screen: XRandR 1.5 support

XRandR 1.5 adds support for the new monitor objects.

'Monitor' is a rectangular subset of the screen which represents a
coherent collection of pixels presented to the user. Each Monitor is be
associated with a list of outputs (which may be empty).

The patch below matches 1:1 screens in AwesomeWM with XRandR's Monitors.
This way I get one screen across my 4K monitor, which is represented by
two CRTCs.

Background info: http://keithp.com/blogs/MST-monitors/

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

objects/screen.c

@@ -152,6 +152,8 @@
  * @function set_newindex_miss_handler
  */
 
+DO_ARRAY(xcb_randr_output_t, randr_output, DO_NOTHING);
+
 struct screen_output_t
 {
     /** The XRandR names of the output */
@@ -159,7 +161,7 @@ struct screen_output_t
     /** The size in millimeters */
     uint32_t mm_width, mm_height;
     /** The XID */
-    xcb_randr_output_t output;
+    randr_output_array_t outputs;
 };
 
 static void
@@ -241,28 +243,76 @@ screens_exist(void)
     return globalconf.screens.len > 0;
 }
 
+/* Monitors were introduced in RandR 1.5 */
+#ifdef XCB_RANDR_GET_MONITORS
 static bool
-screen_scan_randr(void)
+screen_scan_randr_monitors(void)
 {
-    /* Check for extension before checking for XRandR */
+    xcb_randr_get_monitors_cookie_t monitors_c = xcb_randr_get_monitors(globalconf.connection, globalconf.screen->root, 1);
-    if(xcb_get_extension_data(globalconf.connection, &xcb_randr_id)->present)
+    xcb_randr_get_monitors_reply_t *monitors_r = xcb_randr_get_monitors_reply(globalconf.connection, monitors_c, NULL);
-    {
+    xcb_randr_monitor_info_iterator_t monitor_iter;
-        xcb_randr_query_version_reply_t *version_reply =
+    bool found = false;
-            xcb_randr_query_version_reply(globalconf.connection,
-                                          xcb_randr_query_version(globalconf.connection, 1, 3), 0);
-        if(version_reply)
-        {
-            uint32_t major_version = version_reply->major_version;
-            uint32_t minor_version = version_reply->minor_version;
 
-            p_delete(&version_reply);
+    for(monitor_iter = xcb_randr_get_monitors_monitors_iterator(monitors_r);
+            monitor_iter.rem; xcb_randr_monitor_info_next(&monitor_iter))
+    {
+        lua_State *L = globalconf_get_lua_State();
+        screen_t *new_screen;
+        screen_output_t output;
+        xcb_randr_output_t *randr_outputs;
+        xcb_get_atom_name_cookie_t name_c;
+        xcb_get_atom_name_reply_t *name_r;
 
-            /* Do we agree on a supported version? */
+        if(!xcb_randr_monitor_info_outputs_length(monitor_iter.data))
-            if (major_version != 1 || minor_version < 2)
+            continue;
+
+        new_screen = screen_new(L);
+        new_screen->geometry.x = monitor_iter.data->x;
+        new_screen->geometry.y = monitor_iter.data->y;
+        new_screen->geometry.width= monitor_iter.data->width;
+        new_screen->geometry.height= monitor_iter.data->height;
+
+        output.mm_width = monitor_iter.data->width_in_millimeters;
+        output.mm_height = monitor_iter.data->height_in_millimeters;
+
+        name_c = xcb_get_atom_name_unchecked(globalconf.connection, monitor_iter.data->name);
+        name_r = xcb_get_atom_name_reply(globalconf.connection, name_c, NULL);
+        if (name_r) {
+            const char *name = xcb_get_atom_name_name(name_r);
+            size_t len = xcb_get_atom_name_name_length(name_r);
+
+            output.name = memcpy(p_new(char *, len + 1), name, len);
+            output.name[len] = '\0';
+            p_delete(&name_r);
+        } else {
+            output.name = strdup("unknown");
+        }
+        randr_output_array_init(&output.outputs);
+
+        randr_outputs = xcb_randr_monitor_info_outputs(monitor_iter.data);
+        for(int i = 0; i < xcb_randr_monitor_info_outputs_length(monitor_iter.data); i++) {
+            randr_output_array_append(&output.outputs, randr_outputs[i]);
+        }
+
+        screen_output_array_append(&new_screen->outputs, output);
+        found = true;
+
+        screen_add(L, -1);
+    }
+
+    p_delete(&monitors_r);
+    return found;
+}
+#else
+screen_scan_randr_monitors(void)
+{
     return false;
+}
+#endif
 
-            globalconf.have_randr_13 = minor_version >= 3;
+static bool
-
+screen_scan_randr_crtcs(void)
+{
     /* A quick XRandR recall:
      * You have CRTC that manages a part of a SCREEN.
      * Each CRTC can draw stuff on one or more OUTPUT. */
@@ -305,17 +355,21 @@ screen_scan_randr(void)
         {
             xcb_randr_get_output_info_cookie_t output_info_c = xcb_randr_get_output_info(globalconf.connection, randr_outputs[j], XCB_CURRENT_TIME);
             xcb_randr_get_output_info_reply_t *output_info_r = xcb_randr_get_output_info_reply(globalconf.connection, output_info_c, NULL);
+            screen_output_t output;
 
             int len = xcb_randr_get_output_info_name_length(output_info_r);
             /* name is not NULL terminated */
             char *name = memcpy(p_new(char *, len + 1), xcb_randr_get_output_info_name(output_info_r), len);
             name[len] = '\0';
 
-                    screen_output_array_append(&new_screen->outputs,
+            output.name = name;
-                                               (screen_output_t) { .name = name,
+            output.mm_width = output_info_r->mm_width;
-                                                                   .mm_width = output_info_r->mm_width,
+            output.mm_height = output_info_r->mm_height;
-                                                                   .mm_height = output_info_r->mm_height,
+            randr_output_array_init(&output.outputs);
-                                                                   .output = randr_outputs[j] });
+            randr_output_array_append(&output.outputs, randr_outputs[j]);
+
+            screen_output_array_append(&new_screen->outputs, output);
+
 
             p_delete(&output_info_r);
         }
@@ -326,8 +380,42 @@ screen_scan_randr(void)
     }
 
     p_delete(&screen_res_r);
-            screen_update_primary();
 
+    return true;
+}
+
+static bool
+screen_scan_randr(void)
+{
+    /* Check for extension before checking for XRandR */
+    if(xcb_get_extension_data(globalconf.connection, &xcb_randr_id)->present)
+    {
+        xcb_randr_query_version_reply_t *version_reply =
+            xcb_randr_query_version_reply(globalconf.connection,
+                                          xcb_randr_query_version(globalconf.connection, 1, 5), 0);
+        if(version_reply)
+        {
+            uint32_t major_version = version_reply->major_version;
+            uint32_t minor_version = version_reply->minor_version;
+            bool found;
+
+            p_delete(&version_reply);
+
+            /* Do we agree on a supported version? */
+            if (major_version != 1 || minor_version < 2)
+                return false;
+
+            globalconf.have_randr_13 = minor_version >= 3;
+
+            if (minor_version >= 5)
+                found = screen_scan_randr_monitors();
+            else
+                found = screen_scan_randr_crtcs();
+
+            if (found)
+                screen_update_primary();
+            else
+                return false;
             return screens_exist();
         }
     }
@@ -664,7 +752,8 @@ screen_update_primary(void)
     foreach(screen, globalconf.screens)
     {
         foreach(output, (*screen)->outputs)
-            if (output->output == primary->output)
+            foreach (randr_output, output->outputs)
+                if (*randr_output == primary->output)
                     primary_screen = *screen;
     }
     p_delete(&primary);