Ziele Untersuchung
mit Columbo Integrität von
Datenbanken Interaktion und
Portierbarkeit Ergonomie der
Schnittstellen

Angebot Produkte Projekt Beratung

Mittel Analytik Modellierung Sprachen Algebra Logik Hardware Denken Kreativität

Zusammenhänge Gesellschaft Wirtschaft Branche Firma


products/sources/formale Sprachen/C/Firefox/accessible/android/ (Browser von der Mozilla Stiftung Version 136.0.1^©) Datei vom 10.2.2025 mit Größe 8 kB

Quelle TraversalRule.cpp Sprache: C

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

#include "TraversalRule.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/a11y/Accessible.h"

#include "mozilla/a11y/Role.h"
#include "HTMLListAccessible.h"
#include "SessionAccessibility.h"
#include "nsAccUtils.h"
#include "nsIAccessiblePivot.h"

using namespace mozilla;
using namespace mozilla::a11y;

TraversalRule::TraversalRule()
    : TraversalRule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT,
                    true) {}

TraversalRule::TraversalRule(int32_t aGranularity, bool aIsLocal)
    : mGranularity(aGranularity), mIsLocal(aIsLocal) {}

uint16_t TraversalRule::Match(Accessible* aAcc) {
  MOZ_ASSERT(aAcc);

  if (mIsLocal && aAcc->IsRemote()) {
    // If we encounter a remote accessible in a local rule, we should
    // ignore the subtree because we won't encounter anymore local accessibles
    // in it.
    return nsIAccessibleTraversalRule::FILTER_IGNORE |
           nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
  } else if (!mIsLocal && aAcc->IsLocal()) {
    // If we encounter a local accessible in a remote rule we are likely
    // traversing backwards/upwards, we don't ignore its subtree because it is
    // likely the outer doc root of the remote tree.
    return nsIAccessibleTraversalRule::FILTER_IGNORE;
  }

  uint16_t result = nsIAccessibleTraversalRule::FILTER_IGNORE;

  if (nsAccUtils::MustPrune(aAcc)) {
    result |= nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
  }

  uint64_t state = aAcc->State();

  if ((state & states::INVISIBLE) != 0) {
    return result;
  }

  if (aAcc->Opacity() == 0.0f) {
    return result | nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
  }

  switch (mGranularity) {
    case java::SessionAccessibility::HTML_GRANULARITY_LINK:
      result |= LinkMatch(aAcc);
      break;
    case java::SessionAccessibility::HTML_GRANULARITY_CONTROL:
      result |= ControlMatch(aAcc);
      break;
    case java::SessionAccessibility::HTML_GRANULARITY_SECTION:
      result |= SectionMatch(aAcc);
      break;
    case java::SessionAccessibility::HTML_GRANULARITY_HEADING:
      result |= HeadingMatch(aAcc);
      break;
    case java::SessionAccessibility::HTML_GRANULARITY_LANDMARK:
      result |= LandmarkMatch(aAcc);
      break;
    default:
      result |= DefaultMatch(aAcc);
      break;
  }

  return result;
}

bool TraversalRule::IsSingleLineage(Accessible* aAccessible) {
  Accessible* child = aAccessible;
  while (child) {
    switch (child->ChildCount()) {
      case 0:
        return true;
      case 1:
        child = child->FirstChild();
        break;
      case 2:
        if (IsListItemBullet(child->FirstChild())) {
          child = child->LastChild();
        } else {
          return false;
        }
        break;
      default:
        return false;
    }
  }

  return true;
}

bool TraversalRule::IsListItemBullet(const Accessible* aAccessible) {
  return aAccessible->Role() == roles::LISTITEM_MARKER;
}

bool TraversalRule::IsFlatSubtree(const Accessible* aAccessible) {
  for (auto child = aAccessible->FirstChild(); child;
       child = child->NextSibling()) {
    roles::Role role = child->Role();
    if (role == roles::TEXT_LEAF || role == roles::STATICTEXT) {
      continue;
    }

    if (child->ChildCount() > 0 || child->ActionCount() > 0) {
      return false;
    }
  }

  return true;
}

bool TraversalRule::HasName(const Accessible* aAccessible) {
  nsAutoString name;
  aAccessible->Name(name);
  name.CompressWhitespace();
  return !name.IsEmpty();
}

uint16_t TraversalRule::LinkMatch(Accessible* aAccessible) {
  if (aAccessible->Role() == roles::LINK &&
      (aAccessible->State() & states::LINKED) != 0) {
    return nsIAccessibleTraversalRule::FILTER_MATCH |
           nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

uint16_t TraversalRule::HeadingMatch(Accessible* aAccessible) {
  if (aAccessible->Role() == roles::HEADING && aAccessible->ChildCount()) {
    return nsIAccessibleTraversalRule::FILTER_MATCH;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

uint16_t TraversalRule::SectionMatch(Accessible* aAccessible) {
  roles::Role role = aAccessible->Role();
  if (role == roles::HEADING || role == roles::LANDMARK ||
      aAccessible->LandmarkRole()) {
    return nsIAccessibleTraversalRule::FILTER_MATCH;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

uint16_t TraversalRule::LandmarkMatch(Accessible* aAccessible) {
  if (aAccessible->LandmarkRole()) {
    return nsIAccessibleTraversalRule::FILTER_MATCH;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

uint16_t TraversalRule::ControlMatch(Accessible* aAccessible) {
  switch (aAccessible->Role()) {
    case roles::PUSHBUTTON:
    case roles::SPINBUTTON:
    case roles::TOGGLE_BUTTON:
    case roles::BUTTONDROPDOWN:
    case roles::COMBOBOX:
    case roles::LISTBOX:
    case roles::ENTRY:
    case roles::PASSWORD_TEXT:
    case roles::PAGETAB:
    case roles::RADIOBUTTON:
    case roles::RADIO_MENU_ITEM:
    case roles::SLIDER:
    case roles::CHECKBUTTON:
    case roles::CHECK_MENU_ITEM:
    case roles::SWITCH:
    case roles::MENUITEM:
      return nsIAccessibleTraversalRule::FILTER_MATCH |
             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
    case roles::LINK:
      return LinkMatch(aAccessible);
    case roles::EDITCOMBOBOX:
      if (aAccessible->State() & states::EDITABLE) {
        // Only match ARIA 1.0 comboboxes; i.e. where the combobox itself is
        // editable. If it's a 1.1 combobox, the combobox is just a container;
        // we want to stop on the textbox inside it, not the container.
        return nsIAccessibleTraversalRule::FILTER_MATCH |
               nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
      }
      break;
    default:
      break;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

uint16_t TraversalRule::DefaultMatch(Accessible* aAccessible) {
  switch (aAccessible->Role()) {
    case roles::COMBOBOX:
      // We don't want to ignore the subtree because this is often
      // where the list box hangs out.
      return nsIAccessibleTraversalRule::FILTER_MATCH;
    case roles::EDITCOMBOBOX:
      if (aAccessible->State() & states::EDITABLE) {
        // Only match ARIA 1.0 comboboxes; i.e. where the combobox itself is
        // editable. If it's a 1.1 combobox, the combobox is just a container;
        // we want to stop on the textbox inside it.
        return nsIAccessibleTraversalRule::FILTER_MATCH;
      }
      break;
    case roles::TEXT_LEAF:
    case roles::GRAPHIC:
      // Nameless text leaves are boring, skip them.
      if (HasName(aAccessible)) {
        return nsIAccessibleTraversalRule::FILTER_MATCH;
      }
      break;
    case roles::STATICTEXT:
      // Ignore list bullets
      if (!IsListItemBullet(aAccessible)) {
        return nsIAccessibleTraversalRule::FILTER_MATCH;
      }
      break;
    case roles::HEADING:
    case roles::COLUMNHEADER:
    case roles::ROWHEADER:
    case roles::STATUSBAR:
      if ((aAccessible->ChildCount() > 0 || HasName(aAccessible)) &&
          (IsSingleLineage(aAccessible) || IsFlatSubtree(aAccessible))) {
        return nsIAccessibleTraversalRule::FILTER_MATCH |
               nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
      }
      break;
    case roles::GRID_CELL:
      if (IsSingleLineage(aAccessible) || IsFlatSubtree(aAccessible)) {
        return nsIAccessibleTraversalRule::FILTER_MATCH |
               nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
      }
      break;
    case roles::LABEL:
      if (IsFlatSubtree(aAccessible)) {
        // Match if this is a label with text but no nested controls.
        return nsIAccessibleTraversalRule::FILTER_MATCH |
               nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
      }
      break;
    case roles::MENUITEM:
    case roles::LINK:
    case roles::PAGETAB:
    case roles::PUSHBUTTON:
    case roles::CHECKBUTTON:
    case roles::RADIOBUTTON:
    case roles::PROGRESSBAR:
    case roles::BUTTONDROPDOWN:
    case roles::BUTTONMENU:
    case roles::CHECK_MENU_ITEM:
    case roles::PASSWORD_TEXT:
    case roles::RADIO_MENU_ITEM:
    case roles::TOGGLE_BUTTON:
    case roles::ENTRY:
    case roles::KEY:
    case roles::SLIDER:
    case roles::SPINBUTTON:
    case roles::OPTION:
    case roles::SWITCH:
    case roles::MATHML_MATH:
      // Ignore the subtree, if there is one. So that we don't land on
      // the same content that was already presented by its parent.
      return nsIAccessibleTraversalRule::FILTER_MATCH |
             nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
    default:
      break;
  }

  return nsIAccessibleTraversalRule::FILTER_IGNORE;
}

quality98%

¤ Dauer der Verarbeitung: 0.16 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.