1 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 : * vim: sw=2 ts=8 et :
3 : */
4 : /* ***** BEGIN LICENSE BLOCK *****
5 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 : *
7 : * The contents of this file are subject to the Mozilla Public License Version
8 : * 1.1 (the "License"); you may not use this file except in compliance with
9 : * the License. You may obtain a copy of the License at:
10 : * http://www.mozilla.org/MPL/
11 : *
12 : * Software distributed under the License is distributed on an "AS IS" basis,
13 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14 : * for the specific language governing rights and limitations under the
15 : * License.
16 : *
17 : * The Original Code is Mozilla Code.
18 : *
19 : * The Initial Developer of the Original Code is
20 : * The Mozilla Foundation
21 : * Portions created by the Initial Developer are Copyright (C) 2010
22 : * the Initial Developer. All Rights Reserved.
23 : *
24 : * Contributor(s):
25 : *
26 : * Alternatively, the contents of this file may be used under the terms of
27 : * either the GNU General Public License Version 2 or later (the "GPL"), or
28 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29 : * in which case the provisions of the GPL or the LGPL are applicable instead
30 : * of those above. If you wish to allow use of your version of this file only
31 : * under the terms of either the GPL or the LGPL, and not to allow others to
32 : * use your version of this file under the terms of the MPL, indicate your
33 : * decision by deleting the provisions above and replace them with the notice
34 : * and other provisions required by the GPL or the LGPL. If you do not delete
35 : * the provisions above, a recipient may use your version of this file under
36 : * the terms of any one of the MPL, the GPL or the LGPL.
37 : *
38 : * ***** END LICENSE BLOCK ***** */
39 :
40 : #ifndef mozilla_X11Util_h
41 : #define mozilla_X11Util_h
42 :
43 : // Utilities common to all X clients, regardless of UI toolkit.
44 :
45 : #if defined(MOZ_WIDGET_GTK2)
46 : # include <gdk/gdkx.h>
47 : #elif defined(MOZ_WIDGET_QT)
48 : // X11/X.h has #define CursorShape 0, but Qt's qnamespace.h defines
49 : // enum CursorShape { ... }. Good times!
50 : #undef CursorShape
51 : # include <QX11Info>
52 : # include <X11/Xlib.h>
53 : #else
54 : # error Unknown toolkit
55 : #endif
56 :
57 : #include "gfxCore.h"
58 : #include "nsDebug.h"
59 :
60 : namespace mozilla {
61 :
62 : /**
63 : * Return the default X Display created and used by the UI toolkit.
64 : */
65 : inline Display*
66 0 : DefaultXDisplay()
67 : {
68 : #if defined(MOZ_WIDGET_GTK2)
69 0 : return GDK_DISPLAY();
70 : #elif defined(MOZ_WIDGET_QT)
71 : return QX11Info::display();
72 : #endif
73 : }
74 :
75 : /**
76 : * Sets *aVisual to point to aDisplay's Visual struct corresponding to
77 : * aVisualID, and *aDepth to its depth. When aVisualID is None, these are set
78 : * to NULL and 0 respectively. Both out-parameter pointers are assumed
79 : * non-NULL. Returns true in both of these situations, but false if aVisualID
80 : * is not None and not found on the Display.
81 : */
82 : bool
83 : XVisualIDToInfo(Display* aDisplay, VisualID aVisualID,
84 : Visual** aVisual, unsigned int* aDepth);
85 :
86 : /**
87 : * Invoke XFree() on a pointer to memory allocated by Xlib (if the
88 : * pointer is nonnull) when this class goes out of scope.
89 : */
90 : template<typename T>
91 : struct ScopedXFree
92 : {
93 0 : ScopedXFree() : mPtr(NULL) {}
94 0 : ScopedXFree(T* aPtr) : mPtr(aPtr) {}
95 :
96 0 : ~ScopedXFree() { Assign(NULL); }
97 :
98 0 : ScopedXFree& operator=(T* aPtr) { Assign(aPtr); return *this; }
99 :
100 0 : operator T*() const { return get(); }
101 0 : T* operator->() const { return get(); }
102 0 : T* get() const { return mPtr; }
103 :
104 : private:
105 0 : void Assign(T* aPtr)
106 : {
107 0 : NS_ASSERTION(!mPtr || mPtr != aPtr, "double-XFree() imminent");
108 :
109 0 : if (mPtr)
110 0 : XFree(mPtr);
111 0 : mPtr = aPtr;
112 0 : }
113 :
114 : T* mPtr;
115 :
116 : // disable these
117 : ScopedXFree(const ScopedXFree&);
118 : ScopedXFree& operator=(const ScopedXFree&);
119 : static void* operator new (size_t);
120 : static void operator delete (void*);
121 : };
122 :
123 : /**
124 : * On construction, set a graceful X error handler that doesn't crash the application and records X errors.
125 : * On destruction, restore the X error handler to what it was before construction.
126 : *
127 : * The SyncAndGetError() method allows to know whether a X error occurred, optionally allows to get the full XErrorEvent,
128 : * and resets the recorded X error state so that a single X error will be reported only once.
129 : *
130 : * Nesting is correctly handled: multiple nested ScopedXErrorHandler's don't interfere with each other's state. However,
131 : * if SyncAndGetError is not called on the nested ScopedXErrorHandler, then any X errors caused by X calls made while the nested
132 : * ScopedXErrorHandler was in place may then be caught by the other ScopedXErrorHandler. This is just a result of X being
133 : * asynchronous and us not doing any implicit syncing: the only method in this class what causes syncing is SyncAndGetError().
134 : *
135 : * This class is not thread-safe at all. It is assumed that only one thread is using any ScopedXErrorHandler's. Given that it's
136 : * not used on Mac, it should be easy to make it thread-safe by using thread-local storage with __thread.
137 : */
138 : class NS_GFX ScopedXErrorHandler
139 : {
140 : public:
141 : // trivial wrapper around XErrorEvent, just adding ctor initializing by zero.
142 : struct ErrorEvent
143 : {
144 : XErrorEvent mError;
145 :
146 0 : ErrorEvent()
147 : {
148 0 : memset(this, 0, sizeof(ErrorEvent));
149 0 : }
150 : };
151 :
152 : private:
153 :
154 : // this ScopedXErrorHandler's ErrorEvent object
155 : ErrorEvent mXError;
156 :
157 : // static pointer for use by the error handler
158 : static ErrorEvent* sXErrorPtr;
159 :
160 : // what to restore sXErrorPtr to on destruction
161 : ErrorEvent* mOldXErrorPtr;
162 :
163 : // what to restore the error handler to on destruction
164 : int (*mOldErrorHandler)(Display *, XErrorEvent *);
165 :
166 : public:
167 :
168 : static int
169 : ErrorHandler(Display *, XErrorEvent *ev);
170 :
171 : ScopedXErrorHandler();
172 :
173 : ~ScopedXErrorHandler();
174 :
175 : /** \returns true if a X error occurred since the last time this method was called on this ScopedXErrorHandler object,
176 : * or since the creation of this ScopedXErrorHandler object if this method was never called on it.
177 : *
178 : * \param ev this optional parameter, if set, will be filled with the XErrorEvent object. If multiple errors occurred,
179 : * the first one will be returned.
180 : */
181 : bool SyncAndGetError(Display *dpy, XErrorEvent *ev = nsnull);
182 :
183 : /** Like SyncAndGetError, but does not sync. Faster, but only reliably catches errors in synchronous calls.
184 : *
185 : * \param ev this optional parameter, if set, will be filled with the XErrorEvent object. If multiple errors occurred,
186 : * the first one will be returned.
187 : */
188 : bool GetError(XErrorEvent *ev = nsnull);
189 : };
190 :
191 : } // namespace mozilla
192 :
193 : #endif // mozilla_X11Util_h
|