enchant: allow toggling individual dictionaries

Allow disabling and enabling individual dictionaries with the
Enchant/Hunspell backend.

This is mostly relevant in shared systems (where different users want to
enable different sets of languages) or on distributions which install an
exorbitant amount of dictionaries by default.

Depends-On: desktop-app/lib_spellcheck#32

Author: WhyNotHugo

Telegram/SourceFiles/boxes/dictionaries_manager.cpp

@@ -19,6 +19,7 @@ For license and copyright information please follow this link:
 #include "mainwidget.h"
 #include "mtproto/dedicated_file_loader.h"
 #include "spellcheck/spellcheck_utils.h"
+#include "spellcheck/platform/platform_spellcheck.h"
 #include "ui/wrap/vertical_layout.h"
 #include "ui/widgets/buttons.h"
 #include "ui/widgets/labels.h"
@@ -42,6 +43,32 @@ using DictState = BlobState;
 using QueryCallback = Fn<void(const QString &)>;
 constexpr auto kMaxQueryLength = 15;
 
+// Get system dictionaries for enchant backend.
+std::vector<Spellchecker::Dict> SystemDictionaries() {
+	const auto available = Platform::Spellchecker::AvailableLanguages();
+	std::vector<Spellchecker::Dict> result;
+	std::set<int> seenIds;
+	result.reserve(available.size());
+
+	for (const auto &locale : available) {
+		const auto langId = Spellchecker::LangIdFromLocale(locale);
+
+		// Deduplicate langIds. E.g.: en_GB and en_GB-large.
+		if (!seenIds.insert(langId).second) {
+			continue;
+		}
+
+		const auto qlocale = QLocale(locale);
+		auto name = QLocale::languageToString(qlocale.language());
+		if (qlocale.country() != QLocale::AnyCountry) {
+			name += " (" + QLocale::countryToString(qlocale.country()) + ")";
+		}
+		result.push_back(Spellchecker::Dict{ langId, 0, 0, name });
+	}
+
+	return result;
+}
+
 class Inner : public Ui::RpWidget {
 public:
 	Inner(
@@ -63,6 +90,16 @@ class Inner : public Ui::RpWidget {
 };
 
 inline auto DictExists(int langId) {
+	if (Platform::Spellchecker::IsSystemSpellchecker()) {
+		// Check if the locale exists in available languages.
+		const auto available = Platform::Spellchecker::AvailableLanguages();
+		for (const auto &availableLocale : available) {
+			if (Spellchecker::LangIdFromLocale(availableLocale) == langId) {
+				return true;
+			}
+		}
+		return false;
+	}
 	return Spellchecker::DictionaryExists(langId);
 }
 
@@ -77,6 +114,10 @@ DictState ComputeState(int id, bool enabled) {
 	if (DictExists(id)) {
 		return result;
 	}
+	// For system spellchecker, dictionaries that don't exist are not available.
+	if (Platform::Spellchecker::IsSystemSpellchecker()) {
+		return Ready();
+	}
 	return Available{ Spellchecker::GetDownloadSize(id) };
 }
 
@@ -113,6 +154,86 @@ Dictionaries Inner::enabledRows() const {
 	return _enabledRows;
 }
 
+// Simplified button for system dictionaries (no download/remove).
+auto AddSystemDictButton(
+		not_null<Ui::VerticalLayout*> content,
+		const Spellchecker::Dict &dict,
+		bool buttonEnabled,
+		rpl::producer<QStringView> query) {
+	const auto id = dict.id;
+	buttonEnabled &= DictExists(id);
+
+	const auto locale = Spellchecker::LocaleFromLangId(id);
+	const std::vector<QString> indexList = {
+		dict.name,
+		QLocale::languageToString(locale.language()),
+		QLocale::countryToString(locale.country())
+	};
+
+	const auto wrap = content->add(
+		object_ptr<Ui::SlideWrap<Ui::SettingsButton>>(
+			content,
+			object_ptr<Ui::SettingsButton>(
+				content,
+				rpl::single(dict.name),
+				st::dictionariesSectionButton
+			)
+		)
+	);
+	const auto button = wrap->entity();
+
+	std::move(
+		query
+	) | rpl::start_with_next([=](auto string) {
+		wrap->toggle(
+			ranges::any_of(indexList, [&](const QString &s) {
+				return s.startsWith(string, Qt::CaseInsensitive);
+			}),
+			anim::type::instant);
+	}, button->lifetime());
+
+	const auto label = Ui::CreateChild<Ui::FlatLabel>(
+		button,
+		(buttonEnabled
+			? tr::lng_settings_manage_enabled_dictionary(tr::now)
+			: QString()),
+		st::settingsUpdateState);
+	label->setAttribute(Qt::WA_TransparentForMouseEvents);
+
+	rpl::combine(
+		button->widthValue(),
+		label->widthValue()
+	) | rpl::start_with_next([=] {
+		label->moveToLeft(
+			st::settingsUpdateStatePosition.x(),
+			st::settingsUpdateStatePosition.y());
+	}, label->lifetime());
+
+	button->toggleOn(rpl::single(buttonEnabled));
+
+	button->toggledValue(
+	) | rpl::start_with_next([=](bool toggled) {
+		const auto over = !button->isDisabled()
+			&& (button->isDown() || button->isOver());
+		const auto toggledFloat = toggled ? 1. : 0.;
+
+		if (toggledFloat == 0. && !over) {
+			label->setTextColorOverride(std::nullopt);
+		} else {
+			label->setTextColorOverride(anim::color(
+				over ? st::contactsStatusFgOver : st::contactsStatusFg,
+				st::contactsStatusFgOnline,
+				toggledFloat));
+		}
+
+		label->setText(toggled
+			? tr::lng_settings_manage_enabled_dictionary(tr::now)
+			: QString());
+	}, label->lifetime());
+
+	return button;
+}
+
 auto AddButtonWithLoader(
 		not_null<Ui::VerticalLayout*> content,
 		not_null<Main::Session*> session,
@@ -344,14 +465,25 @@ void Inner::setupContent(
 	const auto queryStream = content->lifetime()
 		.make_state<rpl::event_stream<QStringView>>();
 
-	for (const auto &dict : Spellchecker::Dictionaries()) {
+	const auto isSystemSpellchecker = Platform::Spellchecker::IsSystemSpellchecker();
+	const auto dictionaries = isSystemSpellchecker
+		? SystemDictionaries()
+		: Spellchecker::Dictionaries();
+
+	for (const auto &dict : dictionaries) {
 		const auto id = dict.id;
-		const auto row = AddButtonWithLoader(
-			content,
-			session,
-			dict,
-			ranges::contains(enabledDictionaries, id),
-			queryStream->events());
+		const auto row = isSystemSpellchecker
+			? AddSystemDictButton(
+				content,
+				dict,
+				ranges::contains(enabledDictionaries, id),
+				queryStream->events())
+			: AddButtonWithLoader(
+				content,
+				session,
+				dict,
+				ranges::contains(enabledDictionaries, id),
+				queryStream->events());
 		row->toggledValue(
 		) | rpl::start_with_next([=](auto enabled) {
 			if (enabled) {

Telegram/SourceFiles/chat_helpers/spellchecker_common.cpp

@@ -391,6 +391,14 @@ void Start(not_null<Main::Session*> session) {
 		| rpl::take(1)
 		| rpl::start_with_next(AddExceptions, lifetime);
 
+		settings->dictionariesEnabledChanges(
+		) | rpl::start_with_next([](auto dictionaries) {
+			Platform::Spellchecker::UpdateLanguages(dictionaries);
+		}, lifetime);
+
+		settings->spellcheckerEnabledChanges(
+		) | rpl::start_with_next(onEnabled, lifetime);
+
 		return;
 	}
 

Telegram/SourceFiles/settings/settings_advanced.cpp

@@ -306,33 +306,37 @@ void SetupSpellchecker(
 		Core::App().saveSettingsDelayed();
 	}, container->lifetime());
 
-	if (isSystem) {
-		return;
-	}
-
 	const auto sliding = container->add(
 		object_ptr<Ui::SlideWrap<Ui::VerticalLayout>>(
 			container,
 			object_ptr<Ui::VerticalLayout>(container)));
 
-	sliding->entity()->add(object_ptr<Button>(
-		sliding->entity(),
-		tr::lng_settings_auto_download_dictionaries(),
-		st::settingsButtonNoIcon
-	))->toggleOn(
-		rpl::single(settings->autoDownloadDictionaries())
-	)->toggledValue(
-	) | rpl::filter([=](bool enabled) {
-		return (enabled != settings->autoDownloadDictionaries());
-	}) | rpl::start_with_next([=](bool enabled) {
-		settings->setAutoDownloadDictionaries(enabled);
-		Core::App().saveSettingsDelayed();
-	}, sliding->entity()->lifetime());
+	if (!isSystem) {
+		sliding->entity()->add(object_ptr<Button>(
+			sliding->entity(),
+			tr::lng_settings_auto_download_dictionaries(),
+			st::settingsButtonNoIcon
+		))->toggleOn(
+			rpl::single(settings->autoDownloadDictionaries())
+		)->toggledValue(
+		) | rpl::filter([=](bool enabled) {
+			return (enabled != settings->autoDownloadDictionaries());
+		}) | rpl::start_with_next([=](bool enabled) {
+			settings->setAutoDownloadDictionaries(enabled);
+			Core::App().saveSettingsDelayed();
+		}, sliding->entity()->lifetime());
+	}
+
+	if (isSystem && !Platform::Spellchecker::SupportsToggleDictionaries()) {
+		return;
+	}
 
 	AddButtonWithLabel(
 		sliding->entity(),
 		tr::lng_settings_manage_dictionaries(),
-		Spellchecker::ButtonManageDictsState(session),
+		isSystem
+			? rpl::single(QString())
+			: Spellchecker::ButtonManageDictsState(session),
 		st::settingsButtonNoIcon
 	)->addClickHandler([=] {
 		controller->show(