i3 - improved tiling WM

Add support for the _NET_CLIENT_LIST root window property.

Patch status: needinfo

Patch by Steve Jones

Long description:

This sets the the _NET_CLIENT_LIST property in x_push_changes when the
client list changes. Changes to the client list are tracked by the
client_list_changed flag which is updated by x_con_init and x_con_kill.
The client list is maintained in the order of connecting by the TAILQ
with head client_head.

To apply this patch, use:
curl http://cr.i3wm.org/patch/391/raw.patch | git am

b/include/atoms.xmacro

22 
@@ -12,6 +12,7 @@ xmacro(_NET_WM_WINDOW_TYPE_TOOLBAR)
23 
 xmacro(_NET_WM_WINDOW_TYPE_SPLASH)
24 
 xmacro(_NET_WM_DESKTOP)
25 
 xmacro(_NET_WM_STRUT_PARTIAL)
26 
+xmacro(_NET_CLIENT_LIST)
27 
 xmacro(_NET_CLIENT_LIST_STACKING)
28 
 xmacro(_NET_CURRENT_DESKTOP)
29 
 xmacro(_NET_ACTIVE_WINDOW)

b/include/ewmh.h

34 
@@ -28,6 +28,11 @@ void ewmh_update_current_desktop(void);
35 
 void ewmh_update_active_window(xcb_window_t window);
36
37 
 /**
38 
+ * Updates the _NET_CLIENT_LIST hint. Used for window listers.
39 
+ */
40 
+void ewmh_update_client_list(xcb_window_t *list, int num_windows);
41 
+
42 
+/**
43 
  * Updates the _NET_CLIENT_LIST_STACKING hint. Necessary to move tabs in
44 
  * Chromium correctly.
45 
  *

b/src/ewmh.c

50 
@@ -69,6 +69,22 @@ void ewmh_update_workarea(void) {
51 
 }
52
53 
 /*
54 
+ * Updates the _NET_CLIENT_LIST hint.
55 
+ *
56 
+ */
57 
+void ewmh_update_client_list(xcb_window_t *list, int num_windows) {
58 
+    xcb_change_property(
59 
+        conn,
60 
+        XCB_PROP_MODE_REPLACE,
61 
+        root,
62 
+        A__NET_CLIENT_LIST,
63 
+        XCB_ATOM_WINDOW,
64 
+        32,
65 
+        num_windows,
66 
+        list);
67 
+}
68 
+
69 
+/*
70 
  * Updates the _NET_CLIENT_LIST_STACKING hint.
71 
  *
72 
  */

b/src/x.c

77 
@@ -20,6 +20,9 @@ xcb_window_t focused_id = XCB_NONE;
78 
 static xcb_window_t *btt_stack;
79 
 static int btt_stack_num;
80
81 
+/* Flags new clients created or destroyed, used in x_push_changes */
82 
+static bool client_list_changed = false;
83 
+
84 
 /* Stores coordinates to warp mouse pointer to if set */
85 
 static Rect *warp_to;
86
87 
@@ -55,6 +58,7 @@ typedef struct con_state {
88
89 
     CIRCLEQ_ENTRY(con_state) state;
90 
     CIRCLEQ_ENTRY(con_state) old_state;
91 
+    TAILQ_ENTRY(con_state) client_order;
92 
 } con_state;
93
94 
 CIRCLEQ_HEAD(state_head, con_state) state_head =
95 
@@ -63,6 +67,9 @@ CIRCLEQ_HEAD(state_head, con_state) state_head =
96 
 CIRCLEQ_HEAD(old_state_head, con_state) old_state_head =
97 
     CIRCLEQ_HEAD_INITIALIZER(old_state_head);
98
99 
+TAILQ_HEAD(client_head, con_state) client_head =
100 
+    TAILQ_HEAD_INITIALIZER(client_head);
101 
+
102 
 /*
103 
  * Returns the container state for the given frame. This function always
104 
  * returns a container state (otherwise, there is a bug in the code and the
105 
@@ -146,8 +153,11 @@ void x_con_init(Con *con, uint16_t depth) {
106 
     state->id = con->frame;
107 
     state->mapped = false;
108 
     state->initial = true;
109 
+    DLOG("Adding window 0x%08x to lists\n", state->id);
110 
     CIRCLEQ_INSERT_HEAD(&state_head, state, state);
111 
     CIRCLEQ_INSERT_HEAD(&old_state_head, state, old_state);
112 
+    TAILQ_INSERT_TAIL(&client_head, state, client_order);
113 
+    client_list_changed = true;
114 
     DLOG("adding new state for window id 0x%08x\n", state->id);
115 
 }
116
117 
@@ -228,6 +238,8 @@ void x_con_kill(Con *con) {
118 
     state = state_for_frame(con->frame);
119 
     CIRCLEQ_REMOVE(&state_head, state, state);
120 
     CIRCLEQ_REMOVE(&old_state_head, state, old_state);
121 
+    TAILQ_REMOVE(&client_head, state, client_order);
122 
+    client_list_changed = true;
123 
     FREE(state->name);
124 
     free(state);
125
126 
@@ -876,6 +888,8 @@ void x_push_changes(Con *con) {
127 
         btt_stack_num = cnt;
128 
     }
129
130 
+    DLOG("Getting window stacking order\n");
131 
+
132 
     xcb_window_t *walk = btt_stack;
133
134 
     /* X11 correctly represents the stack if we push it from bottom to top */
135 
@@ -906,6 +920,33 @@ void x_push_changes(Con *con) {
136 
     if (stacking_changed)
137 
         ewmh_update_client_list_stacking(btt_stack, btt_stack_num);
138
139 
+    /* If the client list changed since the last call update the
140 
+     * _NET_CLIENT_LIST property. */
141 
+    if (client_list_changed) {
142 
+	xcb_window_t *client_list;
143 
+
144 
+	DLOG("Client list changed (%i clients)\n", cnt);
145 
+
146 
+	if (cnt) {
147 
+	    client_list = smalloc(cnt * sizeof(xcb_window_t));
148 
+	    walk = client_list;
149 
+
150 
+	    TAILQ_FOREACH(state, &client_head, client_order) {
151 
+		assert((client_list - walk) < cnt);
152 
+		if (state->con && state->con->window)
153 
+		    *walk++ = state->con->window->id;
154 
+	    }
155 
+
156 
+	    ewmh_update_client_list(client_list, cnt);
157 
+
158 
+	    free(client_list);
159 
+	} else {
160 
+	    ewmh_update_client_list(NULL, 0);
161 
+	}
162 
+
163 
+	client_list_changed = false;
164 
+    }
165 
+
166 
     DLOG("PUSHING CHANGES\n");
167 
     x_push_node(con);
168