The Tor Browser: dom/events/ContentEventHandler.cpp@6474c204b198 (annotated)

dom/events/ContentEventHandler.cpp@6474c204b198 (annotated)

dom/events/ContentEventHandler.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=2 sw=2 et 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/. */
 #include "ContentEventHandler.h"
 #include "mozilla/IMEStateManager.h"
 #include "mozilla/TextEvents.h"
 #include "mozilla/dom/Element.h"
 #include "nsCaret.h"
 #include "nsCOMPtr.h"
 #include "nsContentUtils.h"
 #include "nsCopySupport.h"
 #include "nsFocusManager.h"
 #include "nsFrameSelection.h"
 #include "nsIContentIterator.h"
 #include "nsIPresShell.h"
 #include "nsISelection.h"
 #include "nsISelectionController.h"
 #include "nsISelectionPrivate.h"
 #include "nsIDOMRange.h"
 #include "nsIFrame.h"
 #include "nsIObjectFrame.h"
 #include "nsLayoutUtils.h"
 #include "nsPresContext.h"
 #include "nsRange.h"
 #include "nsTextFragment.h"
 #include "nsTextFrame.h"
 #include "nsView.h"
 #include <algorithm>
 namespace mozilla {
 using namespace dom;
 using namespace widget;
 /******************************************************************/
 /* ContentEventHandler                                            */
 /******************************************************************/
 ContentEventHandler::ContentEventHandler(nsPresContext* aPresContext)
   : mPresContext(aPresContext)
   , mPresShell(aPresContext->GetPresShell())
   , mSelection(nullptr)
   , mFirstSelectedRange(nullptr)
   , mRootContent(nullptr)
 {
 }
 nsresult
 ContentEventHandler::InitBasic()
 {
   NS_ENSURE_TRUE(mPresShell, NS_ERROR_NOT_AVAILABLE);
   // If text frame which has overflowing selection underline is dirty,
   // we need to flush the pending reflow here.
   mPresShell->FlushPendingNotifications(Flush_Layout);
   // Flushing notifications can cause mPresShell to be destroyed (bug 577963).
   NS_ENSURE_TRUE(!mPresShell->IsDestroying(), NS_ERROR_FAILURE);
   return NS_OK;
 }
 nsresult
 ContentEventHandler::InitCommon()
 {
   if (mSelection) {
     return NS_OK;
   }
   nsresult rv = InitBasic();
   NS_ENSURE_SUCCESS(rv, rv);
   nsCopySupport::GetSelectionForCopy(mPresShell->GetDocument(),
                                      getter_AddRefs(mSelection));
   nsCOMPtr<nsIDOMRange> firstRange;
   rv = mSelection->GetRangeAt(0, getter_AddRefs(firstRange));
   // This shell doesn't support selection.
   if (NS_FAILED(rv)) {
     return NS_ERROR_NOT_AVAILABLE;
   }
   mFirstSelectedRange = static_cast<nsRange*>(firstRange.get());
   nsINode* startNode = mFirstSelectedRange->GetStartParent();
   NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
   nsINode* endNode = mFirstSelectedRange->GetEndParent();
   NS_ENSURE_TRUE(endNode, NS_ERROR_FAILURE);
   // See bug 537041 comment 5, the range could have removed node.
   NS_ENSURE_TRUE(startNode->GetCurrentDoc() == mPresShell->GetDocument(),
                  NS_ERROR_NOT_AVAILABLE);
   NS_ASSERTION(startNode->GetCurrentDoc() == endNode->GetCurrentDoc(),
                "mFirstSelectedRange crosses the document boundary");
   mRootContent = startNode->GetSelectionRootContent(mPresShell);
   NS_ENSURE_TRUE(mRootContent, NS_ERROR_FAILURE);
   return NS_OK;
 }
 nsresult
 ContentEventHandler::Init(WidgetQueryContentEvent* aEvent)
 {
   NS_ASSERTION(aEvent, "aEvent must not be null");
   nsresult rv = InitCommon();
   NS_ENSURE_SUCCESS(rv, rv);
   aEvent->mSucceeded = false;
   aEvent->mReply.mContentsRoot = mRootContent.get();
   bool isCollapsed;
   rv = mSelection->GetIsCollapsed(&isCollapsed);
   NS_ENSURE_SUCCESS(rv, NS_ERROR_NOT_AVAILABLE);
   aEvent->mReply.mHasSelection = !isCollapsed;
   nsRefPtr<nsCaret> caret = mPresShell->GetCaret();
   NS_ASSERTION(caret, "GetCaret returned null");
   nsRect r;
   nsIFrame* frame = caret->GetGeometry(mSelection, &r);
   NS_ENSURE_TRUE(frame, NS_ERROR_FAILURE);
   aEvent->mReply.mFocusedWidget = frame->GetNearestWidget();
   return NS_OK;
 }
 nsresult
 ContentEventHandler::Init(WidgetSelectionEvent* aEvent)
 {
   NS_ASSERTION(aEvent, "aEvent must not be null");
   nsresult rv = InitCommon();
   NS_ENSURE_SUCCESS(rv, rv);
   aEvent->mSucceeded = false;
   return NS_OK;
 }
 nsIContent*
 ContentEventHandler::GetFocusedContent()
 {
   nsIDocument* doc = mPresShell->GetDocument();
   if (!doc) {
     return nullptr;
   }
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(doc->GetWindow());
   nsCOMPtr<nsPIDOMWindow> focusedWindow;
   return nsFocusManager::GetFocusedDescendant(window, true,
                                               getter_AddRefs(focusedWindow));
 }
 bool
 ContentEventHandler::IsPlugin(nsIContent* aContent)
 {
   return aContent &&
          aContent->GetDesiredIMEState().mEnabled == IMEState::PLUGIN;
 }
 nsresult
 ContentEventHandler::QueryContentRect(nsIContent* aContent,
                                       WidgetQueryContentEvent* aEvent)
 {
   NS_PRECONDITION(aContent, "aContent must not be null");
   nsIFrame* frame = aContent->GetPrimaryFrame();
   NS_ENSURE_TRUE(frame, NS_ERROR_FAILURE);
   // get rect for first frame
   nsRect resultRect(nsPoint(0, 0), frame->GetRect().Size());
   nsresult rv = ConvertToRootViewRelativeOffset(frame, resultRect);
   NS_ENSURE_SUCCESS(rv, rv);
   // account for any additional frames
   while ((frame = frame->GetNextContinuation()) != nullptr) {
     nsRect frameRect(nsPoint(0, 0), frame->GetRect().Size());
     rv = ConvertToRootViewRelativeOffset(frame, frameRect);
     NS_ENSURE_SUCCESS(rv, rv);
     resultRect.UnionRect(resultRect, frameRect);
   }
   aEvent->mReply.mRect =
       resultRect.ToOutsidePixels(mPresContext->AppUnitsPerDevPixel());
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 // Editor places a bogus BR node under its root content if the editor doesn't
 // have any text. This happens even for single line editors.
 // When we get text content and when we change the selection,
 // we don't want to include the bogus BRs at the end.
 static bool IsContentBR(nsIContent* aContent)
 {
   return aContent->IsHTML() &&
          aContent->Tag() == nsGkAtoms::br &&
          !aContent->AttrValueIs(kNameSpaceID_None,
                                 nsGkAtoms::type,
                                 nsGkAtoms::moz,
                                 eIgnoreCase) &&
          !aContent->AttrValueIs(kNameSpaceID_None,
                                 nsGkAtoms::mozeditorbogusnode,
                                 nsGkAtoms::_true,
                                 eIgnoreCase);
 }
 static void ConvertToNativeNewlines(nsAFlatString& aString)
 {
 #if defined(XP_MACOSX)
   // XXX Mac OS X doesn't use "\r".
   aString.ReplaceSubstring(NS_LITERAL_STRING("\n"), NS_LITERAL_STRING("\r"));
 #elif defined(XP_WIN)
   aString.ReplaceSubstring(NS_LITERAL_STRING("\n"), NS_LITERAL_STRING("\r\n"));
 #endif
 }
 static void AppendString(nsAString& aString, nsIContent* aContent)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT),
                "aContent is not a text node!");
   const nsTextFragment* text = aContent->GetText();
   if (!text) {
     return;
   }
   text->AppendTo(aString);
 }
 static void AppendSubString(nsAString& aString, nsIContent* aContent,
                             uint32_t aXPOffset, uint32_t aXPLength)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT),
                "aContent is not a text node!");
   const nsTextFragment* text = aContent->GetText();
   if (!text) {
     return;
   }
   text->AppendTo(aString, int32_t(aXPOffset), int32_t(aXPLength));
 }
 #if defined(XP_WIN)
 static uint32_t CountNewlinesInXPLength(nsIContent* aContent,
                                         uint32_t aXPLength)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT),
                "aContent is not a text node!");
   const nsTextFragment* text = aContent->GetText();
   if (!text) {
     return 0;
   }
   // For automated tests, we should abort on debug build.
   NS_ABORT_IF_FALSE(
     (aXPLength == UINT32_MAX || aXPLength <= text->GetLength()),
     "aXPLength is out-of-bounds");
   const uint32_t length = std::min(aXPLength, text->GetLength());
   uint32_t newlines = 0;
   for (uint32_t i = 0; i < length; ++i) {
     if (text->CharAt(i) == '\n') {
       ++newlines;
     }
   }
   return newlines;
 }
 static uint32_t CountNewlinesInNativeLength(nsIContent* aContent,
                                             uint32_t aNativeLength)
 {
   NS_ASSERTION(aContent->IsNodeOfType(nsINode::eTEXT),
                "aContent is not a text node!");
   const nsTextFragment* text = aContent->GetText();
   if (!text) {
     return 0;
   }
   // For automated tests, we should abort on debug build.
   MOZ_ASSERT(
     (aNativeLength == UINT32_MAX || aNativeLength <= text->GetLength() * 2),
     "aNativeLength is unexpected value");
   const uint32_t xpLength = text->GetLength();
   uint32_t newlines = 0;
   for (uint32_t i = 0, nativeOffset = 0;
        i < xpLength && nativeOffset < aNativeLength;
        ++i, ++nativeOffset) {
     // For automated tests, we should abort on debug build.
     NS_ABORT_IF_FALSE(i < text->GetLength(), "i is out-of-bounds");
     if (text->CharAt(i) == '\n') {
       ++newlines;
       ++nativeOffset;
     }
   }
   return newlines;
 }
 #endif
 /* static */ uint32_t
 ContentEventHandler::GetNativeTextLength(nsIContent* aContent,
                                          uint32_t aMaxLength)
 {
   return GetTextLength(aContent, LINE_BREAK_TYPE_NATIVE, aMaxLength);
 }
 /* static */ uint32_t
 ContentEventHandler::GetTextLength(nsIContent* aContent,
                                    LineBreakType aLineBreakType,
                                    uint32_t aMaxLength)
 {
   if (aContent->IsNodeOfType(nsINode::eTEXT)) {
     uint32_t textLengthDifference =
 #if defined(XP_MACOSX)
       // On Mac, the length of a native newline ("\r") is equal to the length of
       // the XP newline ("\n"), so the native length is the same as the XP
       // length.
 ;
 #elif defined(XP_WIN)
       // On Windows, the length of a native newline ("\r\n") is twice the length
       // of the XP newline ("\n"), so XP length is equal to the length of the
       // native offset plus the number of newlines encountered in the string.
       (aLineBreakType == LINE_BREAK_TYPE_NATIVE) ?
         CountNewlinesInXPLength(aContent, aMaxLength) : 0;
 #else
       // On other platforms, the native and XP newlines are the same.
 ;
 #endif
     const nsTextFragment* text = aContent->GetText();
     if (!text) {
       return 0;
     }
     uint32_t length = std::min(text->GetLength(), aMaxLength);
     return length + textLengthDifference;
   } else if (IsContentBR(aContent)) {
 #if defined(XP_WIN)
     // Length of \r\n
     return (aLineBreakType == LINE_BREAK_TYPE_NATIVE) ? 2 : 1;
 #else
     return 1;
 #endif
   }
   return 0;
 }
 static uint32_t ConvertToXPOffset(nsIContent* aContent, uint32_t aNativeOffset)
 {
 #if defined(XP_MACOSX)
   // On Mac, the length of a native newline ("\r") is equal to the length of
   // the XP newline ("\n"), so the native offset is the same as the XP offset.
   return aNativeOffset;
 #elif defined(XP_WIN)
   // On Windows, the length of a native newline ("\r\n") is twice the length of
   // the XP newline ("\n"), so XP offset is equal to the length of the native
   // offset minus the number of newlines encountered in the string.
   return aNativeOffset - CountNewlinesInNativeLength(aContent, aNativeOffset);
 #else
   // On other platforms, the native and XP newlines are the same.
   return aNativeOffset;
 #endif
 }
 static nsresult GenerateFlatTextContent(nsRange* aRange,
                                         nsAFlatString& aString,
                                         LineBreakType aLineBreakType)
 {
   nsCOMPtr<nsIContentIterator> iter = NS_NewContentIterator();
   iter->Init(aRange);
   NS_ASSERTION(aString.IsEmpty(), "aString must be empty string");
   nsINode* startNode = aRange->GetStartParent();
   NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
   nsINode* endNode = aRange->GetEndParent();
   NS_ENSURE_TRUE(endNode, NS_ERROR_FAILURE);
   if (startNode == endNode && startNode->IsNodeOfType(nsINode::eTEXT)) {
     nsIContent* content = static_cast<nsIContent*>(startNode);
     AppendSubString(aString, content, aRange->StartOffset(),
                     aRange->EndOffset() - aRange->StartOffset());
     ConvertToNativeNewlines(aString);
     return NS_OK;
   }
   nsAutoString tmpStr;
   for (; !iter->IsDone(); iter->Next()) {
     nsINode* node = iter->GetCurrentNode();
     if (!node) {
       break;
     }
     if (!node->IsNodeOfType(nsINode::eCONTENT)) {
       continue;
     }
     nsIContent* content = static_cast<nsIContent*>(node);
     if (content->IsNodeOfType(nsINode::eTEXT)) {
       if (content == startNode) {
         AppendSubString(aString, content, aRange->StartOffset(),
                         content->TextLength() - aRange->StartOffset());
       } else if (content == endNode) {
         AppendSubString(aString, content, 0, aRange->EndOffset());
       } else {
         AppendString(aString, content);
       }
     } else if (IsContentBR(content)) {
       aString.Append(char16_t('\n'));
     }
   }
   if (aLineBreakType == LINE_BREAK_TYPE_NATIVE) {
     ConvertToNativeNewlines(aString);
   }
   return NS_OK;
 }
 nsresult
 ContentEventHandler::ExpandToClusterBoundary(nsIContent* aContent,
                                              bool aForward,
                                              uint32_t* aXPOffset)
 {
   // XXX This method assumes that the frame boundaries must be cluster
   // boundaries. It's false, but no problem now, maybe.
   if (!aContent->IsNodeOfType(nsINode::eTEXT) ||
       *aXPOffset == 0 || *aXPOffset == aContent->TextLength()) {
     return NS_OK;
   }
   NS_ASSERTION(*aXPOffset <= aContent->TextLength(),
                "offset is out of range.");
   nsRefPtr<nsFrameSelection> fs = mPresShell->FrameSelection();
   int32_t offsetInFrame;
   nsFrameSelection::HINT hint =
     aForward ? nsFrameSelection::HINTLEFT : nsFrameSelection::HINTRIGHT;
   nsIFrame* frame = fs->GetFrameForNodeOffset(aContent, int32_t(*aXPOffset),
                                               hint, &offsetInFrame);
   if (!frame) {
     // This content doesn't have any frames, we only can check surrogate pair...
     const nsTextFragment* text = aContent->GetText();
     NS_ENSURE_TRUE(text, NS_ERROR_FAILURE);
     if (NS_IS_LOW_SURROGATE(text->CharAt(*aXPOffset)) &&
         NS_IS_HIGH_SURROGATE(text->CharAt(*aXPOffset - 1))) {
       *aXPOffset += aForward ? 1 : -1;
     }
     return NS_OK;
   }
   int32_t startOffset, endOffset;
   nsresult rv = frame->GetOffsets(startOffset, endOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   if (*aXPOffset == static_cast<uint32_t>(startOffset) ||
       *aXPOffset == static_cast<uint32_t>(endOffset)) {
     return NS_OK;
   }
   if (frame->GetType() != nsGkAtoms::textFrame) {
     return NS_ERROR_FAILURE;
   }
   nsTextFrame* textFrame = static_cast<nsTextFrame*>(frame);
   int32_t newOffsetInFrame = *aXPOffset - startOffset;
   newOffsetInFrame += aForward ? -1 : 1;
   textFrame->PeekOffsetCharacter(aForward, &newOffsetInFrame);
   *aXPOffset = startOffset + newOffsetInFrame;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::SetRangeFromFlatTextOffset(nsRange* aRange,
                                                 uint32_t aOffset,
                                                 uint32_t aLength,
                                                 LineBreakType aLineBreakType,
                                                 bool aExpandToClusterBoundaries,
                                                 uint32_t* aNewOffset)
 {
   if (aNewOffset) {
     *aNewOffset = aOffset;
   }
   nsCOMPtr<nsIContentIterator> iter = NS_NewPreContentIterator();
   nsresult rv = iter->Init(mRootContent);
   NS_ENSURE_SUCCESS(rv, rv);
   uint32_t offset = 0;
   uint32_t endOffset = aOffset + aLength;
   bool startSet = false;
   for (; !iter->IsDone(); iter->Next()) {
     nsINode* node = iter->GetCurrentNode();
     if (!node) {
       break;
     }
     if (!node->IsNodeOfType(nsINode::eCONTENT)) {
       continue;
     }
     nsIContent* content = static_cast<nsIContent*>(node);
     uint32_t textLength = GetTextLength(content, aLineBreakType);
     if (!textLength) {
       continue;
     }
     if (offset <= aOffset && aOffset < offset + textLength) {
       nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(content));
       NS_ASSERTION(domNode, "aContent doesn't have nsIDOMNode!");
       uint32_t xpOffset;
       if (!content->IsNodeOfType(nsINode::eTEXT)) {
         xpOffset = 0;
       } else {
         xpOffset = aOffset - offset;
         if (aLineBreakType == LINE_BREAK_TYPE_NATIVE) {
           xpOffset = ConvertToXPOffset(content, xpOffset);
         }
       }
       if (aExpandToClusterBoundaries) {
         uint32_t oldXPOffset = xpOffset;
         rv = ExpandToClusterBoundary(content, false, &xpOffset);
         NS_ENSURE_SUCCESS(rv, rv);
         if (aNewOffset) {
           // This is correct since a cluster shouldn't include line break.
           *aNewOffset -= (oldXPOffset - xpOffset);
         }
       }
       rv = aRange->SetStart(domNode, int32_t(xpOffset));
       NS_ENSURE_SUCCESS(rv, rv);
       startSet = true;
       if (aLength == 0) {
         // Ensure that the end offset and the start offset are same.
         rv = aRange->SetEnd(domNode, int32_t(xpOffset));
         NS_ENSURE_SUCCESS(rv, rv);
         return NS_OK;
       }
     }
     if (endOffset <= offset + textLength) {
       nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(content));
       NS_ASSERTION(domNode, "aContent doesn't have nsIDOMNode!");
       uint32_t xpOffset;
       if (content->IsNodeOfType(nsINode::eTEXT)) {
         xpOffset = endOffset - offset;
         if (aLineBreakType == LINE_BREAK_TYPE_NATIVE) {
           xpOffset = ConvertToXPOffset(content, xpOffset);
         }
         if (aExpandToClusterBoundaries) {
           rv = ExpandToClusterBoundary(content, true, &xpOffset);
           NS_ENSURE_SUCCESS(rv, rv);
         }
       } else {
         // Use first position of next node, because the end node is ignored
         // by ContentIterator when the offset is zero.
         xpOffset = 0;
         iter->Next();
         if (iter->IsDone()) {
           break;
         }
         domNode = do_QueryInterface(iter->GetCurrentNode());
       }
       rv = aRange->SetEnd(domNode, int32_t(xpOffset));
       NS_ENSURE_SUCCESS(rv, rv);
       return NS_OK;
     }
     offset += textLength;
   }
   if (offset < aOffset) {
     return NS_ERROR_FAILURE;
   }
   nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(mRootContent));
   NS_ASSERTION(domNode, "lastContent doesn't have nsIDOMNode!");
   if (!startSet) {
     MOZ_ASSERT(!mRootContent->IsNodeOfType(nsINode::eTEXT));
     rv = aRange->SetStart(domNode, int32_t(mRootContent->GetChildCount()));
     NS_ENSURE_SUCCESS(rv, rv);
     if (aNewOffset) {
       *aNewOffset = offset;
     }
   }
   rv = aRange->SetEnd(domNode, int32_t(mRootContent->GetChildCount()));
   NS_ASSERTION(NS_SUCCEEDED(rv), "nsIDOMRange::SetEnd failed");
   return rv;
 }
 /* static */ LineBreakType
 ContentEventHandler::GetLineBreakType(WidgetQueryContentEvent* aEvent)
 {
   return GetLineBreakType(aEvent->mUseNativeLineBreak);
 }
 /* static */ LineBreakType
 ContentEventHandler::GetLineBreakType(WidgetSelectionEvent* aEvent)
 {
   return GetLineBreakType(aEvent->mUseNativeLineBreak);
 }
 /* static */ LineBreakType
 ContentEventHandler::GetLineBreakType(bool aUseNativeLineBreak)
 {
   return aUseNativeLineBreak ?
     LINE_BREAK_TYPE_NATIVE : LINE_BREAK_TYPE_XP;
 }
 nsresult
 ContentEventHandler::OnQuerySelectedText(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   NS_ASSERTION(aEvent->mReply.mString.IsEmpty(),
                "The reply string must be empty");
   LineBreakType lineBreakType = GetLineBreakType(aEvent);
   rv = GetFlatTextOffsetOfRange(mRootContent, mFirstSelectedRange,
                                 &aEvent->mReply.mOffset, lineBreakType);
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIDOMNode> anchorDomNode, focusDomNode;
   rv = mSelection->GetAnchorNode(getter_AddRefs(anchorDomNode));
   NS_ENSURE_TRUE(anchorDomNode, NS_ERROR_FAILURE);
   rv = mSelection->GetFocusNode(getter_AddRefs(focusDomNode));
   NS_ENSURE_TRUE(focusDomNode, NS_ERROR_FAILURE);
   int32_t anchorOffset, focusOffset;
   rv = mSelection->GetAnchorOffset(&anchorOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = mSelection->GetFocusOffset(&focusOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsINode> anchorNode(do_QueryInterface(anchorDomNode));
   nsCOMPtr<nsINode> focusNode(do_QueryInterface(focusDomNode));
   NS_ENSURE_TRUE(anchorNode && focusNode, NS_ERROR_UNEXPECTED);
   int16_t compare = nsContentUtils::ComparePoints(anchorNode, anchorOffset,
                                                   focusNode, focusOffset);
   aEvent->mReply.mReversed = compare > 0;
   if (compare) {
     rv = GenerateFlatTextContent(mFirstSelectedRange, aEvent->mReply.mString,
                                  lineBreakType);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryTextContent(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   NS_ASSERTION(aEvent->mReply.mString.IsEmpty(),
                "The reply string must be empty");
   LineBreakType lineBreakType = GetLineBreakType(aEvent);
   nsRefPtr<nsRange> range = new nsRange(mRootContent);
   rv = SetRangeFromFlatTextOffset(range, aEvent->mInput.mOffset,
                                   aEvent->mInput.mLength, lineBreakType, false,
                                   &aEvent->mReply.mOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = GenerateFlatTextContent(range, aEvent->mReply.mString, lineBreakType);
   NS_ENSURE_SUCCESS(rv, rv);
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 // Adjust to use a child node if possible
 // to make the returned rect more accurate
 static nsINode* AdjustTextRectNode(nsINode* aNode,
                                    int32_t& aNodeOffset)
 {
   int32_t childCount = int32_t(aNode->GetChildCount());
   nsINode* node = aNode;
   if (childCount) {
     if (aNodeOffset < childCount) {
       node = aNode->GetChildAt(aNodeOffset);
       aNodeOffset = 0;
     } else if (aNodeOffset == childCount) {
       node = aNode->GetChildAt(childCount - 1);
       aNodeOffset = node->IsNodeOfType(nsINode::eTEXT) ?
         static_cast<int32_t>(static_cast<nsIContent*>(node)->TextLength()) : 1;
     }
   }
   return node;
 }
 // Similar to nsFrameSelection::GetFrameForNodeOffset,
 // but this is more flexible for OnQueryTextRect to use
 static nsresult GetFrameForTextRect(nsINode* aNode,
                                     int32_t aNodeOffset,
                                     bool aHint,
                                     nsIFrame** aReturnFrame)
 {
   NS_ENSURE_TRUE(aNode && aNode->IsNodeOfType(nsINode::eCONTENT),
                  NS_ERROR_UNEXPECTED);
   nsIContent* content = static_cast<nsIContent*>(aNode);
   nsIFrame* frame = content->GetPrimaryFrame();
   NS_ENSURE_TRUE(frame, NS_ERROR_FAILURE);
   int32_t childNodeOffset = 0;
   return frame->GetChildFrameContainingOffset(aNodeOffset, aHint,
                                               &childNodeOffset, aReturnFrame);
 }
 nsresult
 ContentEventHandler::OnQueryTextRect(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   LineBreakType lineBreakType = GetLineBreakType(aEvent);
   nsRefPtr<nsRange> range = new nsRange(mRootContent);
   rv = SetRangeFromFlatTextOffset(range, aEvent->mInput.mOffset,
                                   aEvent->mInput.mLength, lineBreakType, true,
                                   &aEvent->mReply.mOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = GenerateFlatTextContent(range, aEvent->mReply.mString, lineBreakType);
   NS_ENSURE_SUCCESS(rv, rv);
   // used to iterate over all contents and their frames
   nsCOMPtr<nsIContentIterator> iter = NS_NewContentIterator();
   iter->Init(range);
   // get the starting frame
   int32_t nodeOffset = range->StartOffset();
   nsINode* node = iter->GetCurrentNode();
   if (!node) {
     node = AdjustTextRectNode(range->GetStartParent(), nodeOffset);
   }
   nsIFrame* firstFrame = nullptr;
   rv = GetFrameForTextRect(node, nodeOffset, true, &firstFrame);
   NS_ENSURE_SUCCESS(rv, rv);
   // get the starting frame rect
   nsRect rect(nsPoint(0, 0), firstFrame->GetRect().Size());
   rv = ConvertToRootViewRelativeOffset(firstFrame, rect);
   NS_ENSURE_SUCCESS(rv, rv);
   nsRect frameRect = rect;
   nsPoint ptOffset;
   firstFrame->GetPointFromOffset(nodeOffset, &ptOffset);
   // minus 1 to avoid creating an empty rect
   rect.x += ptOffset.x - 1;
   rect.width -= ptOffset.x - 1;
   // get the ending frame
   nodeOffset = range->EndOffset();
   node = AdjustTextRectNode(range->GetEndParent(), nodeOffset);
   nsIFrame* lastFrame = nullptr;
   rv = GetFrameForTextRect(node, nodeOffset, range->Collapsed(), &lastFrame);
   NS_ENSURE_SUCCESS(rv, rv);
   // iterate over all covered frames
   for (nsIFrame* frame = firstFrame; frame != lastFrame;) {
     frame = frame->GetNextContinuation();
     if (!frame) {
       do {
         iter->Next();
         node = iter->GetCurrentNode();
         if (!node) {
           break;
         }
         if (!node->IsNodeOfType(nsINode::eCONTENT)) {
           continue;
         }
         frame = static_cast<nsIContent*>(node)->GetPrimaryFrame();
       } while (!frame && !iter->IsDone());
       if (!frame) {
         // this can happen when the end offset of the range is 0.
         frame = lastFrame;
       }
     }
     frameRect.SetRect(nsPoint(0, 0), frame->GetRect().Size());
     rv = ConvertToRootViewRelativeOffset(frame, frameRect);
     NS_ENSURE_SUCCESS(rv, rv);
     if (frame != lastFrame) {
       // not last frame, so just add rect to previous result
       rect.UnionRect(rect, frameRect);
     }
   }
   // get the ending frame rect
   lastFrame->GetPointFromOffset(nodeOffset, &ptOffset);
   // minus 1 to avoid creating an empty rect
   frameRect.width -= lastFrame->GetRect().width - ptOffset.x - 1;
   if (firstFrame == lastFrame) {
     rect.IntersectRect(rect, frameRect);
   } else {
     rect.UnionRect(rect, frameRect);
   }
   aEvent->mReply.mRect =
       rect.ToOutsidePixels(mPresContext->AppUnitsPerDevPixel());
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryEditorRect(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   nsIContent* focusedContent = GetFocusedContent();
   rv = QueryContentRect(IsPlugin(focusedContent) ?
                           focusedContent : mRootContent.get(), aEvent);
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryCaretRect(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   LineBreakType lineBreakType = GetLineBreakType(aEvent);
   nsRefPtr<nsCaret> caret = mPresShell->GetCaret();
   NS_ASSERTION(caret, "GetCaret returned null");
   // When the selection is collapsed and the queried offset is current caret
   // position, we should return the "real" caret rect.
   bool selectionIsCollapsed;
   rv = mSelection->GetIsCollapsed(&selectionIsCollapsed);
   NS_ENSURE_SUCCESS(rv, rv);
   if (selectionIsCollapsed) {
     uint32_t offset;
     rv = GetFlatTextOffsetOfRange(mRootContent, mFirstSelectedRange, &offset,
                                   lineBreakType);
     NS_ENSURE_SUCCESS(rv, rv);
     if (offset == aEvent->mInput.mOffset) {
       nsRect rect;
       nsIFrame* caretFrame = caret->GetGeometry(mSelection, &rect);
       if (!caretFrame) {
         return NS_ERROR_FAILURE;
       }
       rv = ConvertToRootViewRelativeOffset(caretFrame, rect);
       NS_ENSURE_SUCCESS(rv, rv);
       aEvent->mReply.mRect =
         rect.ToOutsidePixels(caretFrame->PresContext()->AppUnitsPerDevPixel());
       aEvent->mReply.mOffset = aEvent->mInput.mOffset;
       aEvent->mSucceeded = true;
       return NS_OK;
     }
   }
   // Otherwise, we should set the guessed caret rect.
   nsRefPtr<nsRange> range = new nsRange(mRootContent);
   rv = SetRangeFromFlatTextOffset(range, aEvent->mInput.mOffset, 0,
                                   lineBreakType, true,
                                   &aEvent->mReply.mOffset);
   NS_ENSURE_SUCCESS(rv, rv);
   int32_t xpOffsetInFrame;
   nsIFrame* frame;
   rv = GetStartFrameAndOffset(range, &frame, &xpOffsetInFrame);
   NS_ENSURE_SUCCESS(rv, rv);
   nsPoint posInFrame;
   rv = frame->GetPointFromOffset(range->StartOffset(), &posInFrame);
   NS_ENSURE_SUCCESS(rv, rv);
   nsRect rect;
   rect.x = posInFrame.x;
   rect.y = posInFrame.y;
   rect.width = caret->GetCaretRect().width;
   rect.height = frame->GetSize().height;
   rv = ConvertToRootViewRelativeOffset(frame, rect);
   NS_ENSURE_SUCCESS(rv, rv);
   aEvent->mReply.mRect =
       rect.ToOutsidePixels(mPresContext->AppUnitsPerDevPixel());
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryContentState(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQuerySelectionAsTransferable(
                        WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   if (!aEvent->mReply.mHasSelection) {
     aEvent->mSucceeded = true;
     aEvent->mReply.mTransferable = nullptr;
     return NS_OK;
   }
   nsCOMPtr<nsIDocument> doc = mPresShell->GetDocument();
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
   rv = nsCopySupport::GetTransferableForSelection(
          mSelection, doc, getter_AddRefs(aEvent->mReply.mTransferable));
   NS_ENSURE_SUCCESS(rv, rv);
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryCharacterAtPoint(WidgetQueryContentEvent* aEvent)
 {
   nsresult rv = Init(aEvent);
   if (NS_FAILED(rv)) {
     return rv;
   }
   nsIFrame* rootFrame = mPresShell->GetRootFrame();
   NS_ENSURE_TRUE(rootFrame, NS_ERROR_FAILURE);
   nsIWidget* rootWidget = rootFrame->GetNearestWidget();
   NS_ENSURE_TRUE(rootWidget, NS_ERROR_FAILURE);
   // The root frame's widget might be different, e.g., the event was fired on
   // a popup but the rootFrame is the document root.
   if (rootWidget != aEvent->widget) {
     NS_PRECONDITION(aEvent->widget, "The event must have the widget");
     nsView* view = nsView::GetViewFor(aEvent->widget);
     NS_ENSURE_TRUE(view, NS_ERROR_FAILURE);
     rootFrame = view->GetFrame();
     NS_ENSURE_TRUE(rootFrame, NS_ERROR_FAILURE);
     rootWidget = rootFrame->GetNearestWidget();
     NS_ENSURE_TRUE(rootWidget, NS_ERROR_FAILURE);
   }
   WidgetQueryContentEvent eventOnRoot(true, NS_QUERY_CHARACTER_AT_POINT,
                                       rootWidget);
   eventOnRoot.mUseNativeLineBreak = aEvent->mUseNativeLineBreak;
   eventOnRoot.refPoint = aEvent->refPoint;
   if (rootWidget != aEvent->widget) {
     eventOnRoot.refPoint += LayoutDeviceIntPoint::FromUntyped(
       aEvent->widget->WidgetToScreenOffset() -
         rootWidget->WidgetToScreenOffset());
   }
   nsPoint ptInRoot =
     nsLayoutUtils::GetEventCoordinatesRelativeTo(&eventOnRoot, rootFrame);
   nsIFrame* targetFrame = nsLayoutUtils::GetFrameForPoint(rootFrame, ptInRoot);
   if (!targetFrame || targetFrame->GetType() != nsGkAtoms::textFrame ||
       !targetFrame->GetContent() ||
       !nsContentUtils::ContentIsDescendantOf(targetFrame->GetContent(),
                                              mRootContent)) {
     // there is no character at the point.
     aEvent->mReply.mOffset = WidgetQueryContentEvent::NOT_FOUND;
     aEvent->mSucceeded = true;
     return NS_OK;
   }
   nsPoint ptInTarget = ptInRoot + rootFrame->GetOffsetToCrossDoc(targetFrame);
   int32_t rootAPD = rootFrame->PresContext()->AppUnitsPerDevPixel();
   int32_t targetAPD = targetFrame->PresContext()->AppUnitsPerDevPixel();
   ptInTarget = ptInTarget.ConvertAppUnits(rootAPD, targetAPD);
   nsTextFrame* textframe = static_cast<nsTextFrame*>(targetFrame);
   nsIFrame::ContentOffsets contentOffsets =
     textframe->GetCharacterOffsetAtFramePoint(ptInTarget);
   NS_ENSURE_TRUE(contentOffsets.content, NS_ERROR_FAILURE);
   uint32_t offset;
   rv = GetFlatTextOffsetOfRange(mRootContent, contentOffsets.content,
                                 contentOffsets.offset, &offset,
                                 GetLineBreakType(aEvent));
   NS_ENSURE_SUCCESS(rv, rv);
   WidgetQueryContentEvent textRect(true, NS_QUERY_TEXT_RECT, aEvent->widget);
   textRect.InitForQueryTextRect(offset, 1, aEvent->mUseNativeLineBreak);
   rv = OnQueryTextRect(&textRect);
   NS_ENSURE_SUCCESS(rv, rv);
   NS_ENSURE_TRUE(textRect.mSucceeded, NS_ERROR_FAILURE);
   // currently, we don't need to get the actual text.
   aEvent->mReply.mOffset = offset;
   aEvent->mReply.mRect = textRect.mReply.mRect;
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 nsresult
 ContentEventHandler::OnQueryDOMWidgetHittest(WidgetQueryContentEvent* aEvent)
 {
   NS_ASSERTION(aEvent, "aEvent must not be null");
   nsresult rv = InitBasic();
   if (NS_FAILED(rv)) {
     return rv;
   }
   aEvent->mSucceeded = false;
   aEvent->mReply.mWidgetIsHit = false;
   NS_ENSURE_TRUE(aEvent->widget, NS_ERROR_FAILURE);
   nsIDocument* doc = mPresShell->GetDocument();
   NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
   nsIFrame* docFrame = mPresShell->GetRootFrame();
   NS_ENSURE_TRUE(docFrame, NS_ERROR_FAILURE);
   LayoutDeviceIntPoint eventLoc = aEvent->refPoint +
     LayoutDeviceIntPoint::FromUntyped(aEvent->widget->WidgetToScreenOffset());
   nsIntRect docFrameRect = docFrame->GetScreenRect(); // Returns CSS pixels
   CSSIntPoint eventLocCSS(
     mPresContext->DevPixelsToIntCSSPixels(eventLoc.x) - docFrameRect.x,
     mPresContext->DevPixelsToIntCSSPixels(eventLoc.y) - docFrameRect.y);
   Element* contentUnderMouse =
     doc->ElementFromPointHelper(eventLocCSS.x, eventLocCSS.y, false, false);
   if (contentUnderMouse) {
     nsIWidget* targetWidget = nullptr;
     nsIFrame* targetFrame = contentUnderMouse->GetPrimaryFrame();
     nsIObjectFrame* pluginFrame = do_QueryFrame(targetFrame);
     if (pluginFrame) {
       targetWidget = pluginFrame->GetWidget();
     } else if (targetFrame) {
       targetWidget = targetFrame->GetNearestWidget();
     }
     if (aEvent->widget == targetWidget) {
       aEvent->mReply.mWidgetIsHit = true;
     }
   }
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 /* static */ nsresult
 ContentEventHandler::GetFlatTextOffsetOfRange(nsIContent* aRootContent,
                                               nsINode* aNode,
                                               int32_t aNodeOffset,
                                               uint32_t* aOffset,
                                               LineBreakType aLineBreakType)
 {
   NS_ENSURE_STATE(aRootContent);
   NS_ASSERTION(aOffset, "param is invalid");
   nsRefPtr<nsRange> prev = new nsRange(aRootContent);
   nsCOMPtr<nsIDOMNode> rootDOMNode(do_QueryInterface(aRootContent));
   prev->SetStart(rootDOMNode, 0);
   nsCOMPtr<nsIDOMNode> startDOMNode(do_QueryInterface(aNode));
   NS_ASSERTION(startDOMNode, "startNode doesn't have nsIDOMNode");
   nsCOMPtr<nsIContentIterator> iter = NS_NewContentIterator();
   if (aNode->Length() >= static_cast<uint32_t>(aNodeOffset)) {
     // Offset is within node's length; set end of range to that offset
     prev->SetEnd(startDOMNode, aNodeOffset);
     iter->Init(prev);
   } else if (aNode != static_cast<nsINode*>(aRootContent)) {
     // Offset is past node's length; set end of range to end of node
     prev->SetEndAfter(startDOMNode);
     iter->Init(prev);
   } else {
     // Offset is past the root node; set end of range to end of root node
     iter->Init(aRootContent);
   }
   nsCOMPtr<nsINode> startNode = do_QueryInterface(startDOMNode);
   nsINode* endNode = aNode;
   *aOffset = 0;
   for (; !iter->IsDone(); iter->Next()) {
     nsINode* node = iter->GetCurrentNode();
     if (!node) {
       break;
     }
     if (!node->IsNodeOfType(nsINode::eCONTENT)) {
       continue;
     }
     nsIContent* content = static_cast<nsIContent*>(node);
     if (node->IsNodeOfType(nsINode::eTEXT)) {
       // Note: our range always starts from offset 0
       if (node == endNode) {
         *aOffset += GetTextLength(content, aLineBreakType, aNodeOffset);
       } else {
         *aOffset += GetTextLength(content, aLineBreakType);
       }
     } else if (IsContentBR(content)) {
 #if defined(XP_WIN)
       // On Windows, the length of the newline is 2.
       *aOffset += (aLineBreakType == LINE_BREAK_TYPE_NATIVE) ? 2 : 1;
 #else
       // On other platforms, the length of the newline is 1.
       *aOffset += 1;
 #endif
     }
   }
   return NS_OK;
 }
 /* static */ nsresult
 ContentEventHandler::GetFlatTextOffsetOfRange(nsIContent* aRootContent,
                                               nsRange* aRange,
                                               uint32_t* aOffset,
                                               LineBreakType aLineBreakType)
 {
   nsINode* startNode = aRange->GetStartParent();
   NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
   int32_t startOffset = aRange->StartOffset();
   return GetFlatTextOffsetOfRange(aRootContent, startNode, startOffset,
                                   aOffset, aLineBreakType);
 }
 nsresult
 ContentEventHandler::GetStartFrameAndOffset(nsRange* aRange,
                                             nsIFrame** aFrame,
                                             int32_t* aOffsetInFrame)
 {
   NS_ASSERTION(aRange && aFrame && aOffsetInFrame, "params are invalid");
   nsIContent* content = nullptr;
   nsINode* node = aRange->GetStartParent();
   if (node && node->IsNodeOfType(nsINode::eCONTENT)) {
     content = static_cast<nsIContent*>(node);
   }
   NS_ASSERTION(content, "the start node doesn't have nsIContent!");
   nsRefPtr<nsFrameSelection> fs = mPresShell->FrameSelection();
   *aFrame = fs->GetFrameForNodeOffset(content, aRange->StartOffset(),
                                       fs->GetHint(), aOffsetInFrame);
   NS_ENSURE_TRUE((*aFrame), NS_ERROR_FAILURE);
   NS_ASSERTION((*aFrame)->GetType() == nsGkAtoms::textFrame,
                "The frame is not textframe");
   return NS_OK;
 }
 nsresult
 ContentEventHandler::ConvertToRootViewRelativeOffset(nsIFrame* aFrame,
                                                      nsRect& aRect)
 {
   NS_ASSERTION(aFrame, "aFrame must not be null");
   nsView* view = nullptr;
   nsPoint posInView;
   aFrame->GetOffsetFromView(posInView, &view);
   if (!view) {
     return NS_ERROR_FAILURE;
   }
   aRect += posInView + view->GetOffsetTo(nullptr);
   return NS_OK;
 }
 static void AdjustRangeForSelection(nsIContent* aRoot,
                                     nsINode** aNode,
                                     int32_t* aNodeOffset)
 {
   nsINode* node = *aNode;
   int32_t nodeOffset = *aNodeOffset;
   if (aRoot != node && node->GetParent()) {
     if (node->IsNodeOfType(nsINode::eTEXT)) {
       // When the offset is at the end of the text node, set it to after the
       // text node, to make sure the caret is drawn on a new line when the last
       // character of the text node is '\n'
       int32_t nodeLength =
         static_cast<int32_t>(static_cast<nsIContent*>(node)->TextLength());
       MOZ_ASSERT(nodeOffset <= nodeLength, "Offset is past length of text node");
       if (nodeOffset == nodeLength) {
         node = node->GetParent();
         nodeOffset = node->IndexOf(*aNode) + 1;
       }
     } else {
       node = node->GetParent();
       nodeOffset = node->IndexOf(*aNode) + (nodeOffset ? 1 : 0);
     }
   }
   nsIContent* brContent = node->GetChildAt(nodeOffset - 1);
   while (brContent && brContent->IsHTML()) {
     if (brContent->Tag() != nsGkAtoms::br || IsContentBR(brContent)) {
       break;
     }
     brContent = node->GetChildAt(--nodeOffset - 1);
   }
   *aNode = node;
   *aNodeOffset = std::max(nodeOffset, 0);
 }
 nsresult
 ContentEventHandler::OnSelectionEvent(WidgetSelectionEvent* aEvent)
 {
   aEvent->mSucceeded = false;
   // Get selection to manipulate
   // XXX why do we need to get them from ISM? This method should work fine
   //     without ISM.
   nsresult rv =
     IMEStateManager::GetFocusSelectionAndRoot(getter_AddRefs(mSelection),
                                               getter_AddRefs(mRootContent));
   if (rv != NS_ERROR_NOT_AVAILABLE) {
     NS_ENSURE_SUCCESS(rv, rv);
   } else {
     rv = Init(aEvent);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   // Get range from offset and length
   nsRefPtr<nsRange> range = new nsRange(mRootContent);
   rv = SetRangeFromFlatTextOffset(range, aEvent->mOffset, aEvent->mLength,
                                   GetLineBreakType(aEvent),
                                   aEvent->mExpandToClusterBoundary);
   NS_ENSURE_SUCCESS(rv, rv);
   nsINode* startNode = range->GetStartParent();
   nsINode* endNode = range->GetEndParent();
   int32_t startNodeOffset = range->StartOffset();
   int32_t endNodeOffset = range->EndOffset();
   AdjustRangeForSelection(mRootContent, &startNode, &startNodeOffset);
   AdjustRangeForSelection(mRootContent, &endNode, &endNodeOffset);
   nsCOMPtr<nsIDOMNode> startDomNode(do_QueryInterface(startNode));
   nsCOMPtr<nsIDOMNode> endDomNode(do_QueryInterface(endNode));
   NS_ENSURE_TRUE(startDomNode && endDomNode, NS_ERROR_UNEXPECTED);
   nsCOMPtr<nsISelectionPrivate> selPrivate(do_QueryInterface(mSelection));
   selPrivate->StartBatchChanges();
   // Clear selection first before setting
   rv = mSelection->RemoveAllRanges();
   // Need to call EndBatchChanges at the end even if call failed
   if (NS_SUCCEEDED(rv)) {
     if (aEvent->mReversed) {
       rv = mSelection->Collapse(endDomNode, endNodeOffset);
     } else {
       rv = mSelection->Collapse(startDomNode, startNodeOffset);
     }
     if (NS_SUCCEEDED(rv) &&
         (startDomNode != endDomNode || startNodeOffset != endNodeOffset)) {
       if (aEvent->mReversed) {
         rv = mSelection->Extend(startDomNode, startNodeOffset);
       } else {
         rv = mSelection->Extend(endDomNode, endNodeOffset);
       }
     }
   }
   selPrivate->EndBatchChanges();
   NS_ENSURE_SUCCESS(rv, rv);
   selPrivate->ScrollIntoViewInternal(
     nsISelectionController::SELECTION_FOCUS_REGION,
     false, nsIPresShell::ScrollAxis(), nsIPresShell::ScrollAxis());
   aEvent->mSucceeded = true;
   return NS_OK;
 }
 } // namespace mozilla

The Tor Browser / annotate

dom/events/ContentEventHandler.cpp@6474c204b198 (annotated)

dom/events/ContentEventHandler.cpp