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 /*
     SPDX-FileCopyrightText: 2003 Lubos Lunak <l.lunak@kde.org>
 
     SPDX-License-Identifier: MIT
 */
 
 #ifndef KXERRORHANDLER_H
 #define KXERRORHANDLER_H
 #include <config-kwindowsystem.h>
 
 #include <QtGlobal>
 
 #include <private/qtx11extras_p.h>
 
 #include <X11/Xlib.h>
 
 class KXErrorHandlerPrivate;
 /**
  * This class simplifies handling of X errors. It shouldn't be necessary to use
  * with Qt classes, as the toolkit should handle X errors itself, so this
  * class will be mainly used with direct Xlib usage, and some lowlevel classes
  * like NETWinInfo.
  *
  * The usual usage is to create a KXErrorHandler instance right before starting
  * operations that might cause X errors, and checking if there was an error
  * by calling error() after the operations are finished. The handlers
  * may be nested, but must be destroyed in reverse order they were created.
  *
  * There's no need to do X sync before creating an instance, every instance
  * will handle only errors for request issued after the instance was created.
  * Errors for older requests will be passed to previous error handler.
  * When checking for error by calling error() at the end, it is necessary
  * to sync with X, to catch all errors that were caused by requests issued
  * before the call to error(). This can be done by passing true to error()
  * to cause explicit XSync(), however, if the last X request needed a roundtrip
  * (e.g. XGetWindowAttributes(), XGetGeometry(), etc.), it is not required
  * to do an explicit sync.
  *
  * @author Lubos Lunak <l.lunak@kde.org>
  * @short Handler for X errors
  */
 class KXErrorHandler
 {
 public:
     /**
      * Creates error handler that will set error flag after encountering
      * any X error.
      */
     explicit KXErrorHandler(Display *dpy = QX11Info::display());
     /**
      * This constructor takes pointer to a function whose prototype matches
      * the one that's used with the XSetErrorHandler() Xlib function.
      * NOTE: For the error flag to be set, the function must return a non-zero
      * value.
      */
     explicit KXErrorHandler(int (*handler)(Display *, XErrorEvent *), Display *dpy = QX11Info::display());
     /**
      * This function returns true if the error flag is set (i.e. no custom handler
      * function was used and there was any error, or the custom handler indicated
      * an error by its return value).
      *
      * @param sync if true, an explicit XSync() will be done. Not necessary
      *             when the last X request required a roundtrip.
      */
     bool error(bool sync) const;
     /**
      * This function returns the error event for the first X error that occurred.
      * The return value is useful only if error() returned true.
      * @since 4.0.1
      */
     XErrorEvent errorEvent() const;
     /**
      * Returns error message for the given error. The error message is not translated,
      * as it is meant for debugging.
      * @since 4.0.1
      */
     static QByteArray errorMessage(const XErrorEvent &e, Display *dpy = QX11Info::display());
     ~KXErrorHandler();
 
 private:
     void addHandler();
     int handle(Display *dpy, XErrorEvent *e);
     bool (*user_handler1)(int request, int error_code, unsigned long resource_id);
     int (*user_handler2)(Display *, XErrorEvent *);
     int (*old_handler)(Display *, XErrorEvent *);
     static int handler_wrapper(Display *, XErrorEvent *);
     static KXErrorHandler **handlers;
     static int pos;
     static int size;
     Q_DISABLE_COPY(KXErrorHandler)
     KXErrorHandlerPrivate *const d;
 };
 
 #endif