/* -*- Mode: C++; tab-width: 4; 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 "mozilla/a11y/SelectionManager.h"

#include "DocAccessible-inl.h"

#include "HyperTextAccessible.h"

#include "HyperTextAccessible-inl.h"

#include "nsAccessibilityService.h"

#include "nsAccUtils.h"

#include "nsCoreUtils.h"

#include "nsEventShell.h"

#include "nsFrameSelection.h"

#include "nsIAccessibleTypes.h"

#include "nsIDocument.h"

#include "nsIPresShell.h"

#include "mozilla/dom/Selection.h"

#include "mozilla/dom/Element.h"

using namespace mozilla;

using namespace mozilla::a11y;

using mozilla::dom::Selection;

struct mozilla::a11y::SelData final

{

  SelData(Selection* aSel, int32_t aReason) :

    mSel(aSel), mReason(aReason) {}

  RefPtr<Selection> mSel;

  int16_t mReason;

  NS_INLINE_DECL_REFCOUNTING(SelData)

private:

  // Private destructor, to discourage deletion outside of Release():

  ~SelData() {}

};

SelectionManager::SelectionManager() :

  mCaretOffset(-1), mAccWithCaret(nullptr)

{

}

void

SelectionManager::ClearControlSelectionListener()

{

  // Remove 'this' registered as selection listener for the normal selection.

  if (mCurrCtrlNormalSel) {

    mCurrCtrlNormalSel->RemoveSelectionListener(this);

    mCurrCtrlNormalSel = nullptr;

  }

  // Remove 'this' registered as selection listener for the spellcheck

  // selection.

  if (mCurrCtrlSpellSel) {

    mCurrCtrlSpellSel->RemoveSelectionListener(this);

    mCurrCtrlSpellSel = nullptr;

  }

}

void

SelectionManager::SetControlSelectionListener(dom::Element* aFocusedElm)

{

  // When focus moves such that the caret is part of a new frame selection

  // this removes the old selection listener and attaches a new one for

  // the current focus.

  ClearControlSelectionListener();

  nsIFrame* controlFrame = aFocusedElm->GetPrimaryFrame();

  if (!controlFrame)

    return;

  const nsFrameSelection* frameSel = controlFrame->GetConstFrameSelection();

  NS_ASSERTION(frameSel, "No frame selection for focused element!");

  if (!frameSel)

    return;

  // Register 'this' as selection listener for the normal selection.

  Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);

  normalSel->AddSelectionListener(this);

  mCurrCtrlNormalSel = normalSel;

  // Register 'this' as selection listener for the spell check selection.

  Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);

  spellSel->AddSelectionListener(this);

  mCurrCtrlSpellSel = spellSel;

}

void

SelectionManager::AddDocSelectionListener(nsIPresShell* aPresShell)

{

  const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();

  // Register 'this' as selection listener for the normal selection.

  Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);

  normalSel->AddSelectionListener(this);

  // Register 'this' as selection listener for the spell check selection.

  Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);

  spellSel->AddSelectionListener(this);

}

void

SelectionManager::RemoveDocSelectionListener(nsIPresShell* aPresShell)

{

  const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();

  // Remove 'this' registered as selection listener for the normal selection.

  Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);

  normalSel->RemoveSelectionListener(this);

  // Remove 'this' registered as selection listener for the spellcheck

  // selection.

  Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);

  spellSel->RemoveSelectionListener(this);

}

void

SelectionManager::ProcessTextSelChangeEvent(AccEvent* aEvent)

{

  // Fire selection change event if it's not pure caret-move selection change,

  // i.e. the accessible has or had not collapsed selection.

  AccTextSelChangeEvent* event = downcast_accEvent(aEvent);

  if (!event->IsCaretMoveOnly())

    nsEventShell::FireEvent(aEvent);

  // Fire caret move event if there's a caret in the selection.

  nsINode* caretCntrNode =

    nsCoreUtils::GetDOMNodeFromDOMPoint(event->mSel->GetFocusNode(),

                                        event->mSel->FocusOffset());

  if (!caretCntrNode)

    return;

  HyperTextAccessible* caretCntr = nsAccUtils::GetTextContainer(caretCntrNode);

  NS_ASSERTION(caretCntr,

               "No text container for focus while there's one for common ancestor?!");

  if (!caretCntr)

    return;

  Selection* selection = caretCntr->DOMSelection();

  // XXX Sometimes we can't get a selection for caretCntr, in that case assume

  // event->mSel is correct.

  if (!selection)

    selection = event->mSel;

  mCaretOffset = caretCntr->DOMPointToOffset(selection->GetFocusNode(),

                                             selection->FocusOffset());

  mAccWithCaret = caretCntr;

  if (mCaretOffset != -1) {

    RefPtr<AccCaretMoveEvent> caretMoveEvent =

      new AccCaretMoveEvent(caretCntr, mCaretOffset, aEvent->FromUserInput());

    nsEventShell::FireEvent(caretMoveEvent);

  }

}

NS_IMETHODIMP

SelectionManager::NotifySelectionChanged(nsIDocument* aDocument,

                                         Selection* aSelection,

                                         int16_t aReason)

{

  if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {

    return NS_ERROR_INVALID_ARG;

  }

  DocAccessible* document = GetAccService()->GetDocAccessible(aDocument);

#ifdef A11Y_LOG

  if (logging::IsEnabled(logging::eSelection))

    logging::SelChange(aSelection, document, aReason);

#endif

  if (document) {

    // Selection manager has longer lifetime than any document accessible,

    // so that we are guaranteed that the notification is processed before

    // the selection manager is destroyed.

    RefPtr<SelData> selData = new SelData(aSelection, aReason);

    document->HandleNotification<SelectionManager, SelData>

      (this, &SelectionManager::ProcessSelectionChanged, selData);

  }

  return NS_OK;

}

void

SelectionManager::ProcessSelectionChanged(SelData* aSelData)

{

  Selection* selection = aSelData->mSel;

  if (!selection->GetPresShell())

    return;

  const nsRange* range = selection->GetAnchorFocusRange();

  nsINode* cntrNode = nullptr;

  if (range)

    cntrNode = range->GetCommonAncestor();

  if (!cntrNode) {

    cntrNode = selection->GetFrameSelection()->GetAncestorLimiter();

    if (!cntrNode) {

      cntrNode = selection->GetPresShell()->GetDocument();

      NS_ASSERTION(aSelData->mSel->GetPresShell()->ConstFrameSelection() == selection->GetFrameSelection(),

                   "Wrong selection container was used!");

    }

  }

  HyperTextAccessible* text = nsAccUtils::GetTextContainer(cntrNode);

  if (!text) {

    // FIXME bug 1126649

    NS_ERROR("We must reach document accessible implementing text interface!");

    return;

  }

  if (selection->GetType() == SelectionType::eNormal) {

    RefPtr<AccEvent> event =

      new AccTextSelChangeEvent(text, selection, aSelData->mReason);

    text->Document()->FireDelayedEvent(event);

  } else if (selection->GetType() == SelectionType::eSpellCheck) {

    // XXX: fire an event for container accessible of the focus/anchor range

    // of the spelcheck selection.

    text->Document()->FireDelayedEvent(nsIAccessibleEvent::EVENT_TEXT_ATTRIBUTE_CHANGED,

                                       text);

  }

}