i3 - improved tiling WM

Support _NET_WM_MOVERESIZE

Patch status: needinfo

Patch by Lukas K

Long description:

Add support for the _NET_WM_MOVERESIZE client message. This message
enables clients to initiate window moving or resizing. Toolkits like
Gtk3 use this message when the user drags a client-side decorated window
by its title bar. When Gtk detects that the window manager does not
support this client message, it uses a slow fallback implementation.

fixes #1432

To apply this patch, use:
curl http://cr.i3wm.org/patch/709/raw.patch | git am

b/include/atoms.xmacro

22 
@@ -1,6 +1,7 @@
23 
 xmacro(_NET_SUPPORTED)
24 
 xmacro(_NET_SUPPORTING_WM_CHECK)
25 
 xmacro(_NET_WM_NAME)
26 
+xmacro(_NET_WM_MOVERESIZE)
27 
 xmacro(_NET_WM_STATE_FULLSCREEN)
28 
 xmacro(_NET_WM_STATE_DEMANDS_ATTENTION)
29 
 xmacro(_NET_WM_STATE_MODAL)

b/src/ewmh.c

34 
@@ -234,5 +234,6 @@ void ewmh_setup_hints(void) {
35 
     /* I’m not entirely sure if we need to keep _NET_WM_NAME on root. */
36 
     xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_WM_NAME, A_UTF8_STRING, 8, strlen("i3"), "i3");
37
38 
-    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTED, XCB_ATOM_ATOM, 32, 23, supported_atoms);
39 
+    /* only send the first 24 atoms (last one is _NET_CLOSE_WINDOW) increment that number when adding supported atoms */
40 
+    xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTED, XCB_ATOM_ATOM, 32, 24, supported_atoms);
41 
 }

b/src/handlers.c

46 
@@ -651,6 +651,19 @@ static void handle_expose_event(xcb_expose_event_t *event) {
47 
     return;
48 
 }
49
50 
+#define _NET_WM_MOVERESIZE_SIZE_TOPLEFT      0
51 
+#define _NET_WM_MOVERESIZE_SIZE_TOP          1
52 
+#define _NET_WM_MOVERESIZE_SIZE_TOPRIGHT     2
53 
+#define _NET_WM_MOVERESIZE_SIZE_RIGHT        3
54 
+#define _NET_WM_MOVERESIZE_SIZE_BOTTOMRIGHT  4
55 
+#define _NET_WM_MOVERESIZE_SIZE_BOTTOM       5
56 
+#define _NET_WM_MOVERESIZE_SIZE_BOTTOMLEFT   6
57 
+#define _NET_WM_MOVERESIZE_SIZE_LEFT         7
58 
+#define _NET_WM_MOVERESIZE_MOVE              8  /* movement only */
59 
+#define _NET_WM_MOVERESIZE_SIZE_KEYBOARD     9  /* size via keyboard */
60 
+#define _NET_WM_MOVERESIZE_MOVE_KEYBOARD     10 /* move via keyboard */
61 
+#define _NET_WM_MOVERESIZE_CANCEL            11 /* cancel operation */
62 
+
63 
 /*
64 
  * Handle client messages (EWMH)
65 
  *
66 
@@ -856,6 +869,33 @@ static void handle_client_message(xcb_client_message_event_t *event) {
67 
         } else {
68 
             DLOG("Couldn't find con for _NET_CLOSE_WINDOW request. (window = %d)\n", event->window);
69 
         }
70 
+    } else if (event->type == A__NET_WM_MOVERESIZE) {
71 
+        /*
72 
+         * Client-side decorated Gtk3 windows emit this signal when being
73 
+         * dragged by their GtkHeaderBar
74 
+         */
75 
+        Con *con = con_by_window_id(event->window);
76 
+        if (!con || !con_is_floating(con)) {
77 
+            DLOG("Couldn't find con for _NET_WM_MOVERESIZE request, or con not floating (window = %d)\n", event->window);
78 
+            return;
79 
+        }
80 
+        DLOG("Handling _NET_WM_MOVERESIZE request (con = %p)\n", con);
81 
+        uint32_t direction = event->data.data32[2];
82 
+        uint32_t x_root = event->data.data32[0];
83 
+        uint32_t y_root = event->data.data32[1];
84 
+        /* construct fake xcb_button_press_event_t */
85 
+        xcb_button_press_event_t fake = {
86 
+            .root_x = x_root,
87 
+            .root_y = y_root,
88 
+            .event_x = x_root - (con->rect.x),
89 
+            .event_y = y_root - (con->rect.y)};
90 
+        if (direction == _NET_WM_MOVERESIZE_MOVE) {
91 
+            floating_drag_window(con->parent, &fake);
92 
+        } else if (direction >= _NET_WM_MOVERESIZE_SIZE_TOPLEFT && direction <= _NET_WM_MOVERESIZE_SIZE_LEFT) {
93 
+            floating_resize_window(con->parent, FALSE, &fake);
94 
+        } else {
95 
+            DLOG("_NET_WM_MOVERESIZE direction %d not implemented\n", direction);
96 
+        }
97 
     } else {
98 
         DLOG("unhandled clientmessage\n");
99 
         return;