/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* Code to start and animate CSS transitions. */

#ifndef nsTransitionManager_h_
#define nsTransitionManager_h_

#include "AnimationCommon.h"
#include "nsCSSPseudoElements.h"

class nsStyleContext;
class nsPresContext;
class nsCSSPropertySet;
struct nsTransition;
struct ElementTransitions;

class nsTransitionManager : public mozilla::css::CommonAnimationManager
{
public:
  nsTransitionManager(nsPresContext *aPresContext)
    : mozilla::css::CommonAnimationManager(aPresContext)
  {
  }

  /**
   * StyleContextChanged 
   *
   * To be called from nsFrameManager::ReResolveStyleContext when the
   * style of an element has changed, to initiate transitions from
   * that style change.  For style contexts with :before and :after
   * pseudos, aElement is expected to be the generated before/after
   * element.
   *
   * It may return a "cover rule" (see CoverTransitionStartStyleRule) to
   * cover up some of the changes for the duration of the restyling of
   * descendants.  If it does, this function will take care of causing
   * the necessary restyle afterwards, but the caller must restyle the
   * element *again* with the original sequence of rules plus the
   * returned cover rule as the most specific rule.
   */
  already_AddRefed<nsIStyleRule>
    StyleContextChanged(mozilla::dom::Element *aElement,
                        nsStyleContext *aOldStyleContext,
                        nsStyleContext *aNewStyleContext);

  // nsIStyleRuleProcessor (parts)
  virtual void RulesMatching(ElementRuleProcessorData* aData);
  virtual void RulesMatching(PseudoElementRuleProcessorData* aData);
  virtual void RulesMatching(AnonBoxRuleProcessorData* aData);
#ifdef MOZ_XUL
  virtual void RulesMatching(XULTreeRuleProcessorData* aData);
#endif
  virtual NS_MUST_OVERRIDE size_t
    SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const MOZ_OVERRIDE;
  virtual NS_MUST_OVERRIDE size_t
    SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) const MOZ_OVERRIDE;

  // nsARefreshObserver
  virtual void WillRefresh(mozilla::TimeStamp aTime);

private:
  void ConsiderStartingTransition(nsCSSProperty aProperty,
                                  const nsTransition& aTransition,
                                  mozilla::dom::Element *aElement,
                                  ElementTransitions *&aElementTransitions,
                                  nsStyleContext *aOldStyleContext,
                                  nsStyleContext *aNewStyleContext,
                                  bool *aStartedAny,
                                  nsCSSPropertySet *aWhichStarted);
  ElementTransitions* GetElementTransitions(mozilla::dom::Element *aElement,
                                            nsCSSPseudoElements::Type aPseudoType,
                                            bool aCreateIfNeeded);
  void WalkTransitionRule(RuleProcessorData* aData,
                          nsCSSPseudoElements::Type aPseudoType);
};

#endif /* !defined(nsTransitionManager_h_) */