gecko-dev/dom/events/IMEContentObserver.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et 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 "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsIDocShell.h" // XXX Why does only this need to be included here?
#include "nsIEditor.h"
#include "nsIEditorObserver.h"
#include "nsIReflowObserver.h"
#include "nsISelectionListener.h"
#include "nsIScrollObserver.h"
#include "nsIWidget.h" // for nsIMEUpdatePreference
#include "nsStubMutationObserver.h"
#include "nsWeakReference.h"
class nsIContent;
class nsINode;
class nsISelection;
class nsPresContext;
namespace mozilla {
class EventStateManager;
// IMEContentObserver notifies widget of any text and selection changes
// in the currently focused editor
class IMEContentObserver final : public nsISelectionListener
, public nsStubMutationObserver
, public nsIReflowObserver
, public nsIScrollObserver
, public nsSupportsWeakReference
, public nsIEditorObserver
{
friend class AsyncMergeableNotificationsFlusher;
public:
IMEContentObserver();
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(IMEContentObserver,
nsISelectionListener)
NS_DECL_NSIEDITOROBSERVER
NS_DECL_NSISELECTIONLISTENER
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;
bool OnMouseButtonEvent(nsPresContext* aPresContext,
WidgetMouseEvent* aMouseEvent);
void Init(nsIWidget* aWidget, nsPresContext* aPresContext,
nsIContent* aContent, nsIEditor* aEditor);
void Destroy();
/**
* IMEContentObserver is stored by EventStateManager during observing.
* DisconnectFromEventStateManager() is called when EventStateManager stops
* storing the instance.
*/
void DisconnectFromEventStateManager();
bool IsManaging(nsPresContext* aPresContext, nsIContent* aContent);
bool IsEditorHandlingEventForComposition() const;
bool KeepAliveDuringDeactive() const
{
return mUpdatePreference.WantDuringDeactive();
}
nsIWidget* GetWidget() const { return mWidget; }
nsresult GetSelectionAndRoot(nsISelection** aSelection,
nsIContent** aRoot) const;
struct TextChangeData
{
// mStartOffset is the start offset of modified or removed text in
// original content and inserted text in new content.
uint32_t mStartOffset;
// mRemovalEndOffset is the end offset of modified or removed text in
// original content. If the value is same as mStartOffset, no text hasn't
// been removed yet.
uint32_t mRemovedEndOffset;
// mAddedEndOffset is the end offset of inserted text or same as
// mStartOffset if just removed. The vlaue is offset in the new content.
uint32_t mAddedEndOffset;
bool mCausedOnlyByComposition;
bool mStored;
TextChangeData()
: mStartOffset(0)
, mRemovedEndOffset(0)
, mAddedEndOffset(0)
, mCausedOnlyByComposition(false)
, mStored(false)
{
}
TextChangeData(uint32_t aStartOffset,
uint32_t aRemovedEndOffset,
uint32_t aAddedEndOffset,
bool aCausedByComposition)
: mStartOffset(aStartOffset)
, mRemovedEndOffset(aRemovedEndOffset)
, mAddedEndOffset(aAddedEndOffset)
, mCausedOnlyByComposition(aCausedByComposition)
, mStored(true)
{
MOZ_ASSERT(aRemovedEndOffset >= aStartOffset,
"removed end offset must not be smaller than start offset");
MOZ_ASSERT(aAddedEndOffset >= aStartOffset,
"added end offset must not be smaller than start offset");
}
// Positive if text is added. Negative if text is removed.
int64_t Difference() const
{
return mAddedEndOffset - mRemovedEndOffset;
}
};
private:
~IMEContentObserver() {}
void MaybeNotifyIMEOfTextChange(const TextChangeData& aTextChangeData);
void MaybeNotifyIMEOfSelectionChange(bool aCausedByComposition);
void MaybeNotifyIMEOfPositionChange();
void NotifyContentAdded(nsINode* aContainer, int32_t aStart, int32_t aEnd);
void ObserveEditableNode();
/**
* UnregisterObservers() unresiters all listeners and observers.
* @param aPostEvent When true, DOM event will be posted to the thread.
* Otherwise, dispatched when safe.
*/
void UnregisterObservers(bool aPostEvent);
void StoreTextChangeData(const TextChangeData& aTextChangeData);
void FlushMergeableNotifications();
#ifdef DEBUG
void TestMergingTextChangeData();
#endif
nsCOMPtr<nsIWidget> mWidget;
nsCOMPtr<nsISelection> mSelection;
nsCOMPtr<nsIContent> mRootContent;
nsCOMPtr<nsINode> mEditableNode;
nsCOMPtr<nsIDocShell> mDocShell;
nsCOMPtr<nsIEditor> mEditor;
/**
* FlatTextCache stores flat text length from start of the content to
* mNodeOffset of mContainerNode.
*/
struct FlatTextCache
{
// mContainerNode and mNodeOffset represent a point in DOM tree. E.g.,
// if mContainerNode is a div element, mNodeOffset is index of its child.
nsCOMPtr<nsINode> mContainerNode;
int32_t mNodeOffset;
// 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()
: mNodeOffset(0)
, mFlatTextLength(0)
{
}
void Clear()
{
mContainerNode = nullptr;
mNodeOffset = 0;
mFlatTextLength = 0;
}
void Cache(nsINode* aContainer, int32_t aNodeOffset,
uint32_t aFlatTextLength)
{
MOZ_ASSERT(aContainer, "aContainer must not be null");
MOZ_ASSERT(
aNodeOffset <= static_cast<int32_t>(aContainer->GetChildCount()),
"aNodeOffset must be same as or less than the count of children");
mContainerNode = aContainer;
mNodeOffset = aNodeOffset;
mFlatTextLength = aFlatTextLength;
}
bool Match(nsINode* aContainer, int32_t aNodeOffset) const
{
return aContainer == mContainerNode && aNodeOffset == mNodeOffset;
}
};
// 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;
TextChangeData mTextChangeData;
EventStateManager* mESM;
nsIMEUpdatePreference mUpdatePreference;
uint32_t mPreAttrChangeLength;
int64_t mPreCharacterDataChangeLength;
bool mIsSelectionChangeEventPending;
bool mSelectionChangeCausedOnlyByComposition;
bool mIsPositionChangeEventPending;
bool mIsFlushingPendingNotifications;
};
} // namespace mozilla
#endif // mozilla_IMEContentObserver_h_