Quelle SelectionChangeEventDispatcher.cpp Sprache: C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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/. */

/*
* Implementation of mozilla::SelectionChangeEventDispatcher
*/

#include "SelectionChangeEventDispatcher.h"

#include "mozilla/AsyncEventDispatcher.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Selection.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsFrameSelection.h"
#include "nsRange.h"

namespace mozilla {

using namespace dom;

SelectionChangeEventDispatcher::RawRangeData::RawRangeData(
    const nsRange* aRange) {
  if (aRange->IsPositioned()) {
    mStartContainer = aRange->GetStartContainer();
    mEndContainer = aRange->GetEndContainer();
    mStartOffset = aRange->StartOffset();
    mEndOffset = aRange->EndOffset();
  } else {
    mStartContainer = nullptr;
    mEndContainer = nullptr;
    mStartOffset = 0;
    mEndOffset = 0;
  }
}

bool SelectionChangeEventDispatcher::RawRangeData::Equals(
    const nsRange* aRange) {
  if (!aRange->IsPositioned()) {
    return !mStartContainer;
  }
  return mStartContainer == aRange->GetStartContainer() &&
         mEndContainer == aRange->GetEndContainer() &&
         mStartOffset == aRange->StartOffset() &&
         mEndOffset == aRange->EndOffset();
}

inline void ImplCycleCollectionTraverse(
    nsCycleCollectionTraversalCallback& aCallback,
    SelectionChangeEventDispatcher::RawRangeData& aField, const char* aName,
    uint32_t aFlags = 0) {
  ImplCycleCollectionTraverse(aCallback, aField.mStartContainer,
                              "mStartContainer", aFlags);
  ImplCycleCollectionTraverse(aCallback, aField.mEndContainer, "mEndContainer",
                              aFlags);
}

NS_IMPL_CYCLE_COLLECTION_CLASS(SelectionChangeEventDispatcher)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(SelectionChangeEventDispatcher)
  tmp->mOldRanges.Clear();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(SelectionChangeEventDispatcher)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOldRanges);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

void SelectionChangeEventDispatcher::OnSelectionChange(Document* aDoc,
                                                       Selection* aSel,
                                                       int16_t aReason) {
  // Check if the ranges have actually changed
  // Don't bother checking this if we are hiding changes.
  if (mOldRanges.Length() == aSel->RangeCount() &&
      !aSel->IsBlockingSelectionChangeEvents()) {
    bool changed = mOldDirection != aSel->GetDirection();
    if (!changed) {
      for (const uint32_t i : IntegerRange(mOldRanges.Length())) {
        if (!mOldRanges[i].Equals(aSel->GetRangeAt(i))) {
          changed = true;
          break;
        }
      }
    }

    if (!changed) {
      return;
    }
  }

  // The ranges have actually changed, update the mOldRanges array
  mOldRanges.ClearAndRetainStorage();
  for (const uint32_t i : IntegerRange(aSel->RangeCount())) {
    mOldRanges.AppendElement(RawRangeData(aSel->GetRangeAt(i)));
  }
  mOldDirection = aSel->GetDirection();

  // If we are hiding changes, then don't do anything else. We do this after we
  // update mOldRanges so that changes after the changes stop being hidden don't
  // incorrectly trigger a change, even though they didn't change anything
  if (aSel->IsBlockingSelectionChangeEvents()) {
    return;
  }

  const Document* doc = aSel->GetParentObject();
  if (MOZ_UNLIKELY(!doc)) {
    return;
  }
  const nsPIDOMWindowInner* inner = doc->GetInnerWindow();
  if (MOZ_UNLIKELY(!inner)) {
    return;
  }
  const bool maybeHasSelectionChangeEventListeners =
      !inner || inner->HasSelectionChangeEventListeners();
  const bool maybeHasFormSelectEventListeners =
      !inner || inner->HasFormSelectEventListeners();
  if (!maybeHasSelectionChangeEventListeners &&
      !maybeHasFormSelectEventListeners) {
    return;
  }

  // Be aware, don't call GetTextControlFromSelectionLimiter once you might
  // run script because selection limit may have already been changed by it.
  nsCOMPtr<nsIContent> textControl;
  if ((maybeHasFormSelectEventListeners &&
       (aReason & nsISelectionListener::JS_REASON)) ||
      maybeHasSelectionChangeEventListeners) {
    if (const nsFrameSelection* fs = aSel->GetFrameSelection()) {
      if (nsCOMPtr<nsIContent> root = fs->GetLimiter()) {
        textControl = root->GetClosestNativeAnonymousSubtreeRootParentOrHost();
        MOZ_ASSERT_IF(textControl,
                      textControl->IsTextControlElement() &&
                          !textControl->IsInNativeAnonymousSubtree());
      }
    }
  };

  // Selection changes with non-JS reason only cares about whether the new
  // selection is collapsed or not. See TextInputListener::OnSelectionChange.
  if (textControl && maybeHasFormSelectEventListeners &&
      (aReason & nsISelectionListener::JS_REASON)) {
    RefPtr<AsyncEventDispatcher> asyncDispatcher =
        new AsyncEventDispatcher(textControl, eFormSelect, CanBubble::eYes);
    asyncDispatcher->PostDOMEvent();
  }

  if (!maybeHasSelectionChangeEventListeners) {
    return;
  }

  // The spec currently doesn't say that we should dispatch this event on text
  // controls, so for now we only support doing that under a pref, disabled by
  // default.
  // See https://github.com/w3c/selection-api/issues/53.
  if (textControl &&
      !StaticPrefs::dom_select_events_textcontrols_selectionchange_enabled()) {
    return;
  }

  nsINode* target =
      textControl ? static_cast<nsINode*>(textControl.get()) : aDoc;
  if (!target) {
    return;
  }

  if (target->HasScheduledSelectionChangeEvent()) {
    return;
  }

  target->SetHasScheduledSelectionChangeEvent();

  CanBubble canBubble = textControl ? CanBubble::eYes : CanBubble::eNo;
  RefPtr<AsyncEventDispatcher> asyncDispatcher =
      new AsyncSelectionChangeEventDispatcher(target, eSelectionChange,
                                              canBubble);
  asyncDispatcher->PostDOMEvent();
}

}  // namespace mozilla

quality94%

¤ Dauer der Verarbeitung: 0.19 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.