1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef REMOTING_HOST_LINUX_X11_UTIL_H_ 6 #define REMOTING_HOST_LINUX_X11_UTIL_H_ 7 8 // Xlib.h defines XErrorEvent as an anonymous struct, so we can't forward- 9 // declare it in this header. Since Xlib.h is not generally something you 10 // should #include into arbitrary code, please refrain from #including this 11 // header in another header. 12 #include <X11/Xlib.h> 13 14 #include "base/callback.h" 15 16 namespace remoting { 17 18 // Temporarily install an alternative handler for X errors. The default handler 19 // exits the process, which is not what we want. 20 // 21 // Note that X error handlers are global, which means that this class is not 22 // thread safe. 23 class ScopedXErrorHandler { 24 public: 25 typedef base::Callback<void(Display*, XErrorEvent*)> Handler; 26 27 explicit ScopedXErrorHandler(const Handler& handler); 28 ~ScopedXErrorHandler(); 29 30 // Return false if any X errors have been encountered in the scope of this 31 // handler. ok()32 bool ok() const { return ok_; } 33 34 // Basic handler that ignores X errors. 35 static Handler Ignore(); 36 37 private: 38 static int HandleXErrors(Display* display, XErrorEvent* error); 39 40 Handler handler_; 41 int (*previous_handler_)(Display*, XErrorEvent*); 42 bool ok_; 43 44 DISALLOW_COPY_AND_ASSIGN(ScopedXErrorHandler); 45 }; 46 47 48 // Grab/release the X server within a scope. This can help avoid race 49 // conditions that would otherwise lead to X errors. 50 class ScopedXGrabServer { 51 public: 52 ScopedXGrabServer(Display* display); 53 ~ScopedXGrabServer(); 54 55 private: 56 Display* display_; 57 58 DISALLOW_COPY_AND_ASSIGN(ScopedXGrabServer); 59 }; 60 61 } // namespace remoting 62 63 #endif // REMOTING_HOST_LINUX_X11_UTIL_H_ 64