File indexing completed on 2024-04-21 14:56:00
0001 /* 0002 0003 Copyright (c) 2003 Lubos Lunak <l.lunak@kde.org> 0004 0005 Permission is hereby granted, free of charge, to any person obtaining a 0006 copy of this software and associated documentation files (the "Software"), 0007 to deal in the Software without restriction, including without limitation 0008 the rights to use, copy, modify, merge, publish, distribute, sublicense, 0009 and/or sell copies of the Software, and to permit persons to whom the 0010 Software is furnished to do so, subject to the following conditions: 0011 0012 The above copyright notice and this permission notice shall be included in 0013 all copies or substantial portions of the Software. 0014 0015 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 0016 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 0017 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 0018 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 0019 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 0020 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 0021 DEALINGS IN THE SOFTWARE. 0022 0023 */ 0024 0025 #ifndef KXERRORHANDLER_H 0026 #define KXERRORHANDLER_H 0027 0028 #include <QWidget> 0029 #include <QWidgetList> 0030 0031 #include <kdelibs4support_export.h> 0032 #include <X11/Xlib.h> 0033 0034 class KXErrorHandlerPrivate; 0035 /** 0036 * This class simplifies handling of X errors. It shouldn't be necessary to use 0037 * with Qt classes, as the toolkit should handle X errors itself, so this 0038 * class will be mainly used with direct Xlib usage, and some lowlevel classes 0039 * like NETWinInfo. 0040 * 0041 * The usual usage is to create a KXErrorHandler instance right before starting 0042 * operations that might cause X errors, and checking if there was an error 0043 * by calling error() after the operations are finished. The handlers 0044 * may be nested, but must be destroyed in reverse order they were created. 0045 * 0046 * There's no need to do X sync before creating an instance, every instance 0047 * will handle only errors for request issued after the instance was created. 0048 * Errors for older requests will be passed to previous error handler. 0049 * When checking for error by calling error() at the end, it is necessary 0050 * to sync with X, to catch all errors that were caused by requests issued 0051 * before the call to error(). This can be done by passing true to error() 0052 * to cause explicit XSync(), however, if the last X request needed a roundtrip 0053 * (e.g. XGetWindowAttributes(), XGetGeometry(), etc.), it is not required 0054 * to do an explicit sync. 0055 * 0056 * @author Lubos Lunak <l.lunak@kde.org> 0057 * @short Handler for X errors 0058 */ 0059 class KDELIBS4SUPPORT_DEPRECATED_EXPORT KXErrorHandler 0060 { 0061 public: 0062 /** This function simply wraps QX11Info::display(), to make sure the public interface doesn't require QtX11Extras */ 0063 static Display *display(); 0064 /** 0065 * Creates error handler that will set error flag after encountering 0066 * any X error. 0067 */ 0068 KDELIBS4SUPPORT_DEPRECATED explicit KXErrorHandler(Display *dpy = display()); 0069 /** 0070 * This constructor takes pointer to a function whose prototype matches 0071 * the one that's used with the XSetErrorHandler() Xlib function. 0072 * NOTE: For the error flag to be set, the function must return a non-zero 0073 * value. 0074 */ 0075 KDELIBS4SUPPORT_DEPRECATED explicit KXErrorHandler(int (*handler)(Display *, XErrorEvent *), Display *dpy = display()); 0076 /** 0077 * This constructor takes pointer to a function that will get request number, 0078 * error code number and resource id of the failed request, as provided 0079 * by XErrorEvent. If the function returns true, the error flag will be set. 0080 * @deprecated Use the variant with XErrorEvent. 0081 */ 0082 #ifndef KDELIBS4SUPPORT_NO_DEPRECATED 0083 KDELIBS4SUPPORT_DEPRECATED explicit KXErrorHandler(bool (*handler)(int request, int error_code, unsigned long resource_id), Display *dpy = display()) KDELIBS4SUPPORT_DEPRECATED; 0084 #endif 0085 /** 0086 * This function returns true if the error flag is set (i.e. no custom handler 0087 * function was used and there was any error, or the custom handler indicated 0088 * an error by its return value). 0089 * 0090 * @param sync if true, an explicit XSync() will be done. Not necessary 0091 * when the last X request required a roundtrip. 0092 */ 0093 bool error(bool sync) const; 0094 /** 0095 * This function returns the error event for the first X error that occurred. 0096 * The return value is useful only if error() returned true. 0097 * @since 4.0.1 0098 */ 0099 XErrorEvent errorEvent() const; 0100 /** 0101 * Returns error message for the given error. The error message is not translated, 0102 * as it is meant for debugging. 0103 * @since 4.0.1 0104 */ 0105 static QByteArray errorMessage(const XErrorEvent &e, Display *dpy = display()); 0106 ~KXErrorHandler(); 0107 private: 0108 void addHandler(); 0109 int handle(Display *dpy, XErrorEvent *e); 0110 bool (*user_handler1)(int request, int error_code, unsigned long resource_id); 0111 int (*user_handler2)(Display *, XErrorEvent *); 0112 int (*old_handler)(Display *, XErrorEvent *); 0113 static int handler_wrapper(Display *, XErrorEvent *); 0114 static KXErrorHandler **handlers; 0115 static int pos; 0116 static int size; 0117 Q_DISABLE_COPY(KXErrorHandler) 0118 KXErrorHandlerPrivate *const d; 0119 }; 0120 0121 #endif