michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * a class that walks the lexicographic tree of rule nodes as style
michael@0:  * rules are matched
michael@0:  */
michael@0: 
michael@0: #ifndef nsRuleWalker_h_
michael@0: #define nsRuleWalker_h_
michael@0: 
michael@0: #include "nsRuleNode.h"
michael@0: #include "nsIStyleRule.h"
michael@0: #include "StyleRule.h"
michael@0: 
michael@0: class nsRuleWalker {
michael@0: public:
michael@0:   nsRuleNode* CurrentNode() { return mCurrent; }
michael@0:   void SetCurrentNode(nsRuleNode* aNode) {
michael@0:     NS_ASSERTION(aNode, "Must have node here!");
michael@0:     mCurrent = aNode;
michael@0:   }
michael@0: 
michael@0: protected:
michael@0:   void DoForward(nsIStyleRule* aRule) {
michael@0:     mCurrent = mCurrent->Transition(aRule, mLevel, mImportance);
michael@0:     NS_POSTCONDITION(mCurrent, "Transition messed up");
michael@0:   }
michael@0: 
michael@0: public:
michael@0:   void Forward(nsIStyleRule* aRule) {
michael@0:     NS_PRECONDITION(!nsRefPtr<mozilla::css::StyleRule>(do_QueryObject(aRule)),
michael@0:                     "Calling the wrong Forward() overload");
michael@0:     DoForward(aRule);
michael@0:   }
michael@0:   void Forward(mozilla::css::StyleRule* aRule) {
michael@0:     DoForward(aRule);
michael@0:     mCheckForImportantRules =
michael@0:       mCheckForImportantRules && !aRule->GetImportantRule();
michael@0:   }
michael@0:   // ForwardOnPossiblyCSSRule should only be used by callers that have
michael@0:   // an explicit list of rules they need to walk, with the list
michael@0:   // already containing any important rules they care about.
michael@0:   void ForwardOnPossiblyCSSRule(nsIStyleRule* aRule) {
michael@0:     DoForward(aRule);
michael@0:   }
michael@0: 
michael@0:   void Reset() { mCurrent = mRoot; }
michael@0: 
michael@0:   bool AtRoot() { return mCurrent == mRoot; }
michael@0: 
michael@0:   void SetLevel(uint8_t aLevel, bool aImportance,
michael@0:                 bool aCheckForImportantRules) {
michael@0:     NS_ASSERTION(!aCheckForImportantRules || !aImportance,
michael@0:                  "Shouldn't be checking for important rules while walking "
michael@0:                  "important rules");
michael@0:     mLevel = aLevel;
michael@0:     mImportance = aImportance;
michael@0:     mCheckForImportantRules = aCheckForImportantRules;
michael@0:   }
michael@0:   uint8_t GetLevel() const { return mLevel; }
michael@0:   bool GetImportance() const { return mImportance; }
michael@0:   bool GetCheckForImportantRules() const { return mCheckForImportantRules; }
michael@0: 
michael@0:   bool AuthorStyleDisabled() const { return mAuthorStyleDisabled; }
michael@0: 
michael@0:   // We define the visited-relevant link to be the link that is the
michael@0:   // nearest self-or-ancestor to the node being matched.
michael@0:   enum VisitedHandlingType {
michael@0:     // Do rule matching as though all links are unvisited.
michael@0:     eRelevantLinkUnvisited,
michael@0:     // Do rule matching as though the relevant link is visited and all
michael@0:     // other links are unvisited.
michael@0:     eRelevantLinkVisited,
michael@0:     // Do rule matching as though a rule should match if it would match
michael@0:     // given any set of visitedness states.  (used by users other than
michael@0:     // nsRuleWalker)
michael@0:     eLinksVisitedOrUnvisited
michael@0:   };
michael@0: 
michael@0: private:
michael@0:   nsRuleNode* mCurrent; // Our current position.  Never null.
michael@0:   nsRuleNode* mRoot; // The root of the tree we're walking.
michael@0:   uint8_t mLevel; // an nsStyleSet::sheetType
michael@0:   bool mImportance;
michael@0:   bool mCheckForImportantRules; // If true, check for important rules as
michael@0:                                 // we walk and set to false if we find
michael@0:                                 // one.
michael@0:   bool mAuthorStyleDisabled;
michael@0: 
michael@0: public:
michael@0:   nsRuleWalker(nsRuleNode* aRoot, bool aAuthorStyleDisabled)
michael@0:     : mCurrent(aRoot)
michael@0:     , mRoot(aRoot)
michael@0:     , mAuthorStyleDisabled(aAuthorStyleDisabled)
michael@0:   {
michael@0:     NS_ASSERTION(mCurrent, "Caller screwed up and gave us null node");
michael@0:     MOZ_COUNT_CTOR(nsRuleWalker);
michael@0:   }
michael@0:   ~nsRuleWalker() { MOZ_COUNT_DTOR(nsRuleWalker); }
michael@0: };
michael@0: 
michael@0: #endif /* !defined(nsRuleWalker_h_) */