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Diffstat (limited to 'tdecore/kxerrorhandler.h')
-rw-r--r-- | tdecore/kxerrorhandler.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/tdecore/kxerrorhandler.h b/tdecore/kxerrorhandler.h new file mode 100644 index 000000000..9c0bd1e24 --- /dev/null +++ b/tdecore/kxerrorhandler.h @@ -0,0 +1,104 @@ +/* + + Copyright (c) 2003 Lubos Lunak <l.lunak@kde.org> + + Permission is hereby granted, free of charge, to any person obtaining a + copy of this software and associated documentation files (the "Software"), + to deal in the Software without restriction, including without limitation + the rights to use, copy, modify, merge, publish, distribute, sublicense, + and/or sell copies of the Software, and to permit persons to whom the + Software is furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice shall be included in + all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + DEALINGS IN THE SOFTWARE. + +*/ + +#ifndef KXERRORHANDLER_H +#define KXERRORHANDLER_H + +#include <tqvaluelist.h> +#include <tqwindowdefs.h> +#include <kdelibs_export.h> +#include <X11/Xlib.h> + +/** + * 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 KDECORE_EXPORT KXErrorHandler + { + public: + /** + * Creates error handler that will set error flag after encountering + * any X error. + */ + KXErrorHandler( Display* dpy = qt_xdisplay()); + /** + * This constructor takes pointer to a function that will get request number, + * error code number and resource id of the failed request, as provided + * by XErrorEvent. If the function returns true, the error flag will be set. + */ + KXErrorHandler( bool (*handler)( int request, int error_code, unsigned long resource_id ), Display* dpy = qt_xdisplay()); + /** + * 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 non-zero + * value. + */ + KXErrorHandler( int (*handler)( Display*, XErrorEvent* ), Display* dpy = qt_xdisplay()); + /** + * 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, and explicit XSync() will be done. Not necessary + * when the last X request required a roundtrip. + */ + bool error( bool sync ) const; + ~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* ); + unsigned long first_request; + Display* display; + bool was_error; + static int handler_wrapper( Display*, XErrorEvent* ); + static KXErrorHandler** handlers; + static int pos; + static int size; + class KXErrorHandlerPrivate* d; + }; + +#endif |