gecko-dev/accessible/mac/Platform.mm

/* clang-format off */
/* -*- Mode: Objective-C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* clang-format on */
/* 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/. */

#import <Cocoa/Cocoa.h>

#import "MOXTextMarkerDelegate.h"

#include "Platform.h"
#include "ProxyAccessible.h"
#include "AccessibleOrProxy.h"
#include "DocAccessibleParent.h"
#include "mozTableAccessible.h"
#include "MOXWebAreaAccessible.h"

#include "nsAppShell.h"
#include "mozilla/Telemetry.h"

// Available from 10.13 onwards; test availability at runtime before using
@interface NSWorkspace (AvailableSinceHighSierra)
@property(readonly) BOOL isVoiceOverEnabled;
@end

namespace mozilla {
namespace a11y {

// Mac a11y whitelisting
static bool sA11yShouldBeEnabled = false;

bool ShouldA11yBeEnabled() {
  EPlatformDisabledState disabledState = PlatformDisabledState();
  return (disabledState == ePlatformIsForceEnabled) ||
         ((disabledState == ePlatformIsEnabled) && sA11yShouldBeEnabled);
}

void PlatformInit() {}

void PlatformShutdown() {}

void ProxyCreated(ProxyAccessible* aProxy, uint32_t) {
  ProxyAccessible* parent = aProxy->Parent();
  if ((parent && nsAccUtils::MustPrune(parent)) ||
      aProxy->Role() == roles::WHITESPACE) {
    // We don't create a native object if we're child of a "flat" accessible;
    // for example, on OS X buttons shouldn't have any children, because that
    // makes the OS confused. We also don't create accessibles for <br>
    // (whitespace) elements.
    return;
  }

  // Pass in dummy state for now as retrieving proxy state requires IPC.
  // Note that we can use ProxyAccessible::IsTable* functions here because they
  // do not use IPC calls but that might change after bug 1210477.
  Class type;
  if (aProxy->IsTable()) {
    type = [mozTableAccessible class];
  } else if (aProxy->IsTableRow()) {
    type = [mozTableRowAccessible class];
  } else if (aProxy->IsTableCell()) {
    type = [mozTableCellAccessible class];
  } else if (aProxy->IsDoc()) {
    type = [MOXWebAreaAccessible class];
  } else {
    type = GetTypeFromRole(aProxy->Role());
  }

  mozAccessible* mozWrapper = [[type alloc] initWithAccessible:aProxy];
  aProxy->SetWrapper(reinterpret_cast<uintptr_t>(mozWrapper));
}

void ProxyDestroyed(ProxyAccessible* aProxy) {
  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aProxy);
  [wrapper expire];
  [wrapper release];
  aProxy->SetWrapper(0);

  if (aProxy->IsDoc()) {
    [MOXTextMarkerDelegate destroyForDoc:aProxy];
  }
}

void ProxyEvent(ProxyAccessible* aProxy, uint32_t aEventType) {
  // Ignore event that we don't escape below, they aren't yet supported.
  if (aEventType != nsIAccessibleEvent::EVENT_FOCUS &&
      aEventType != nsIAccessibleEvent::EVENT_VALUE_CHANGE &&
      aEventType != nsIAccessibleEvent::EVENT_TEXT_VALUE_CHANGE &&
      aEventType != nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED &&
      aEventType != nsIAccessibleEvent::EVENT_DOCUMENT_LOAD_COMPLETE &&
      aEventType != nsIAccessibleEvent::EVENT_REORDER &&
      aEventType != nsIAccessibleEvent::EVENT_LIVE_REGION_ADDED &&
      aEventType != nsIAccessibleEvent::EVENT_LIVE_REGION_REMOVED &&
      aEventType != nsIAccessibleEvent::EVENT_NAME_CHANGE)
    return;

  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aProxy);
  if (wrapper) {
    [wrapper handleAccessibleEvent:aEventType];
  }
}

void ProxyStateChangeEvent(ProxyAccessible* aProxy, uint64_t aState,
                           bool aEnabled) {
  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aProxy);
  if (wrapper) {
    [wrapper stateChanged:aState isEnabled:aEnabled];
  }
}

void ProxyCaretMoveEvent(ProxyAccessible* aTarget, int32_t aOffset,
                         bool aIsSelectionCollapsed) {
  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aTarget);
  if (aIsSelectionCollapsed) {
    // If selection is collapsed, invalidate selection.
    MOXTextMarkerDelegate* delegate =
        [MOXTextMarkerDelegate getOrCreateForDoc:aTarget->Document()];
    [delegate setSelectionFrom:aTarget at:aOffset to:aTarget at:aOffset];
  }

  if (wrapper) {
    if (mozTextAccessible* textAcc =
            static_cast<mozTextAccessible*>([wrapper moxEditableAncestor])) {
      [textAcc
          handleAccessibleEvent:nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED];
    } else {
      [wrapper
          handleAccessibleEvent:nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED];
    }
  }
}

void ProxyTextChangeEvent(ProxyAccessible* aTarget, const nsString& aStr,
                          int32_t aStart, uint32_t aLen, bool aIsInsert,
                          bool aFromUser) {
  ProxyAccessible* acc = aTarget;
  // If there is a text input ancestor, use it as the event source.
  while (acc && GetTypeFromRole(acc->Role()) != [mozTextAccessible class]) {
    acc = acc->Parent();
  }
  mozAccessible* wrapper = GetNativeFromGeckoAccessible(acc ? acc : aTarget);
  [wrapper handleAccessibleTextChangeEvent:nsCocoaUtils::ToNSString(aStr)
                                  inserted:aIsInsert
                               inContainer:aTarget
                                        at:aStart];
}

void ProxyShowHideEvent(ProxyAccessible*, ProxyAccessible*, bool, bool) {}

void ProxySelectionEvent(ProxyAccessible* aTarget, ProxyAccessible* aWidget,
                         uint32_t aEventType) {
  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aWidget);
  if (wrapper) {
    [wrapper handleAccessibleEvent:aEventType];
  }
}

void ProxyTextSelectionChangeEvent(ProxyAccessible* aTarget,
                                   const nsTArray<TextRangeData>& aSelection) {
  if (aSelection.Length()) {
    MOXTextMarkerDelegate* delegate =
        [MOXTextMarkerDelegate getOrCreateForDoc:aTarget->Document()];
    DocAccessibleParent* doc = aTarget->Document();
    ProxyAccessible* startContainer =
        doc->GetAccessible(aSelection[0].StartID());
    ProxyAccessible* endContainer = doc->GetAccessible(aSelection[0].EndID());
    // Cache the selection.
    [delegate setSelectionFrom:startContainer
                            at:aSelection[0].StartOffset()
                            to:endContainer
                            at:aSelection[0].EndOffset()];
  }

  mozAccessible* wrapper = GetNativeFromGeckoAccessible(aTarget);
  if (wrapper) {
    [wrapper
        handleAccessibleEvent:nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED];
  }
}

void ProxyRoleChangedEvent(ProxyAccessible* aTarget, const a11y::role& aRole) {
  if (mozAccessible* wrapper = GetNativeFromGeckoAccessible(aTarget)) {
    [wrapper handleRoleChanged:aRole];
  }
}

}  // namespace a11y
}  // namespace mozilla

@interface GeckoNSApplication (a11y)
- (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute;
@end

@implementation GeckoNSApplication (a11y)

- (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute {
  if ([attribute isEqualToString:@"AXEnhancedUserInterface"]) {
    mozilla::a11y::sA11yShouldBeEnabled = ([value intValue] == 1);
#if defined(MOZ_TELEMETRY_REPORTING)
    if ([[NSWorkspace sharedWorkspace]
            respondsToSelector:@selector(isVoiceOverEnabled)] &&
        [[NSWorkspace sharedWorkspace] isVoiceOverEnabled]) {
      Telemetry::ScalarSet(Telemetry::ScalarID::A11Y_INSTANTIATORS,
                           u"VoiceOver"_ns);
    }
#endif  // defined(MOZ_TELEMETRY_REPORTING)
  }

  return [super accessibilitySetValue:value forAttribute:attribute];
}

@end