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Diffstat (limited to 'dom/events/IMEContentObserver.h')
| -rw-r--r-- | dom/events/IMEContentObserver.h | 538 |
1 files changed, 538 insertions, 0 deletions
diff --git a/dom/events/IMEContentObserver.h b/dom/events/IMEContentObserver.h new file mode 100644 index 0000000000..83822168b9 --- /dev/null +++ b/dom/events/IMEContentObserver.h @@ -0,0 +1,538 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/. */ + +#ifndef mozilla_IMEContentObserver_h +#define mozilla_IMEContentObserver_h + +#include "mozilla/Attributes.h" +#include "mozilla/EditorBase.h" +#include "mozilla/dom/Element.h" +#include "mozilla/dom/Selection.h" +#include "nsCOMPtr.h" +#include "nsCycleCollectionParticipant.h" +#include "nsIDocShell.h" // XXX Why does only this need to be included here? +#include "nsIReflowObserver.h" +#include "nsIScrollObserver.h" +#include "nsIWidget.h" +#include "nsStubDocumentObserver.h" +#include "nsStubMutationObserver.h" +#include "nsThreadUtils.h" +#include "nsWeakReference.h" + +class nsIContent; +class nsINode; +class nsPresContext; + +namespace mozilla { + +class EventStateManager; +class TextComposition; + +namespace dom { +class Selection; +} // namespace dom + +// IMEContentObserver notifies widget of any text and selection changes +// in the currently focused editor +class IMEContentObserver final : public nsStubMutationObserver, + public nsIReflowObserver, + public nsIScrollObserver, + public nsSupportsWeakReference { + public: + using SelectionChangeData = widget::IMENotification::SelectionChangeData; + using TextChangeData = widget::IMENotification::TextChangeData; + using TextChangeDataBase = widget::IMENotification::TextChangeDataBase; + using IMENotificationRequests = widget::IMENotificationRequests; + using IMEMessage = widget::IMEMessage; + + IMEContentObserver(); + + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(IMEContentObserver, + nsIReflowObserver) + NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATAWILLCHANGE + NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED + NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED + NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED + NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED + NS_DECL_NSIREFLOWOBSERVER + + // nsIScrollObserver + virtual void ScrollPositionChanged() override; + + /** + * OnSelectionChange() is called when selection is changed in the editor. + */ + void OnSelectionChange(dom::Selection& aSelection); + + MOZ_CAN_RUN_SCRIPT bool OnMouseButtonEvent(nsPresContext& aPresContext, + WidgetMouseEvent& aMouseEvent); + + MOZ_CAN_RUN_SCRIPT nsresult + HandleQueryContentEvent(WidgetQueryContentEvent* aEvent); + + /** + * Handle eSetSelection event if and only if aEvent changes selection offset + * or length. Doing nothing when selection range is same is important to + * honer users' intention or web app's intention because ContentEventHandler + * does not support to put range boundaries to arbitrary side of element + * boundaries. E.g., `<b>bold[]</b> normal` vs. `<b>bold</b>[] normal`. + * Note that this compares given range with selection cache which has been + * notified IME via widget. Therefore, the caller needs to guarantee that + * pending notifications should've been flushed. If you test this, you need + * to wait 2 animation frames before sending eSetSelection event. + */ + MOZ_CAN_RUN_SCRIPT nsresult MaybeHandleSelectionEvent( + nsPresContext* aPresContext, WidgetSelectionEvent* aEvent); + + /** + * Init() initializes the instance, i.e., retrieving necessary objects and + * starts to observe something. + * Be aware, callers of this method need to guarantee that the instance + * won't be released during calling this. + * + * @param aWidget The widget which can access native IME. + * @param aPresContext The PresContext which has aContent. + * @param aElement An editable element or nullptr if this will observe + * design mode document. + * @param aEditorBase The editor which is associated with aContent. + */ + MOZ_CAN_RUN_SCRIPT void Init(nsIWidget& aWidget, nsPresContext& aPresContext, + dom::Element* aElement, EditorBase& aEditorBase); + + /** + * Destroy() finalizes the instance, i.e., stops observing contents and + * clearing the members. + * Be aware, callers of this method need to guarantee that the instance + * won't be released during calling this. + */ + void Destroy(); + + /** + * Returns false if the instance refers some objects and observing them. + * Otherwise, true. + */ + bool Destroyed() const; + + /** + * IMEContentObserver is stored by EventStateManager during observing. + * DisconnectFromEventStateManager() is called when EventStateManager stops + * storing the instance. + */ + void DisconnectFromEventStateManager(); + + /** + * MaybeReinitialize() tries to restart to observe the editor's root node. + * This is useful when the editor is reframed and all children are replaced + * with new node instances. + * Be aware, callers of this method need to guarantee that the instance + * won't be released during calling this. + * + * @return Returns true if the instance is managing the content. + * Otherwise, false. + */ + MOZ_CAN_RUN_SCRIPT bool MaybeReinitialize(nsIWidget& aWidget, + nsPresContext& aPresContext, + dom::Element* aElement, + EditorBase& aEditorBase); + + bool IsManaging(const nsPresContext& aPresContext, + const dom::Element* aElement) const; + bool IsBeingInitializedFor(const nsPresContext& aPresContext, + const dom::Element* aElement) const; + bool IsManaging(const TextComposition& aTextComposition) const; + bool WasInitializedWith(const EditorBase& aEditorBase) const { + return mEditorBase == &aEditorBase; + } + bool IsEditorHandlingEventForComposition() const; + bool KeepAliveDuringDeactive() const { + return mIMENotificationRequests && + mIMENotificationRequests->WantDuringDeactive(); + } + nsIWidget* GetWidget() const { return mWidget; } + void SuppressNotifyingIME(); + void UnsuppressNotifyingIME(); + nsPresContext* GetPresContext() const; + nsresult GetSelectionAndRoot(dom::Selection** aSelection, + dom::Element** aRootElement) const; + + /** + * TryToFlushPendingNotifications() should be called when pending events + * should be flushed. This tries to run the queued IMENotificationSender. + * Doesn't do anything in child processes where flushing happens + * asynchronously unless aAllowAsync is false. + */ + void TryToFlushPendingNotifications(bool aAllowAsync); + + /** + * MaybeNotifyCompositionEventHandled() posts composition event handled + * notification into the pseudo queue. + */ + void MaybeNotifyCompositionEventHandled(); + + /** + * Following methods are called when the editor: + * - an edit action handled. + * - before handling an edit action. + * - canceled handling an edit action after calling BeforeEditAction(). + */ + void OnEditActionHandled(); + void BeforeEditAction(); + void CancelEditAction(); + + /** + * Called when text control value is changed while this is not observing + * mRootElement. This is typically there is no frame for the editor (i.e., + * no proper anonymous <div> element for the editor yet) or the TextEditor + * has not been created (i.e., IMEStateManager has not been reinitialized + * this instance with new anonymous <div> element yet). + */ + void OnTextControlValueChangedWhileNotObservable(const nsAString& aNewValue); + + dom::Element* GetObservingElement() const { + return mIsObserving ? mRootElement.get() : nullptr; + } + + private: + ~IMEContentObserver() = default; + + enum State { + eState_NotObserving, + eState_Initializing, + eState_StoppedObserving, + eState_Observing + }; + State GetState() const; + MOZ_CAN_RUN_SCRIPT bool InitWithEditor(nsPresContext& aPresContext, + dom::Element* aElement, + EditorBase& aEditorBase); + void OnIMEReceivedFocus(); + void Clear(); + [[nodiscard]] bool IsObservingContent(const nsPresContext& aPresContext, + const dom::Element* aElement) const; + [[nodiscard]] bool IsReflowLocked() const; + [[nodiscard]] bool IsSafeToNotifyIME() const; + [[nodiscard]] bool IsEditorComposing() const; + + // Following methods are called by DocumentObserver when + // beginning to update the contents and ending updating the contents. + void BeginDocumentUpdate(); + void EndDocumentUpdate(); + + // Following methods manages added nodes during a document change. + + /** + * MaybeNotifyIMEOfAddedTextDuringDocumentChange() may send text change + * notification caused by the nodes added between mFirstAddedContent in + * mFirstAddedContainer and mLastAddedContent in + * mLastAddedContainer and forgets the range. + */ + void MaybeNotifyIMEOfAddedTextDuringDocumentChange(); + + /** + * IsInDocumentChange() returns true while the DOM tree is being modified + * with mozAutoDocUpdate. E.g., it's being modified by setting innerHTML or + * insertAdjacentHTML(). This returns false when user types something in + * the focused editor editor. + */ + bool IsInDocumentChange() const { + return mDocumentObserver && mDocumentObserver->IsUpdating(); + } + + /** + * Forget the range of added nodes during a document change. + */ + void ClearAddedNodesDuringDocumentChange(); + + /** + * HasAddedNodesDuringDocumentChange() returns true when this stores range + * of nodes which were added into the DOM tree during a document change but + * have not been sent to IME. Note that this should always return false when + * IsInDocumentChange() returns false. + */ + bool HasAddedNodesDuringDocumentChange() const { + return mFirstAddedContainer && mLastAddedContainer; + } + + /** + * Returns true if the passed-in node in aParent is the next node of + * mLastAddedContent in pre-order tree traversal of the DOM. + */ + bool IsNextNodeOfLastAddedNode(nsINode* aParent, nsIContent* aChild) const; + + void PostFocusSetNotification(); + void MaybeNotifyIMEOfFocusSet(); + void PostTextChangeNotification(); + void MaybeNotifyIMEOfTextChange(const TextChangeDataBase& aTextChangeData); + void CancelNotifyingIMEOfTextChange(); + void PostSelectionChangeNotification(); + void MaybeNotifyIMEOfSelectionChange(bool aCausedByComposition, + bool aCausedBySelectionEvent, + bool aOccurredDuringComposition); + void PostPositionChangeNotification(); + void MaybeNotifyIMEOfPositionChange(); + void CancelNotifyingIMEOfPositionChange(); + void PostCompositionEventHandledNotification(); + + void NotifyContentAdded(nsINode* aContainer, nsIContent* aFirstContent, + nsIContent* aLastContent); + void ObserveEditableNode(); + /** + * NotifyIMEOfBlur() notifies IME of blur. + */ + void NotifyIMEOfBlur(); + /** + * UnregisterObservers() unregisters all listeners and observers. + */ + void UnregisterObservers(); + void FlushMergeableNotifications(); + bool NeedsTextChangeNotification() const { + return mIMENotificationRequests && + mIMENotificationRequests->WantTextChange(); + } + bool NeedsPositionChangeNotification() const { + return mIMENotificationRequests && + mIMENotificationRequests->WantPositionChanged(); + } + void ClearPendingNotifications() { + mNeedsToNotifyIMEOfFocusSet = false; + mNeedsToNotifyIMEOfTextChange = false; + mNeedsToNotifyIMEOfSelectionChange = false; + mNeedsToNotifyIMEOfPositionChange = false; + mNeedsToNotifyIMEOfCompositionEventHandled = false; + mTextChangeData.Clear(); + } + bool NeedsToNotifyIMEOfSomething() const { + return mNeedsToNotifyIMEOfFocusSet || mNeedsToNotifyIMEOfTextChange || + mNeedsToNotifyIMEOfSelectionChange || + mNeedsToNotifyIMEOfPositionChange || + mNeedsToNotifyIMEOfCompositionEventHandled; + } + + /** + * UpdateSelectionCache() updates mSelectionData with the latest selection. + * This should be called only when IsSafeToNotifyIME() returns true. + */ + MOZ_CAN_RUN_SCRIPT bool UpdateSelectionCache(bool aRequireFlush = true); + + nsCOMPtr<nsIWidget> mWidget; + // mFocusedWidget has the editor observed by the instance. E.g., if the + // focused editor is in XUL panel, this should be the widget of the panel. + // On the other hand, mWidget is its parent which handles IME. + nsCOMPtr<nsIWidget> mFocusedWidget; + RefPtr<dom::Selection> mSelection; + RefPtr<dom::Element> mRootElement; + nsCOMPtr<nsINode> mEditableNode; + nsCOMPtr<nsIDocShell> mDocShell; + RefPtr<EditorBase> mEditorBase; + + /** + * Helper classes to notify IME. + */ + + class AChangeEvent : public Runnable { + protected: + enum ChangeEventType { + eChangeEventType_Focus, + eChangeEventType_Selection, + eChangeEventType_Text, + eChangeEventType_Position, + eChangeEventType_CompositionEventHandled + }; + + explicit AChangeEvent(const char* aName, + IMEContentObserver* aIMEContentObserver) + : Runnable(aName), + mIMEContentObserver(do_GetWeakReference( + static_cast<nsIReflowObserver*>(aIMEContentObserver))) { + MOZ_ASSERT(aIMEContentObserver); + } + + already_AddRefed<IMEContentObserver> GetObserver() const { + nsCOMPtr<nsIReflowObserver> observer = + do_QueryReferent(mIMEContentObserver); + return observer.forget().downcast<IMEContentObserver>(); + } + + nsWeakPtr mIMEContentObserver; + + /** + * CanNotifyIME() checks if mIMEContentObserver can and should notify IME. + */ + bool CanNotifyIME(ChangeEventType aChangeEventType) const; + + /** + * IsSafeToNotifyIME() checks if it's safe to noitify IME. + */ + bool IsSafeToNotifyIME(ChangeEventType aChangeEventType) const; + }; + + class IMENotificationSender : public AChangeEvent { + public: + explicit IMENotificationSender(IMEContentObserver* aIMEContentObserver) + : AChangeEvent("IMENotificationSender", aIMEContentObserver), + mIsRunning(false) {} + MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHOD Run() override; + + void Dispatch(nsIDocShell* aDocShell); + + private: + MOZ_CAN_RUN_SCRIPT void SendFocusSet(); + MOZ_CAN_RUN_SCRIPT void SendSelectionChange(); + void SendTextChange(); + void SendPositionChange(); + void SendCompositionEventHandled(); + + bool mIsRunning; + }; + + // mQueuedSender is, it was put into the event queue but not run yet. + RefPtr<IMENotificationSender> mQueuedSender; + + /** + * IMEContentObserver is a mutation observer of mRootContent. However, + * it needs to know the beginning of content changes and end of it too for + * reducing redundant computation of text offset with ContentEventHandler. + * Therefore, it needs helper class to listen only them since if + * both mutations were observed by IMEContentObserver directly, each + * methods need to check if the changing node is in mRootContent but it's + * too expensive. + */ + class DocumentObserver final : public nsStubDocumentObserver { + public: + explicit DocumentObserver(IMEContentObserver& aIMEContentObserver) + : mIMEContentObserver(&aIMEContentObserver), mDocumentUpdating(0) { + SetEnabledCallbacks(nsIMutationObserver::kBeginUpdate | + nsIMutationObserver::kEndUpdate); + } + + NS_DECL_CYCLE_COLLECTION_CLASS(DocumentObserver) + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_NSIDOCUMENTOBSERVER_BEGINUPDATE + NS_DECL_NSIDOCUMENTOBSERVER_ENDUPDATE + + void Observe(dom::Document*); + void StopObserving(); + void Destroy(); + + bool Destroyed() const { return !mIMEContentObserver; } + bool IsObserving() const { return mDocument != nullptr; } + bool IsUpdating() const { return mDocumentUpdating != 0; } + + private: + DocumentObserver() = delete; + virtual ~DocumentObserver() { Destroy(); } + + RefPtr<IMEContentObserver> mIMEContentObserver; + RefPtr<dom::Document> mDocument; + uint32_t mDocumentUpdating; + }; + RefPtr<DocumentObserver> mDocumentObserver; + + /** + * FlatTextCache stores flat text length from start of the content to + * mNodeOffset of mContainerNode. + */ + struct FlatTextCache { + // mContainerNode and mNode represent a point in DOM tree. E.g., + // if mContainerNode is a div element, mNode is a child. + nsCOMPtr<nsINode> mContainerNode; + // mNode points to the last child which participates in the current + // mFlatTextLength. If mNode is null, then that means that the end point for + // mFlatTextLength is immediately before the first child of mContainerNode. + nsCOMPtr<nsINode> mNode; + // Length of flat text generated from contents between the start of content + // and a child node whose index is mNodeOffset of mContainerNode. + uint32_t mFlatTextLength; + + FlatTextCache() : mFlatTextLength(0) {} + + void Clear() { + mContainerNode = nullptr; + mNode = nullptr; + mFlatTextLength = 0; + } + + void Cache(nsINode* aContainer, nsINode* aNode, uint32_t aFlatTextLength) { + MOZ_ASSERT(aContainer, "aContainer must not be null"); + MOZ_ASSERT(!aNode || aNode->GetParentNode() == aContainer, + "aNode must be either null or a child of aContainer"); + mContainerNode = aContainer; + mNode = aNode; + mFlatTextLength = aFlatTextLength; + } + + bool Match(nsINode* aContainer, nsINode* aNode) const { + return aContainer == mContainerNode && aNode == mNode; + } + }; + // mEndOfAddedTextCache caches text length from the start of content to + // the end of the last added content only while an edit action is being + // handled by the editor and no other mutation (e.g., removing node) + // occur. + FlatTextCache mEndOfAddedTextCache; + // mStartOfRemovingTextRangeCache caches text length from the start of content + // to the start of the last removed content only while an edit action is being + // handled by the editor and no other mutation (e.g., adding node) occur. + FlatTextCache mStartOfRemovingTextRangeCache; + + // mFirstAddedContainer is parent node of first added node in current + // document change. So, this is not nullptr only when a node was added + // during a document change and the change has not been included into + // mTextChangeData yet. + // Note that this shouldn't be in cycle collection since this is not nullptr + // only during a document change. + nsCOMPtr<nsINode> mFirstAddedContainer; + // mLastAddedContainer is parent node of last added node in current + // document change. So, this is not nullptr only when a node was added + // during a document change and the change has not been included into + // mTextChangeData yet. + // Note that this shouldn't be in cycle collection since this is not nullptr + // only during a document change. + nsCOMPtr<nsINode> mLastAddedContainer; + + // mFirstAddedContent is the first node added in mFirstAddedContainer. + nsCOMPtr<nsIContent> mFirstAddedContent; + // mLastAddedContent is the last node added in mLastAddedContainer; + nsCOMPtr<nsIContent> mLastAddedContent; + + TextChangeData mTextChangeData; + + // mSelectionData is the last selection data which was notified. The + // selection information is modified by UpdateSelectionCache(). The reason + // of the selection change is modified by MaybeNotifyIMEOfSelectionChange(). + SelectionChangeData mSelectionData; + + EventStateManager* mESM; + + const IMENotificationRequests* mIMENotificationRequests; + int64_t mPreCharacterDataChangeLength = -1; + uint32_t mSuppressNotifications = 0; + + // If the observing editor is a text control's one, this is set to the value + // length. + uint32_t mTextControlValueLength = 0; + + // mSendingNotification is a notification which is now sending from + // IMENotificationSender. When the value is NOTIFY_IME_OF_NOTHING, it's + // not sending any notification. + IMEMessage mSendingNotification; + + bool mIsObserving; + bool mIMEHasFocus; + bool mNeedsToNotifyIMEOfFocusSet; + bool mNeedsToNotifyIMEOfTextChange; + bool mNeedsToNotifyIMEOfSelectionChange; + bool mNeedsToNotifyIMEOfPositionChange; + bool mNeedsToNotifyIMEOfCompositionEventHandled; + // mIsHandlingQueryContentEvent is true when IMEContentObserver is handling + // WidgetQueryContentEvent with ContentEventHandler. + bool mIsHandlingQueryContentEvent; +}; + +} // namespace mozilla + +#endif // mozilla_IMEContentObserver_h |