/*
    This file is part of the KDE libraries
    SPDX-FileCopyrightText: 2000 Reginald Stadlbauer <reggie@kde.org>
    SPDX-FileCopyrightText: 1997 Stephan Kulow <coolo@kde.org>
    SPDX-FileCopyrightText: 1997-2000 Sven Radej <radej@kde.org>
    SPDX-FileCopyrightText: 1997-2000 Matthias Ettrich <ettrich@kde.org>
    SPDX-FileCopyrightText: 1999 Chris Schlaeger <cs@kde.org>
    SPDX-FileCopyrightText: 2002 Joseph Wenninger <jowenn@kde.org>
    SPDX-FileCopyrightText: 2005-2006 Hamish Rodda <rodda@kde.org>
    SPDX-FileCopyrightText: 2000-2008 David Faure <faure@kde.org>

    SPDX-License-Identifier: LGPL-2.0-only
*/

#ifndef KMAINWINDOW_H
#define KMAINWINDOW_H

#include <kxmlgui_export.h>

#include <QMainWindow>
#include <memory>

class QMenu;
class KConfig;
class KConfigGroup;
class KMWSessionManager;
class KMainWindowPrivate;
class KToolBar;

/**
 * @class KMainWindow kmainwindow.h KMainWindow
 *
 * @brief KMainWindow represents a top-level main window.
 *
 * It extends QMainWindow with session management capabilities. For ready-made window functionality and simpler UI management, use KXmlGuiWindow instead.
 *
 * Define the minimum/maximum height/width of your central widget and KMainWindow will take this into account.
 * For fixed size windows set your main widget to a fixed size. Fixed aspect ratios (QWidget::heightForWidth()) and fixed width widgets are not supported.
 *
 * Use toolBar() to generate a main toolbar "mainToolBar" or refer to a specific toolbar.
 * For a simpler way to manage your toolbars, use KXmlGuiWindow::setupGUI() instead.
 *
 * Use setAutoSaveSettings() to automatically save and restore the window geometry and toolbar/menubar/statusbar state when the application is restarted.
 *
 * Use kRestoreMainWindows() in your main function to restore your windows when the session is restored.
 *
 * The window state is saved when the application is exited.
 * Reimplement queryClose() to warn the user of unsaved data upon close or exit.
 *
 * Reimplement saveProperties() / readProperties() or saveGlobalProperties() / readGlobalProperties()
 * to save/restore application-specific state during session management.
 *
 * Note that session saving is automatically called, session restoring is not,
 * and so it needs to be implemented in your main() function.
 *
 * See https://develop.kde.org/docs/use/session-managment for more information on session management.
 */

class KXMLGUI_EXPORT KMainWindow : public QMainWindow
{
    friend class KMWSessionManager;
    friend class DockResizeListener;
    Q_OBJECT
    Q_PROPERTY(bool hasMenuBar READ hasMenuBar)
    Q_PROPERTY(bool autoSaveSettings READ autoSaveSettings)
    Q_PROPERTY(QString autoSaveGroup READ autoSaveGroup)

public:
    /**
     * @brief Constructs a main window.
     *
     * @param parent The parent widget. This is usually @c nullptr, but it may also be
     * the window group leader. In that case,
     * the KMainWindow becomes a secondary window.
     *
     * @param flags Specify the window flags. The default is none.
     *
     * Note that by default a KMainWindow is created with the
     * Qt::WA_DeleteOnClose attribute set, i.e. it is automatically destroyed
     * when the window is closed. If you do not want this behavior, call
     * \code
     * window->setAttribute(Qt::WA_DeleteOnClose, false);
     * \endcode
     *
     * KMainWindows must be created on the heap with 'new', like:
     * \code
     * KMainWindow *kmw = new KMainWindow(...);
     * kmw->setObjectName(...);
     * \endcode
     *
     * Since KDE Frameworks 5.16, KMainWindow will enter information regarding
     * the application's translators by default, using KAboutData::setTranslator(). This only occurs
     * if no translators are already assigned in KAboutData (see KAboutData::setTranslator() for
     * details -- the auto-assignment here uses the same translated strings as specified for that
     * function).
     *
     * IMPORTANT: For session management and window management to work
     * properly, all main windows in the application should have a
     * different name. Otherwise, KMainWindow will create
     * a unique name, but it's recommended to explicitly pass a window name that will
     * also describe the type of the window. If there can be several windows of the same
     * type, append '#' (hash) to the name, and KMainWindow will replace it with numbers to make
     * the names unique. For example, for a mail client which has one main window showing
     * the mails and folders, and which can also have one or more windows for composing
     * mails, the name for the folders window should be e.g. "mainwindow" and
     * for the composer windows "composer#".
     *
     * @see KAboutData
     */
    explicit KMainWindow(QWidget *parent = nullptr, Qt::WindowFlags flags = Qt::WindowFlags());

    /**
     * @brief Destructor.
     *
     * Will also destroy the toolbars and menubar if
     * needed.
     */
    ~KMainWindow() override;

    /**
     * @param numberOfInstances The number of KMainWindow instances in the application.
     * @returns @c true if the number of KMainWindow instances of the previous session did contain the requested @p numberOfInstances, @c false otherwise.
     * @see restore()
     **/
    static bool canBeRestored(int numberOfInstances);

    /**
     * @brief Useful if your application uses
     * different kinds of top-level windows.
     *
     * @returns The class name of the top-level window to be restored
     * that corresponds to @p instanceNumber.
     *
     * @param instanceNumber
     * @see restore()
     */
    static const QString classNameOfToplevel(int instanceNumber);

    /**
     * @brief Attempt to restore the top-level widget as defined by @p numberOfInstances (1..X).
     *
     * You should call canBeRestored() first.
     *
     * If the session did not contain so high a number, the configuration
     * is not changed and @c false is returned.
     *
     * That means clients could simply do the following:
     * \code
     * if (qApp->isSessionRestored()){
     *   int n = 1;
     *   while (KMainWindow::canBeRestored(n)){
     *     (new childMW)->restore(n);
     *     n++;
     *   }
     * } else {
     *   // create default application as usual
     * }
     * \endcode
     * Note that if @p show is @c true (default), QWidget::show() is called
     * implicitly in restore.
     *
     * With this you can easily restore all top-level windows of your
     * application.
     *
     * If your application uses different kinds of top-level
     * windows, then you can use KMainWindow::classNameOfToplevel(n)
     * to determine the exact type before calling the childMW
     * constructor in the example from above.
     *
     * @note You don't need to deal with this function. Use the
     * kRestoreMainWindows() convenience template function instead!
     *
     * @param numberOfInstances The number of KMainWindow instances from the last session.
     * @param show Whether the KMainWindow instances will be visible by default.
     *
     * @returns @c true if the session contained
     * the same number of instances as the requested number,
     * @c false if the session contained less instances than the requested number,
     * in which case no configuration is changed.
     *
     * @see kRestoreMainWindows()
     * @see readProperties()
     * @see canBeRestored()
     */
    bool restore(int numberOfInstances, bool show = true);

    /**
     * @returns @c true if there is a menubar, @c false otherwise.
     */
    bool hasMenuBar();

    /**
     * @returns The list of members of the KMainWindow class.
     */
    static QList<KMainWindow *> memberList();

    /**
     * @brief This is useful to both call specific toolbars that have been created
     * or to generate a default one upon call.
     *
     * This refers to toolbars created dynamically from the XML UI
     * framework via KConfig or appnameui.rc.
     *
     * If the toolbar does not exist, one will be created.
     *
     * @param name The internal name of the toolbar. If no name is
     *             specified, "mainToolBar" is assumed.
     *
     * @return A pointer to the toolbar with the specified name.
     * @see toolBars()
     **/
    KToolBar *toolBar(const QString &name = QString());

    /**
     * @return A list of all toolbars for this window
     */
    QList<KToolBar *> toolBars() const;

    /**
     * @brief This enables autosave of toolbar/menubar/statusbar settings
     * (and optionally window size).
     * @param groupName A name that identifies the type of window.
     * You can have several types of window in the same application.
     * If no @p groupName is specified, the value defaults to "MainWindow".
     *
     * @param saveWindowSize Whether to include the window size
     * when saving. @c true by default.
     *
     * If the *bars were modified when the window is closed,
     * saveMainWindowSettings( KConfigGroup(KSharedConfig::openConfig(), groupName) ) will be called.
     *
     * Typically, you will call setAutoSaveSettings() in your
     * KMainWindow-inherited class constructor, and it will take care
     * of restoring and saving automatically.
     *
     * By default, this generates an
     * appnamerc ini file as if using default KConfig constructor or KConfig::SimpleConfig.
     *
     * Make sure you call this @em after all your *bars have been created.
     *
     * To make sure that KMainWindow properly obtains the default
     * size of the window you should do the following:
     * - Remove hardcoded resize() calls in the constructor or main
     *   to let the automatic resizing determine the default window size.
     *   Hardcoded window sizes will be wrong for users that have big fonts,
     *   use different styles, long/small translations, large toolbars, and other factors.
     * - Put the setAutoSaveSettings() call after all widgets
     *   have been created and placed inside the main window
     *   (for most apps this means QMainWindow::setCentralWidget())
     * - QWidget-based objects should overload "virtual QSize sizeHint() const;"
     *   to specify a default size.
     * @see KConfig
     * @see KSharedConfig
     * @see saveMainWindowSettings()
     * @see toolBar()
     * @see KXmlGuiWindow::setupGUI()
     */
    void setAutoSaveSettings(const QString &groupName = QStringLiteral("MainWindow"), bool saveWindowSize = true);

    /**
     * This is an overloaded function.
     * This allows the settings to be saved into a different file
     * that does not correspond to that used for KSharedConfig::openConfig().
     * @see setAutoSaveSettings(const QString &groupName, bool saveWindowSize)
     * @see KConfig
     * @see KSharedConfig
     * @since 4.1
     */
    void setAutoSaveSettings(const KConfigGroup &group, bool saveWindowSize = true);

    /**
     * @brief Disables the autosave settings feature.
     * You don't normally need to call this, ever.
     * @see setAutoSaveSettings()
     * @see autoSaveSettings()
     */
    void resetAutoSaveSettings();

    /**
     * @return @c true if setAutoSaveSettings() was called,
     * @c false by default or if resetAutoSaveSettings() was called.
     * @see setAutoSaveSettings()
     * @see resetAutoSaveSettings()
     */
    bool autoSaveSettings() const;

    /**
     * @return The group used for autosaving settings.
     *
     * Do not mistake this with autoSaveConfigGroup.
     *
     * Only meaningful if setAutoSaveSettings(const QString&, bool) was called.
     *
     * Do not use this method if setAutoSaveSettings(const KConfigGroup&, bool) was called.
     *
     * This can be useful for forcing a save or an apply, e.g. before and after
     * using KEditToolBar.
     *
     * @note Prefer saveAutoSaveSettings() for saving or autoSaveConfigGroup() for loading.
     *
     * @see autoSaveSettings()
     * @see setAutoSaveSettings()
     * @see saveAutoSaveSettings()
     * @see resetAutoSaveSettings()
     * @see autoSaveConfigGroup()
     */
    QString autoSaveGroup() const;

    /**
     * @return The group used for autosaving settings.
     *
     * Only meaningful if setAutoSaveSettings(const QString&, bool) was called.
     *
     * Do not use this method if setAutoSaveSettings(const KConfigGroup&, bool) was called.
     *
     * This can be useful for forcing an apply, e.g. after using KEditToolBar.
     *
     * @see setAutoSaveSettings()
     * @see autoSaveGroup()
     * @since 4.1
     */
    KConfigGroup autoSaveConfigGroup() const;

    /**
     * @brief Assigns the config group name for the KConfigGroup returned by stateConfigGroup.
     * @param configGroup The config group to be assigned.
     * Window size and state are stored in the resulting KConfigGroup when this function is called.
     * @note If this is used in combination with setAutoSaveSettings, you should call this method first.
     *
     * @see KConfigGroup()
     * @see KSharedConfig::openStateConfig()
     * @see stateConfigGroup()
     *
     * @since 5.88
     */
    void setStateConfigGroup(const QString &configGroup);

    /**
     * @returns The KConfigGroup used to store state data like window sizes or window state.
     *
     * The resulting group is invalid if setStateConfig is not called explicitly.
     *
     * @see KConfigGroup
     * @since 5.88
     */
    KConfigGroup stateConfigGroup() const;

    /**
     * @brief Read settings for statusbar, menubar and toolbar from their respective
     * groups in the config file and apply them.
     *
     * @param config Config group to read the settings from.
     */
    virtual void applyMainWindowSettings(const KConfigGroup &config);

    /**
     * @brief Manually save the settings for statusbar, menubar and toolbar to their respective
     * groups in the KConfigGroup @p config.
     *
     * Example:
     * \code
     * KConfigGroup group(KSharedConfig::openConfig(), "MainWindow");
     * saveMainWindowSettings(group);
     * \endcode
     *
     * @param config Config group to save the settings to.
     * @see setAutoSaveSettings()
     * @see KConfig
     * @see KSharedConfig
     * @see KConfigGroup
     */
    void saveMainWindowSettings(KConfigGroup &config);

    /**
     * @returns The path for the exported window's D-Bus object.
     * @since 4.0.1
     */
    QString dbusName() const;

public Q_SLOTS:
    /**
     * @brief Assigns a KDE compliant caption (window title).
     *
     * @param caption The string that will be
     * displayed in the window title, before the application name.
     *
     * @note This function does the same as setPlainCaption().
     *
     * @note Do not include the application name
     * in this string. It will be added automatically according to the KDE
     * standard.
     *
     * @see setPlainCaption()
     */
    virtual void setCaption(const QString &caption);
    /**
     * @brief Makes a KDE compliant caption.
     * @param caption Your caption.
     * @param modified Whether the document is modified. This displays
     * an additional sign in the title bar, usually "**".
     *
     * This is an overloaded function.
     *
     * @note Do not include the application name
     * in this string. It will be added automatically according to the KDE
     * standard.
     */
    virtual void setCaption(const QString &caption, bool modified);

    /**
     * @brief Make a plain caption without any modifications.
     *
     * @param caption The string that will be
     * displayed in the window title, before the application name.
     *
     * @note This function does the same as setCaption().
     *
     * @note Do not include the application name
     * in this string. It will be added automatically according to the KDE
     * standard.
     *
     * @see setCaption()
     */
    virtual void setPlainCaption(const QString &caption);

    /**
     * @brief Opens the help page for the application.
     *
     * The application name is
     * used as a key to determine what to display and the system will attempt
     * to open \<appName\>/index.html.
     *
     * This method is intended for use by a help button in the toolbar or
     * components outside the regular help menu.
     *
     * Use helpMenu() when you
     * want to provide access to the help system from the help menu.
     *
     * Example (adding a help button to the first toolbar):
     *
     * \code
     * toolBar()->addAction(QIcon::fromTheme("help-contents"), i18n("Help"),
     *                       this, &KMainWindow::appHelpActivated);
     * \endcode
     *
     * @see helpMenu()
     * @see toolBar()
     */
    void appHelpActivated();

    /**
     * @brief Tell the main window that it should save its settings when being closed.
     *
     * This is part of the autosave settings feature.
     *
     * For everything related to toolbars this happens automatically,
     * but you have to call setSettingsDirty() in the slot that toggles
     * the visibility of the statusbar.
     *
     * @see saveAutoSaveSettings()
     */
    void setSettingsDirty();

protected:
    /**
     * Reimplemented to catch QEvent::Polish in order to adjust the object name
     * if needed, once all constructor code for the main window has run.
     * Also reimplemented to catch when a QDockWidget is added or removed.
     */
    bool event(QEvent *event) override;

    /**
     * Reimplemented to open context menus on Shift+F10.
     */
    void keyPressEvent(QKeyEvent *keyEvent) override;

    /**
     * Reimplemented to autosave settings and call queryClose().
     *
     * We recommend that you reimplement queryClose() rather than closeEvent().
     * If you do it anyway, ensure to call the base implementation to keep
     * the feature of autosaving window settings working.
     */
    void closeEvent(QCloseEvent *) override;

    /**
     * @brief This function is called before the window is closed,
     * either by the user or indirectly by the session manager.
     *
     * This can be used to prompt the user to save unsaved data before the window is closed.
     *
     * Example:
     * \code
     * switch ( KMessageBox::warningTwoActionsCancel( this,
     *          i18n("Save changes to document foo?"), QString(),
     *          KStandardGuiItem::save(), KStandardGuiItem::discard())) ) {
     *   case KMessageBox::PrimaryAction :
     *     // save document here. If saving fails, return false;
     *     return true;
     *   case KMessageBox::SecondaryAction :
     *     return true;
     *   default: // cancel
     *     return false;
     * \endcode
     *
     * @note Do @em not close the document from within this method,
     * as it may be called by the session manager before the
     * session is saved. If the document is closed before the session save occurs,
     * its location might not be properly saved. In addition, the session shutdown
     * may be canceled, in which case the document should remain open.
     *
     * @return @c true by default, @c false according to the reimplementation.
     * Returning @c false will cancel the closing operation,
     * and if KApplication::sessionSaving() is true, it cancels logout.
     *
     * @see KApplication::sessionSaving()
     */
    virtual bool queryClose();

    /**
     * @brief Saves your instance-specific properties.
     *
     * The function is
     * invoked when the session manager requests your application
     * to save its state.
     *
     * Reimplement this function in child classes.
     *
     * \code
     * void MainWindow::saveProperties(KConfigGroup &config) {
     *   config.writeEntry("myKey", "newValue");
     *   ...
     * }
     * \endcode
     *
     * @note No user interaction is allowed
     * in this function!
     *
     */
    virtual void saveProperties(KConfigGroup &)
    {
    }

    /**
     * @brief Reads your instance-specific properties.
     *
     * This function is called indirectly by restore().
     *
     * \code
     * void MainWindow::readProperties(KConfigGroup &config) {
     *   if (config.hasKey("myKey")) {
     *     config.readEntry("myKey", "DefaultValue");
     *   }
     *   ...
     * }
     * \endcode
     *
     * @see readGlobalProperties()
     */
    virtual void readProperties(const KConfigGroup &)
    {
    }

    /**
     * @brief Saves your application-wide properties.
     *
     * @param sessionConfig A pointer to the KConfig instance
     * used to save the session data.
     *
     * This function is invoked when the session manager
     * requests your application to save its state.
     * It is similar to saveProperties(), but it is only called for
     * the first main window. This is useful to save global state of your application
     * that isn't bound to a particular window.
     *
     * The default implementation does nothing.
     *
     * @see readGlobalProperties()
     * @see saveProperties()
     */
    virtual void saveGlobalProperties(KConfig *sessionConfig);

    /**
     * @brief Reads your application-wide properties.
     *
     * @param sessionConfig A pointer to the KConfig instance
     * used to load the session data.
     *
     * @see saveGlobalProperties()
     * @see readProperties()
     *
     */
    virtual void readGlobalProperties(KConfig *sessionConfig);
    void savePropertiesInternal(KConfig *, int);
    bool readPropertiesInternal(KConfig *, int);

    /**
     * For inherited classes
     */
    bool settingsDirty() const;

protected Q_SLOTS:
    /**
     * This slot should only be called in case you reimplement closeEvent() and
     * if you are using the autosave feature. In all other cases,
     * setSettingsDirty() should be called instead to benefit from the delayed
     * saving.
     *
     * Example:
     * \code
     *
     * void MyMainWindow::closeEvent( QCloseEvent *e )
     * {
     *   // Save settings if autosave is enabled, and settings have changed
     *   if ( settingsDirty() && autoSaveSettings() )
     *     saveAutoSaveSettings();
     *   ..
     * }
     * \endcode
     *
     * @see setAutoSaveSettings()
     * @see setSettingsDirty()
     */
    void saveAutoSaveSettings();

protected:
    KXMLGUI_NO_EXPORT KMainWindow(KMainWindowPrivate &dd, QWidget *parent, Qt::WindowFlags f);

    std::unique_ptr<KMainWindowPrivate> const d_ptr;

private:
    Q_DECLARE_PRIVATE(KMainWindow)

    Q_PRIVATE_SLOT(d_func(), void _k_slotSettingsChanged(int))
    Q_PRIVATE_SLOT(d_func(), void _k_slotSaveAutoSaveSize())
    Q_PRIVATE_SLOT(d_func(), void _k_slotSaveAutoSavePosition())
};

/**
 * @defgroup KXMLGUI_Session KXMLGUI Session Macros and Functions
 *
 * @{
 */

/**
 * @def KDE_RESTORE_MAIN_WINDOWS_NUM_TEMPLATE_ARGS
 * Returns the maximal number of arguments that are actually
 * supported by kRestoreMainWindows().
 **/
#define KDE_RESTORE_MAIN_WINDOWS_NUM_TEMPLATE_ARGS 3

/**
 * @brief Restores the last session. (To be used in your main function).
 *
 * These functions work also if you have more than one kind of top-level
 * widget (each derived from KMainWindow, of course).
 *
 * Imagine you have three kinds of top-level widgets: the classes @c childMW1,
 * @c childMW2 and @c childMW3. Then you can just do:
 *
 * \code
 * int main(int argc, char *argv[])
 * {
 *     // [...]
 *     if (qApp->isSessionRestored())
 *         kRestoreMainWindows<childMW1, childMW2, childMW3>();
 *     else {
 *       // create default application as usual
 *     }
 *     // [...]
 * }
 * \endcode
 *
 * kRestoreMainWindows<>() will create (on the heap) as many instances
 * of your main windows as have existed in the last session and
 * call KMainWindow::restore() with the correct arguments. Note that
 * also QWidget::show() is called implicitly.
 *
 * Currently, these functions are provided for up to three
 * template arguments. If you need more, tell us. To help you in
 * deciding whether or not you can use kRestoreMainWindows, a
 * define #KDE_RESTORE_MAIN_WINDOWS_NUM_TEMPLATE_ARGS is provided.
 *
 * @note Prefer this function over directly calling KMainWindow::restore().
 *
 * @tparam T Top-level widget class
 *
 * @see KMainWindow::restore()
 * @see KMainWindow::classNameOfToplevel()
 **/
template<typename T>
inline void kRestoreMainWindows()
{
    for (int n = 1; KMainWindow::canBeRestored(n); ++n) {
        const QString className = KMainWindow::classNameOfToplevel(n);
        if (className == QLatin1String(T::staticMetaObject.className())) {
            (new T)->restore(n);
        }
    }
}

/**
 * @brief Restores the last session.
 * This is an overloaded function.
 *
 * Use this with multiple different top-level widget classes.
 *
 * @tparam T0 One top-level widget class
 * @tparam T1 Explicit other top-level widget class for disambiguation from base template
 * @tparam Tn Parameter pack to take 0..n further KMainWindows
 * @see kRestoreMainWindows()
 */
template<typename T0, typename T1, typename... Tn>
inline void kRestoreMainWindows()
{
    kRestoreMainWindows<T0>();
    kRestoreMainWindows<T1, Tn...>();
}
/** @}  */

#endif