recalcTreeState(HTMLImport* root); |
| |
| #if !defined(NDEBUG) |
| void show(); |
| void showTree(HTMLImport* highlight, unsigned depth); |
| virtual void showThis(); |
| #endif |
| |
| private: |
| HTMLImportState m_state; |
| unsigned m_sync : 1; |
| }; |
| |
| } // namespace blink |
| |
| #endif // HTMLImport_h |
