Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
#include "Platform.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/GRefPtr.h"
#include "mozilla/GUniquePtr.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsIAccessibleEvent.h"
#include "nsIGSettingsService.h"
#include "nsMai.h"
#include "nsServiceManagerUtils.h"
#include "nsWindow.h"
#include "prenv.h"
#include "prlink.h"
#ifdef MOZ_ENABLE_DBUS
# include "mozilla/widget/AsyncDBus.h"
#endif
#include <gtk/gtk.h>
using namespace mozilla;
using namespace mozilla::a11y;
int atkMajorVersion = 1, atkMinorVersion = 12, atkMicroVersion = 0;
GType (*gAtkTableCellGetTypeFunc)();
extern "C" {
typedef GType (*AtkGetTypeType)(void);
typedef void (*AtkBridgeAdaptorInit)(int*, char**[]);
}
static PRLibrary* sATKLib = nullptr;
static const char sATKLibName[] = "libatk-1.0.so.0";
static const char sATKHyperlinkImplGetTypeSymbol[] =
"atk_hyperlink_impl_get_type";
gboolean toplevel_event_watcher(GSignalInvocationHint*, guint, const GValue*,
gpointer);
static bool sToplevel_event_hook_added = false;
static gulong sToplevel_show_hook = 0;
static gulong sToplevel_hide_hook = 0;
GType g_atk_hyperlink_impl_type = G_TYPE_INVALID;
struct AtkBridgeModule {
const char* libName;
PRLibrary* lib;
const char* initName;
AtkBridgeAdaptorInit init;
};
static AtkBridgeModule sAtkBridge = {"libatk-bridge-2.0.so.0", nullptr,
"atk_bridge_adaptor_init", nullptr};
static nsresult LoadGtkModule(AtkBridgeModule& aModule) {
NS_ENSURE_ARG(aModule.libName);
if (!(aModule.lib = PR_LoadLibrary(aModule.libName))) {
return NS_ERROR_FAILURE;
}
// we have loaded the library, try to get the function ptrs
if (!(aModule.init = (AtkBridgeAdaptorInit)PR_FindFunctionSymbol(
aModule.lib, aModule.initName))) {
// fail, :(
PR_UnloadLibrary(aModule.lib);
aModule.lib = nullptr;
return NS_ERROR_FAILURE;
}
return NS_OK;
}
void a11y::PlatformInit() {
if (!ShouldA11yBeEnabled()) return;
sATKLib = PR_LoadLibrary(sATKLibName);
if (!sATKLib) return;
AtkGetTypeType pfn_atk_hyperlink_impl_get_type =
(AtkGetTypeType)PR_FindFunctionSymbol(sATKLib,
sATKHyperlinkImplGetTypeSymbol);
if (pfn_atk_hyperlink_impl_get_type) {
g_atk_hyperlink_impl_type = pfn_atk_hyperlink_impl_get_type();
}
gAtkTableCellGetTypeFunc =
(GType(*)())PR_FindFunctionSymbol(sATKLib, "atk_table_cell_get_type");
const char* (*atkGetVersion)() =
(const char* (*)())PR_FindFunctionSymbol(sATKLib, "atk_get_version");
if (atkGetVersion) {
const char* version = atkGetVersion();
if (version) {
char* endPtr = nullptr;
atkMajorVersion = strtol(version, &endPtr, 10);
if (atkMajorVersion != 0L) {
atkMinorVersion = strtol(endPtr + 1, &endPtr, 10);
if (atkMinorVersion != 0L) {
atkMicroVersion = strtol(endPtr + 1, &endPtr, 10);
}
}
}
}
// Initialize the MAI Utility class, it will overwrite gail_util.
g_type_class_unref(g_type_class_ref(mai_util_get_type()));
// Init atk-bridge now
PR_SetEnv("NO_AT_BRIDGE=0");
nsresult rv = LoadGtkModule(sAtkBridge);
if (NS_SUCCEEDED(rv)) {
(*sAtkBridge.init)(nullptr, nullptr);
}
if (!sToplevel_event_hook_added) {
sToplevel_event_hook_added = true;
sToplevel_show_hook = g_signal_add_emission_hook(
g_signal_lookup("show", GTK_TYPE_WINDOW), 0, toplevel_event_watcher,
reinterpret_cast<gpointer>(nsIAccessibleEvent::EVENT_SHOW), nullptr);
sToplevel_hide_hook = g_signal_add_emission_hook(
g_signal_lookup("hide", GTK_TYPE_WINDOW), 0, toplevel_event_watcher,
reinterpret_cast<gpointer>(nsIAccessibleEvent::EVENT_HIDE), nullptr);
}
}
void a11y::PlatformShutdown() {
if (sToplevel_event_hook_added) {
sToplevel_event_hook_added = false;
g_signal_remove_emission_hook(g_signal_lookup("show", GTK_TYPE_WINDOW),
sToplevel_show_hook);
g_signal_remove_emission_hook(g_signal_lookup("hide", GTK_TYPE_WINDOW),
sToplevel_hide_hook);
}
if (sAtkBridge.lib) {
// Do not shutdown/unload atk-bridge,
// an exit function registered will take care of it
// PR_UnloadLibrary(sAtkBridge.lib);
sAtkBridge.lib = nullptr;
sAtkBridge.init = nullptr;
}
// if (sATKLib) {
// PR_UnloadLibrary(sATKLib);
// sATKLib = nullptr;
// }
}
static const char sAccEnv[] = "GNOME_ACCESSIBILITY";
#ifdef MOZ_ENABLE_DBUS
StaticRefPtr<GDBusProxy> sA11yBusProxy;
StaticRefPtr<GCancellable> sCancellable;
#endif
static void StartAccessibility() {
if (nsWindow* window = nsWindow::GetFocusedWindow()) {
window->DispatchActivateEventAccessible();
}
}
static void A11yBusProxyPropertyChanged(GDBusProxy* aProxy,
GVariant* aChangedProperties,
char** aInvalidatedProperties,
gpointer aUserData) {
gboolean isEnabled;
g_variant_lookup(aChangedProperties, "IsEnabled", "b", &isEnabled);
if (isEnabled) {
StartAccessibility();
}
}
// Called from `nsWindow::Create()` before the window is shown.
void a11y::PreInit() {
#ifdef MOZ_ENABLE_DBUS
static bool sInited = false;
if (sInited) {
return;
}
sInited = true;
sCancellable = dont_AddRef(g_cancellable_new());
widget::CreateDBusProxyForBus(G_BUS_TYPE_SESSION, G_DBUS_PROXY_FLAGS_NONE,
/* aInterfaceInfo = */ nullptr, "org.a11y.Bus",
"/org/a11y/bus", "org.a11y.Status",
sCancellable)
->Then(
GetCurrentSerialEventTarget(), __func__,
[](RefPtr<GDBusProxy>&& aProxy) {
sA11yBusProxy = std::move(aProxy);
sCancellable = nullptr;
g_signal_connect(sA11yBusProxy, "g-properties-changed",
G_CALLBACK(A11yBusProxyPropertyChanged), nullptr);
RefPtr<GVariant> isEnabled = dont_AddRef(
g_dbus_proxy_get_cached_property(sA11yBusProxy, "IsEnabled"));
if (isEnabled && g_variant_get_boolean(isEnabled)) {
// If a window is already focused, `StartAccessibility()` will
// initialize a11y by sending an activate event. If the window has
// not yet been shown/focused, nothing will happen. We now have
// the `IsEnabled` property cached so when `ShouldA11yBeEnabled()`
// is called from `nsWindow::Show()`, a root accessible will be
// created and events will be dispatched henceforth.
StartAccessibility();
}
},
[](GUniquePtr<GError>&& aError) {
sCancellable = nullptr;
if (!g_error_matches(aError.get(), G_IO_ERROR,
G_IO_ERROR_CANCELLED)) {
g_warning(
"Failed to create DBus proxy for org.a11y.Bus: "
"%s\n",
aError->message);
}
});
RunOnShutdown([] {
if (sCancellable) {
g_cancellable_cancel(sCancellable);
sCancellable = nullptr;
}
if (sA11yBusProxy) {
sA11yBusProxy = nullptr;
}
});
#endif
}
bool a11y::ShouldA11yBeEnabled() {
EPlatformDisabledState disabledState = PlatformDisabledState();
if (disabledState == ePlatformIsDisabled) {
return false;
}
if (disabledState == ePlatformIsForceEnabled) {
return true;
}
// check if accessibility enabled/disabled by environment variable
if (const char* envValue = PR_GetEnv(sAccEnv)) {
return !!atoi(envValue);
}
#ifdef MOZ_ENABLE_DBUS
if (sA11yBusProxy) {
RefPtr<GVariant> isEnabled = dont_AddRef(
g_dbus_proxy_get_cached_property(sA11yBusProxy, "IsEnabled"));
// result can be null if proxy isn't actually working.
if (isEnabled) {
return g_variant_get_boolean(isEnabled);
}
}
#endif
// check GSettings
nsCOMPtr<nsIGSettingsService> gsettings =
do_GetService(NS_GSETTINGSSERVICE_CONTRACTID);
if (gsettings) {
bool shouldEnable = false;
nsCOMPtr<nsIGSettingsCollection> a11y_settings;
gsettings->GetCollectionForSchema(
nsLiteralCString("org.gnome.desktop.interface"),
getter_AddRefs(a11y_settings));
if (a11y_settings) {
a11y_settings->GetBoolean(nsLiteralCString("toolkit-accessibility"),
&shouldEnable);
}
return shouldEnable;
}
return false;
}
uint64_t a11y::GetCacheDomainsForKnownClients(uint64_t aCacheDomains) {
return aCacheDomains;
}