calamares/src/libcalamares/utils/Retranslator.h
Adriaan de Groot 559c53b09c [libcalamares]: stronger type for translation name
QString -> Id for translations in the external API, to avoid
accidentally converting a QLocale name (e.g. ca_ES) into a
Calamares translation name. This preserves special-cases
like ca@valencia and sr@latin.
2021-07-28 14:22:28 +02:00

146 lines
5.1 KiB
C++

/* === This file is part of Calamares - <https://calamares.io> ===
*
* SPDX-FileCopyrightText: 2014-2015 Teo Mrnjavac <teo@kde.org>
* SPDX-License-Identifier: GPL-3.0-or-later
*
* Calamares is Free Software: see the License-Identifier above.
*
*
*/
#ifndef UTILS_RETRANSLATOR_H
#define UTILS_RETRANSLATOR_H
#include "DllMacro.h"
#include "locale/Translation.h"
#include <QObject>
#include <QString>
#include <functional>
class QEvent;
class QLocale;
class QTranslator;
namespace CalamaresUtils
{
/** @brief changes the application language.
* @param locale the new locale (names as defined by Calamares).
* @param brandingTranslationsPrefix the branding path prefix, from Calamares::Branding.
*/
DLLEXPORT void installTranslator( const CalamaresUtils::Locale::Translation::Id& locale, const QString& brandingTranslationsPrefix );
/** @brief Initializes the translations with the current system settings
*/
DLLEXPORT void installTranslator();
/** @brief The name of the (locale of the) most recently installed translator
*
* May return something different from the locale.name() of the
* QLocale passed in, because Calamares will munge some names and
* may remap translations.
*/
DLLEXPORT CalamaresUtils::Locale::Translation::Id translatorLocaleName();
/** @brief Loads <prefix><locale> translations into the given @p translator
*
* This function is not intended for general use: it is for those special
* cases where modules need their own translator / translations for data
* that is locale to the module. Tries to load a .qm from "sensible"
* locations, which are the same ones that installTranslator() would use.
* Takes local-translations into account.
*
* Note that @p prefix should end with an underscore '_' -- this function
* does not introduce one by itself.
*
* @returns @c true on success
*/
DLLEXPORT bool loadTranslator( const CalamaresUtils::Locale::Translation::Id& locale, const QString& prefix, QTranslator* translator );
/** @brief Set @p allow to true to load translations from current dir.
*
* If false, (or never called) the translations are loaded only from
* system locations (the AppData dir) and from QRC (compiled in).
* Enable local translations to test translations stored in the
* current directory.
*/
DLLEXPORT void setAllowLocalTranslation( bool allow );
/** @brief Handles change-of-language events
*
* There is one single Retranslator object. Use `instance()` to get it.
* The top-level widget of the application should call
* `installEventFilter( Retranslator::instance() )`
* to set up event-handling for translation events. The Retranslator
* will emit signal `languageChanged()` if there is such an event.
*
* Normal consumers should not have to use the Retranslator directly,
* but use the macros `CALAMARES_RETRANSLATE*` to set things up
* in code -- the macros will connect to the Retranslator's signals.
*/
class Retranslator : public QObject
{
Q_OBJECT
public:
/// @brief Gets the global (single) Retranslator object
static Retranslator* instance();
/// @brief Helper function for attaching lambdas
static void attach( QObject* o, std::function< void( void ) > f);
signals:
void languageChanged();
protected:
bool eventFilter( QObject* obj, QEvent* e ) override;
private:
explicit Retranslator( QObject* parent );
};
} // namespace CalamaresUtils
/** @brief Call code for this object when language changes
*
* @p body should be a code block (it does not need braces) that can be wrapped
* up as a lambda. When the language changes, the lambda is called. Note that
* this macro should be used in constructors or other code that is run only
* once, since otherwise you will end up with multiple calls to @p body.
*
* NOTE: unlike plain QObject::connect(), the body is **also** called
* immediately after setting up the connection. This allows
* setup and translation code to be mixed together.
*/
#define CALAMARES_RETRANSLATE( body ) CalamaresUtils::Retranslator::attach( this, [=] { body } )
/** @brief Call code for the given object (widget) when language changes
*
* This is identical to CALAMARES_RETRANSLATE, except the @p body is called
* for the given object, not this object.
*
* NOTE: unlike plain QObject::connect(), the body is **also** called
* immediately after setting up the connection. This allows
* setup and translation code to be mixed together.
*/
#define CALAMARES_RETRANSLATE_FOR( object, body ) CalamaresUtils::Retranslator::attach( object, [=] { body } )
/** @brief Call a slot in this object when language changes
*
* Given a slot (in method-function-pointer notation), call that slot when the
* language changes. This is shorthand for connecting the Retranslator's
* signal to the given slot.
*
* NOTE: unlike plain QObject::connect(), the slot is **also** called
* immediately after setting up the connection. This allows
* setup and translation code to be mixed together.
*/
#define CALAMARES_RETRANSLATE_SLOT( slotfunc ) \
do \
{ \
connect( CalamaresUtils::Retranslator::instance(), &CalamaresUtils::Retranslator::languageChanged, this, slotfunc ); \
(this->*slotfunc)(); \
} while ( false )
#endif