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39 | |
40 | #include "qxcbxsettings.h" |
41 | |
42 | #include <QtCore/QByteArray> |
43 | #include <QtCore/QtEndian> |
44 | |
45 | #include <vector> |
46 | #include <algorithm> |
47 | |
48 | QT_BEGIN_NAMESPACE |
49 | /* Implementation of http://standards.freedesktop.org/xsettings-spec/xsettings-0.5.html */ |
50 | |
51 | enum XSettingsType { |
52 | XSettingsTypeInteger = 0, |
53 | XSettingsTypeString = 1, |
54 | XSettingsTypeColor = 2 |
55 | }; |
56 | |
57 | struct QXcbXSettingsCallback |
58 | { |
59 | QXcbXSettings::PropertyChangeFunc func; |
60 | void *handle; |
61 | }; |
62 | |
63 | class QXcbXSettingsPropertyValue |
64 | { |
65 | public: |
66 | QXcbXSettingsPropertyValue() |
67 | : last_change_serial(-1) |
68 | {} |
69 | |
70 | void updateValue(QXcbVirtualDesktop *screen, const QByteArray &name, const QVariant &value, int last_change_serial) |
71 | { |
72 | if (last_change_serial <= this->last_change_serial) |
73 | return; |
74 | this->value = value; |
75 | this->last_change_serial = last_change_serial; |
76 | for (const auto &callback : callback_links) |
77 | callback.func(screen, name, value, callback.handle); |
78 | } |
79 | |
80 | void addCallback(QXcbXSettings::PropertyChangeFunc func, void *handle) |
81 | { |
82 | QXcbXSettingsCallback callback = { .func: func, .handle: handle }; |
83 | callback_links.push_back(x: callback); |
84 | } |
85 | |
86 | QVariant value; |
87 | int last_change_serial; |
88 | std::vector<QXcbXSettingsCallback> callback_links; |
89 | |
90 | }; |
91 | |
92 | class QXcbXSettingsPrivate |
93 | { |
94 | public: |
95 | QXcbXSettingsPrivate(QXcbVirtualDesktop *screen) |
96 | : screen(screen) |
97 | , initialized(false) |
98 | { |
99 | } |
100 | |
101 | QByteArray getSettings() |
102 | { |
103 | QXcbConnectionGrabber connectionGrabber(screen->connection()); |
104 | |
105 | int offset = 0; |
106 | QByteArray settings; |
107 | xcb_atom_t _xsettings_atom = screen->connection()->atom(qatom: QXcbAtom::_XSETTINGS_SETTINGS); |
108 | while (1) { |
109 | auto reply = Q_XCB_REPLY_UNCHECKED(xcb_get_property, |
110 | screen->xcb_connection(), |
111 | false, |
112 | x_settings_window, |
113 | _xsettings_atom, |
114 | _xsettings_atom, |
115 | offset/4, |
116 | 8192); |
117 | bool more = false; |
118 | if (!reply) |
119 | return settings; |
120 | |
121 | const auto property_value_length = xcb_get_property_value_length(R: reply.get()); |
122 | settings.append(s: static_cast<const char *>(xcb_get_property_value(R: reply.get())), len: property_value_length); |
123 | offset += property_value_length; |
124 | more = reply->bytes_after != 0; |
125 | |
126 | if (!more) |
127 | break; |
128 | } |
129 | |
130 | return settings; |
131 | } |
132 | |
133 | static int round_to_nearest_multiple_of_4(int value) |
134 | { |
135 | int remainder = value % 4; |
136 | if (!remainder) |
137 | return value; |
138 | return value + 4 - remainder; |
139 | } |
140 | |
141 | void populateSettings(const QByteArray &xSettings) |
142 | { |
143 | if (xSettings.length() < 12) |
144 | return; |
145 | char byteOrder = xSettings.at(i: 0); |
146 | if (byteOrder != XCB_IMAGE_ORDER_LSB_FIRST && byteOrder != XCB_IMAGE_ORDER_MSB_FIRST) { |
147 | qWarning(msg: "ByteOrder byte %d not 0 or 1" , byteOrder); |
148 | return; |
149 | } |
150 | |
151 | #define ADJUST_BO(b, t, x) \ |
152 | ((b == XCB_IMAGE_ORDER_LSB_FIRST) ? \ |
153 | qFromLittleEndian<t>(x) : \ |
154 | qFromBigEndian<t>(x)) |
155 | #define VALIDATE_LENGTH(x) \ |
156 | if ((size_t)xSettings.length() < (offset + local_offset + 12 + x)) { \ |
157 | qWarning("Length %d runs past end of data", x); \ |
158 | return; \ |
159 | } |
160 | |
161 | uint number_of_settings = ADJUST_BO(byteOrder, quint32, xSettings.mid(8,4).constData()); |
162 | const char *data = xSettings.constData() + 12; |
163 | size_t offset = 0; |
164 | for (uint i = 0; i < number_of_settings; i++) { |
165 | int local_offset = 0; |
166 | VALIDATE_LENGTH(2); |
167 | XSettingsType type = static_cast<XSettingsType>(*reinterpret_cast<const quint8 *>(data + offset)); |
168 | local_offset += 2; |
169 | |
170 | VALIDATE_LENGTH(2); |
171 | quint16 name_len = ADJUST_BO(byteOrder, quint16, data + offset + local_offset); |
172 | local_offset += 2; |
173 | |
174 | VALIDATE_LENGTH(name_len); |
175 | QByteArray name(data + offset + local_offset, name_len); |
176 | local_offset += round_to_nearest_multiple_of_4(value: name_len); |
177 | |
178 | VALIDATE_LENGTH(4); |
179 | int last_change_serial = ADJUST_BO(byteOrder, qint32, data + offset + local_offset); |
180 | Q_UNUSED(last_change_serial); |
181 | local_offset += 4; |
182 | |
183 | QVariant value; |
184 | if (type == XSettingsTypeString) { |
185 | VALIDATE_LENGTH(4); |
186 | int value_length = ADJUST_BO(byteOrder, qint32, data + offset + local_offset); |
187 | local_offset+=4; |
188 | VALIDATE_LENGTH(value_length); |
189 | QByteArray value_string(data + offset + local_offset, value_length); |
190 | value.setValue(value_string); |
191 | local_offset += round_to_nearest_multiple_of_4(value: value_length); |
192 | } else if (type == XSettingsTypeInteger) { |
193 | VALIDATE_LENGTH(4); |
194 | int value_length = ADJUST_BO(byteOrder, qint32, data + offset + local_offset); |
195 | local_offset += 4; |
196 | value.setValue(value_length); |
197 | } else if (type == XSettingsTypeColor) { |
198 | VALIDATE_LENGTH(2*4); |
199 | quint16 red = ADJUST_BO(byteOrder, quint16, data + offset + local_offset); |
200 | local_offset += 2; |
201 | quint16 green = ADJUST_BO(byteOrder, quint16, data + offset + local_offset); |
202 | local_offset += 2; |
203 | quint16 blue = ADJUST_BO(byteOrder, quint16, data + offset + local_offset); |
204 | local_offset += 2; |
205 | quint16 alpha= ADJUST_BO(byteOrder, quint16, data + offset + local_offset); |
206 | local_offset += 2; |
207 | QColor color_value(red,green,blue,alpha); |
208 | value.setValue(color_value); |
209 | } |
210 | offset += local_offset; |
211 | settings[name].updateValue(screen,name,value,last_change_serial); |
212 | } |
213 | |
214 | } |
215 | |
216 | QXcbVirtualDesktop *screen; |
217 | xcb_window_t x_settings_window; |
218 | QMap<QByteArray, QXcbXSettingsPropertyValue> settings; |
219 | bool initialized; |
220 | }; |
221 | |
222 | |
223 | QXcbXSettings::QXcbXSettings(QXcbVirtualDesktop *screen) |
224 | : d_ptr(new QXcbXSettingsPrivate(screen)) |
225 | { |
226 | QByteArray settings_atom_for_screen("_XSETTINGS_S" ); |
227 | settings_atom_for_screen.append(a: QByteArray::number(screen->number())); |
228 | auto atom_reply = Q_XCB_REPLY(xcb_intern_atom, |
229 | screen->xcb_connection(), |
230 | true, |
231 | settings_atom_for_screen.length(), |
232 | settings_atom_for_screen.constData()); |
233 | if (!atom_reply) |
234 | return; |
235 | |
236 | xcb_atom_t selection_owner_atom = atom_reply->atom; |
237 | |
238 | auto selection_result = Q_XCB_REPLY(xcb_get_selection_owner, |
239 | screen->xcb_connection(), selection_owner_atom); |
240 | if (!selection_result) |
241 | return; |
242 | |
243 | d_ptr->x_settings_window = selection_result->owner; |
244 | if (!d_ptr->x_settings_window) |
245 | return; |
246 | |
247 | screen->connection()->addWindowEventListener(id: d_ptr->x_settings_window, eventListener: this); |
248 | const uint32_t event = XCB_CW_EVENT_MASK; |
249 | const uint32_t event_mask[] = { XCB_EVENT_MASK_STRUCTURE_NOTIFY|XCB_EVENT_MASK_PROPERTY_CHANGE }; |
250 | xcb_change_window_attributes(c: screen->xcb_connection(),window: d_ptr->x_settings_window,value_mask: event,value_list: event_mask); |
251 | |
252 | d_ptr->populateSettings(xSettings: d_ptr->getSettings()); |
253 | d_ptr->initialized = true; |
254 | } |
255 | |
256 | QXcbXSettings::~QXcbXSettings() |
257 | { |
258 | delete d_ptr; |
259 | d_ptr = nullptr; |
260 | } |
261 | |
262 | bool QXcbXSettings::initialized() const |
263 | { |
264 | Q_D(const QXcbXSettings); |
265 | return d->initialized; |
266 | } |
267 | |
268 | void QXcbXSettings::handlePropertyNotifyEvent(const xcb_property_notify_event_t *event) |
269 | { |
270 | Q_D(QXcbXSettings); |
271 | if (event->window != d->x_settings_window) |
272 | return; |
273 | |
274 | d->populateSettings(xSettings: d->getSettings()); |
275 | } |
276 | |
277 | void QXcbXSettings::registerCallbackForProperty(const QByteArray &property, QXcbXSettings::PropertyChangeFunc func, void *handle) |
278 | { |
279 | Q_D(QXcbXSettings); |
280 | d->settings[property].addCallback(func,handle); |
281 | } |
282 | |
283 | void QXcbXSettings::removeCallbackForHandle(const QByteArray &property, void *handle) |
284 | { |
285 | Q_D(QXcbXSettings); |
286 | auto &callbacks = d->settings[property].callback_links; |
287 | |
288 | auto isCallbackForHandle = [handle](const QXcbXSettingsCallback &cb) { return cb.handle == handle; }; |
289 | |
290 | callbacks.erase(first: std::remove_if(first: callbacks.begin(), last: callbacks.end(), |
291 | pred: isCallbackForHandle), |
292 | last: callbacks.end()); |
293 | } |
294 | |
295 | void QXcbXSettings::removeCallbackForHandle(void *handle) |
296 | { |
297 | Q_D(QXcbXSettings); |
298 | for (QMap<QByteArray, QXcbXSettingsPropertyValue>::const_iterator it = d->settings.cbegin(); |
299 | it != d->settings.cend(); ++it) { |
300 | removeCallbackForHandle(property: it.key(),handle); |
301 | } |
302 | } |
303 | |
304 | QVariant QXcbXSettings::setting(const QByteArray &property) const |
305 | { |
306 | Q_D(const QXcbXSettings); |
307 | return d->settings.value(akey: property).value; |
308 | } |
309 | |
310 | QT_END_NAMESPACE |
311 | |