1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/accessible/src/base/NotificationController.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,313 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef mozilla_a11y_NotificationController_h_
1.10 +#define mozilla_a11y_NotificationController_h_
1.11 +
1.12 +#include "EventQueue.h"
1.13 +
1.14 +#include "nsCycleCollectionParticipant.h"
1.15 +#include "nsRefreshDriver.h"
1.16 +
1.17 +#ifdef A11Y_LOG
1.18 +#include "Logging.h"
1.19 +#endif
1.20 +
1.21 +namespace mozilla {
1.22 +namespace a11y {
1.23 +
1.24 +class DocAccessible;
1.25 +
1.26 +/**
1.27 + * Notification interface.
1.28 + */
1.29 +class Notification
1.30 +{
1.31 +public:
1.32 + NS_INLINE_DECL_REFCOUNTING(Notification)
1.33 +
1.34 + /**
1.35 + * Process notification.
1.36 + */
1.37 + virtual void Process() = 0;
1.38 +
1.39 +protected:
1.40 + Notification() { }
1.41 +
1.42 + /**
1.43 + * Protected destructor, to discourage deletion outside of Release():
1.44 + */
1.45 + virtual ~Notification() { }
1.46 +
1.47 +private:
1.48 + Notification(const Notification&);
1.49 + Notification& operator = (const Notification&);
1.50 +};
1.51 +
1.52 +
1.53 +/**
1.54 + * Template class for generic notification.
1.55 + *
1.56 + * @note Instance is kept as a weak ref, the caller must guarantee it exists
1.57 + * longer than the document accessible owning the notification controller
1.58 + * that this notification is processed by.
1.59 + */
1.60 +template<class Class, class Arg>
1.61 +class TNotification : public Notification
1.62 +{
1.63 +public:
1.64 + typedef void (Class::*Callback)(Arg*);
1.65 +
1.66 + TNotification(Class* aInstance, Callback aCallback, Arg* aArg) :
1.67 + mInstance(aInstance), mCallback(aCallback), mArg(aArg) { }
1.68 + virtual ~TNotification() { mInstance = nullptr; }
1.69 +
1.70 + virtual void Process()
1.71 + {
1.72 + (mInstance->*mCallback)(mArg);
1.73 +
1.74 + mInstance = nullptr;
1.75 + mCallback = nullptr;
1.76 + mArg = nullptr;
1.77 + }
1.78 +
1.79 +private:
1.80 + TNotification(const TNotification&);
1.81 + TNotification& operator = (const TNotification&);
1.82 +
1.83 + Class* mInstance;
1.84 + Callback mCallback;
1.85 + nsRefPtr<Arg> mArg;
1.86 +};
1.87 +
1.88 +/**
1.89 + * Used to process notifications from core for the document accessible.
1.90 + */
1.91 +class NotificationController : public EventQueue,
1.92 + public nsARefreshObserver
1.93 +{
1.94 +public:
1.95 + NotificationController(DocAccessible* aDocument, nsIPresShell* aPresShell);
1.96 + virtual ~NotificationController();
1.97 +
1.98 + NS_IMETHOD_(MozExternalRefCountType) AddRef(void);
1.99 + NS_IMETHOD_(MozExternalRefCountType) Release(void);
1.100 +
1.101 + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(NotificationController)
1.102 +
1.103 + /**
1.104 + * Shutdown the notification controller.
1.105 + */
1.106 + void Shutdown();
1.107 +
1.108 + /**
1.109 + * Put an accessible event into the queue to process it later.
1.110 + */
1.111 + void QueueEvent(AccEvent* aEvent)
1.112 + {
1.113 + if (PushEvent(aEvent))
1.114 + ScheduleProcessing();
1.115 + }
1.116 +
1.117 + /**
1.118 + * Schedule binding the child document to the tree of this document.
1.119 + */
1.120 + void ScheduleChildDocBinding(DocAccessible* aDocument);
1.121 +
1.122 + /**
1.123 + * Schedule the accessible tree update because of rendered text changes.
1.124 + */
1.125 + inline void ScheduleTextUpdate(nsIContent* aTextNode)
1.126 + {
1.127 + if (mTextHash.PutEntry(aTextNode))
1.128 + ScheduleProcessing();
1.129 + }
1.130 +
1.131 + /**
1.132 + * Pend accessible tree update for content insertion.
1.133 + */
1.134 + void ScheduleContentInsertion(Accessible* aContainer,
1.135 + nsIContent* aStartChildNode,
1.136 + nsIContent* aEndChildNode);
1.137 +
1.138 + /**
1.139 + * Process the generic notification synchronously if there are no pending
1.140 + * layout changes and no notifications are pending or being processed right
1.141 + * now. Otherwise, queue it up to process asynchronously.
1.142 + *
1.143 + * @note The caller must guarantee that the given instance still exists when
1.144 + * the notification is processed.
1.145 + */
1.146 + template<class Class, class Arg>
1.147 + inline void HandleNotification(Class* aInstance,
1.148 + typename TNotification<Class, Arg>::Callback aMethod,
1.149 + Arg* aArg)
1.150 + {
1.151 + if (!IsUpdatePending()) {
1.152 +#ifdef A11Y_LOG
1.153 + if (mozilla::a11y::logging::IsEnabled(mozilla::a11y::logging::eNotifications))
1.154 + mozilla::a11y::logging::Text("sync notification processing");
1.155 +#endif
1.156 + (aInstance->*aMethod)(aArg);
1.157 + return;
1.158 + }
1.159 +
1.160 + nsRefPtr<Notification> notification =
1.161 + new TNotification<Class, Arg>(aInstance, aMethod, aArg);
1.162 + if (notification && mNotifications.AppendElement(notification))
1.163 + ScheduleProcessing();
1.164 + }
1.165 +
1.166 + /**
1.167 + * Schedule the generic notification to process asynchronously.
1.168 + *
1.169 + * @note The caller must guarantee that the given instance still exists when
1.170 + * the notification is processed.
1.171 + */
1.172 + template<class Class, class Arg>
1.173 + inline void ScheduleNotification(Class* aInstance,
1.174 + typename TNotification<Class, Arg>::Callback aMethod,
1.175 + Arg* aArg)
1.176 + {
1.177 + nsRefPtr<Notification> notification =
1.178 + new TNotification<Class, Arg>(aInstance, aMethod, aArg);
1.179 + if (notification && mNotifications.AppendElement(notification))
1.180 + ScheduleProcessing();
1.181 + }
1.182 +
1.183 +#ifdef DEBUG
1.184 + bool IsUpdating() const
1.185 + { return mObservingState == eRefreshProcessingForUpdate; }
1.186 +#endif
1.187 +
1.188 +protected:
1.189 + nsCycleCollectingAutoRefCnt mRefCnt;
1.190 + NS_DECL_OWNINGTHREAD
1.191 +
1.192 + /**
1.193 + * Start to observe refresh to make notifications and events processing after
1.194 + * layout.
1.195 + */
1.196 + void ScheduleProcessing();
1.197 +
1.198 + /**
1.199 + * Return true if the accessible tree state update is pending.
1.200 + */
1.201 + bool IsUpdatePending();
1.202 +
1.203 +private:
1.204 + NotificationController(const NotificationController&);
1.205 + NotificationController& operator = (const NotificationController&);
1.206 +
1.207 + // nsARefreshObserver
1.208 + virtual void WillRefresh(mozilla::TimeStamp aTime);
1.209 +
1.210 +private:
1.211 + /**
1.212 + * Indicates whether we're waiting on an event queue processing from our
1.213 + * notification controller to flush events.
1.214 + */
1.215 + enum eObservingState {
1.216 + eNotObservingRefresh,
1.217 + eRefreshObserving,
1.218 + eRefreshProcessing,
1.219 + eRefreshProcessingForUpdate
1.220 + };
1.221 + eObservingState mObservingState;
1.222 +
1.223 + /**
1.224 + * The presshell of the document accessible.
1.225 + */
1.226 + nsIPresShell* mPresShell;
1.227 +
1.228 + /**
1.229 + * Child documents that needs to be bound to the tree.
1.230 + */
1.231 + nsTArray<nsRefPtr<DocAccessible> > mHangingChildDocuments;
1.232 +
1.233 + /**
1.234 + * Storage for content inserted notification information.
1.235 + */
1.236 + class ContentInsertion
1.237 + {
1.238 + public:
1.239 + ContentInsertion(DocAccessible* aDocument, Accessible* aContainer);
1.240 + virtual ~ContentInsertion() { mDocument = nullptr; }
1.241 +
1.242 + NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(ContentInsertion)
1.243 + NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(ContentInsertion)
1.244 +
1.245 + bool InitChildList(nsIContent* aStartChildNode, nsIContent* aEndChildNode);
1.246 + void Process();
1.247 +
1.248 + private:
1.249 + ContentInsertion();
1.250 + ContentInsertion(const ContentInsertion&);
1.251 + ContentInsertion& operator = (const ContentInsertion&);
1.252 +
1.253 + // The document used to process content insertion, matched to document of
1.254 + // the notification controller that this notification belongs to, therefore
1.255 + // it's ok to keep it as weak ref.
1.256 + DocAccessible* mDocument;
1.257 +
1.258 + // The container accessible that content insertion occurs within.
1.259 + nsRefPtr<Accessible> mContainer;
1.260 +
1.261 + // Array of inserted contents.
1.262 + nsTArray<nsCOMPtr<nsIContent> > mInsertedContent;
1.263 + };
1.264 +
1.265 + /**
1.266 + * A pending accessible tree update notifications for content insertions.
1.267 + * Don't make this an nsAutoTArray; we use SwapElements() on it.
1.268 + */
1.269 + nsTArray<nsRefPtr<ContentInsertion> > mContentInsertions;
1.270 +
1.271 + template<class T>
1.272 + class nsCOMPtrHashKey : public PLDHashEntryHdr
1.273 + {
1.274 + public:
1.275 + typedef T* KeyType;
1.276 + typedef const T* KeyTypePointer;
1.277 +
1.278 + nsCOMPtrHashKey(const T* aKey) : mKey(const_cast<T*>(aKey)) {}
1.279 + nsCOMPtrHashKey(const nsPtrHashKey<T> &aToCopy) : mKey(aToCopy.mKey) {}
1.280 + ~nsCOMPtrHashKey() { }
1.281 +
1.282 + KeyType GetKey() const { return mKey; }
1.283 + bool KeyEquals(KeyTypePointer aKey) const { return aKey == mKey; }
1.284 +
1.285 + static KeyTypePointer KeyToPointer(KeyType aKey) { return aKey; }
1.286 + static PLDHashNumber HashKey(KeyTypePointer aKey)
1.287 + { return NS_PTR_TO_INT32(aKey) >> 2; }
1.288 +
1.289 + enum { ALLOW_MEMMOVE = true };
1.290 +
1.291 + protected:
1.292 + nsCOMPtr<T> mKey;
1.293 + };
1.294 +
1.295 + /**
1.296 + * A pending accessible tree update notifications for rendered text changes.
1.297 + */
1.298 + nsTHashtable<nsCOMPtrHashKey<nsIContent> > mTextHash;
1.299 +
1.300 + /**
1.301 + * Update the accessible tree for pending rendered text change notifications.
1.302 + */
1.303 + static PLDHashOperator TextEnumerator(nsCOMPtrHashKey<nsIContent>* aEntry,
1.304 + void* aUserArg);
1.305 +
1.306 + /**
1.307 + * Other notifications like DOM events. Don't make this an nsAutoTArray; we
1.308 + * use SwapElements() on it.
1.309 + */
1.310 + nsTArray<nsRefPtr<Notification> > mNotifications;
1.311 +};
1.312 +
1.313 +} // namespace a11y
1.314 +} // namespace mozilla
1.315 +
1.316 +#endif // mozilla_a11y_NotificationController_h_
