i3 - improved tiling WM

Respect Motif hint for window decorations

Patch status: needinfo

Patch by Tony Crisci

Long description:

When the _MOTIF_WM_HINTS property of a window specifies it should have
no title bar, or no decorations at all, respond by setting the border
style of that container to BS_PIXEL or BS_NONE respectively.

This comes from the old Motif window manager. It was originally intended
to specify exactly what sort of decorations a window should have, and
exactly what sort of user input it should respond to. The EWMH spec
intended to replace Motif hints with _NET_WM_WINDOW_TYPE, but it is
still in use by popular widget toolkits such as GTK+ and Java AWT.

i3's implementation simply mirrors Gnome's Metacity. Official
documentation of this hint is nowhere to be found.

For more information see:
https://people.gnome.org/~tthurman/docs/metacity/xprops_8h-source.html
http://stackoverflow.com/questions/13787553/detect-if-a-x11-window-has-decorations

To apply this patch, use:
curl http://cr.i3wm.org/patch/362/raw.patch | git am

b/include/atoms.xmacro

32 
@@ -31,3 +31,4 @@ xmacro(I3_SHMLOG_PATH)
33 
 xmacro(I3_PID)
34 
 xmacro(_NET_REQUEST_FRAME_EXTENTS)
35 
 xmacro(_NET_FRAME_EXTENTS)
36 
+xmacro(_MOTIF_WM_HINTS)

b/include/window.h

41 
@@ -61,3 +61,10 @@ void window_update_role(i3Window *win, xcb_get_property_reply_t *prop, bool befo
42 
  *
43 
  */
44 
 void window_update_hints(i3Window *win, xcb_get_property_reply_t *prop, bool *urgency_hint);
45 
+
46 
+/**
47 
+ * Updates the MOTIF_WM_HINTS. The container's border style should be set to
48 
+ * `motif_border_style' if border style is not BS_NORMAL.
49 
+ *
50 
+ */
51 
+void window_update_motif_hints(i3Window *win, xcb_get_property_reply_t *prop, border_style_t *motif_border_style);

b/src/manage.c

56 
@@ -118,7 +118,8 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
57 
     xcb_get_property_cookie_t wm_type_cookie, strut_cookie, state_cookie,
58 
                               utf8_title_cookie, title_cookie,
59 
                               class_cookie, leader_cookie, transient_cookie,
60 
-                              role_cookie, startup_id_cookie, wm_hints_cookie;
61 
+                              role_cookie, startup_id_cookie, wm_hints_cookie,
62 
+                              motif_wm_hints_cookie;
63
64
65 
     geomc = xcb_get_geometry(conn, d);
66 
@@ -188,6 +189,7 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
67 
     role_cookie = GET_PROPERTY(A_WM_WINDOW_ROLE, 128);
68 
     startup_id_cookie = GET_PROPERTY(A__NET_STARTUP_ID, 512);
69 
     wm_hints_cookie = xcb_icccm_get_wm_hints(conn, window);
70 
+    motif_wm_hints_cookie = GET_PROPERTY(A__MOTIF_WM_HINTS, 5 * sizeof(long));
71 
     /* TODO: also get wm_normal_hints here. implement after we got rid of xcb-event */
72
73 
     DLOG("Managing window 0x%08x\n", window);
74 
@@ -222,6 +224,8 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
75 
     window_update_role(cwindow, xcb_get_property_reply(conn, role_cookie, NULL), true);
76 
     bool urgency_hint;
77 
     window_update_hints(cwindow, xcb_get_property_reply(conn, wm_hints_cookie, NULL), &urgency_hint);
78 
+    border_style_t motif_border_style = BS_NORMAL;
79 
+    window_update_motif_hints(cwindow, xcb_get_property_reply(conn, motif_wm_hints_cookie, NULL), &motif_border_style);
80
81 
     xcb_get_property_reply_t *startup_id_reply;
82 
     startup_id_reply = xcb_get_property_reply(conn, startup_id_cookie, NULL);
83 
@@ -444,6 +448,11 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
84 
         floating_enable(nc, true);
85 
     }
86
87 
+    if (motif_border_style != BS_NORMAL) {
88 
+        DLOG("MOTIF_WM_HINTS specifies decorations (border_style = %d)\n", motif_border_style);
89 
+        con_set_border_style(nc, motif_border_style, config.default_border_width);
90 
+    }
91 
+
92 
     /* to avoid getting an UnmapNotify event due to reparenting, we temporarily
93 
      * declare no interest in any state change event of this window */
94 
     values[0] = XCB_NONE;

b/src/window.c

99 
@@ -11,6 +11,12 @@
100 
  */
101 
 #include "all.h"
102
103 
+#define MWM_HINTS_DECORATIONS   (1L << 1)
104 
+
105 
+#define MWM_DECOR_ALL           (1L << 0)
106 
+#define MWM_DECOR_BORDER        (1L << 1)
107 
+#define MWM_DECOR_TITLE         (1L << 3)
108 
+
109 
 /*
110 
  * Updates the WM_CLASS (consisting of the class and instance) for the
111 
  * given window.
112 
@@ -254,3 +260,53 @@ void window_update_hints(i3Window *win, xcb_get_property_reply_t *prop, bool *ur
113
114 
     free(prop);
115 
 }
116 
+
117 
+/**
118 
+ * Updates the MOTIF_WM_HINTS. The container's border style should be set to
119 
+ * `motif_border_style' if border style is not BS_NORMAL.
120 
+ *
121 
+ * i3 only uses this hint when it specifies a window should have no
122 
+ * title bar, or no decorations at all, which is how most window managers
123 
+ * handle it.
124 
+ *
125 
+ * This comes from the old Motif window manager. It was originally intended to
126 
+ * specify exactly what sort of decorations a window should have, and exactly
127 
+ * what sort of user input it should respond to. The EWMH spec intended to
128 
+ * replace Motif hints with _NET_WM_WINDOW_TYPE, but it is still in use by
129 
+ * popular widget toolkits such as GTK+ and Java AWT.
130 
+ *
131 
+ */
132 
+void window_update_motif_hints(i3Window *win, xcb_get_property_reply_t *prop, border_style_t *motif_border_style) {
133 
+    /* This implementation simply mirrors Gnome's Metacity. Official
134 
+     * documentation of this hint is nowhere to be found.
135 
+     * For more information see:
136 
+     * https://people.gnome.org/~tthurman/docs/metacity/xprops_8h-source.html
137 
+     * http://stackoverflow.com/questions/13787553/detect-if-a-x11-window-has-decorations
138 
+     */
139 
+
140 
+    if (motif_border_style != NULL)
141 
+        *motif_border_style = BS_NORMAL;
142 
+
143 
+    if (prop == NULL || xcb_get_property_value_length(prop) == 0) {
144 
+        FREE(prop);
145 
+        return;
146 
+    }
147 
+
148 
+    /* The property consists of an array of 5 `long's. The first value is a bit
149 
+     * mask of what properties the hint will specify. We are only interested in
150 
+     * MWM_HINTS_DECORATIONS because it indicates that the second value of the
151 
+     * array tells us which decorations the window should have, each flag being
152 
+     * a particular decoration. */
153 
+    long *motif_hints = (long *)xcb_get_property_value(prop);
154 
+
155 
+    if (motif_border_style != NULL && motif_hints[0] & MWM_HINTS_DECORATIONS) {
156 
+        if (motif_hints[1] & MWM_DECOR_ALL || motif_hints[1] & MWM_DECOR_TITLE)
157 
+            *motif_border_style = BS_NORMAL;
158 
+        else if (motif_hints[1] & MWM_DECOR_BORDER)
159 
+            *motif_border_style = BS_PIXEL;
160 
+        else
161 
+            *motif_border_style = BS_NONE;
162 
+    }
163 
+
164 
+    FREE(prop);
165 
+}