i3 - improved tiling WM

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Add optional bidirectional interface to i3bar. (ver.4)

Patch status: needinfo

Patch by enkore

Long description:

If the child specifies bidirectional:1 in the protocl header,
a JSON array will be streamed to it's stdin.
It consists of maps with at least one key (command).

Such a map is emitted if the user clicks on a status block. i.e.
{"command":"block_clicked","name":"some_block_name","instance":"optional_instance"}

The basic output format is like the rest of the i3bar protocol (i.e.
a new line after each element (map in this case))

The second version of this patch mainly introduced a better API for sending
commands.

The third version of this patch introduced the additional button parameter and thus
added support for right clicks. Now root window coordinates are passed instead of
window coordinates.

The fourth version of this patch (re-)added closing of unused pipe fd's.
Some superfluous whitespace was removed, too.

To apply this patch, use:
curl http://cr.i3wm.org/patch/73/raw.patch | git am

b/docs/i3bar-protocol

@@ -51,7 +51,7 @@ consists of a single JSON hash:
 
 *All features example*:
 ------------------------------
-{ "version": 1, "stop_signal": 10, "cont_signal": 12 }
+{ "version": 1, "stop_signal": 10, "cont_signal": 12, "bidirectional": 1 }
 ------------------------------
 
 (Note that before i3 v4.3 the precise format had to be +{"version":1}+,
@@ -110,6 +110,9 @@ cont_signal::
 	Specify to i3bar the signal (as an integer)to send to continue your
 	processing.
 	The default value (if none is specified) is SIGCONT.
+bidirectional::
+	If specified and 1 i3bar will write a infinite array (same as above)
+	to your stdin.
 
 === Blocks in detail
 
@@ -183,3 +186,33 @@ An example of a block which uses all possible entries follows:
  "instance": "eth0"
 }
 ------------------------------------------
+
+=== Bidirectional communication
+
+If enabled i3bar will send you notifications about certain events, currently
+only one such notification is implmented: block_clicked.
+It is send if the user clicks on a block and looks like this:
+
+command::
+	Always block_clicked at the moment, but more are maybe added later.
+name::
+	Name of the block, if set
+instance::
+	Instance of the block, if set
+x, y::
+	X11 root window coordinates where the click occured
+button:
+	X11 button ID, either 1 or 3 for left or right mouse button,
+	respectively.
+
+*Example*:
+------------------------------------------
+{
+ "command": "block_clicked",
+ "name": "ethernet",
+ "instance": "eth0",
+ "button": 1,
+ "x": 1320,
+ "y": 1400
+}
+------------------------------------------

b/i3bar/include/child.h

@@ -33,6 +33,12 @@ typedef struct {
      * The signal requested by the client to inform it of theun hidden state of i3bar
      */
     int cont_signal;
+
+    /**
+     * Enable bi-directional communication, i.e. on-click events
+     */
+    bool bidirectional;
+    int bidirectional_init;
 } i3bar_child;
 
 /*
@@ -68,4 +74,10 @@ void stop_child(void);
  */
 void cont_child(void);
 
+/*
+ * ends the block_clicked command to the child
+ *
+ */
+void send_block_clicked(int button, const char *name, const char *instance, int x, int y);
+
 #endif

b/i3bar/include/common.h

@@ -50,6 +50,10 @@ struct status_block {
     uint32_t x_offset;
     uint32_t x_append;
 
+    /* Optional */
+    char *name;
+    char *instance;
+
     TAILQ_ENTRY(status_block) blocks;
 };
 

b/i3bar/src/child.c

@@ -21,6 +21,7 @@
 #include <yajl/yajl_common.h>
 #include <yajl/yajl_parse.h>
 #include <yajl/yajl_version.h>
+#include <yajl/yajl_gen.h>
 
 #include "common.h"
 
@@ -35,6 +36,9 @@ ev_child *child_sig;
 yajl_callbacks callbacks;
 yajl_handle parser;
 
+/* JSON generator for stdout */
+yajl_gen gen;
+
 typedef struct parser_ctx {
     /* True if one of the parsed blocks was urgent */
     bool has_urgent;
@@ -141,6 +145,18 @@ static int stdin_string(void *context, const unsigned char *val, unsigned int le
             ctx->block.align = ALIGN_CENTER;
         }
     }
+    if (strcasecmp(ctx->last_map_key, "name") == 0) {
+        char *copy = (char*)malloc(len+1);
+        strncpy(copy, (const char *)val, len);
+        copy[len] = 0;
+        ctx->block.name = copy;
+    }
+    if (strcasecmp(ctx->last_map_key, "instance") == 0) {
+        char *copy = (char*)malloc(len+1);
+        strncpy(copy, (const char *)val, len);
+        copy[len] = 0;
+        ctx->block.instance = copy;
+    }
     return 1;
 }
 
@@ -322,6 +338,18 @@ void child_sig_cb(struct ev_loop *loop, ev_child *watcher, int revents) {
     cleanup();
 }
 
+void child_write_output(void) {
+    if(child.bidirectional) {
+        const unsigned char *output;
+        size_t size;
+        yajl_gen_get_buf(gen, &output, &size);
+        fwrite(output, 1, size, stdout);
+        fwrite("\n", 1, 1, stdout);
+        fflush(stdout);
+        yajl_gen_clear(gen);
+    }
+}
+
 /*
  * Start a child-process with the specified command and reroute stdin.
  * We actually start a $SHELL to execute the command so we don't have to care
@@ -347,10 +375,14 @@ void start_child(char *command) {
     parser = yajl_alloc(&callbacks, NULL, &parser_context);
 #endif
 
+    gen = yajl_gen_alloc(NULL);
+
     if (command != NULL) {
-        int fd[2];
+        int fd[4];
         if (pipe(fd) == -1)
             err(EXIT_FAILURE, "pipe(fd)");
+        if (pipe(&fd[2]) == -1)
+            err(EXIT_FAILURE, "pipe(fd)");
 
         child.pid = fork();
         switch (child.pid) {
@@ -358,10 +390,13 @@ void start_child(char *command) {
                 ELOG("Couldn't fork(): %s\n", strerror(errno));
                 exit(EXIT_FAILURE);
             case 0:
-                /* Child-process. Reroute stdout and start shell */
+                /* Child-process. Reroute streams and start shell */
+
                 close(fd[0]);
+                close(fd[3]);
 
                 dup2(fd[1], STDOUT_FILENO);
+                dup2(fd[2], STDIN_FILENO);
 
                 static const char *shell = NULL;
 
@@ -371,10 +406,13 @@ void start_child(char *command) {
                 execl(shell, shell, "-c", command, (char*) NULL);
                 return;
             default:
-                /* Parent-process. Rerout stdin */
+                /* Parent-process. Reroute streams */
+
                 close(fd[1]);
+                close(fd[2]);
 
                 dup2(fd[0], STDIN_FILENO);
+                dup2(fd[3], STDOUT_FILENO);
 
                 break;
         }
@@ -396,6 +434,69 @@ void start_child(char *command) {
 }
 
 /*
+ * Internal helper functions for bidirectional comms
+ *
+ */
+void child_bidi_initialize(void) {
+    if(!child.bidirectional_init) {
+        yajl_gen_array_open(gen);
+        child_write_output();
+        child.bidirectional_init = 1;
+    }
+}
+
+void child_bidi_key(const char *key) {
+    yajl_gen_string(gen, (const unsigned char *)key, strlen(key));
+}
+
+void child_bidi_open(const char *command) {
+    child_bidi_initialize();
+
+    yajl_gen_map_open(gen);
+
+    child_bidi_key("command");
+    yajl_gen_string(gen, (const unsigned char *)command, strlen(command));
+}
+
+void child_bidi_close(void) {
+    yajl_gen_map_close(gen);
+    child_write_output();
+}
+
+/*
+ * sends the block_clicked command to the child
+ *
+ */
+void send_block_clicked(int button, const char *name, const char *instance, int x, int y) {
+    if(child.bidirectional) {
+        child_bidi_open("block_clicked");
+
+        if(name) {
+            child_bidi_key("name");
+            yajl_gen_string(gen, (const unsigned char *)name, strlen(name));
+        }
+
+        if(instance) {
+            child_bidi_key("instance");
+            yajl_gen_string(gen, (const unsigned char *)instance, strlen(instance));
+        }
+
+        child_bidi_key("button");
+        yajl_gen_integer(gen, button);
+
+        child_bidi_key("x");
+        yajl_gen_integer(gen, x);
+
+        child_bidi_key("y");
+        yajl_gen_integer(gen, y);
+
+        yajl_gen_map_close(gen);
+
+        child_write_output();
+    }
+}
+
+/*
  * kill()s the child-process (if any). Called when exit()ing.
  *
  */

b/i3bar/src/parse_json_header.c

@@ -31,6 +31,7 @@ static enum {
     KEY_VERSION,
     KEY_STOP_SIGNAL,
     KEY_CONT_SIGNAL,
+    KEY_BIDIRECTIONAL,
     NO_KEY
 } current_key;
 
@@ -51,6 +52,8 @@ static int header_integer(void *ctx, long val) {
         case KEY_CONT_SIGNAL:
             child->cont_signal = val;
             break;
+        case KEY_BIDIRECTIONAL:
+            child->bidirectional = val;
         default:
             break;
     }
@@ -71,6 +74,8 @@ static int header_map_key(void *ctx, const unsigned char *stringval, unsigned in
         current_key = KEY_STOP_SIGNAL;
     } else if (CHECK_KEY("cont_signal")) {
         current_key = KEY_CONT_SIGNAL;
+    } else if (CHECK_KEY("bidirectional")) {
+        current_key = KEY_BIDIRECTIONAL;
     }
     return 1;
 }

b/i3bar/src/xcb.c

@@ -306,12 +306,14 @@ void handle_button(xcb_button_press_event_t *event) {
     }
 
     int32_t x = event->event_x >= 0 ? event->event_x : 0;
+    int32_t original_x = x;
 
     DLOG("Got Button %d\n", event->detail);
 
     switch (event->detail) {
         case 1:
-            /* Left Mousbutton. We determine, which button was clicked
+        case 3:
+            /* Left or right Mousbutton. We determine, which button was clicked
              * and set cur_ws accordingly */
             TAILQ_FOREACH(cur_ws, walk->workspaces, tailq) {
                 DLOG("x = %d\n", x);
@@ -321,8 +323,43 @@ void handle_button(xcb_button_press_event_t *event) {
                 x -= cur_ws->name_width + 11;
             }
             if (cur_ws == NULL) {
+                /* No workspace button was pressed.
+                 * Check if a status block has been clicked.
+                 * This of course only has an effect,
+                 * if the child reported bidirectional protocol usage. */
+
+                /* First calculate width of tray area */
+                trayclient *trayclient;
+                int tray_width = 0;
+                TAILQ_FOREACH_REVERSE(trayclient, walk->trayclients, tc_head, tailq) {
+                    if (!trayclient->mapped)
+                        continue;
+                    tray_width += (font.height + 2);
+                }
+
+                int block_x = 0, last_block_x;
+                int offset = (walk->rect.w - (statusline_width + tray_width)) - 10;
+
+                x = original_x - offset > 0 ? original_x - offset : 0;
+
+                struct status_block *block;
+
+                TAILQ_FOREACH(block, &statusline_head, blocks) {
+                    last_block_x = block_x;
+                    block_x += block->width + block->x_offset + block->x_append;
+
+                    if(x <= block_x && x >= last_block_x) {
+                        send_block_clicked(event->detail, block->name, block->instance, event->root_x, event->root_y);
+                        return;
+                    }
+                }
                 return;
             }
+            if (event->detail == 3)
+                /* Don't actually switch the
+                 * workspace if it was the right mouse button
+                 */
+                return;
             break;
         case 4:
             /* Mouse wheel up. We select the previous ws, if any.

122	@@ -50,6 +50,10 @@ struct status_block {
123	uint32_t x_offset;
124	uint32_t x_append;
125
126	+ /* Optional */
127	+ char *name;
128	+ char *instance;
129	+
130	TAILQ_ENTRY(status_block) blocks;
131	};
132

137	@@ -21,6 +21,7 @@
138	#include <yajl/yajl_common.h>
139	#include <yajl/yajl_parse.h>
140	#include <yajl/yajl_version.h>
141	+#include <yajl/yajl_gen.h>
142
143	#include "common.h"
144
145	@@ -35,6 +36,9 @@ ev_child *child_sig;
146	yajl_callbacks callbacks;
147	yajl_handle parser;
148
149	+/* JSON generator for stdout */
150	+yajl_gen gen;
151	+
152	typedef struct parser_ctx {
153	/* True if one of the parsed blocks was urgent */
154	bool has_urgent;
155	@@ -141,6 +145,18 @@ static int stdin_string(void context, const unsigned char val, unsigned int le
156	ctx->block.align = ALIGN_CENTER;
157	}
158	}
159	+ if (strcasecmp(ctx->last_map_key, "name") == 0) {
160	+ char copy = (char)malloc(len+1);
161	+ strncpy(copy, (const char *)val, len);
162	+ copy[len] = 0;
163	+ ctx->block.name = copy;
164	+ }
165	+ if (strcasecmp(ctx->last_map_key, "instance") == 0) {
166	+ char copy = (char)malloc(len+1);
167	+ strncpy(copy, (const char *)val, len);
168	+ copy[len] = 0;
169	+ ctx->block.instance = copy;
170	+ }
171	return 1;
172	}
173
174	@@ -322,6 +338,18 @@ void child_sig_cb(struct ev_loop loop, ev_child watcher, int revents) {
175	cleanup();
176	}
177
178	+void child_write_output(void) {
179	+ if(child.bidirectional) {
180	+ const unsigned char *output;
181	+ size_t size;
182	+ yajl_gen_get_buf(gen, &output, &size);
183	+ fwrite(output, 1, size, stdout);
184	+ fwrite("\n", 1, 1, stdout);
185	+ fflush(stdout);
186	+ yajl_gen_clear(gen);
187	+ }
188	+}
189	+
190	/*
191	* Start a child-process with the specified command and reroute stdin.
192	* We actually start a $SHELL to execute the command so we don't have to care
193	@@ -347,10 +375,14 @@ void start_child(char *command) {
194	parser = yajl_alloc(&callbacks, NULL, &parser_context);
195	#endif
196
197	+ gen = yajl_gen_alloc(NULL);
198	+
199	if (command != NULL) {
200	- int fd[2];
201	+ int fd[4];
202	if (pipe(fd) == -1)
203	err(EXIT_FAILURE, "pipe(fd)");
204	+ if (pipe(&fd[2]) == -1)
205	+ err(EXIT_FAILURE, "pipe(fd)");
206
207	child.pid = fork();
208	switch (child.pid) {
209	@@ -358,10 +390,13 @@ void start_child(char *command) {
210	ELOG("Couldn't fork(): %s\n", strerror(errno));
211	exit(EXIT_FAILURE);
212	case 0:
213	- /* Child-process. Reroute stdout and start shell */
214	+ /* Child-process. Reroute streams and start shell */
215	+
216	close(fd[0]);
217	+ close(fd[3]);
218
219	dup2(fd[1], STDOUT_FILENO);
220	+ dup2(fd[2], STDIN_FILENO);
221
222	static const char *shell = NULL;
223
224	@@ -371,10 +406,13 @@ void start_child(char *command) {
225	execl(shell, shell, "-c", command, (char*) NULL);
226	return;
227	default:
228	- /* Parent-process. Rerout stdin */
229	+ /* Parent-process. Reroute streams */
230	+
231	close(fd[1]);
232	+ close(fd[2]);
233
234	dup2(fd[0], STDIN_FILENO);
235	+ dup2(fd[3], STDOUT_FILENO);
236
237	break;
238	}
239	@@ -396,6 +434,69 @@ void start_child(char *command) {
240	}
241
242	/*
243	+ * Internal helper functions for bidirectional comms
244	+ *
245	+ */
246	+void child_bidi_initialize(void) {
247	+ if(!child.bidirectional_init) {
248	+ yajl_gen_array_open(gen);
249	+ child_write_output();
250	+ child.bidirectional_init = 1;
251	+ }
252	+}
253	+
254	+void child_bidi_key(const char *key) {
255	+ yajl_gen_string(gen, (const unsigned char *)key, strlen(key));
256	+}
257	+
258	+void child_bidi_open(const char *command) {
259	+ child_bidi_initialize();
260	+
261	+ yajl_gen_map_open(gen);
262	+
263	+ child_bidi_key("command");
264	+ yajl_gen_string(gen, (const unsigned char *)command, strlen(command));
265	+}
266	+
267	+void child_bidi_close(void) {
268	+ yajl_gen_map_close(gen);
269	+ child_write_output();
270	+}
271	+
272	+/*
273	+ * sends the block_clicked command to the child
274	+ *
275	+ */
276	+void send_block_clicked(int button, const char name, const char instance, int x, int y) {
277	+ if(child.bidirectional) {
278	+ child_bidi_open("block_clicked");
279	+
280	+ if(name) {
281	+ child_bidi_key("name");
282	+ yajl_gen_string(gen, (const unsigned char *)name, strlen(name));
283	+ }
284	+
285	+ if(instance) {
286	+ child_bidi_key("instance");
287	+ yajl_gen_string(gen, (const unsigned char *)instance, strlen(instance));
288	+ }
289	+
290	+ child_bidi_key("button");
291	+ yajl_gen_integer(gen, button);
292	+
293	+ child_bidi_key("x");
294	+ yajl_gen_integer(gen, x);
295	+
296	+ child_bidi_key("y");
297	+ yajl_gen_integer(gen, y);
298	+
299	+ yajl_gen_map_close(gen);
300	+
301	+ child_write_output();
302	+ }
303	+}
304	+
305	+/*
306	* kill()s the child-process (if any). Called when exit()ing.
307	*
308	*/

37	@@ -51,7 +51,7 @@ consists of a single JSON hash:
38
39	All features example:
40	------------------------------
41	-{ "version": 1, "stop_signal": 10, "cont_signal": 12 }
42	+{ "version": 1, "stop_signal": 10, "cont_signal": 12, "bidirectional": 1 }
43	------------------------------
44
45	(Note that before i3 v4.3 the precise format had to be +{"version":1}+,
46	@@ -110,6 +110,9 @@ cont_signal::
47	Specify to i3bar the signal (as an integer)to send to continue your
48	processing.
49	The default value (if none is specified) is SIGCONT.
50	+bidirectional::
51	+ If specified and 1 i3bar will write a infinite array (same as above)
52	+ to your stdin.
53
54	=== Blocks in detail
55
56	@@ -183,3 +186,33 @@ An example of a block which uses all possible entries follows:
57	"instance": "eth0"
58	}
59	------------------------------------------
60	+
61	+=== Bidirectional communication
62	+
63	+If enabled i3bar will send you notifications about certain events, currently
64	+only one such notification is implmented: block_clicked.
65	+It is send if the user clicks on a block and looks like this:
66	+
67	+command::
68	+ Always block_clicked at the moment, but more are maybe added later.
69	+name::
70	+ Name of the block, if set
71	+instance::
72	+ Instance of the block, if set
73	+x, y::
74	+ X11 root window coordinates where the click occured
75	+button:
76	+ X11 button ID, either 1 or 3 for left or right mouse button,
77	+ respectively.
78	+
79	+Example:
80	+------------------------------------------
81	+{
82	+ "command": "block_clicked",
83	+ "name": "ethernet",
84	+ "instance": "eth0",
85	+ "button": 1,
86	+ "x": 1320,
87	+ "y": 1400
88	+}
89	+------------------------------------------

94	@@ -33,6 +33,12 @@ typedef struct {
95	* The signal requested by the client to inform it of theun hidden state of i3bar
96	*/
97	int cont_signal;
98	+
99	+ /**
100	+ * Enable bi-directional communication, i.e. on-click events
101	+ */
102	+ bool bidirectional;
103	+ int bidirectional_init;
104	} i3bar_child;
105
106	/*
107	@@ -68,4 +74,10 @@ void stop_child(void);
108	*/
109	void cont_child(void);
110
111	+/*
112	+ * ends the block_clicked command to the child
113	+ *
114	+ */
115	+void send_block_clicked(int button, const char name, const char instance, int x, int y);
116	+
117	#endif

313	@@ -31,6 +31,7 @@ static enum {
314	KEY_VERSION,
315	KEY_STOP_SIGNAL,
316	KEY_CONT_SIGNAL,
317	+ KEY_BIDIRECTIONAL,
318	NO_KEY
319	} current_key;
320
321	@@ -51,6 +52,8 @@ static int header_integer(void *ctx, long val) {
322	case KEY_CONT_SIGNAL:
323	child->cont_signal = val;
324	break;
325	+ case KEY_BIDIRECTIONAL:
326	+ child->bidirectional = val;
327	default:
328	break;
329	}
330	@@ -71,6 +74,8 @@ static int header_map_key(void ctx, const unsigned char stringval, unsigned in
331	current_key = KEY_STOP_SIGNAL;
332	} else if (CHECK_KEY("cont_signal")) {
333	current_key = KEY_CONT_SIGNAL;
334	+ } else if (CHECK_KEY("bidirectional")) {
335	+ current_key = KEY_BIDIRECTIONAL;
336	}
337	return 1;
338	}

343	@@ -306,12 +306,14 @@ void handle_button(xcb_button_press_event_t *event) {
344	}
345
346	int32_t x = event->event_x >= 0 ? event->event_x : 0;
347	+ int32_t original_x = x;
348
349	DLOG("Got Button %d\n", event->detail);
350
351	switch (event->detail) {
352	case 1:
353	- /* Left Mousbutton. We determine, which button was clicked
354	+ case 3:
355	+ /* Left or right Mousbutton. We determine, which button was clicked
356	* and set cur_ws accordingly */
357	TAILQ_FOREACH(cur_ws, walk->workspaces, tailq) {
358	DLOG("x = %d\n", x);
359	@@ -321,8 +323,43 @@ void handle_button(xcb_button_press_event_t *event) {
360	x -= cur_ws->name_width + 11;
361	}
362	if (cur_ws == NULL) {
363	+ /* No workspace button was pressed.
364	+ * Check if a status block has been clicked.
365	+ * This of course only has an effect,
366	+ * if the child reported bidirectional protocol usage. */
367	+
368	+ /* First calculate width of tray area */
369	+ trayclient *trayclient;
370	+ int tray_width = 0;
371	+ TAILQ_FOREACH_REVERSE(trayclient, walk->trayclients, tc_head, tailq) {
372	+ if (!trayclient->mapped)
373	+ continue;
374	+ tray_width += (font.height + 2);
375	+ }
376	+
377	+ int block_x = 0, last_block_x;
378	+ int offset = (walk->rect.w - (statusline_width + tray_width)) - 10;
379	+
380	+ x = original_x - offset > 0 ? original_x - offset : 0;
381	+
382	+ struct status_block *block;
383	+
384	+ TAILQ_FOREACH(block, &statusline_head, blocks) {
385	+ last_block_x = block_x;
386	+ block_x += block->width + block->x_offset + block->x_append;
387	+
388	+ if(x <= block_x && x >= last_block_x) {
389	+ send_block_clicked(event->detail, block->name, block->instance, event->root_x, event->root_y);
390	+ return;
391	+ }
392	+ }
393	return;
394	}
395	+ if (event->detail == 3)
396	+ /* Don't actually switch the
397	+ * workspace if it was the right mouse button
398	+ */
399	+ return;
400	break;
401	case 4:
402	/* Mouse wheel up. We select the previous ws, if any.