gecko-dev/accessible/public/nsIAccessibleText.idl
2014-02-27 11:33:09 -05:00

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/* -*- 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/. */
#include "nsISupports.idl"
typedef long AccessibleTextBoundary;
interface nsIAccessible;
interface nsIArray;
interface nsIPersistentProperties;
interface nsIAccessibleTextRange;
[scriptable, uuid(88789f40-54c9-494a-846d-3acaaf4cf46a)]
interface nsIAccessibleText : nsISupports
{
// In parameters for character offsets:
// -1 will be treated as the equal to the end of the text
// -2 will be treated as the caret position
const int32_t TEXT_OFFSET_END_OF_TEXT = -1;
const int32_t TEXT_OFFSET_CARET = -2;
const AccessibleTextBoundary BOUNDARY_CHAR = 0;
const AccessibleTextBoundary BOUNDARY_WORD_START = 1;
const AccessibleTextBoundary BOUNDARY_WORD_END = 2;
const AccessibleTextBoundary BOUNDARY_SENTENCE_START = 3; // don't use, deprecated
const AccessibleTextBoundary BOUNDARY_SENTENCE_END = 4; // don't use, deprecated
const AccessibleTextBoundary BOUNDARY_LINE_START = 5;
const AccessibleTextBoundary BOUNDARY_LINE_END = 6;
/**
* The current current caret offset.
* If set < 0 then caret will be placed at the end of the text
*/
[binaryname(ScriptableCaretOffset)]
attribute long caretOffset;
readonly attribute long characterCount;
readonly attribute long selectionCount;
/**
* String methods may need to return multibyte-encoded strings,
* since some locales can't be encoded using 16-bit chars.
* So the methods below might return UTF-16 strings, or they could
* return "string" values which are UTF-8.
*/
AString getText (in long startOffset, in long endOffset);
AString getTextAfterOffset (in long offset,
in AccessibleTextBoundary boundaryType,
out long startOffset,
out long endOffset);
AString getTextAtOffset (in long offset,
in AccessibleTextBoundary boundaryType,
out long startOffset,
out long endOffset);
AString getTextBeforeOffset (in long offset,
in AccessibleTextBoundary boundaryType,
out long startOffset,
out long endOffset);
/**
* It would be better to return an unsigned long here,
* to allow unicode chars > 16 bits
*/
wchar getCharacterAtOffset (in long offset);
/**
* Get the accessible start/end offsets around the given offset,
* return the text attributes for this range of text.
*
* @param includeDefAttrs [in] points whether text attributes applied to
* the entire accessible should be included or not.
* @param offset [in] text offset
* @param rangeStartOffset [out] start offset of the range of text
* @param rangeEndOffset [out] end offset of the range of text
*/
nsIPersistentProperties getTextAttributes(in boolean includeDefAttrs,
in long offset,
out long rangeStartOffset,
out long rangeEndOffset);
/**
* Return the text attributes that apply to the entire accessible.
*/
readonly attribute nsIPersistentProperties defaultTextAttributes;
/**
* Returns the bounding box of the specified position.
*
* The virtual character after the last character of the represented text,
* i.e. the one at position length is a special case. It represents the
* current input position and will therefore typically be queried by AT more
* often than other positions. Because it does not represent an existing
* character its bounding box is defined in relation to preceding characters.
* It should be roughly equivalent to the bounding box of some character when
* inserted at the end of the text. Its height typically being the maximal
* height of all the characters in the text or the height of the preceding
* character, its width being at least one pixel so that the bounding box is
* not degenerate.
*
* @param offset - Index of the character for which to return its bounding
* box. The valid range is 0..length.
* @param x - X coordinate of the bounding box of the referenced character.
* @param y - Y coordinate of the bounding box of the referenced character.
* @param width - Width of the bounding box of the referenced character.
* @param height - Height of the bounding box of the referenced character.
* @param coordType - Specifies if the coordinates are relative to the screen
* or to the parent window (see constants declared in
* nsIAccessibleCoordinateType).
*/
void getCharacterExtents (in long offset,
out long x,
out long y,
out long width,
out long height,
in unsigned long coordType);
void getRangeExtents (in long startOffset,
in long endOffset,
out long x,
out long y,
out long width,
out long height,
in unsigned long coordType);
/**
* Get the text offset at the given point, or return -1
* if no character exists at that point
*
* @param x - The position's x value for which to look up the index of the
* character that is rendered on to the display at that point.
* @param y - The position's y value for which to look up the index of the
* character that is rendered on to the display at that point.
* @param coordType - Screen coordinates or window coordinates (see constants
* declared in nsIAccessibleCoordinateType).
* @return offset - Index of the character under the given point or -1 if
* the point is invalid or there is no character under
* the point.
*/
long getOffsetAtPoint (in long x, in long y,
in unsigned long coordType);
void getSelectionBounds (in long selectionNum,
out long startOffset,
out long endOffset);
/**
* Set the bounds for the given selection range
*/
void setSelectionBounds (in long selectionNum,
in long startOffset,
in long endOffset);
void addSelection (in long startOffset, in long endOffset);
void removeSelection (in long selectionNum);
/**
* Makes a specific part of string visible on screen.
*
* @param startIndex 0-based character offset
* @param endIndex 0-based character offset - the offset of the
* character just past the last character of the
* string
* @param scrollType defines how to scroll (see nsIAccessibleScrollType for
* available constants)
*/
[binaryname(ScriptableScrollSubstringTo)]
void scrollSubstringTo(in long startIndex, in long endIndex,
in unsigned long scrollType);
/**
* Moves the top left of a substring to a specified location.
*
* @param startIndex 0-based character offset
* @param endIndex 0-based character offset - the offset of the
* character just past the last character of
* the string
* @param coordinateType specifies the coordinates origin (for available
* constants refer to nsIAccessibleCoordinateType)
* @param x defines the x coordinate
* @param y defines the y coordinate
*/
[binaryname(ScriptableScrollSubstringToPoint)]
void scrollSubstringToPoint(in long startIndex, in long endIndex,
in unsigned long coordinateType,
in long x, in long y);
/**
* Return a range that encloses this text control or otherwise the document
* this text accessible belongs to.
*/
readonly attribute nsIAccessibleTextRange enclosingRange;
/**
* Return an array of disjoint ranges for selected text within the text control
* or otherwise the document this accessible belongs to.
*/
readonly attribute nsIArray selectionRanges;
/**
* Return an array of disjoint ranges of visible text within the text control
* or otherwise the document this accessible belongs to.
*/
readonly attribute nsIArray visibleRanges;
/**
* Return a range containing the given accessible.
*/
nsIAccessibleTextRange getRangeByChild(in nsIAccessible child);
/**
* Return a range containing an accessible at the given point.
*/
nsIAccessibleTextRange getRangeAtPoint(in long x, in long y);
};
/*
Assumptions:
Using wstring (UCS2) instead of string encoded in UTF-8.
Multibyte encodings (or at least potentially multi-byte
encodings) would be preferred for the reasons cited above.
The following methods will throw an exception on failure
(since not every text component will allow every operation):
setSelectionBounds, addSelection, removeSelection, setCaretOffset.
we assume that all text components support the idea of
a caret offset, whether visible or "virtual". If this
isn't the case, caretOffset can be made readonly and
a setCaretOffset method provided which throws an exception
on failure (as with *selection methods above).
*/