DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (15984bd142b7)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510
/* -*- 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/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:
  typedef widget::IMENotification::SelectionChangeData SelectionChangeData;
  typedef widget::IMENotification::TextChangeData TextChangeData;
  typedef widget::IMENotification::TextChangeDataBase TextChangeDataBase;
  typedef widget::IMENotificationRequests IMENotificationRequests;
  typedef widget::IMEMessage 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_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE
  NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
  NS_DECL_NSIREFLOWOBSERVER

  // nsIScrollObserver
  virtual void ScrollPositionChanged() override;

  /**
   * OnSelectionChange() is called when selection is changed in the editor.
   */
  void OnSelectionChange(dom::Selection& aSelection);

  bool OnMouseButtonEvent(nsPresContext* aPresContext,
                          WidgetMouseEvent* aMouseEvent);

  nsresult HandleQueryContentEvent(WidgetQueryContentEvent* 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 aContent        An editable element or a plugin host element which
   *                        user may use IME in.
   *                        Or nullptr if this will observe design mode
   *                        document.
   * @param aEditorBase     When aContent is an editable element or nullptr,
   *                        non-nullptr referring an editor instance which
   *                        manages aContent.
   *                        Otherwise, i.e., this will observe a plugin content,
   *                        should be nullptr.
   */
  void Init(nsIWidget* aWidget, nsPresContext* aPresContext,
            nsIContent* aContent, 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.
   */
  bool MaybeReinitialize(nsIWidget* aWidget, nsPresContext* aPresContext,
                         nsIContent* aContent, EditorBase* aEditorBase);

  bool IsManaging(nsPresContext* aPresContext, nsIContent* aContent) const;
  bool IsManaging(const TextComposition* aTextComposition) const;
  bool WasInitializedWithPlugin() 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,
                               nsIContent** aRoot) 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();

 private:
  ~IMEContentObserver() {}

  enum State {
    eState_NotObserving,
    eState_Initializing,
    eState_StoppedObserving,
    eState_Observing
  };
  State GetState() const;
  bool InitWithEditor(nsPresContext* aPresContext, nsIContent* aContent,
                      EditorBase* aEditorBase);
  bool InitWithPlugin(nsPresContext* aPresContext, nsIContent* aContent);
  bool IsInitializedWithPlugin() const { return !mEditorBase; }
  void OnIMEReceivedFocus();
  void Clear();
  bool IsObservingContent(nsPresContext* aPresContext,
                          nsIContent* aContent) const;
  bool IsReflowLocked() const;
  bool IsSafeToNotifyIME() const;
  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.
   *
   * Note that this does nothing if WasInitializedWithPlugin() returns true.
   */
  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;
  nsCOMPtr<nsIContent> mRootContent;
  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) {}
    NS_IMETHOD Run() override;

    void Dispatch(nsIDocShell* aDocShell);

   private:
    void SendFocusSet();
    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) {}

    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;
  uint32_t mPreAttrChangeLength;
  uint32_t mSuppressNotifications;
  int64_t mPreCharacterDataChangeLength;

  // 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