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| -rw-r--r-- | accessible/generic/HyperTextAccessible.h | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/accessible/generic/HyperTextAccessible.h b/accessible/generic/HyperTextAccessible.h new file mode 100644 index 0000000000..112587a242 --- /dev/null +++ b/accessible/generic/HyperTextAccessible.h @@ -0,0 +1,561 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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_a11y_HyperTextAccessible_h__ +#define mozilla_a11y_HyperTextAccessible_h__ + +#include "AccessibleWrap.h" +#include "nsIAccessibleText.h" +#include "nsIAccessibleTypes.h" +#include "nsIFrame.h" // only for nsSelectionAmount +#include "nsISelectionController.h" +#include "nsDirection.h" +#include "WordMovementType.h" + +class nsFrameSelection; +class nsIFrame; +class nsRange; +class nsIWidget; + +namespace mozilla { +class TextEditor; +namespace dom { +class Selection; +} + +namespace a11y { + +class TextRange; + +struct DOMPoint { + DOMPoint() : node(nullptr), idx(0) {} + DOMPoint(nsINode* aNode, int32_t aIdx) : node(aNode), idx(aIdx) {} + + nsINode* node; + int32_t idx; +}; + +// This character marks where in the text returned via Text interface, +// that embedded object characters exist +const char16_t kEmbeddedObjectChar = 0xfffc; +const char16_t kImaginaryEmbeddedObjectChar = ' '; +const char16_t kForcedNewLineChar = '\n'; + +/** + * Special Accessible that knows how contain both text and embedded objects + */ +class HyperTextAccessible : public AccessibleWrap { + public: + HyperTextAccessible(nsIContent* aContent, DocAccessible* aDoc); + + NS_INLINE_DECL_REFCOUNTING_INHERITED(HyperTextAccessible, AccessibleWrap) + + // Accessible + virtual nsAtom* LandmarkRole() const override; + virtual int32_t GetLevelInternal() override; + virtual already_AddRefed<nsIPersistentProperties> NativeAttributes() override; + virtual mozilla::a11y::role NativeRole() const override; + virtual uint64_t NativeState() const override; + + virtual void Shutdown() override; + virtual bool RemoveChild(Accessible* aAccessible) override; + virtual bool InsertChildAt(uint32_t aIndex, Accessible* aChild) override; + virtual Relation RelationByType(RelationType aType) const override; + + // HyperTextAccessible (static helper method) + + // Convert content offset to rendered text offset + nsresult ContentToRenderedOffset(nsIFrame* aFrame, int32_t aContentOffset, + uint32_t* aRenderedOffset) const; + + // Convert rendered text offset to content offset + nsresult RenderedToContentOffset(nsIFrame* aFrame, uint32_t aRenderedOffset, + int32_t* aContentOffset) const; + + ////////////////////////////////////////////////////////////////////////////// + // HyperLinkAccessible + + /** + * Return link count within this hypertext accessible. + */ + uint32_t LinkCount() { return EmbeddedChildCount(); } + + /** + * Return link accessible at the given index. + */ + Accessible* LinkAt(uint32_t aIndex) { return GetEmbeddedChildAt(aIndex); } + + /** + * Return index for the given link accessible. + */ + int32_t LinkIndexOf(Accessible* aLink) { + return GetIndexOfEmbeddedChild(aLink); + } + + /** + * Return link accessible at the given text offset. + */ + int32_t LinkIndexAtOffset(uint32_t aOffset) { + Accessible* child = GetChildAtOffset(aOffset); + return child ? LinkIndexOf(child) : -1; + } + + ////////////////////////////////////////////////////////////////////////////// + // HyperTextAccessible: DOM point to text offset conversions. + + /** + * Turn a DOM point (node and offset) into a character offset of this + * hypertext. Will look for closest match when the DOM node does not have + * an accessible object associated with it. Will return an offset for the end + * of the string if the node is not found. + * + * @param aNode [in] the node to look for + * @param aNodeOffset [in] the offset to look for + * if -1 just look directly for the node + * if >=0 and aNode is text, this represents a char + * offset if >=0 and aNode is not text, this represents a child node offset + * @param aIsEndOffset [in] if true, then then this offset is not inclusive. + * The character indicated by the offset returned is at [offset - 1]. This + * means if the passed-in offset is really in a descendant, then the offset + * returned will come just after the relevant embedded object characer. If + * false, then the offset is inclusive. The character indicated by the offset + * returned is at [offset]. If the passed-in offset in inside a descendant, + * then the returned offset will be on the relevant embedded object char. + */ + uint32_t DOMPointToOffset(nsINode* aNode, int32_t aNodeOffset, + bool aIsEndOffset = false) const; + + /** + * Transform the given a11y point into the offset relative this hypertext. + */ + uint32_t TransformOffset(Accessible* aDescendant, uint32_t aOffset, + bool aIsEndOffset) const; + + /** + * Convert the given offset into DOM point. + * + * If offset is at text leaf then DOM point is (text node, offsetInTextNode), + * if before embedded object then (parent node, indexInParent), if after then + * (parent node, indexInParent + 1). + */ + DOMPoint OffsetToDOMPoint(int32_t aOffset) const; + + /** + * Return true if the used ARIA role (if any) allows the hypertext accessible + * to expose text interfaces. + */ + bool IsTextRole(); + + ////////////////////////////////////////////////////////////////////////////// + // TextAccessible + + /** + * Return character count within the hypertext accessible. + */ + uint32_t CharacterCount() const { return GetChildOffset(ChildCount()); } + + /** + * Get a character at the given offset (don't support magic offsets). + */ + bool CharAt(int32_t aOffset, nsAString& aChar, + int32_t* aStartOffset = nullptr, int32_t* aEndOffset = nullptr) { + NS_ASSERTION(!aStartOffset == !aEndOffset, + "Offsets should be both defined or both undefined!"); + + int32_t childIdx = GetChildIndexAtOffset(aOffset); + if (childIdx == -1) return false; + + Accessible* child = GetChildAt(childIdx); + child->AppendTextTo(aChar, aOffset - GetChildOffset(childIdx), 1); + + if (aStartOffset && aEndOffset) { + *aStartOffset = aOffset; + *aEndOffset = aOffset + aChar.Length(); + } + return true; + } + + char16_t CharAt(int32_t aOffset) { + nsAutoString charAtOffset; + CharAt(aOffset, charAtOffset); + return charAtOffset.CharAt(0); + } + + /** + * Return true if char at the given offset equals to given char. + */ + bool IsCharAt(int32_t aOffset, char16_t aChar) { + return CharAt(aOffset) == aChar; + } + + /** + * Return true if terminal char is at the given offset. + */ + bool IsLineEndCharAt(int32_t aOffset) { return IsCharAt(aOffset, '\n'); } + + /** + * Return text between given offsets. + */ + void TextSubstring(int32_t aStartOffset, int32_t aEndOffset, + nsAString& aText); + + /** + * Return text before/at/after the given offset corresponding to + * the boundary type. + */ + void TextBeforeOffset(int32_t aOffset, AccessibleTextBoundary aBoundaryType, + int32_t* aStartOffset, int32_t* aEndOffset, + nsAString& aText); + void TextAtOffset(int32_t aOffset, AccessibleTextBoundary aBoundaryType, + int32_t* aStartOffset, int32_t* aEndOffset, + nsAString& aText); + void TextAfterOffset(int32_t aOffset, AccessibleTextBoundary aBoundaryType, + int32_t* aStartOffset, int32_t* aEndOffset, + nsAString& aText); + + /** + * Return text attributes for the given text range. + */ + already_AddRefed<nsIPersistentProperties> TextAttributes( + bool aIncludeDefAttrs, int32_t aOffset, int32_t* aStartOffset, + int32_t* aEndOffset); + + /** + * Return text attributes applied to the accessible. + */ + already_AddRefed<nsIPersistentProperties> DefaultTextAttributes(); + + /** + * Return text offset of the given child accessible within hypertext + * accessible. + * + * @param aChild [in] accessible child to get text offset for + * @param aInvalidateAfter [in, optional] indicates whether invalidate + * cached offsets for next siblings of the child + */ + int32_t GetChildOffset(const Accessible* aChild, + bool aInvalidateAfter = false) const { + int32_t index = GetIndexOf(aChild); + return index == -1 ? -1 : GetChildOffset(index, aInvalidateAfter); + } + + /** + * Return text offset for the child accessible index. + */ + int32_t GetChildOffset(uint32_t aChildIndex, + bool aInvalidateAfter = false) const; + + /** + * Return child accessible at the given text offset. + * + * @param aOffset [in] the given text offset + */ + int32_t GetChildIndexAtOffset(uint32_t aOffset) const; + + /** + * Return child accessible at the given text offset. + * + * @param aOffset [in] the given text offset + */ + Accessible* GetChildAtOffset(uint32_t aOffset) const { + return GetChildAt(GetChildIndexAtOffset(aOffset)); + } + + /** + * Return true if the given offset/range is valid. + */ + bool IsValidOffset(int32_t aOffset); + bool IsValidRange(int32_t aStartOffset, int32_t aEndOffset); + + /** + * Return an offset at the given point. + */ + int32_t OffsetAtPoint(int32_t aX, int32_t aY, uint32_t aCoordType); + + /** + * Return a rect of the given text range relative given coordinate system. + */ + nsIntRect TextBounds( + int32_t aStartOffset, int32_t aEndOffset, + uint32_t aCoordType = + nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE); + + /** + * Return a rect for character at given offset relative given coordinate + * system. + */ + nsIntRect CharBounds(int32_t aOffset, uint32_t aCoordType) { + int32_t endOffset = aOffset == static_cast<int32_t>(CharacterCount()) + ? aOffset + : aOffset + 1; + return TextBounds(aOffset, endOffset, aCoordType); + } + + /** + * Get/set caret offset, if no caret then -1. + */ + int32_t CaretOffset() const; + void SetCaretOffset(int32_t aOffset); + + /** + * Provide the line number for the caret. + * @return 1-based index for the line number with the caret + */ + int32_t CaretLineNumber(); + + /** + * Return the caret rect and the widget containing the caret within this + * text accessible. + * + * @param [out] the widget containing the caret + * @return the caret rect + */ + mozilla::LayoutDeviceIntRect GetCaretRect(nsIWidget** aWidget); + + /** + * Return selected regions count within the accessible. + */ + int32_t SelectionCount(); + + /** + * Return the start and end offset of the specified selection. + */ + bool SelectionBoundsAt(int32_t aSelectionNum, int32_t* aStartOffset, + int32_t* aEndOffset); + + /* + * Changes the start and end offset of the specified selection. + * @return true if succeeded + */ + // TODO: annotate this with `MOZ_CAN_RUN_SCRIPT` instead. + MOZ_CAN_RUN_SCRIPT_BOUNDARY bool SetSelectionBoundsAt(int32_t aSelectionNum, + int32_t aStartOffset, + int32_t aEndOffset); + + /** + * Adds a selection bounded by the specified offsets. + * @return true if succeeded + */ + bool AddToSelection(int32_t aStartOffset, int32_t aEndOffset); + + /* + * Removes the specified selection. + * @return true if succeeded + */ + // TODO: annotate this with `MOZ_CAN_RUN_SCRIPT` instead. + MOZ_CAN_RUN_SCRIPT_BOUNDARY bool RemoveFromSelection(int32_t aSelectionNum); + + /** + * Scroll the given text range into view. + */ + void ScrollSubstringTo(int32_t aStartOffset, int32_t aEndOffset, + uint32_t aScrollType); + + /** + * Scroll the given text range to the given point. + */ + void ScrollSubstringToPoint(int32_t aStartOffset, int32_t aEndOffset, + uint32_t aCoordinateType, int32_t aX, int32_t aY); + + /** + * Return a range that encloses the text control or the document this + * accessible belongs to. + */ + void EnclosingRange(TextRange& aRange) const; + + /** + * Return an array of disjoint ranges for selected text within the text + * control or the document this accessible belongs to. + */ + void SelectionRanges(nsTArray<TextRange>* aRanges) const; + + /** + * Return an array of disjoint ranges of visible text within the text control + * or the document this accessible belongs to. + */ + void VisibleRanges(nsTArray<TextRange>* aRanges) const; + + /** + * Return a range containing the given accessible. + */ + void RangeByChild(Accessible* aChild, TextRange& aRange) const; + + /** + * Return a range containing an accessible at the given point. + */ + void RangeAtPoint(int32_t aX, int32_t aY, TextRange& aRange) const; + + ////////////////////////////////////////////////////////////////////////////// + // EditableTextAccessible + + MOZ_CAN_RUN_SCRIPT_BOUNDARY void ReplaceText(const nsAString& aText); + MOZ_CAN_RUN_SCRIPT_BOUNDARY void InsertText(const nsAString& aText, + int32_t aPosition); + void CopyText(int32_t aStartPos, int32_t aEndPos); + MOZ_CAN_RUN_SCRIPT_BOUNDARY void CutText(int32_t aStartPos, int32_t aEndPos); + MOZ_CAN_RUN_SCRIPT_BOUNDARY void DeleteText(int32_t aStartPos, + int32_t aEndPos); + MOZ_CAN_RUN_SCRIPT + void PasteText(int32_t aPosition); + + /** + * Return the editor associated with the accessible. + * The result may be either TextEditor or HTMLEditor. + */ + virtual already_AddRefed<TextEditor> GetEditor() const; + + /** + * Return DOM selection object for the accessible. + */ + dom::Selection* DOMSelection() const; + + protected: + virtual ~HyperTextAccessible() {} + + // Accessible + virtual ENameValueFlag NativeName(nsString& aName) const override; + + // HyperTextAccessible + + /** + * Transform magic offset into text offset. + */ + index_t ConvertMagicOffset(int32_t aOffset) const; + + /** + * Adjust an offset the caret stays at to get a text by line boundary. + */ + uint32_t AdjustCaretOffset(uint32_t aOffset) const; + + /** + * Return true if caret is at end of line. + */ + bool IsCaretAtEndOfLine() const; + + /** + * Return true if the given offset points to terminal empty line if any. + */ + bool IsEmptyLastLineOffset(int32_t aOffset) { + return aOffset == static_cast<int32_t>(CharacterCount()) && + IsLineEndCharAt(aOffset - 1); + } + + /** + * Return an offset of the found word boundary. + */ + uint32_t FindWordBoundary(uint32_t aOffset, nsDirection aDirection, + EWordMovementType aWordMovementType); + + /** + * Used to get begin/end of previous/this/next line. Note: end of line + * is an offset right before '\n' character if any, the offset is right after + * '\n' character is begin of line. In case of wrap word breaks these offsets + * are equal. + */ + enum EWhichLineBoundary { + ePrevLineBegin, + ePrevLineEnd, + eThisLineBegin, + eThisLineEnd, + eNextLineBegin, + eNextLineEnd + }; + + /** + * Return an offset for requested line boundary. See constants above. + */ + uint32_t FindLineBoundary(uint32_t aOffset, + EWhichLineBoundary aWhichLineBoundary); + + /** + * Find the start offset for a paragraph , taking into account + * inner block elements and line breaks. + */ + int32_t FindParagraphStartOffset(uint32_t aOffset); + + /** + * Find the end offset for a paragraph , taking into account + * inner block elements and line breaks. + */ + int32_t FindParagraphEndOffset(uint32_t aOffset); + + /** + * Return an offset corresponding to the given direction and selection amount + * relative the given offset. A helper used to find word or line boundaries. + */ + uint32_t FindOffset(uint32_t aOffset, nsDirection aDirection, + nsSelectionAmount aAmount, + EWordMovementType aWordMovementType = eDefaultBehavior); + + /** + * Return the boundaries of the substring in case of textual frame or + * frame boundaries in case of non textual frame, offsets are ignored. + */ + nsIntRect GetBoundsInFrame(nsIFrame* aFrame, uint32_t aStartRenderedOffset, + uint32_t aEndRenderedOffset); + + // Selection helpers + + /** + * Return frame selection object for the accessible. + */ + already_AddRefed<nsFrameSelection> FrameSelection() const; + + /** + * Return selection ranges within the accessible subtree. + */ + void GetSelectionDOMRanges(SelectionType aSelectionType, + nsTArray<nsRange*>* aRanges); + + // TODO: annotate this with `MOZ_CAN_RUN_SCRIPT` instead. + MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult SetSelectionRange(int32_t aStartPos, + int32_t aEndPos); + + // Helpers + nsresult GetDOMPointByFrameOffset(nsIFrame* aFrame, int32_t aOffset, + Accessible* aAccessible, + mozilla::a11y::DOMPoint* aPoint); + + /** + * Set 'misspelled' text attribute and return range offsets where the + * attibute is stretched. If the text is not misspelled at the given offset + * then we expose only range offsets where text is not misspelled. The method + * is used by TextAttributes() method. + * + * @param aIncludeDefAttrs [in] points whether text attributes having default + * values of attributes should be included + * @param aSourceNode [in] the node we start to traverse from + * @param aStartOffset [in, out] the start offset + * @param aEndOffset [in, out] the end offset + * @param aAttributes [out, optional] result attributes + */ + void GetSpellTextAttr(nsINode* aNode, int32_t aNodeOffset, + uint32_t* aStartOffset, uint32_t* aEndOffset, + nsIPersistentProperties* aAttributes); + + /** + * Set xml-roles attributes for MathML elements. + * @param aAttributes + */ + void SetMathMLXMLRoles(nsIPersistentProperties* aAttributes); + + private: + /** + * End text offsets array. + */ + mutable nsTArray<uint32_t> mOffsets; +}; + +//////////////////////////////////////////////////////////////////////////////// +// Accessible downcasting method + +inline HyperTextAccessible* Accessible::AsHyperText() { + return IsHyperText() ? static_cast<HyperTextAccessible*>(this) : nullptr; +} + +} // namespace a11y +} // namespace mozilla + +#endif |