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Send IPC window events for focus and title changes

Patch status: needinfo

Patch by Marco Hunsicker

Long description:

This patch provides an implementation for ticket #1168: 'Add IPC
window events for focus and title changes'. To support more use cases
for client programming, i3 should send IPC events for window focus
and title changes.

With this patch, window events are send whenever a window gains focus
or changes its title.

All window events use the same, already established format. The change
field that holds the type of the window event. And the container field
that provides the serialized window container.

This patch supersedes the earlier patch 'Add IPC event for window title
changes' which only added support for window title change notification.
Unlike the old patch that added a whole new event type, this patch
merely extends the existing window event with new properties.

To apply this patch, use:
curl http://cr.i3wm.org/patch/387/raw.patch | git am

b/docs/ipc

@@ -1,7 +1,7 @@
 IPC interface (interprocess communication)
 ==========================================
 Michael Stapelberg <michael@i3wm.org>
-October 2012
+January 2014
 
 This document describes how to interface with i3 from a separate process. This
 is useful for example to remote-control i3 (to write test cases for example) or
@@ -632,7 +632,8 @@ mode (2)::
 	Sent whenever i3 changes its binding mode.
 window (3)::
 	Sent when a client's window is successfully reparented (that is when i3
-	has finished fitting it into a container).
+	has finished fitting it into a container), when a window received input
+	focus or when a window title was upated.
 barconfig_update (4)::
     Sent when the hidden_state or mode field in the barconfig of any bar
     instance was updated.
@@ -712,14 +713,14 @@ mode is simply named default.
 === window event
 
 This event consists of a single serialized map containing a property
-+change (string)+ which currently can indicate only that a new window
-has been successfully reparented (the value will be "new").
++change (string)+ which indicates the type of the change ("focus", "new",
+"title").
 
 Additionally a +container (object)+ field will be present, which consists
-of the window's parent container. Be aware that the container will hold
-the initial name of the newly reparented window (e.g. if you run urxvt
-with a shell that changes the title, you will still at this point get the
-window title as "urxvt").
+of the window's parent container. Be aware that for the "new" event, the
+container will hold the initial name of the newly reparented window (e.g.
+if you run urxvt with a shell that changes the title, you will still at
+this point get the window title as "urxvt").
 
 *Example:*
 ---------------------------

b/include/ipc.h

@@ -87,3 +87,21 @@ void dump_node(yajl_gen gen, Con *con, bool inplace_restart);
  * respectively.
  */
 void ipc_send_workspace_focus_event(Con *current, Con *old);
+
+/**
+ * For the window "focus" event we send, along the usual "change" field,
+ * also the window container, in "container".
+ */
+void ipc_send_window_focus_event(Con *con);
+
+/**
+ * For the window "new" event we send, along the usual "change" field,
+ * also the window container, in "container".
+ */
+void ipc_send_window_new_event(Con *con);
+
+/**
+ * For the window "title" event we send, along the usual "change" field,
+ * also the window container, in "container".
+ */
+void ipc_send_window_title_event(Con *con);

b/src/con.c

@@ -213,6 +213,8 @@ void con_focus(Con *con) {
     assert(con != NULL);
     DLOG("con_focus = %p\n", con);
 
+    bool already_focused = (con == focused);
+
     /* 1: set focused-pointer to the new con */
     /* 2: exchange the position of the container in focus stack of the parent all the way up */
     TAILQ_REMOVE(&(con->parent->focus_head), con, focused);
@@ -221,15 +223,21 @@ void con_focus(Con *con) {
         con_focus(con->parent);
 
     focused = con;
+
+    if (con_is_leaf(con)) {
+        if (!already_focused)
+            ipc_send_window_focus_event(con);
+
     /* We can't blindly reset non-leaf containers since they might have
      * other urgent children. Therefore we only reset leafs and propagate
      * the changes upwards via con_update_parents_urgency() which does proper
      * checks before resetting the urgency.
      */
-    if (con->urgent && con_is_leaf(con)) {
+        if (con->urgent) {
         con->urgent = false;
         con_update_parents_urgency(con);
         workspace_update_urgent_flag(con_get_workspace(con));
+        }
     }
 }
 

b/src/handlers.c

@@ -22,6 +22,8 @@
 
 int randr_base = -1;
 
+char *current_windowtitle = NULL;
+
 /* After mapping/unmapping windows, a notify event is generated. However, we don’t want it,
    since it’d trigger an infinite loop of switching between the different windows when
    changing workspaces */
@@ -528,6 +530,30 @@ static void handle_destroy_notify_event(xcb_destroy_notify_event_t *event) {
     handle_unmap_notify_event(&unmap);
 }
 
+const char* get_title(Con *con) {
+    return (con != NULL && con->window != NULL && con->window->name != NULL) ? i3string_as_utf8(con->window->name) : "";
+}
+
+bool is_title_changed(Con *con) {
+    if (con == focused ) {
+        const char* title = get_title(con);
+
+        if (current_windowtitle != NULL && strcmp(current_windowtitle, title) == 0)
+            return FALSE;
+
+        FREE(current_windowtitle);
+
+        current_windowtitle = strdup(title);
+    }
+
+    return TRUE;
+}
+
+void send_window_title_event(Con *con) {
+    if (is_title_changed(con))
+        ipc_send_window_title_event(con);
+}
+
 /*
  * Called when a window changes its title
  *
@@ -542,6 +568,8 @@ static bool handle_windowname_change(void *data, xcb_connection_t *conn, uint8_t
 
     x_push_changes(croot);
 
+    send_window_title_event(con);
+
     return true;
 }
 
@@ -560,6 +588,8 @@ static bool handle_windowname_change_legacy(void *data, xcb_connection_t *conn,
 
     x_push_changes(croot);
 
+    send_window_title_event(con);
+
     return true;
 }
 

b/src/ipc.c

@@ -1056,3 +1056,39 @@ void ipc_send_workspace_focus_event(Con *current, Con *old) {
     y(free);
     setlocale(LC_NUMERIC, "");
 }
+
+void ipc_send_window_event(const char *property, Con *con) {
+    setlocale(LC_NUMERIC, "C");
+    yajl_gen gen = ygenalloc();
+
+    y(map_open);
+
+    ystr("change");
+    ystr(property);
+
+    ystr("container");
+    dump_node(gen, con, false);
+
+    y(map_close);
+
+    const unsigned char *payload;
+    ylength length;
+    y(get_buf, &payload, &length);
+
+    ipc_send_event("window", I3_IPC_EVENT_WINDOW, (const char *)payload);
+    y(free);
+    setlocale(LC_NUMERIC, "");
+}
+
+void ipc_send_window_focus_event(Con *con) {
+    ipc_send_window_event("focus", con);
+}
+
+void ipc_send_window_new_event(Con *con) {
+    ipc_send_window_event("new", con);
+}
+
+void ipc_send_window_title_event(Con *con) {
+    ipc_send_window_event("title", con);
+}
+

b/src/manage.c

@@ -76,35 +76,6 @@ void restore_geometry(void) {
 }
 
 /*
- * The following function sends a new window event, which consists
- * of fields "change" and "container", the latter containing a dump
- * of the window's container.
- *
- */
-static void ipc_send_window_new_event(Con *con) {
-    setlocale(LC_NUMERIC, "C");
-    yajl_gen gen = ygenalloc();
-
-    y(map_open);
-
-    ystr("change");
-    ystr("new");
-
-    ystr("container");
-    dump_node(gen, con, false);
-
-    y(map_close);
-
-    const unsigned char *payload;
-    ylength length;
-    y(get_buf, &payload, &length);
-
-    ipc_send_event("window", I3_IPC_EVENT_WINDOW, (const char *)payload);
-    y(free);
-    setlocale(LC_NUMERIC, "");
-}
-
-/*
  * Do some sanity checks and then reparent the window.
  *
  */

104	@@ -213,6 +213,8 @@ void con_focus(Con *con) {
105	assert(con != NULL);
106	DLOG("con_focus = %p\n", con);
107
108	+ bool already_focused = (con == focused);
109	+
110	/* 1: set focused-pointer to the new con */
111	/* 2: exchange the position of the container in focus stack of the parent all the way up */
112	TAILQ_REMOVE(&(con->parent->focus_head), con, focused);
113	@@ -221,15 +223,21 @@ void con_focus(Con *con) {
114	con_focus(con->parent);
115
116	focused = con;
117	+
118	+ if (con_is_leaf(con)) {
119	+ if (!already_focused)
120	+ ipc_send_window_focus_event(con);
121	+
122	/* We can't blindly reset non-leaf containers since they might have
123	* other urgent children. Therefore we only reset leafs and propagate
124	* the changes upwards via con_update_parents_urgency() which does proper
125	* checks before resetting the urgency.
126	*/
127	- if (con->urgent && con_is_leaf(con)) {
128	+ if (con->urgent) {
129	con->urgent = false;
130	con_update_parents_urgency(con);
131	workspace_update_urgent_flag(con_get_workspace(con));
132	+ }
133	}
134	}
135

140	@@ -22,6 +22,8 @@
141
142	int randr_base = -1;
143
144	+char *current_windowtitle = NULL;
145	+
146	/* After mapping/unmapping windows, a notify event is generated. However, we don’t want it,
147	since it’d trigger an infinite loop of switching between the different windows when
148	changing workspaces */
149	@@ -528,6 +530,30 @@ static void handle_destroy_notify_event(xcb_destroy_notify_event_t *event) {
150	handle_unmap_notify_event(&unmap);
151	}
152
153	+const char* get_title(Con *con) {
154	+ return (con != NULL && con->window != NULL && con->window->name != NULL) ? i3string_as_utf8(con->window->name) : "";
155	+}
156	+
157	+bool is_title_changed(Con *con) {
158	+ if (con == focused ) {
159	+ const char* title = get_title(con);
160	+
161	+ if (current_windowtitle != NULL && strcmp(current_windowtitle, title) == 0)
162	+ return FALSE;
163	+
164	+ FREE(current_windowtitle);
165	+
166	+ current_windowtitle = strdup(title);
167	+ }
168	+
169	+ return TRUE;
170	+}
171	+
172	+void send_window_title_event(Con *con) {
173	+ if (is_title_changed(con))
174	+ ipc_send_window_title_event(con);
175	+}
176	+
177	/*
178	* Called when a window changes its title
179	*
180	@@ -542,6 +568,8 @@ static bool handle_windowname_change(void data, xcb_connection_t conn, uint8_t
181
182	x_push_changes(croot);
183
184	+ send_window_title_event(con);
185	+
186	return true;
187	}
188
189	@@ -560,6 +588,8 @@ static bool handle_windowname_change_legacy(void data, xcb_connection_t conn,
190
191	x_push_changes(croot);
192
193	+ send_window_title_event(con);
194	+
195	return true;
196	}
197

202	@@ -1056,3 +1056,39 @@ void ipc_send_workspace_focus_event(Con current, Con old) {
203	y(free);
204	setlocale(LC_NUMERIC, "");
205	}
206	+
207	+void ipc_send_window_event(const char property, Con con) {
208	+ setlocale(LC_NUMERIC, "C");
209	+ yajl_gen gen = ygenalloc();
210	+
211	+ y(map_open);
212	+
213	+ ystr("change");
214	+ ystr(property);
215	+
216	+ ystr("container");
217	+ dump_node(gen, con, false);
218	+
219	+ y(map_close);
220	+
221	+ const unsigned char *payload;
222	+ ylength length;
223	+ y(get_buf, &payload, &length);
224	+
225	+ ipc_send_event("window", I3_IPC_EVENT_WINDOW, (const char *)payload);
226	+ y(free);
227	+ setlocale(LC_NUMERIC, "");
228	+}
229	+
230	+void ipc_send_window_focus_event(Con *con) {
231	+ ipc_send_window_event("focus", con);
232	+}
233	+
234	+void ipc_send_window_new_event(Con *con) {
235	+ ipc_send_window_event("new", con);
236	+}
237	+
238	+void ipc_send_window_title_event(Con *con) {
239	+ ipc_send_window_event("title", con);
240	+}
241	+

246	@@ -76,35 +76,6 @@ void restore_geometry(void) {
247	}
248
249	/*
250	- * The following function sends a new window event, which consists
251	- * of fields "change" and "container", the latter containing a dump
252	- * of the window's container.
253	- *
254	- */
255	-static void ipc_send_window_new_event(Con *con) {
256	- setlocale(LC_NUMERIC, "C");
257	- yajl_gen gen = ygenalloc();
258	-
259	- y(map_open);
260	-
261	- ystr("change");
262	- ystr("new");
263	-
264	- ystr("container");
265	- dump_node(gen, con, false);
266	-
267	- y(map_close);
268	-
269	- const unsigned char *payload;
270	- ylength length;
271	- y(get_buf, &payload, &length);
272	-
273	- ipc_send_event("window", I3_IPC_EVENT_WINDOW, (const char *)payload);
274	- y(free);
275	- setlocale(LC_NUMERIC, "");
276	-}
277	-
278	-/*
279	* Do some sanity checks and then reparent the window.
280	*
281	*/

34	@@ -1,7 +1,7 @@
35	IPC interface (interprocess communication)
36	==========================================
37	Michael Stapelberg <michael@i3wm.org>
38	-October 2012
39	+January 2014
40
41	This document describes how to interface with i3 from a separate process. This
42	is useful for example to remote-control i3 (to write test cases for example) or
43	@@ -632,7 +632,8 @@ mode (2)::
44	Sent whenever i3 changes its binding mode.
45	window (3)::
46	Sent when a client's window is successfully reparented (that is when i3
47	- has finished fitting it into a container).
48	+ has finished fitting it into a container), when a window received input
49	+ focus or when a window title was upated.
50	barconfig_update (4)::
51	Sent when the hidden_state or mode field in the barconfig of any bar
52	instance was updated.
53	@@ -712,14 +713,14 @@ mode is simply named default.
54	=== window event
55
56	This event consists of a single serialized map containing a property
57	-+change (string)+ which currently can indicate only that a new window
58	-has been successfully reparented (the value will be "new").
59	++change (string)+ which indicates the type of the change ("focus", "new",
60	+"title").
61
62	Additionally a +container (object)+ field will be present, which consists
63	-of the window's parent container. Be aware that the container will hold
64	-the initial name of the newly reparented window (e.g. if you run urxvt
65	-with a shell that changes the title, you will still at this point get the
66	-window title as "urxvt").
67	+of the window's parent container. Be aware that for the "new" event, the
68	+container will hold the initial name of the newly reparented window (e.g.
69	+if you run urxvt with a shell that changes the title, you will still at
70	+this point get the window title as "urxvt").
71
72	Example:
73	---------------------------

78	@@ -87,3 +87,21 @@ void dump_node(yajl_gen gen, Con *con, bool inplace_restart);
79	* respectively.
80	*/
81	void ipc_send_workspace_focus_event(Con current, Con old);
82	+
83	+/**
84	+ * For the window "focus" event we send, along the usual "change" field,
85	+ * also the window container, in "container".
86	+ */
87	+void ipc_send_window_focus_event(Con *con);
88	+
89	+/**
90	+ * For the window "new" event we send, along the usual "change" field,
91	+ * also the window container, in "container".
92	+ */
93	+void ipc_send_window_new_event(Con *con);
94	+
95	+/**
96	+ * For the window "title" event we send, along the usual "change" field,
97	+ * also the window container, in "container".
98	+ */
99	+void ipc_send_window_title_event(Con *con);