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: #ifndef ScrollbarActivity_h___
michael@0: #define ScrollbarActivity_h___
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsIDOMEventListener.h"
michael@0: #include "mozilla/TimeStamp.h"
michael@0: #include "nsRefreshDriver.h"
michael@0: 
michael@0: class nsIContent;
michael@0: class nsIScrollbarOwner;
michael@0: class nsITimer;
michael@0: class nsIAtom;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace layout {
michael@0: 
michael@0: /**
michael@0:  * ScrollbarActivity
michael@0:  *
michael@0:  * This class manages scrollbar behavior that imitates the native Mac OS X
michael@0:  * Lion overlay scrollbar behavior: Scrollbars are only shown while "scrollbar
michael@0:  * activity" occurs, and they're hidden with a fade animation after a short
michael@0:  * delay.
michael@0:  *
michael@0:  * Scrollbar activity has these states:
michael@0:  *  - inactive:
michael@0:  *      Scrollbars are hidden.
michael@0:  *  - ongoing activity:
michael@0:  *      Scrollbars are visible and being operated on in some way, for example
michael@0:  *      because they're hovered or pressed.
michael@0:  *  - active, but waiting for fade out
michael@0:  *      Scrollbars are still completely visible but are about to fade away.
michael@0:  *  - fading out
michael@0:  *      Scrollbars are subject to a fade-out animation.
michael@0:  *
michael@0:  * Initial scrollbar activity needs to be reported by the scrollbar holder that
michael@0:  * owns the ScrollbarActivity instance. This needs to happen via a call to
michael@0:  * ActivityOccurred(), for example when the current scroll position or the size
michael@0:  * of the scroll area changes.
michael@0:  *
michael@0:  * As soon as scrollbars are visible, the ScrollbarActivity class manages the
michael@0:  * rest of the activity behavior: It ensures that mouse motions inside the
michael@0:  * scroll area keep the scrollbars visible, and that scrollbars don't fade away
michael@0:  * while they're being hovered / dragged. It also sets a sticky hover attribute
michael@0:  * on the most recently hovered scrollbar.
michael@0:  *
michael@0:  * ScrollbarActivity falls into hibernation after the scrollbars have faded
michael@0:  * out. It only starts acting after the next call to ActivityOccurred() /
michael@0:  * ActivityStarted().
michael@0:  */
michael@0: 
michael@0: class ScrollbarActivity : public nsIDOMEventListener,
michael@0:                           public nsARefreshObserver {
michael@0: public:
michael@0:   ScrollbarActivity(nsIScrollbarOwner* aScrollableFrame)
michael@0:    : mScrollableFrame(aScrollableFrame)
michael@0:    , mNestedActivityCounter(0)
michael@0:    , mIsActive(false)
michael@0:    , mIsFading(false)
michael@0:    , mListeningForScrollbarEvents(false)
michael@0:    , mListeningForScrollAreaEvents(false)
michael@0:    , mHScrollbarHovered(false)
michael@0:    , mVScrollbarHovered(false)
michael@0:    , mDisplayOnMouseMove(false)
michael@0:    , mScrollbarFadeBeginDelay(0)
michael@0:    , mScrollbarFadeDuration(0)
michael@0:   {
michael@0:     QueryLookAndFeelVals();
michael@0:   }
michael@0: 
michael@0:   NS_DECL_ISUPPORTS
michael@0:   NS_DECL_NSIDOMEVENTLISTENER
michael@0: 
michael@0:   virtual ~ScrollbarActivity() {}
michael@0: 
michael@0:   void Destroy();
michael@0: 
michael@0:   void ActivityOccurred();
michael@0:   void ActivityStarted();
michael@0:   void ActivityStopped();
michael@0: 
michael@0:   virtual void WillRefresh(TimeStamp aTime) MOZ_OVERRIDE;
michael@0: 
michael@0:   static void FadeBeginTimerFired(nsITimer* aTimer, void* aSelf) {
michael@0:     nsRefPtr<ScrollbarActivity> scrollbarActivity(
michael@0:       reinterpret_cast<ScrollbarActivity*>(aSelf));
michael@0:     scrollbarActivity->BeginFade();
michael@0:   }
michael@0: 
michael@0: protected:
michael@0: 
michael@0:   bool IsActivityOngoing()
michael@0:   { return mNestedActivityCounter > 0; }
michael@0:   bool IsStillFading(TimeStamp aTime);
michael@0:   void QueryLookAndFeelVals();
michael@0: 
michael@0:   void HandleEventForScrollbar(const nsAString& aType,
michael@0:                                nsIContent* aTarget,
michael@0:                                nsIContent* aScrollbar,
michael@0:                                bool* aStoredHoverState);
michael@0: 
michael@0:   void SetIsActive(bool aNewActive);
michael@0:   bool SetIsFading(bool aNewFading); // returns false if 'this' was destroyed
michael@0: 
michael@0:   void BeginFade();
michael@0:   void EndFade();
michael@0: 
michael@0:   void StartFadeBeginTimer();
michael@0:   void CancelFadeBeginTimer();
michael@0: 
michael@0:   void StartListeningForScrollbarEvents();
michael@0:   void StartListeningForScrollAreaEvents();
michael@0:   void StopListeningForScrollbarEvents();
michael@0:   void StopListeningForScrollAreaEvents();
michael@0:   void AddScrollbarEventListeners(nsIDOMEventTarget* aScrollbar);
michael@0:   void RemoveScrollbarEventListeners(nsIDOMEventTarget* aScrollbar);
michael@0: 
michael@0:   void RegisterWithRefreshDriver();
michael@0:   void UnregisterFromRefreshDriver();
michael@0: 
michael@0:   bool UpdateOpacity(TimeStamp aTime); // returns false if 'this' was destroyed
michael@0:   void HoveredScrollbar(nsIContent* aScrollbar);
michael@0: 
michael@0:   nsRefreshDriver* GetRefreshDriver();
michael@0:   nsIContent* GetScrollbarContent(bool aVertical);
michael@0:   nsIContent* GetHorizontalScrollbar() { return GetScrollbarContent(false); }
michael@0:   nsIContent* GetVerticalScrollbar() { return GetScrollbarContent(true); }
michael@0: 
michael@0:   const TimeDuration FadeDuration() {
michael@0:     return TimeDuration::FromMilliseconds(mScrollbarFadeDuration);
michael@0:   }
michael@0: 
michael@0:   nsIScrollbarOwner* mScrollableFrame;
michael@0:   TimeStamp mFadeBeginTime;
michael@0:   nsCOMPtr<nsITimer> mFadeBeginTimer;
michael@0:   nsCOMPtr<nsIDOMEventTarget> mHorizontalScrollbar; // null while inactive
michael@0:   nsCOMPtr<nsIDOMEventTarget> mVerticalScrollbar;   // null while inactive
michael@0:   int mNestedActivityCounter;
michael@0:   bool mIsActive;
michael@0:   bool mIsFading;
michael@0:   bool mListeningForScrollbarEvents;
michael@0:   bool mListeningForScrollAreaEvents;
michael@0:   bool mHScrollbarHovered;
michael@0:   bool mVScrollbarHovered;
michael@0: 
michael@0:   // LookAndFeel values we load on creation
michael@0:   bool mDisplayOnMouseMove;
michael@0:   int mScrollbarFadeBeginDelay;
michael@0:   int mScrollbarFadeDuration;
michael@0: };
michael@0: 
michael@0: } // namespace layout
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif /* ScrollbarActivity_h___ */