File indexing completed on 2024-05-12 03:54:29

 /*
     SPDX-FileCopyrightText: 2022 Volker Krause <vkrause@kde.org>
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #ifndef KWINDOWSTATESAVER_H
 #define KWINDOWSTATESAVER_H
 
 #include <kconfiggroup.h>
 #include <kconfiggui_export.h>
 
 #include <QObject>
 
 class QWindow;
 class KWindowStateSaverPrivate;
 
 /**
  * Saves and restores a window size and (when possible) position.
  *
  * This is useful for retrofitting persisting window geometry on existing windows or dialogs,
  * without having to modify those classes themselves, or having to inherit from them.
  * For this, create a new instance of KWindowStateSaver for every window that should have it's
  * state persisted, and pass it the window or widget as well as the config group the state
  * should be stored in. The KWindowStateSaver will restore an existing state and then monitor
  * the window for subsequent changes to persist. It will delete itself once the window is
  * deleted.
  *
  * @code
  * QPrintPreviewDialog dlg = ...
  * new KWindowStateSaver(&dlg, "printPreviewDialogState");
  * ...
  * dlg.exec();
  * @endcode
  *
  * Note that freshly created top-level QWidgets (such as the dialog in the above example)
  * do not have an associated QWindow yet (ie. windowHandle() return @c nullptr). KWindowStateSaver
  * supports this with its QWidget constructors which will monitor the widget for having
  * its associated QWindow created before continuing with that.
  *
  * When implementing your own windows/dialogs, using KWindowConfig directly can be an
  * alternative.
  *
  * @see KWindowConfig
  * @since 5.92
  */
 class KCONFIGGUI_EXPORT KWindowStateSaver : public QObject
 {
     Q_OBJECT
 public:
     /**
      * Create a new window state saver for @p window.
      * @param configGroup A KConfigGroup that holds the window state.
      */
     explicit KWindowStateSaver(QWindow *window, const KConfigGroup &configGroup);
     /**
      * Create a new window state saver for @p window.
      * @param configGroupName The name of a KConfigGroup in the default state
      * configuration (see KSharedConfig::openStateConfig) that holds the window state.
      */
     explicit KWindowStateSaver(QWindow *window, const QString &configGroupName);
 
     /**
      * Create a new window state saver for @p widget.
      * Use this for widgets that aren't shown yet and would still return @c nullptr from windowHandle().
      * @param configGroup A KConfigGroup that holds the window state.
      */
     template<typename Widget>
     explicit inline KWindowStateSaver(Widget *widget, const KConfigGroup &configGroup);
     /**
      * Create a new window state saver for @p widget.
      * Use this for widgets that aren't shown yet and would still return @c nullptr from windowHandle().
      * @param configGroupName The name of a KConfigGroup in the default state
      * configuration (see KSharedConfig::openStateConfig) that holds the window state.
      */
     template<typename Widget>
     explicit inline KWindowStateSaver(Widget *widget, const QString &configGroupName);
 
     ~KWindowStateSaver();
 
 private:
     void timerEvent(QTimerEvent *event) override;
     bool eventFilter(QObject *watched, QEvent *event) override;
 
     // API used by template code, so technically part of the ABI
     void initWidget(QObject *widget, const std::function<QWindow *()> &windowHandleCallback, const KConfigGroup &configGroup);
     void initWidget(QObject *widget, const std::function<QWindow *()> &windowHandleCallback, const QString &configGroupName);
 
     // cannot use std::unique_ptr due to the template ctors
     // not seeing the full private class
     KWindowStateSaverPrivate *d = nullptr;
 };
 
 template<typename Widget>
 KWindowStateSaver::KWindowStateSaver(Widget *widget, const KConfigGroup &configGroup)
     : QObject(widget)
 {
     initWidget(
         widget,
         [widget]() {
             return widget->windowHandle();
         },
         configGroup);
 }
 
 template<typename Widget>
 KWindowStateSaver::KWindowStateSaver(Widget *widget, const QString &configGroupName)
     : QObject(widget)
 {
     initWidget(
         widget,
         [widget]() {
             return widget->windowHandle();
         },
         configGroupName);
 }
 
 #endif // KWINDOWSTATESAVER_H