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+/* -*- 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_ContentEventHandler_h_
+#define mozilla_ContentEventHandler_h_
+
+#include "js/GCAPI.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/EventForwards.h"
+#include "mozilla/RangeBoundary.h"
+#include "mozilla/dom/Selection.h"
+#include "mozilla/dom/Text.h"
+#include "nsCOMPtr.h"
+#include "nsIFrame.h"
+#include "nsINode.h"
+
+class nsPresContext;
+class nsRange;
+
+struct nsRect;
+
+namespace mozilla {
+
+namespace dom {
+class Element;
+} // namespace dom
+
+enum LineBreakType { LINE_BREAK_TYPE_NATIVE, LINE_BREAK_TYPE_XP };
+
+/*
+ * Query Content Event Handler
+ * ContentEventHandler is a helper class for EventStateManager.
+ * The platforms request some content informations, e.g., the selected text,
+ * the offset of the selected text and the text for specified range.
+ * This class answers to NS_QUERY_* events from actual contents.
+ */
+
+class MOZ_STACK_CLASS ContentEventHandler {
+ private:
+ /**
+ * SimpleRangeBase is a helper template class of ContentEventHandler class
+ * that stores 2 DOM points as a range without observing the mutation. I.e.,
+ * similar to dom::StaticRange, but can only be on the stack and does not have
+ * unnecessary features for ContentEventHandler so it is fast.
+ * Therefore, initializers are responsible for making sure the start/end nodes
+ * are in document order. This is enforced by assertions in DEBUG builds.
+ */
+ template <typename NodeType, typename RangeBoundaryType>
+ class MOZ_STACK_CLASS SimpleRangeBase final {
+ public:
+ SimpleRangeBase();
+ SimpleRangeBase(SimpleRangeBase<NodeType, RangeBoundaryType>&&) noexcept;
+ template <typename OtherNodeType, typename OtherRangeBoundaryType>
+ explicit SimpleRangeBase(
+ const SimpleRangeBase<OtherNodeType, OtherRangeBoundaryType>& aOther);
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+ ~SimpleRangeBase();
+#endif
+
+ void Clear() {
+ mRoot = nullptr;
+ mStart = {};
+ mEnd = {};
+ }
+
+ bool IsPositioned() const { return mStart.IsSet() && mEnd.IsSet(); }
+ bool Collapsed() const { return mStart == mEnd && IsPositioned(); }
+ nsINode* GetStartContainer() const { return mStart.Container(); }
+ nsINode* GetEndContainer() const { return mEnd.Container(); }
+ uint32_t StartOffset() const {
+ return *mStart.Offset(
+ RangeBoundaryType::OffsetFilter::kValidOrInvalidOffsets);
+ }
+ uint32_t EndOffset() const {
+ return *mEnd.Offset(
+ RangeBoundaryType::OffsetFilter::kValidOrInvalidOffsets);
+ }
+ nsIContent* StartRef() const { return mStart.Ref(); }
+ nsIContent* EndRef() const { return mEnd.Ref(); }
+
+ const RangeBoundaryType& Start() const { return mStart; }
+ const RangeBoundaryType& End() const { return mEnd; }
+
+ nsINode* GetRoot() const { return mRoot; }
+
+ // XXX: Make these use RangeBoundaries...
+ nsresult CollapseTo(const RawRangeBoundary& aBoundary) {
+ return SetStartAndEnd(aBoundary, aBoundary);
+ }
+ nsresult SetStart(const RawRangeBoundary& aStart);
+ nsresult SetEnd(const RawRangeBoundary& aEnd);
+
+ // NOTE: These helpers can hide performance problems, as they perform a
+ // search to find aStartOffset in aStartContainer.
+ nsresult SetStart(nsINode* aStartContainer, uint32_t aStartOffset) {
+ return SetStart(RawRangeBoundary(aStartContainer, aStartOffset));
+ }
+ nsresult SetEnd(nsINode* aEndContainer, uint32_t aEndOffset) {
+ return SetEnd(RawRangeBoundary(aEndContainer, aEndOffset));
+ }
+
+ nsresult SetEndAfter(nsINode* aEndContainer);
+ void SetStartAndEnd(const nsRange* aRange);
+ nsresult SetStartAndEnd(const RawRangeBoundary& aStart,
+ const RawRangeBoundary& aEnd);
+
+ nsresult SelectNodeContents(const nsINode* aNodeToSelectContents);
+
+ private:
+ inline void AssertStartIsBeforeOrEqualToEnd();
+
+ NodeType mRoot;
+
+ RangeBoundaryType mStart;
+ RangeBoundaryType mEnd;
+
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+ nsMutationGuard mMutationGuard;
+ Maybe<JS::AutoAssertNoGC> mAssertNoGC;
+#endif
+ };
+
+ using SimpleRange = SimpleRangeBase<RefPtr<nsINode>, RangeBoundary>;
+ using UnsafeSimpleRange = SimpleRangeBase<nsINode*, RawRangeBoundary>;
+
+ public:
+ using Element = dom::Element;
+ using Selection = dom::Selection;
+
+ explicit ContentEventHandler(nsPresContext* aPresContext);
+
+ // Handle aEvent in the current process.
+ MOZ_CAN_RUN_SCRIPT nsresult
+ HandleQueryContentEvent(WidgetQueryContentEvent* aEvent);
+
+ // eQuerySelectedText event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQuerySelectedText(WidgetQueryContentEvent* aEvent);
+ // eQueryTextContent event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryTextContent(WidgetQueryContentEvent* aEvent);
+ // eQueryCaretRect event handler
+ MOZ_CAN_RUN_SCRIPT nsresult OnQueryCaretRect(WidgetQueryContentEvent* aEvent);
+ // eQueryTextRect event handler
+ MOZ_CAN_RUN_SCRIPT nsresult OnQueryTextRect(WidgetQueryContentEvent* aEvent);
+ // eQueryTextRectArray event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryTextRectArray(WidgetQueryContentEvent* aEvent);
+ // eQueryEditorRect event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryEditorRect(WidgetQueryContentEvent* aEvent);
+ // eQueryContentState event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryContentState(WidgetQueryContentEvent* aEvent);
+ // eQuerySelectionAsTransferable event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQuerySelectionAsTransferable(WidgetQueryContentEvent* aEvent);
+ // eQueryCharacterAtPoint event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryCharacterAtPoint(WidgetQueryContentEvent* aEvent);
+ // eQueryDOMWidgetHittest event handler
+ MOZ_CAN_RUN_SCRIPT nsresult
+ OnQueryDOMWidgetHittest(WidgetQueryContentEvent* aEvent);
+
+ // NS_SELECTION_* event
+ MOZ_CAN_RUN_SCRIPT nsresult OnSelectionEvent(WidgetSelectionEvent* aEvent);
+
+ protected:
+ RefPtr<dom::Document> mDocument;
+ // mSelection is typically normal selection but if OnQuerySelectedText()
+ // is called, i.e., handling eQuerySelectedText, it's the specified selection
+ // by WidgetQueryContentEvent::mInput::mSelectionType.
+ RefPtr<Selection> mSelection;
+ // mFirstSelectedSimpleRange is initialized from the first range of
+ // mSelection, if it exists. Otherwise, it is reset by Clear().
+ SimpleRange mFirstSelectedSimpleRange;
+ RefPtr<Element> mRootElement;
+
+ MOZ_CAN_RUN_SCRIPT nsresult Init(WidgetQueryContentEvent* aEvent);
+ MOZ_CAN_RUN_SCRIPT nsresult Init(WidgetSelectionEvent* aEvent);
+
+ nsresult InitBasic(bool aRequireFlush = true);
+ MOZ_CAN_RUN_SCRIPT nsresult
+ InitCommon(EventMessage aEventMessage,
+ SelectionType aSelectionType = SelectionType::eNormal,
+ bool aRequireFlush = true);
+ /**
+ * InitRootContent() computes the root content of current focused editor.
+ *
+ * @param aNormalSelection This must be a Selection instance whose type is
+ * SelectionType::eNormal.
+ */
+ MOZ_CAN_RUN_SCRIPT nsresult
+ InitRootContent(const Selection& aNormalSelection);
+
+ public:
+ // FlatText means the text that is generated from DOM tree. The BR elements
+ // are replaced to native linefeeds. Other elements are ignored.
+
+ // RawNodePosition stores a pair of node and offset in the node.
+ // When mNode is an element and mOffset is 0, the start position means after
+ // the open tag of mNode.
+ // This is useful to receive one or more sets of them instead of nsRange.
+ // This type is intended to be used for short-lived operations, and is thus
+ // marked MOZ_STACK_CLASS.
+ struct MOZ_STACK_CLASS RawNodePosition : public RawRangeBoundary {
+ // Only when mNode is an element node and mOffset is 0, mAfterOpenTag is
+ // referred.
+ bool mAfterOpenTag = true;
+
+ RawNodePosition() = default;
+ explicit RawNodePosition(const RawNodePosition& aOther)
+ : RawRangeBoundary(aOther),
+ mAfterOpenTag(aOther.mAfterOpenTag)
+ // Don't use the copy constructor of mAssertNoGC.
+ {}
+
+ RawNodePosition(nsINode* aContainer, uint32_t aOffset)
+ : RawRangeBoundary(aContainer, aOffset) {}
+
+ RawNodePosition(nsINode* aContainer, nsIContent* aRef)
+ : RawRangeBoundary(aContainer, aRef) {}
+
+ explicit RawNodePosition(const nsIFrame::ContentOffsets& aContentOffsets)
+ : RawRangeBoundary(aContentOffsets.content, aContentOffsets.offset) {}
+
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+ ~RawNodePosition() { MOZ_DIAGNOSTIC_ASSERT(!mMutationGuard.Mutated(0)); }
+#endif // #ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+
+ public:
+ const RawNodePosition& operator=(const RawNodePosition& aOther) {
+ if (this != &aOther) {
+ RawRangeBoundary::operator=(aOther);
+ mAfterOpenTag = aOther.mAfterOpenTag;
+ }
+ return *this;
+ }
+
+ bool operator==(const RawNodePosition& aOther) const {
+ return RawRangeBoundary::operator==(aOther) &&
+ mAfterOpenTag == aOther.mAfterOpenTag;
+ }
+
+ bool IsBeforeOpenTag() const {
+ return IsSet() && Container()->IsElement() && !Ref() && !mAfterOpenTag;
+ }
+ bool IsImmediatelyAfterOpenTag() const {
+ return IsSet() && Container()->IsElement() && !Ref() && mAfterOpenTag;
+ }
+
+#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+ private:
+ nsMutationGuard mMutationGuard;
+ JS::AutoAssertNoGC mAssertNoGC;
+#endif // #ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
+ };
+
+ // RawNodePositionBefore isn't good name if Container() isn't an element node
+ // nor Offset() is not 0, though, when Container() is an element node and
+ // mOffset is 0, this is treated as before the open tag of Container().
+ struct MOZ_STACK_CLASS RawNodePositionBefore final : public RawNodePosition {
+ RawNodePositionBefore(nsINode* aContainer, uint32_t aOffset)
+ : RawNodePosition(aContainer, aOffset) {
+ mAfterOpenTag = false;
+ }
+
+ RawNodePositionBefore(nsINode* aContainer, nsIContent* aRef)
+ : RawNodePosition(aContainer, aRef) {
+ mAfterOpenTag = false;
+ }
+ };
+
+ // Get the flatten text length in the range.
+ // @param aStartPosition Start node and offset in the node of the range.
+ // @param aEndPosition End node and offset in the node of the range.
+ // @param aRootElement The root element of the editor or document.
+ // aRootElement won't cause any text including
+ // line breaks.
+ // @param aLength The result of the flatten text length of the
+ // range.
+ // @param aLineBreakType Whether this computes flatten text length with
+ // native line breakers on the platform or
+ // with XP line breaker (\n).
+ // @param aIsRemovingNode Should be true only when this is called from
+ // nsIMutationObserver::ContentRemoved().
+ // When this is true, aStartPosition.mNode should
+ // be the root node of removing nodes and mOffset
+ // should be 0 and aEndPosition.mNode should be
+ // same as aStartPosition.mNode and mOffset should
+ // be number of the children of mNode.
+ static nsresult GetFlatTextLengthInRange(
+ const RawNodePosition& aStartPosition,
+ const RawNodePosition& aEndPosition, const Element* aRootElement,
+ uint32_t* aLength, LineBreakType aLineBreakType,
+ bool aIsRemovingNode = false);
+ // Computes the native text length between aStartOffset and aEndOffset of
+ // aTextNode.
+ static uint32_t GetNativeTextLength(const dom::Text& aTextNode,
+ uint32_t aStartOffset,
+ uint32_t aEndOffset);
+ // Get the native text length of aTextNode.
+ static uint32_t GetNativeTextLength(const dom::Text& aTextNode,
+ uint32_t aMaxLength = UINT32_MAX);
+
+ static uint32_t GetNativeTextLength(const nsAString& aText);
+
+ protected:
+ // Get the text length of aTextNode.
+ static uint32_t GetTextLength(const dom::Text& aTextNode,
+ LineBreakType aLineBreakType,
+ uint32_t aMaxLength = UINT32_MAX);
+ // Get the text length of a given range of a content node in
+ // the given line break type.
+ static uint32_t GetTextLengthInRange(const dom::Text& aTextNode,
+ uint32_t aXPStartOffset,
+ uint32_t aXPEndOffset,
+ LineBreakType aLineBreakType);
+ // Get the contents in aElement (meaning all children of aElement) as plain
+ // text. E.g., specifying mRootElement gets whole text in it.
+ // Note that the result is not same as .textContent. The result is
+ // optimized for native IMEs. For example, <br> element and some block
+ // elements causes "\n" (or "\r\n"), see also ShouldBreakLineBefore().
+ nsresult GenerateFlatTextContent(const Element* aElement, nsString& aString,
+ LineBreakType aLineBreakType);
+ // Get the contents of aRange as plain text.
+ template <typename NodeType, typename RangeBoundaryType>
+ nsresult GenerateFlatTextContent(
+ const SimpleRangeBase<NodeType, RangeBoundaryType>& aSimpleRange,
+ nsString& aString, LineBreakType aLineBreakType);
+ // Get offset of start of aRange. Note that the result includes the length
+ // of line breaker caused by the start of aContent because aRange never
+ // includes the line breaker caused by its start node.
+ template <typename SimpleRangeType>
+ nsresult GetStartOffset(const SimpleRangeType& aSimpleRange,
+ uint32_t* aOffset, LineBreakType aLineBreakType);
+ // Check if we should insert a line break before aContent.
+ // This should return false only when aContent is an html element which
+ // is typically used in a paragraph like <em>.
+ static bool ShouldBreakLineBefore(const nsIContent& aContent,
+ const Element* aRootElement);
+ // Get the line breaker length.
+ static inline uint32_t GetBRLength(LineBreakType aLineBreakType);
+ static LineBreakType GetLineBreakType(WidgetQueryContentEvent* aEvent);
+ static LineBreakType GetLineBreakType(WidgetSelectionEvent* aEvent);
+ static LineBreakType GetLineBreakType(bool aUseNativeLineBreak);
+ // Returns focused content (including its descendant documents).
+ nsIContent* GetFocusedContent();
+ // QueryContentRect() sets the rect of aContent's frame(s) to aEvent.
+ nsresult QueryContentRect(nsIContent* aContent,
+ WidgetQueryContentEvent* aEvent);
+
+ template <typename RangeType, typename TextNodeType>
+ struct MOZ_STACK_CLASS DOMRangeAndAdjustedOffsetInFlattenedTextBase {
+ bool RangeStartsFromLastTextNode() const {
+ return mLastTextNode && mRange.GetStartContainer() == mLastTextNode;
+ }
+ bool RangeStartsFromEndOfContainer() const {
+ return mRange.GetStartContainer() &&
+ mRange.GetStartContainer()->Length() == mRange.StartOffset();
+ }
+ bool RangeStartsFromContent() const {
+ return mRange.GetStartContainer() &&
+ mRange.GetStartContainer()->IsContent();
+ }
+
+ // The range in the DOM tree.
+ RangeType mRange;
+ // Actual start offset of the range in the flattened text. If aOffset
+ // of ConvertFlatTextOffsetToDOMRange() is middle of a surrogate pair,
+ // a CRLF or a complex character of some languages, this may be set to
+ // different offset.
+ uint32_t mAdjustedOffset = 0;
+ // The last text node which is found while walking the tree.
+ // If the range ends in a text node, this is the text node. Otherwise,
+ // the last found text node before the end container of mRange.
+ TextNodeType mLastTextNode = nullptr;
+ };
+ using DOMRangeAndAdjustedOffsetInFlattenedText =
+ DOMRangeAndAdjustedOffsetInFlattenedTextBase<SimpleRange,
+ RefPtr<dom::Text>>;
+ using UnsafeDOMRangeAndAdjustedOffsetInFlattenedText =
+ DOMRangeAndAdjustedOffsetInFlattenedTextBase<UnsafeSimpleRange,
+ dom::Text*>;
+
+ /**
+ * Scans the DOM tree and set mRange as same as from aOffset to aOffset +
+ * aLength in the flattened text.
+ * NOTE: Use ConvertFlatTextOffsetToDOMRange() or
+ * ConvertFlatTextOffsetToUnsafeDOMRange() instead of
+ * ConvertFlatTextOffsetToDOMRangeBase<RangeType, TextNodeType>().
+ */
+ template <typename RangeType, typename TextNodeType>
+ Result<DOMRangeAndAdjustedOffsetInFlattenedTextBase<RangeType, TextNodeType>,
+ nsresult>
+ ConvertFlatTextOffsetToDOMRangeBase(uint32_t aOffset, uint32_t aLength,
+ LineBreakType aLineBreakType,
+ bool aExpandToClusterBoundaries);
+ MOZ_ALWAYS_INLINE Result<DOMRangeAndAdjustedOffsetInFlattenedText, nsresult>
+ ConvertFlatTextOffsetToDOMRange(uint32_t aOffset, uint32_t aLength,
+ LineBreakType aLineBreakType,
+ bool aExpandToClusterBoundaries) {
+ return ConvertFlatTextOffsetToDOMRangeBase<SimpleRange, RefPtr<dom::Text>>(
+ aOffset, aLength, aLineBreakType, aExpandToClusterBoundaries);
+ }
+ MOZ_ALWAYS_INLINE
+ Result<UnsafeDOMRangeAndAdjustedOffsetInFlattenedText, nsresult>
+ ConvertFlatTextOffsetToUnsafeDOMRange(uint32_t aOffset, uint32_t aLength,
+ LineBreakType aLineBreakType,
+ bool aExpandToClusterBoundaries) {
+ return ConvertFlatTextOffsetToDOMRangeBase<UnsafeSimpleRange, dom::Text*>(
+ aOffset, aLength, aLineBreakType, aExpandToClusterBoundaries);
+ }
+
+ // If the aSimpleRange isn't in text node but next to a text node,
+ // this method modifies it in the text node. Otherwise, not modified.
+ // Note that aSimpleRange must be collapsed.
+ nsresult AdjustCollapsedRangeMaybeIntoTextNode(SimpleRange& aSimpleRange);
+ // Convert the frame relative offset to be relative to the root frame of the
+ // root presContext (but still measured in appUnits of aFrame's presContext).
+ nsresult ConvertToRootRelativeOffset(nsIFrame* aFrame, nsRect& aRect);
+ // Expand aXPOffset to the nearest offset in cluster boundary. aForward is
+ // true, it is expanded to forward.
+ // FYI: Due to `nsFrameSelection::GetFrameForNodeOffset()`, this cannot
+ // take `const dom::Text&`.
+ nsresult ExpandToClusterBoundary(dom::Text& aTextNode, bool aForward,
+ uint32_t* aXPOffset) const;
+
+ using FontRangeArray = nsTArray<mozilla::FontRange>;
+ static void AppendFontRanges(FontRangeArray& aFontRanges,
+ const dom::Text& aTextNode, uint32_t aBaseOffset,
+ uint32_t aXPStartOffset, uint32_t aXPEndOffset,
+ LineBreakType aLineBreakType);
+ nsresult GenerateFlatFontRanges(const UnsafeSimpleRange& aSimpleRange,
+ FontRangeArray& aFontRanges,
+ uint32_t& aLength,
+ LineBreakType aLineBreakType);
+ nsresult QueryTextRectByRange(const SimpleRange& aSimpleRange,
+ LayoutDeviceIntRect& aRect,
+ WritingMode& aWritingMode);
+
+ struct MOZ_STACK_CLASS FrameAndNodeOffset final {
+ // mFrame is safe since this can live in only stack class and
+ // ContentEventHandler doesn't modify layout after
+ // ContentEventHandler::Init() flushes pending layout. In other words,
+ // this struct shouldn't be used before calling
+ // ContentEventHandler::Init().
+ nsIFrame* mFrame;
+ // offset in the node of mFrame
+ int32_t mOffsetInNode;
+
+ FrameAndNodeOffset() : mFrame(nullptr), mOffsetInNode(-1) {}
+
+ FrameAndNodeOffset(nsIFrame* aFrame, int32_t aStartOffsetInNode)
+ : mFrame(aFrame), mOffsetInNode(aStartOffsetInNode) {}
+
+ nsIFrame* operator->() { return mFrame; }
+ const nsIFrame* operator->() const { return mFrame; }
+ operator nsIFrame*() { return mFrame; }
+ operator const nsIFrame*() const { return mFrame; }
+ bool IsValid() const { return mFrame && mOffsetInNode >= 0; }
+ };
+ // Get first frame after the start of the given range for computing text rect.
+ // This returns invalid FrameAndNodeOffset if there is no content which
+ // should affect to computing text rect in the range. mOffsetInNode is start
+ // offset in the frame.
+ template <typename NodeType, typename RangeBoundaryType>
+ FrameAndNodeOffset GetFirstFrameInRangeForTextRect(
+ const SimpleRangeBase<NodeType, RangeBoundaryType>& aSimpleRange);
+
+ // Get last frame before the end of the given range for computing text rect.
+ // This returns invalid FrameAndNodeOffset if there is no content which
+ // should affect to computing text rect in the range. mOffsetInNode is end
+ // offset in the frame.
+ template <typename NodeType, typename RangeBoundaryType>
+ FrameAndNodeOffset GetLastFrameInRangeForTextRect(
+ const SimpleRangeBase<NodeType, RangeBoundaryType>& aSimpleRange);
+
+ struct MOZ_STACK_CLASS FrameRelativeRect final {
+ // mRect is relative to the mBaseFrame's position.
+ nsRect mRect;
+ nsIFrame* mBaseFrame;
+
+ FrameRelativeRect() : mBaseFrame(nullptr) {}
+
+ explicit FrameRelativeRect(nsIFrame* aBaseFrame) : mBaseFrame(aBaseFrame) {}
+
+ FrameRelativeRect(const nsRect& aRect, nsIFrame* aBaseFrame)
+ : mRect(aRect), mBaseFrame(aBaseFrame) {}
+
+ bool IsValid() const { return mBaseFrame != nullptr; }
+
+ // Returns an nsRect relative to aBaseFrame instead of mBaseFrame.
+ nsRect RectRelativeTo(nsIFrame* aBaseFrame) const;
+ };
+
+ // Returns a rect for line breaker before the node of aFrame (If aFrame is
+ // a <br> frame or a block level frame, it causes a line break at its
+ // element's open tag, see also ShouldBreakLineBefore()). Note that this
+ // doesn't check if aFrame should cause line break in non-debug build.
+ FrameRelativeRect GetLineBreakerRectBefore(nsIFrame* aFrame);
+
+ // Returns a line breaker rect after aTextNode as there is a line breaker
+ // immediately after aTextNode. This is useful when following block
+ // element causes a line break before it and it needs to compute the line
+ // breaker's rect. For example, if there is |<p>abc</p><p>def</p>|, the
+ // rect of 2nd <p>'s line breaker should be at right of "c" in the first
+ // <p>, not the start of 2nd <p>. The result is relative to the last text
+ // frame which represents the last character of aTextNode.
+ FrameRelativeRect GuessLineBreakerRectAfter(const dom::Text& aTextNode);
+
+ // Returns a guessed first rect. I.e., it may be different from actual
+ // caret when selection is collapsed at start of aFrame. For example, this
+ // guess the caret rect only with the content box of aFrame and its font
+ // height like:
+ // +-aFrame----------------- (border box)
+ // |
+ // | +--------------------- (content box)
+ // | | I
+ // ^ guessed caret rect
+ // However, actual caret is computed with more information like line-height,
+ // child frames of aFrame etc. But this does not emulate actual caret
+ // behavior exactly for simpler and faster code because it's difficult and
+ // we're not sure it's worthwhile to do it with complicated implementation.
+ FrameRelativeRect GuessFirstCaretRectIn(nsIFrame* aFrame);
+
+ // Make aRect non-empty. If width and/or height is 0, these methods set them
+ // to 1. Note that it doesn't set nsRect's width nor height to one device
+ // pixel because using nsRect::ToOutsidePixels() makes actual width or height
+ // to 2 pixels because x and y may not be aligned to device pixels.
+ void EnsureNonEmptyRect(nsRect& aRect) const;
+ void EnsureNonEmptyRect(LayoutDeviceIntRect& aRect) const;
+
+ /**
+ * Compute caret rect before or after a character rect.
+ */
+ static LayoutDeviceIntRect GetCaretRectBefore(
+ const LayoutDeviceIntRect& aCharRect, const WritingMode& aWritingMode);
+ static LayoutDeviceIntRect GetCaretRectAfter(
+ const LayoutDeviceIntRect& aCharRect, const WritingMode& aWritingMode);
+ static nsRect GetCaretRectBefore(const nsRect& aCharRect,
+ const WritingMode& aWritingMode);
+ static nsRect GetCaretRectAfter(nsPresContext& aPresContext,
+ const nsRect& aCharRect,
+ const WritingMode& aWritingMode);
+};
+
+} // namespace mozilla
+
+#endif // mozilla_ContentEventHandler_h_