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Diffstat (limited to 'accessible/basetypes/HyperTextAccessibleBase.h')
| -rw-r--r-- | accessible/basetypes/HyperTextAccessibleBase.h | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/accessible/basetypes/HyperTextAccessibleBase.h b/accessible/basetypes/HyperTextAccessibleBase.h new file mode 100644 index 0000000000..e7a7bda016 --- /dev/null +++ b/accessible/basetypes/HyperTextAccessibleBase.h @@ -0,0 +1,317 @@ +/* -*- 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 _HyperTextAccessibleBase_H_ +#define _HyperTextAccessibleBase_H_ + +#include "AccAttributes.h" +#include "nsIAccessibleText.h" +#include "nsIAccessibleTypes.h" + +namespace mozilla::a11y { +class Accessible; +class TextLeafPoint; +class TextRange; + +// 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'; + +/** + * An index type. Assert if out of range value was attempted to be used. + */ +class index_t { + public: + MOZ_IMPLICIT index_t(int32_t aVal) : mVal(aVal) {} + + operator uint32_t() const { + MOZ_ASSERT(mVal >= 0, "Attempt to use wrong index!"); + return mVal; + } + + bool IsValid() const { return mVal >= 0; } + + private: + int32_t mVal; +}; + +class HyperTextAccessibleBase { + public: + /** + * Return child accessible at the given text offset. + * + * @param aOffset [in] the given text offset + */ + virtual int32_t GetChildIndexAtOffset(uint32_t aOffset) const; + + /** + * Return child accessible at the given text offset. + * + * @param aOffset [in] the given text offset + */ + virtual Accessible* GetChildAtOffset(uint32_t aOffset) const; + + /** + * 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 to invalidate + * cached offsets for subsequent siblings of the + * child. + */ + int32_t GetChildOffset(const Accessible* aChild, + bool aInvalidateAfter = false) const; + + /** + * Return text offset for the child accessible index. + */ + virtual int32_t GetChildOffset(uint32_t aChildIndex, + bool aInvalidateAfter = false) const; + + /** + * Return character count within the hypertext accessible. + */ + uint32_t CharacterCount() const; + + /** + * Get/set caret offset, if no caret then -1. + */ + virtual int32_t CaretOffset() const; + virtual void SetCaretOffset(int32_t aOffset) = 0; + + /** + * Provide the line number for the caret. + * @return 1-based index for the line number with the caret + */ + virtual int32_t CaretLineNumber(); + + /** + * Transform magic offset into text offset. + */ + index_t ConvertMagicOffset(int32_t aOffset) const; + + /** + * Return text between given offsets. + */ + void TextSubstring(int32_t aStartOffset, int32_t aEndOffset, + nsAString& aText) const; + + /** + * 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); + + char16_t CharAt(int32_t aOffset) { + nsAutoString charAtOffset; + CharAt(aOffset, charAtOffset); + return charAtOffset.CharAt(0); + } + + /** + * Return a rect (in dev pixels) for character at given offset relative + * given coordinate system. + */ + LayoutDeviceIntRect CharBounds(int32_t aOffset, uint32_t aCoordType); + + /** + * Return a rect (in dev pixels) of the given text range relative given + * coordinate system. + */ + LayoutDeviceIntRect TextBounds( + int32_t aStartOffset, int32_t aEndOffset, + uint32_t aCoordType = + nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE); + + /** + * Return the offset of the char that contains the given coordinates. + */ + virtual int32_t OffsetAtPoint(int32_t aX, int32_t aY, uint32_t aCoordType); + + /** + * Get a TextLeafPoint for a given offset in this HyperTextAccessible. + * If the offset points to an embedded object and aDescendToEnd is true, + * the point right at the end of this subtree will be returned instead of the + * start. + */ + TextLeafPoint ToTextLeafPoint(int32_t aOffset, bool aDescendToEnd = false); + + /** + * 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 true if the given offset/range is valid. + */ + bool IsValidOffset(int32_t aOffset); + bool IsValidRange(int32_t aStartOffset, int32_t aEndOffset); + + /** + * Return link count within this hypertext accessible. + */ + uint32_t LinkCount(); + + /** + * Return link accessible at the given index. + */ + Accessible* LinkAt(uint32_t aIndex); + + /** + * Return index for the given link accessible. + */ + int32_t LinkIndexOf(Accessible* aLink); + + /** + * Return link accessible at the given text offset. + */ + int32_t LinkIndexAtOffset(uint32_t aOffset) { + Accessible* child = GetChildAtOffset(aOffset); + return child ? LinkIndexOf(child) : -1; + } + + /** + * Transform the given a11y point into an offset relative to this hypertext. + * Returns {success, offset}, where success is true if successful. + * If unsuccessful, the returned offset will be CharacterCount() if + * aIsEndOffset is true, 0 otherwise. This means most callers can ignore the + * success return value. + */ + std::pair<bool, int32_t> TransformOffset(Accessible* aDescendant, + int32_t aOffset, + bool aIsEndOffset) const; + + /** + * Return text attributes for the given text range. + */ + already_AddRefed<AccAttributes> TextAttributes(bool aIncludeDefAttrs, + int32_t aOffset, + int32_t* aStartOffset, + int32_t* aEndOffset); + + /** + * Return text attributes applied to the accessible. + */ + virtual already_AddRefed<AccAttributes> DefaultTextAttributes() = 0; + + /** + * Return an array of disjoint ranges for selected text within the text + * control or the document this accessible belongs to. + */ + virtual void SelectionRanges(nsTArray<TextRange>* aRanges) const = 0; + + /** + * Return text selection ranges cropped to this Accessible (rather than for + * the entire text control or document). This also excludes collapsed ranges. + */ + void CroppedSelectionRanges(nsTArray<TextRange>& aRanges) const; + + /** + * Return selected regions count within the accessible. + */ + virtual int32_t SelectionCount(); + + /** + * Return the start and end offset of the specified selection. + */ + virtual 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 virtual 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) { + return SetSelectionBoundsAt(-1, aStartOffset, aEndOffset); + } + + /** + * Removes the specified selection. + * @return true if succeeded + */ + // TODO: annotate this with `MOZ_CAN_RUN_SCRIPT` instead. + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual bool RemoveFromSelection( + int32_t aSelectionNum) = 0; + + /** + * Scroll the given text range into view. + */ + MOZ_CAN_RUN_SCRIPT_BOUNDARY void ScrollSubstringTo(int32_t aStartOffset, + int32_t aEndOffset, + uint32_t aScrollType); + + /** + * Scroll the given text range to the given point. + */ + virtual void ScrollSubstringToPoint(int32_t aStartOffset, int32_t aEndOffset, + uint32_t aCoordinateType, int32_t aX, + int32_t aY) = 0; + + ////////////////////////////////////////////////////////////////////////////// + // EditableTextAccessible + + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void ReplaceText( + const nsAString& aText) = 0; + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void InsertText(const nsAString& aText, + int32_t aPosition) = 0; + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void CopyText(int32_t aStartPos, + int32_t aEndPos) = 0; + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void CutText(int32_t aStartPos, + int32_t aEndPos) = 0; + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual void DeleteText(int32_t aStartPos, + int32_t aEndPos) = 0; + MOZ_CAN_RUN_SCRIPT virtual void PasteText(int32_t aPosition) = 0; + + protected: + virtual const Accessible* Acc() const = 0; + Accessible* Acc() { + const Accessible* acc = + const_cast<const HyperTextAccessibleBase*>(this)->Acc(); + return const_cast<Accessible*>(acc); + } + + /** + * Get the cached map of child indexes to HyperText offsets. + * This is an array which contains the exclusive end offset for each child. + * That is, the start offset for child c is array index c - 1. + */ + virtual nsTArray<int32_t>& GetCachedHyperTextOffsets() = 0; + + private: + /** + * Helper method for TextBefore/At/AfterOffset. + * If BOUNDARY_LINE_END was requested and the origin is itself a line end + * boundary, we must use the line which ends at the origin. We must do + * similarly for BOUNDARY_WORD_END. This method adjusts the origin + * accordingly. + */ + void AdjustOriginIfEndBoundary(TextLeafPoint& aOrigin, + AccessibleTextBoundary aBoundaryType, + bool aAtOffset = false) const; +}; + +} // namespace mozilla::a11y + +#endif |