1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/base/nsRefreshDriver.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,344 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/*
1.11 + * Code to notify things that animate before a refresh, at an appropriate
1.12 + * refresh rate. (Perhaps temporary, until replaced by compositor.)
1.13 + */
1.14 +
1.15 +#ifndef nsRefreshDriver_h_
1.16 +#define nsRefreshDriver_h_
1.17 +
1.18 +#include "mozilla/TimeStamp.h"
1.19 +#include "mozFlushType.h"
1.20 +#include "nsTObserverArray.h"
1.21 +#include "nsTArray.h"
1.22 +#include "nsTHashtable.h"
1.23 +#include "nsClassHashtable.h"
1.24 +#include "nsHashKeys.h"
1.25 +#include "mozilla/Attributes.h"
1.26 +#include "mozilla/Maybe.h"
1.27 +
1.28 +class nsPresContext;
1.29 +class nsIPresShell;
1.30 +class nsIDocument;
1.31 +class imgIRequest;
1.32 +class nsIRunnable;
1.33 +
1.34 +namespace mozilla {
1.35 +class RefreshDriverTimer;
1.36 +}
1.37 +
1.38 +/**
1.39 + * An abstract base class to be implemented by callers wanting to be
1.40 + * notified at refresh times. When nothing needs to be painted, callers
1.41 + * may not be notified.
1.42 + */
1.43 +class nsARefreshObserver {
1.44 +public:
1.45 + // AddRef and Release signatures that match nsISupports. Implementors
1.46 + // must implement reference counting, and those that do implement
1.47 + // nsISupports will already have methods with the correct signature.
1.48 + //
1.49 + // The refresh driver does NOT hold references to refresh observers
1.50 + // except while it is notifying them.
1.51 + NS_IMETHOD_(MozExternalRefCountType) AddRef(void) = 0;
1.52 + NS_IMETHOD_(MozExternalRefCountType) Release(void) = 0;
1.53 +
1.54 + virtual void WillRefresh(mozilla::TimeStamp aTime) = 0;
1.55 +};
1.56 +
1.57 +/**
1.58 + * An abstract base class to be implemented by callers wanting to be notified
1.59 + * that a refresh has occurred. Callers must ensure an observer is removed
1.60 + * before it is destroyed.
1.61 + */
1.62 +class nsAPostRefreshObserver {
1.63 +public:
1.64 + virtual void DidRefresh() = 0;
1.65 +};
1.66 +
1.67 +class nsRefreshDriver MOZ_FINAL : public nsISupports {
1.68 +public:
1.69 + nsRefreshDriver(nsPresContext *aPresContext);
1.70 + ~nsRefreshDriver();
1.71 +
1.72 + static void InitializeStatics();
1.73 + static void Shutdown();
1.74 +
1.75 + // nsISupports implementation
1.76 + NS_DECL_ISUPPORTS
1.77 +
1.78 + /**
1.79 + * Methods for testing, exposed via nsIDOMWindowUtils. See
1.80 + * nsIDOMWindowUtils.advanceTimeAndRefresh for description.
1.81 + */
1.82 + void AdvanceTimeAndRefresh(int64_t aMilliseconds);
1.83 + void RestoreNormalRefresh();
1.84 + void DoTick();
1.85 + bool IsTestControllingRefreshesEnabled() const
1.86 + {
1.87 + return mTestControllingRefreshes;
1.88 + }
1.89 +
1.90 + /**
1.91 + * Return the time of the most recent refresh. This is intended to be
1.92 + * used by callers who want to start an animation now and want to know
1.93 + * what time to consider the start of the animation. (This helps
1.94 + * ensure that multiple animations started during the same event off
1.95 + * the main event loop have the same start time.)
1.96 + */
1.97 + mozilla::TimeStamp MostRecentRefresh() const;
1.98 + /**
1.99 + * Same thing, but in microseconds since the epoch.
1.100 + */
1.101 + int64_t MostRecentRefreshEpochTime() const;
1.102 +
1.103 + /**
1.104 + * Add / remove refresh observers. Returns whether the operation
1.105 + * succeeded.
1.106 + *
1.107 + * The flush type affects:
1.108 + * + the order in which the observers are notified (lowest flush
1.109 + * type to highest, in order registered)
1.110 + * + (in the future) which observers are suppressed when the display
1.111 + * doesn't require current position data or isn't currently
1.112 + * painting, and, correspondingly, which get notified when there
1.113 + * is a flush during such suppression
1.114 + * and it must be either Flush_Style, Flush_Layout, or Flush_Display.
1.115 + *
1.116 + * The refresh driver does NOT own a reference to these observers;
1.117 + * they must remove themselves before they are destroyed.
1.118 + *
1.119 + * The observer will be called even if there is no other activity.
1.120 + */
1.121 + bool AddRefreshObserver(nsARefreshObserver *aObserver,
1.122 + mozFlushType aFlushType);
1.123 + bool RemoveRefreshObserver(nsARefreshObserver *aObserver,
1.124 + mozFlushType aFlushType);
1.125 +
1.126 + /**
1.127 + * Add an observer that will be called after each refresh. The caller
1.128 + * must remove the observer before it is deleted. This does not trigger
1.129 + * refresh driver ticks.
1.130 + */
1.131 + void AddPostRefreshObserver(nsAPostRefreshObserver *aObserver);
1.132 + void RemovePostRefreshObserver(nsAPostRefreshObserver *aObserver);
1.133 +
1.134 + /**
1.135 + * Add/Remove imgIRequest versions of observers.
1.136 + *
1.137 + * These are used for hooking into the refresh driver for
1.138 + * controlling animated images.
1.139 + *
1.140 + * @note The refresh driver owns a reference to these listeners.
1.141 + *
1.142 + * @note Technically, imgIRequest objects are not nsARefreshObservers, but
1.143 + * for controlling animated image repaint events, we subscribe the
1.144 + * imgIRequests to the nsRefreshDriver for notification of paint events.
1.145 + *
1.146 + * @returns whether the operation succeeded, or void in the case of removal.
1.147 + */
1.148 + bool AddImageRequest(imgIRequest* aRequest);
1.149 + void RemoveImageRequest(imgIRequest* aRequest);
1.150 +
1.151 + /**
1.152 + * Add / remove presshells that we should flush style and layout on
1.153 + */
1.154 + bool AddStyleFlushObserver(nsIPresShell* aShell) {
1.155 + NS_ASSERTION(!mStyleFlushObservers.Contains(aShell),
1.156 + "Double-adding style flush observer");
1.157 + bool appended = mStyleFlushObservers.AppendElement(aShell) != nullptr;
1.158 + EnsureTimerStarted(false);
1.159 + return appended;
1.160 + }
1.161 + void RemoveStyleFlushObserver(nsIPresShell* aShell) {
1.162 + mStyleFlushObservers.RemoveElement(aShell);
1.163 + }
1.164 + bool AddLayoutFlushObserver(nsIPresShell* aShell) {
1.165 + NS_ASSERTION(!IsLayoutFlushObserver(aShell),
1.166 + "Double-adding layout flush observer");
1.167 + bool appended = mLayoutFlushObservers.AppendElement(aShell) != nullptr;
1.168 + EnsureTimerStarted(false);
1.169 + return appended;
1.170 + }
1.171 + void RemoveLayoutFlushObserver(nsIPresShell* aShell) {
1.172 + mLayoutFlushObservers.RemoveElement(aShell);
1.173 + }
1.174 + bool IsLayoutFlushObserver(nsIPresShell* aShell) {
1.175 + return mLayoutFlushObservers.Contains(aShell);
1.176 + }
1.177 + bool AddPresShellToInvalidateIfHidden(nsIPresShell* aShell) {
1.178 + NS_ASSERTION(!mPresShellsToInvalidateIfHidden.Contains(aShell),
1.179 + "Double-adding style flush observer");
1.180 + bool appended = mPresShellsToInvalidateIfHidden.AppendElement(aShell) != nullptr;
1.181 + EnsureTimerStarted(false);
1.182 + return appended;
1.183 + }
1.184 + void RemovePresShellToInvalidateIfHidden(nsIPresShell* aShell) {
1.185 + mPresShellsToInvalidateIfHidden.RemoveElement(aShell);
1.186 + }
1.187 +
1.188 + /**
1.189 + * Remember whether our presshell's view manager needs a flush
1.190 + */
1.191 + void ScheduleViewManagerFlush();
1.192 + void RevokeViewManagerFlush() {
1.193 + mViewManagerFlushIsPending = false;
1.194 + }
1.195 + bool ViewManagerFlushIsPending() {
1.196 + return mViewManagerFlushIsPending;
1.197 + }
1.198 +
1.199 + /**
1.200 + * Add a document for which we have nsIFrameRequestCallbacks
1.201 + */
1.202 + void ScheduleFrameRequestCallbacks(nsIDocument* aDocument);
1.203 +
1.204 + /**
1.205 + * Remove a document for which we have nsIFrameRequestCallbacks
1.206 + */
1.207 + void RevokeFrameRequestCallbacks(nsIDocument* aDocument);
1.208 +
1.209 + /**
1.210 + * Tell the refresh driver that it is done driving refreshes and
1.211 + * should stop its timer and forget about its pres context. This may
1.212 + * be called from within a refresh.
1.213 + */
1.214 + void Disconnect() {
1.215 + StopTimer();
1.216 + mPresContext = nullptr;
1.217 + }
1.218 +
1.219 + bool IsFrozen() { return mFreezeCount > 0; }
1.220 +
1.221 + /**
1.222 + * Freeze the refresh driver. It should stop delivering future
1.223 + * refreshes until thawed. Note that the number of calls to Freeze() must
1.224 + * match the number of calls to Thaw() in order for the refresh driver to
1.225 + * be un-frozen.
1.226 + */
1.227 + void Freeze();
1.228 +
1.229 + /**
1.230 + * Thaw the refresh driver. If the number of calls to Freeze() matches the
1.231 + * number of calls to this function, the refresh driver should start
1.232 + * delivering refreshes again.
1.233 + */
1.234 + void Thaw();
1.235 +
1.236 + /**
1.237 + * Throttle or unthrottle the refresh driver. This is done if the
1.238 + * corresponding presshell is hidden or shown.
1.239 + */
1.240 + void SetThrottled(bool aThrottled);
1.241 +
1.242 + /**
1.243 + * Return the prescontext we were initialized with
1.244 + */
1.245 + nsPresContext* PresContext() const { return mPresContext; }
1.246 +
1.247 +#ifdef DEBUG
1.248 + /**
1.249 + * Check whether the given observer is an observer for the given flush type
1.250 + */
1.251 + bool IsRefreshObserver(nsARefreshObserver *aObserver,
1.252 + mozFlushType aFlushType);
1.253 +#endif
1.254 +
1.255 + /**
1.256 + * Default interval the refresh driver uses, in ms.
1.257 + */
1.258 + static int32_t DefaultInterval();
1.259 +
1.260 + bool IsInRefresh() { return mInRefresh; }
1.261 +
1.262 +private:
1.263 + typedef nsTObserverArray<nsARefreshObserver*> ObserverArray;
1.264 + typedef nsTHashtable<nsISupportsHashKey> RequestTable;
1.265 + struct ImageStartData {
1.266 + ImageStartData()
1.267 + {
1.268 + }
1.269 +
1.270 + mozilla::Maybe<mozilla::TimeStamp> mStartTime;
1.271 + RequestTable mEntries;
1.272 + };
1.273 + typedef nsClassHashtable<nsUint32HashKey, ImageStartData> ImageStartTable;
1.274 +
1.275 + void Tick(int64_t aNowEpoch, mozilla::TimeStamp aNowTime);
1.276 +
1.277 + void EnsureTimerStarted(bool aAdjustingTimer);
1.278 + void StopTimer();
1.279 +
1.280 + uint32_t ObserverCount() const;
1.281 + uint32_t ImageRequestCount() const;
1.282 + static PLDHashOperator ImageRequestEnumerator(nsISupportsHashKey* aEntry,
1.283 + void* aUserArg);
1.284 + static PLDHashOperator StartTableRequestCounter(const uint32_t& aKey,
1.285 + ImageStartData* aEntry,
1.286 + void* aUserArg);
1.287 + static PLDHashOperator StartTableRefresh(const uint32_t& aKey,
1.288 + ImageStartData* aEntry,
1.289 + void* aUserArg);
1.290 + static PLDHashOperator BeginRefreshingImages(nsISupportsHashKey* aEntry,
1.291 + void* aUserArg);
1.292 + ObserverArray& ArrayFor(mozFlushType aFlushType);
1.293 + // Trigger a refresh immediately, if haven't been disconnected or frozen.
1.294 + void DoRefresh();
1.295 +
1.296 + double GetRefreshTimerInterval() const;
1.297 + double GetRegularTimerInterval(bool *outIsDefault = nullptr) const;
1.298 + double GetThrottledTimerInterval() const;
1.299 +
1.300 + bool HaveFrameRequestCallbacks() const {
1.301 + return mFrameRequestCallbackDocs.Length() != 0;
1.302 + }
1.303 +
1.304 + mozilla::RefreshDriverTimer* ChooseTimer() const;
1.305 + mozilla::RefreshDriverTimer *mActiveTimer;
1.306 +
1.307 + nsPresContext *mPresContext; // weak; pres context passed in constructor
1.308 + // and unset in Disconnect
1.309 +
1.310 + uint32_t mFreezeCount;
1.311 + bool mThrottled;
1.312 + bool mTestControllingRefreshes;
1.313 + bool mViewManagerFlushIsPending;
1.314 + bool mRequestedHighPrecision;
1.315 + bool mInRefresh;
1.316 +
1.317 + int64_t mMostRecentRefreshEpochTime;
1.318 + mozilla::TimeStamp mMostRecentRefresh;
1.319 +
1.320 + // separate arrays for each flush type we support
1.321 + ObserverArray mObservers[3];
1.322 + RequestTable mRequests;
1.323 + ImageStartTable mStartTable;
1.324 +
1.325 + nsAutoTArray<nsIPresShell*, 16> mStyleFlushObservers;
1.326 + nsAutoTArray<nsIPresShell*, 16> mLayoutFlushObservers;
1.327 + nsAutoTArray<nsIPresShell*, 16> mPresShellsToInvalidateIfHidden;
1.328 + // nsTArray on purpose, because we want to be able to swap.
1.329 + nsTArray<nsIDocument*> mFrameRequestCallbackDocs;
1.330 + nsTArray<nsAPostRefreshObserver*> mPostRefreshObservers;
1.331 +
1.332 + // Helper struct for processing image requests
1.333 + struct ImageRequestParameters {
1.334 + mozilla::TimeStamp mCurrent;
1.335 + mozilla::TimeStamp mPrevious;
1.336 + RequestTable* mRequests;
1.337 + mozilla::TimeStamp mDesired;
1.338 + };
1.339 +
1.340 + friend class mozilla::RefreshDriverTimer;
1.341 +
1.342 + // turn on or turn off high precision based on various factors
1.343 + void ConfigureHighPrecision();
1.344 + void SetHighPrecisionTimersEnabled(bool aEnable);
1.345 +};
1.346 +
1.347 +#endif /* !defined(nsRefreshDriver_h_) */
