i3 - improved tiling WM

Handle WM_CLASS changes

Patch status: merged

Patch by Tony Crisci

Long description:

http://tronche.com/gui/x/icccm/sec-4.html

> The WM_CLASS property (of type STRING without control characters)
> contains two consecutive null-terminated strings. These specify the
> Instance and Class names to be used by both the client and the window
> manager for looking up resources for the application or as identifying
> information.

i3 processes changes to WM_CLASS by updating the cached property and
running assignments. This allows the property to be used in criteria
selection.

fixes #1052

To apply this patch, use:
curl http://cr.i3wm.org/patch/626/raw.patch | git am

b/src/handlers.c

28 
@@ -1092,6 +1092,29 @@ static void handle_focus_in(xcb_focus_in_event_t *event) {
29 
     return;
30 
 }
31
32 
+/*
33 
+ * Handles the WM_CLASS property for assignments and criteria selection.
34 
+ *
35 
+ */
36 
+static bool handle_class_change(void *data, xcb_connection_t *conn, uint8_t state, xcb_window_t window,
37 
+                                xcb_atom_t name, xcb_get_property_reply_t *prop) {
38 
+    Con *con;
39 
+    if ((con = con_by_window_id(window)) == NULL || con->window == NULL)
40 
+        return false;
41 
+
42 
+    if (prop == NULL) {
43 
+        prop = xcb_get_property_reply(conn, xcb_get_property_unchecked(conn,
44 
+                    false, window, XCB_ATOM_WM_CLASS, XCB_ATOM_STRING, 0, 32), NULL);
45 
+
46 
+        if (prop == NULL)
47 
+            return false;
48 
+    }
49 
+
50 
+    window_update_class(con->window, prop, false);
51 
+
52 
+    return true;
53 
+}
54 
+
55 
 /* Returns false if the event could not be processed (e.g. the window could not
56 
  * be found), true otherwise */
57 
 typedef bool (*cb_property_handler_t)(void *data, xcb_connection_t *c, uint8_t state, xcb_window_t window, xcb_atom_t atom, xcb_get_property_reply_t *property);
58 
@@ -1109,7 +1132,9 @@ static struct property_handler_t property_handlers[] = {
59 
     {0, UINT_MAX, handle_normal_hints},
60 
     {0, UINT_MAX, handle_clientleader_change},
61 
     {0, UINT_MAX, handle_transient_for},
62 
-    {0, 128, handle_windowrole_change}};
63 
+    {0, 128, handle_windowrole_change},
64 
+    {0, 128, handle_class_change}
65 
+};
66 
 #define NUM_HANDLERS (sizeof(property_handlers) / sizeof(struct property_handler_t))
67
68 
 /*
69 
@@ -1127,6 +1152,7 @@ void property_handlers_init(void) {
70 
     property_handlers[4].atom = A_WM_CLIENT_LEADER;
71 
     property_handlers[5].atom = XCB_ATOM_WM_TRANSIENT_FOR;
72 
     property_handlers[6].atom = A_WM_WINDOW_ROLE;
73 
+    property_handlers[7].atom = XCB_ATOM_WM_CLASS;
74 
 }
75
76 
 static void property_notify(uint8_t state, xcb_window_t window, xcb_atom_t atom) {

b/testcases/t/235-wm-class-change-handler.t

82 
@@ -0,0 +1,70 @@
83 
+#!perl
84 
+# vim:ts=4:sw=4:expandtab
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+#
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+# Please read the following documents before working on tests:
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+# • http://build.i3wm.org/docs/testsuite.html
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+#   (or docs/testsuite)
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+#
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+# • http://build.i3wm.org/docs/lib-i3test.html
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+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
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+#
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+# • http://build.i3wm.org/docs/ipc.html
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+#   (or docs/ipc)
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+#
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+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
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+#   (unless you are already familiar with Perl)
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+#
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+# Test that changes to WM_CLASS are internally processed by i3 by updating the
100 
+# cached property and running assignments. This allows the property to be used
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+# in criteria selection
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+# Ticket: #1052
103 
+# Bug still in: 4.8-73-g6bf7f8e
104 
+use i3test i3_autostart => 0;
105 
+use X11::XCB qw(PROP_MODE_REPLACE);
106 
+
107 
+my $config = <<EOT;
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+# i3 config file (v4)
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+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
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+for_window [class="Special"] mark special_class_mark
111 
+EOT
112 
+
113 
+my $pid = launch_with_config($config);
114 
+
115 
+sub change_window_class {
116 
+    my ($window, $class) = @_;
117 
+    my $atomname = $x->atom(name => 'WM_CLASS');
118 
+    my $atomtype = $x->atom(name => 'STRING');
119 
+    $x->change_property(
120 
+        PROP_MODE_REPLACE,
121 
+        $window->id,
122 
+        $atomname->id,
123 
+        $atomtype->id,
124 
+        8,
125 
+        length($class) + 1,
126 
+        $class
127 
+    );
128 
+    sync_with_i3;
129 
+}
130 
+
131 
+my $ws = fresh_workspace;
132 
+
133 
+my $win = open_window;
134 
+
135 
+change_window_class($win, "special\0Special");
136 
+
137 
+my $con = @{get_ws_content($ws)}[0];
138 
+
139 
+is($con->{window_properties}->{class}, 'Special',
140 
+    'The container class should be updated when a window changes class');
141 
+
142 
+is($con->{window_properties}->{instance}, 'special',
143 
+    'The container instance should be updated when a window changes instance');
144 
+
145 
+# The mark `special_class_mark` is added in a `for_window` assignment in the
146 
+# config for testing purposes
147 
+is($con->{mark}, 'special_class_mark',
148 
+    'A `for_window` assignment should run for a match when the window changes class');
149 
+
150 
+exit_gracefully($pid);
151 
+
152 
+done_testing;