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+/*
+
+ 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