/*
  This file is part of KDDockWidgets.

  Copyright (C) 2019-2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
  Author: Sérgio Martins <sergio.martins@kdab.com>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @file
 * @brief Application-wide config to tune certain behaviours of the framework.
 *
 * @author Sérgio Martins \<sergio.martins@kdab.com\>
 */

#ifndef KD_DOCKWIDGETS_CONFIG_H
#define KD_DOCKWIDGETS_CONFIG_H

#include "docks_export.h"

QT_BEGIN_NAMESPACE
class QQmlEngine;
QT_END_NAMESPACE

namespace KDDockWidgets
{

class DockWidgetBase;
class FrameworkWidgetFactory;

typedef KDDockWidgets::DockWidgetBase* (*DockWidgetFactoryFunc)(const QString &name);

/**
 * @brief Singleton to allow to choose certain behaviours of the framework.
 *
 * The setters should only be used before creating any DockWidget or MainWindow,
 * preferably right after creating the QApplication.
 */
class DOCKS_EXPORT Config
{
public:

    ///@brief returns the singleton Config instance
    static Config &self();

    ///@brief destructor, called at shutdown
    ~Config();

    ///@brief Flag enum to tune certain behaviours, the defaults are Flag_Default
    enum Flag {
        Flag_None = 0, ///> No option set
        Flag_NativeTitleBar = 1, ///> Enables the Native OS title bar on OSes that support it (Windows 10, macOS), ignored otherwise. This is mutually exclusive with Flag_AeroSnap
        Flag_AeroSnapWithClientDecos = 2, ///> Enables AeroSnap even if we're not using the native title bar. Only supported on Windows 10.
        Flag_HideTitleBarWhenTabsVisible = 8, ///> Hides the title bar if there's tabs visible. The empty space in the tab bar becomes draggable.
        Flag_AlwaysShowTabs = 16, ///> Always show tabs, even if there's only one,
        Flag_AllowReorderTabs = 32, /// Allows user to re-order tabs by dragging them
        Flag_LazyResize = 32, /// The dock widgets are resized in a lazy manner. The actual resize only happens when you release the mouse button.
        Flag_TabsHaveCloseButton = 64, /// Tabs will have a close button. Equivalent to QTabWidget::setTabsClosable(true).
        Flag_DoubleClickMaximizes = 128, /// Double clicking the titlebar will maximize a floating window instead of re-docking it
        Flag_Default = Flag_AeroSnapWithClientDecos ///> The defaults
    };
    Q_DECLARE_FLAGS(Flags, Flag)

    ///@brief returns the chosen flags
    Flags flags() const;

    ///@brief setter for the flags
    ///@param flags the flags to set
    ///Not all flags are guaranteed to be set, as the OS might not supported them
    ///Call @ref flags() after the setter if you need to know what was really set
    void setFlags(Flags flags);

    /**
     * @brief Registers a DockWidgetFactoryFunc.
     *
     * This is optional, the default is nullptr.
     *
     * A DockWidgetFactoryFunc is a function that receives a dock widget name
     * and returns a DockWidget instance.
     *
     * While restoring, @ref LayoutSaver requires all dock widgets to exist.
     * If a DockWidget doesn't exist then a DockWidgetFactoryFunc function is
     * required, so the layout saver can ask to create the DockWidget and then
     * restore it.
     */
    void setDockWidgetFactoryFunc(DockWidgetFactoryFunc);

    ///@brief Returns the DockWidgetFactoryFunc.
    ///nullptr by default
    DockWidgetFactoryFunc dockWidgetFactoryFunc() const;

    /**
     * @brief Sets the WidgetFactory.
     *
     * By default DefaultWidgetFactory is used, which gives you FrameWidget, TitleBarWidget,
     * TabBarWidget, TabWidgetWidget etc. You can set your own factory, to supply your own variants
     * of those classes, for the purposes of changing GUI appearance and such.
     *
     * Also potentially useful to return QtQuick classes instead of the QtWidget based ones.
     * Ownership is taken.
     */
    void setFrameworkWidgetFactory(FrameworkWidgetFactory *);

    ///@brief getter for the framework widget factory
    FrameworkWidgetFactory *frameworkWidgetFactory() const;

    /**
     * @brief Returns the thickness of the separator.
     *
     * Returns the width if the separator is vertical, otherwise the height.
     * If @p staticSeparator is true, then returns for the static separators.
     * The static separators are the ones at the edges of the window (top, left, bottom, right).
     *
     * Default is 0px for static separators and 5px for normal separators.
     */
    int separatorThickness(bool staticSeparator) const;

    ///@brief setter for @ref separatorThickness
    ///Note: Only use this function at startup before creating any DockWidget or MainWindow.
    void setSeparatorThickness(int value, bool staticSeparator);

    ///@brief Sets the QQmlEngine to use. Applicable only when using QtQuick.
    void setQmlEngine(QQmlEngine *);
    QQmlEngine* qmlEngine() const;

private:
    Q_DISABLE_COPY(Config)
    Config();
    class Private;
    Private *const d;
};

}

Q_DECLARE_OPERATORS_FOR_FLAGS(KDDockWidgets::Config::Flags)

#endif