Bug 151048 Implemetation of nsIAccessibleText

r=aaronl, sr=jst
first step: the new files

accessible/src/base/nsTextAccessible.cpp

@@ -0,0 +1,459 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is 
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *     John Gaunt (jgaunt@netscape.com)
+ *     Aaron Leventhal (aaronl@netscape.com)
+ *     Kyle Yuan (kyle.yuan@sun.com)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the NPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+// NOTE: alphabetically ordered
+#include "nsContentCID.h"
+#include "nsIDOMRange.h"
+#include "nsIFrame.h"
+#include "nsITextContent.h"
+#include "nsTextAccessible.h"
+#include "nsTextFragment.h"
+
+static NS_DEFINE_IID(kRangeCID, NS_RANGE_CID);
+
+// ------------
+// Text Accessibles
+// ------------
+
+nsTextAccessible::nsTextAccessible(nsIDOMNode* aDomNode, nsIWeakReference* aShell):
+nsLinkableAccessible(aDomNode, aShell)
+{ 
+}
+
+NS_IMPL_ISUPPORTS_INHERITED1(nsTextAccessible, nsLinkableAccessible, nsIAccessibleText)
+
+/**
+  * We are text
+  */
+NS_IMETHODIMP nsTextAccessible::GetAccRole(PRUint32 *_retval)
+{
+  *_retval = ROLE_TEXT;
+  return NS_OK;
+}
+
+/**
+  * No Children
+  */
+NS_IMETHODIMP nsTextAccessible::GetAccFirstChild(nsIAccessible **_retval)
+{
+  *_retval = nsnull;
+  return NS_OK;
+}
+
+/**
+  * No Children
+  */
+NS_IMETHODIMP nsTextAccessible::GetAccLastChild(nsIAccessible **_retval)
+{
+  *_retval = nsnull;
+  return NS_OK;
+}
+
+/**
+  * No Children
+  */
+NS_IMETHODIMP nsTextAccessible::GetAccChildCount(PRInt32 *_retval)
+{
+  *_retval = 0;
+  return NS_OK;
+}
+
+/**
+  * nsIAccessibleText support
+  */
+nsresult nsTextAccessible::GetSelections(nsISelectionController **aSelCon, nsISelection **aDomSel)
+{
+  nsCOMPtr<nsIPresShell> shell(do_QueryReferent(mPresShell));
+  if (!shell)
+    return NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIPresContext> context;
+  shell->GetPresContext(getter_AddRefs(context));
+  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
+  nsIFrame *frame = nsnull;
+  if (content && NS_SUCCEEDED(shell->GetPrimaryFrameFor(content, &frame)) && frame) {
+    frame->GetSelectionController(context, aSelCon);
+    if (*aSelCon)
+      (*aSelCon)->GetSelection(nsISelectionController::SELECTION_NORMAL, aDomSel);
+  }
+
+  if (*aSelCon && *aDomSel)
+    return NS_OK;
+
+  return NS_ERROR_FAILURE;
+}
+
+/*
+Gets the specified text.
+
+aBoundaryType means:
+
+ATK_TEXT_BOUNDARY_CHAR 
+  The character before/at/after the offset is returned.
+
+ATK_TEXT_BOUNDARY_WORD_START 
+  The returned string is from the word start before/at/after the offset to the next word start.
+
+ATK_TEXT_BOUNDARY_WORD_END 
+  The returned string is from the word end before/at/after the offset to the next work end.
+
+ATK_TEXT_BOUNDARY_SENTENCE_START 
+  The returned string is from the sentence start before/at/after the offset to the next sentence start.
+
+ATK_TEXT_BOUNDARY_SENTENCE_END 
+  The returned string is from the sentence end before/at/after the offset to the next sentence end.
+
+ATK_TEXT_BOUNDARY_LINE_START 
+  The returned string is from the line start before/at/after the offset to the next line start.
+
+ATK_TEXT_BOUNDARY_LINE_END 
+  The returned string is from the line end before/at/after the offset to the next line start.
+*/
+nsresult nsTextAccessible::GetTextHelper(EGetTextType aType, nsAccessibleTextBoundary aBoundaryType, 
+                                         PRInt32 aOffset, PRInt32 *aStartOffset, PRInt32 *aEndOffset, nsAString & _retval)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIDOMRange> range(do_CreateInstance(kRangeCID));
+  if (!range)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  *aStartOffset = *aEndOffset = aOffset;
+
+  // Move caret position to offset
+  range->SetStart(mDOMNode, aOffset);
+  range->SetEnd(mDOMNode, aOffset);
+  domSel->RemoveAllRanges();
+  domSel->AddRange(range);
+
+  // Step1: move caret to an appropriate start position
+  // Step2: move caret to end postion and select the text
+  PRBool isStep1Forward, isStep2Forward;  // Moving directions for two steps
+  switch (aType)
+  {
+  case eGetBefore:
+    isStep1Forward = PR_FALSE;
+    isStep2Forward = PR_FALSE;
+    break;
+  case eGetAt:
+    isStep1Forward = PR_FALSE;
+    isStep2Forward = PR_TRUE;
+    break;
+  case eGetAfter:
+    isStep1Forward = PR_TRUE;
+    isStep2Forward = PR_TRUE;
+    break;
+  default:
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  switch (aBoundaryType)
+  {
+  case BOUNDARY_CHAR:
+    if (aType == eGetAfter) { // We need the character next to current position
+      selCon->CharacterMove(isStep1Forward, PR_FALSE);
+      domSel->GetFocusOffset(aStartOffset);
+    }
+    selCon->CharacterMove(isStep2Forward, PR_TRUE);
+    domSel->GetFocusOffset(aEndOffset);
+    break;
+  case BOUNDARY_WORD_START:
+    selCon->WordMove(isStep1Forward, PR_FALSE); // Move caret to previous/next word start boundary
+    domSel->GetFocusOffset(aStartOffset);
+    selCon->WordMove(isStep2Forward, PR_TRUE);  // Select previous/next word
+    domSel->GetFocusOffset(aEndOffset);
+    break;
+  case BOUNDARY_LINE_START:
+    if (aType != eGetAt) { // We need adjust the caret position to previous/next line
+      selCon->LineMove(isStep1Forward, PR_TRUE);
+      domSel->GetFocusOffset(aEndOffset);
+    }
+    selCon->IntraLineMove(PR_FALSE, PR_FALSE);  // Move caret to the line start
+    domSel->GetFocusOffset(aStartOffset);
+    selCon->IntraLineMove(PR_TRUE, PR_TRUE);    // Move caret to the line end and select the whole line
+    domSel->GetFocusOffset(aEndOffset);
+    break;
+  case BOUNDARY_WORD_END:
+  case BOUNDARY_LINE_END:
+  case BOUNDARY_SENTENCE_START:
+  case BOUNDARY_SENTENCE_END:
+  case BOUNDARY_ATTRIBUTE_RANGE:
+    return NS_ERROR_NOT_IMPLEMENTED;
+  default:
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsXPIDLString text;
+  // Get text from selection
+  domSel->ToString(getter_Copies(text));
+  domSel->RemoveAllRanges();
+  _retval = text;
+
+  // Ensure aStartOffset <= aEndOffset
+  if (*aStartOffset > *aEndOffset) {
+    PRInt32 tmp = *aStartOffset;
+    *aStartOffset = *aEndOffset;
+    *aEndOffset = tmp;
+  }
+
+  return NS_OK;
+}
+
+/*
+ * Gets the offset position of the caret (cursor).
+ */
+NS_IMETHODIMP nsTextAccessible::GetCaretOffset(PRInt32 *aCaretOffset)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  return domSel->GetFocusOffset(aCaretOffset);
+}
+
+/*
+ * Sets the caret (cursor) position to the specified offset.
+ */
+NS_IMETHODIMP nsTextAccessible::SetCaretOffset(PRInt32 aCaretOffset)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIDOMRange> range(do_CreateInstance(kRangeCID));
+  if (! range)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  range->SetStart(mDOMNode, aCaretOffset);
+  range->SetEnd(mDOMNode, aCaretOffset);
+  return domSel->AddRange(range);
+}
+
+/*
+ * Gets the character count.
+ */
+NS_IMETHODIMP nsTextAccessible::GetCharacterCount(PRInt32 *aCharacterCount)
+{
+  nsCOMPtr<nsITextContent> textContent(do_QueryInterface(mDOMNode));
+  if (!textContent)
+    return NS_ERROR_FAILURE;
+
+  return textContent->GetTextLength(aCharacterCount);
+}
+
+/*
+ * Gets the number of selected regions.
+ */
+NS_IMETHODIMP nsTextAccessible::GetSelectionCount(PRInt32 *aSelectionCount)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  return domSel->GetRangeCount(aSelectionCount);
+}
+
+/*
+ * Gets the specified text.
+ */
+NS_IMETHODIMP nsTextAccessible::GetText(PRInt32 aStartOffset, PRInt32 aEndOffset, nsAString & _retval)
+{
+  nsAutoString text;
+  mDOMNode->GetNodeValue(text);
+  _retval = Substring(text, aStartOffset, aEndOffset - aStartOffset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsTextAccessible::GetTextBeforeOffset(PRInt32 aOffset, nsAccessibleTextBoundary aBoundaryType, PRInt32 *aStartOffset, PRInt32 *aEndOffset, nsAString & _retval)
+{
+  return GetTextHelper(eGetBefore, aBoundaryType, aOffset, aStartOffset, aEndOffset, _retval);
+}
+
+NS_IMETHODIMP nsTextAccessible::GetTextAtOffset(PRInt32 aOffset, nsAccessibleTextBoundary aBoundaryType, PRInt32 *aStartOffset, PRInt32 *aEndOffset, nsAString & _retval)
+{
+  return GetTextHelper(eGetAt, aBoundaryType, aOffset, aStartOffset, aEndOffset, _retval);
+}
+
+NS_IMETHODIMP nsTextAccessible::GetTextAfterOffset(PRInt32 aOffset, nsAccessibleTextBoundary aBoundaryType, PRInt32 *aStartOffset, PRInt32 *aEndOffset, nsAString & _retval)
+{
+  return GetTextHelper(eGetAfter, aBoundaryType, aOffset, aStartOffset, aEndOffset, _retval);
+}
+
+/*
+ * Gets the specified text.
+ */
+NS_IMETHODIMP nsTextAccessible::GetCharacterAtOffset(PRInt32 aOffset, PRUnichar *_retval)
+{
+  nsCOMPtr<nsITextContent> textContent(do_QueryInterface(mDOMNode));
+  if (!textContent)
+    return NS_ERROR_FAILURE;
+
+  const nsTextFragment *textFrag;
+  textContent->GetText(&textFrag);
+  *_retval = textFrag->CharAt(aOffset);
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsTextAccessible::GetAttributeRange(PRInt32 aOffset, PRInt32 *aRangeStartOffset, PRInt32 *aRangeEndOffset, nsISupports **_retval)
+{
+  // will do better job later
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+/*
+ * Given an offset, the x, y, width, and height values are filled appropriately.
+ */
+NS_IMETHODIMP nsTextAccessible::GetCharacterExtents(PRInt32 aOffset, PRInt32 *aX, PRInt32 *aY, PRInt32 *aLength, PRInt32 *aWidth, nsAccessibleCoordType aCoordType)
+{
+  // will do better job later
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+/*
+ * Gets the offset of the character located at coordinates x and y. x and y are interpreted as being relative to 
+ * the screen or this widget's window depending on coords.
+ */
+NS_IMETHODIMP nsTextAccessible::GetOffsetAtPoint(PRInt32 aX, PRInt32 aY, nsAccessibleCoordType aCoordType, PRInt32 *_retval)
+{
+  // will do better job later
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+/*
+ * Gets the start and end offset of the specified selection.
+ */
+NS_IMETHODIMP nsTextAccessible::GetSelectionBounds(PRInt32 aSelectionNum, PRInt32 *aStartOffset, PRInt32 *aEndOffset)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  PRInt32 rangeCount;
+  domSel->GetRangeCount(&rangeCount);
+  if (aSelectionNum < 0 || aSelectionNum >= rangeCount)
+    return NS_ERROR_INVALID_ARG;
+
+  nsCOMPtr<nsIDOMRange> range;
+  domSel->GetRangeAt(aSelectionNum, getter_AddRefs(range));
+  range->GetStartOffset(aStartOffset);
+  range->GetEndOffset(aEndOffset);
+  return NS_OK;
+}
+
+/*
+ * Changes the start and end offset of the specified selection.
+ */
+NS_IMETHODIMP nsTextAccessible::SetSelectionBounds(PRInt32 aSelectionNum, PRInt32 aStartOffset, PRInt32 aEndOffset)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  PRInt32 rangeCount;
+  domSel->GetRangeCount(&rangeCount);
+  if (aSelectionNum < 0 || aSelectionNum >= rangeCount)
+    return NS_ERROR_INVALID_ARG;
+
+  nsCOMPtr<nsIDOMRange> range;
+  domSel->GetRangeAt(aSelectionNum, getter_AddRefs(range));
+
+  nsCOMPtr<nsIDOMNode> startParent;
+  nsCOMPtr<nsIDOMNode> endParent;
+  range->GetStartContainer(getter_AddRefs(startParent));
+  range->GetEndContainer(getter_AddRefs(endParent));
+  range->SetStart(startParent, aStartOffset);
+  range->SetEnd(endParent, aEndOffset);
+  return NS_OK;
+}
+
+/*
+ * Adds a selection bounded by the specified offsets.
+ */
+NS_IMETHODIMP nsTextAccessible::AddSelection(PRInt32 aStartOffset, PRInt32 aEndOffset)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+  
+  nsCOMPtr<nsIDOMRange> range(do_CreateInstance(kRangeCID));
+  if (! range)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  range->SetStart(mDOMNode, aStartOffset);
+  range->SetEnd(mDOMNode, aEndOffset);
+  return domSel->AddRange(range);
+}
+
+/*
+ * Removes the specified selection.
+ */
+NS_IMETHODIMP nsTextAccessible::RemoveSelection(PRInt32 aSelectionNum)
+{
+  nsCOMPtr<nsISelectionController> selCon;
+  nsCOMPtr<nsISelection> domSel;
+
+  if (NS_FAILED(GetSelections(getter_AddRefs(selCon), getter_AddRefs(domSel))))
+    return NS_ERROR_FAILURE;
+
+  PRInt32 rangeCount;
+  domSel->GetRangeCount(&rangeCount);
+  if (aSelectionNum < 0 || aSelectionNum >= rangeCount)
+    return NS_ERROR_INVALID_ARG;
+
+  nsCOMPtr<nsIDOMRange> range;
+  domSel->GetRangeAt(aSelectionNum, getter_AddRefs(range));
+  return domSel->RemoveRange(range);
+}

accessible/src/base/nsTextAccessible.h

@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: NPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is 
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1998
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ * Author: Eric D Vaughan (evaughan@netscape.com)
+ *
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the NPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the NPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef _nsTextAccessible_H_
+#define _nsTextAccessible_H_
+
+#include "nsBaseWidgetAccessible.h"
+#include "nsIAccessibleText.h"
+#include "nsISelectionController.h"
+
+/**
+  * Text nodes have no children, but since double inheritance
+  *  no-worky we have to re-impl the LeafAccessiblity blocks 
+  *  this way.
+  */
+class nsTextAccessible : public nsLinkableAccessible,
+                         public nsIAccessibleText
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIACCESSIBLETEXT
+
+  nsTextAccessible(nsIDOMNode* aDomNode, nsIWeakReference* aShell);
+  NS_IMETHOD GetAccRole(PRUint32 *_retval); 
+  NS_IMETHOD GetAccFirstChild(nsIAccessible **_retval);
+  NS_IMETHOD GetAccLastChild(nsIAccessible **_retval);
+  NS_IMETHOD GetAccChildCount(PRInt32 *_retval);
+
+private:
+  enum EGetTextType { eGetBefore=-1, eGetAt=0, eGetAfter=1 };
+
+  nsresult GetSelections(nsISelectionController **aSelCon, nsISelection **aDomSel);
+  nsresult GetTextHelper(EGetTextType aType, nsAccessibleTextBoundary aBoundaryType, 
+                         PRInt32 aOffset, PRInt32 *aStartOffset, PRInt32 *aEndOffset, nsAString & _retval);
+};
+
+
+#endif
+