fix(xrandr): Less strict monitor matching

Be less strict when matching randr outputs
against specified name. This is a workaround
to fix the output naming issue when switching
between graphic drivers.

On my system the output names include a dash
when using the nvidia drivers but the intel
driver does not.

   nvidia:
      HDMI-1
      eDP-1
   xf86-video-intel:
      HDMI1
      eDP1

When strict mode is disabled the matching
won't care about the connection state.

The user can re-enable exact matching and
connection state testing by setting the
config parameter `monitor-strict = true`

include/x11/randr.hpp

@@ -20,20 +20,31 @@ struct backlight_values {
 };
 
 struct randr_output {
-  xcb_randr_output_t randr_output;
   string name;
   int w = 0;
   int h = 0;
   int x = 0;
   int y = 0;
+  xcb_randr_output_t output;
   backlight_values backlight;
+
+  /**
+   * Workaround for the inconsistent naming
+   * of outputs between my intel and nvidia
+   * drivers (xf86-video-intel drops the dash)
+   */
+  bool match(const string& o, bool strict = false) const {
+    if (strict && name != o)
+      return false;
+    return name == o || name == string_util::replace(o, "-", "");
+  }
 };
 
 using monitor_t = shared_ptr<randr_output>;
 
 namespace randr_util {
   monitor_t make_monitor(xcb_randr_output_t randr, string name, int w, int h, int x, int y);
-  vector<monitor_t> get_monitors(connection& conn, xcb_window_t root);
+  vector<monitor_t> get_monitors(connection& conn, xcb_window_t root, bool connected_only = false);
 
   void get_backlight_range(connection& conn, const monitor_t& mon, backlight_values& dst);
   void get_backlight_value(connection& conn, const monitor_t& mon, backlight_values& dst);

src/components/bar.cpp

@@ -532,19 +532,22 @@ void bar::configure_geom() {  // {{{
 void bar::create_monitor() {  // {{{
   m_log.trace("bar: Create monitor from matching X RandR output");
 
-  auto monitors = randr_util::get_monitors(m_connection, m_screen->root);
+  auto strict = m_conf.get<bool>(m_conf.bar_section(), "monitor-strict", false);
+  auto monitors = randr_util::get_monitors(m_connection, m_screen->root, strict);
+
   if (monitors.empty()) {
     throw application_error("No monitors found");
   }
 
   auto name = m_conf.get<string>(m_conf.bar_section(), "monitor", "");
+
   if (name.empty()) {
     name = monitors[0]->name;
     m_log.warn("No monitor specified, using \"%s\"", name);
   }
 
   for (auto&& monitor : monitors) {
-    if (name == monitor->name) {
+    if (monitor->match(name, strict)) {
       m_opts.monitor = move(monitor);
       break;
     }
@@ -841,18 +844,14 @@ void bar::handle(const evt::expose& evt) {  // {{{
 /**
  * Event handler for XCB_PROPERTY_NOTIFY events
  *
- * Used to emit events whenever the bar window's
- * visibility gets changes. This allows us to toggle the
+ * - Emit events whenever the bar window's
+ * visibility gets changed. This allows us to toggle the
  * state of the tray container even though the tray
- * window restacking failed.
+ * window restacking failed.  Used as a fallback for
+ * tedious WM's, like i3.
  *
- * This is used as a fallback for tedious WM's, like i3.
- *
- * Some might call it a dirty hack, others a crappy
- * solution... I choose to call it a masterpiece! Plus
- * it's not really any overhead worth talking about.
- *
- * Also tracks the root pixmap
+ * - Track the root pixmap atom to update the
+ * pseudo-transparent background when it changes
  */
 void bar::handle(const evt::property_notify& evt) {  // {{{
 #ifdef DEBUG

src/modules/xbacklight.cpp

@@ -10,10 +10,11 @@ namespace modules {
    */
   void xbacklight_module::setup() {
     auto output = m_conf.get<string>(name(), "output", m_bar.monitor->name);
+    auto strict = m_conf.get<bool>(name(), "monitor-strict", false);
 
     // Grab a list of all outputs and try to find the one defined in the config
-    for (auto&& mon : randr_util::get_monitors(m_connection, m_connection.root())) {
-      if (mon->name == output) {
+    for (auto&& mon : randr_util::get_monitors(m_connection, m_connection.root(), strict)) {
+      if (mon->match(output, strict)) {
         m_output.swap(mon);
         break;
       }
@@ -70,7 +71,7 @@ namespace modules {
       return;
     else if (evt->u.op.window != m_proxy)
       return;
-    else if (evt->u.op.output != m_output->randr_output)
+    else if (evt->u.op.output != m_output->output)
       return;
     else if (evt->u.op.atom != m_output->backlight.atom)
       return;
@@ -164,7 +165,7 @@ namespace modules {
       const int values[1]{new_value};
 
       m_connection.change_output_property_checked(
-          m_output->randr_output, m_output->backlight.atom, XCB_ATOM_INTEGER, 32, XCB_PROP_MODE_REPLACE, 1, values);
+          m_output->output, m_output->backlight.atom, XCB_ATOM_INTEGER, 32, XCB_PROP_MODE_REPLACE, 1, values);
     } catch (const exception& err) {
       m_log.err("%s: %s", name(), err.what());
     }

src/x11/randr.cpp

@@ -8,7 +8,7 @@ namespace randr_util {
    */
   monitor_t make_monitor(xcb_randr_output_t randr, string name, int w, int h, int x, int y) {
     monitor_t mon{new monitor_t::element_type{}};
-    mon->randr_output = randr;
+    mon->output = randr;
     mon->name = name;
     mon->x = x;
     mon->y = y;
@@ -20,14 +20,14 @@ namespace randr_util {
   /**
    * Create a list of all available randr outputs
    */
-  vector<monitor_t> get_monitors(connection& conn, xcb_window_t root) {
+  vector<monitor_t> get_monitors(connection& conn, xcb_window_t root, bool connected_only) {
     vector<monitor_t> monitors;
     auto outputs = conn.get_screen_resources(root).outputs();
 
     for (auto it = outputs.begin(); it != outputs.end(); it++) {
       try {
         auto info = conn.get_output_info(*it);
-        if (info->connection != XCB_RANDR_CONNECTION_CONNECTED)
+        if (connected_only && info->connection != XCB_RANDR_CONNECTION_CONNECTED)
           continue;
         auto crtc = conn.get_crtc_info(info->crtc);
         string name{info.name().begin(), info.name().end()};
@@ -54,14 +54,14 @@ namespace randr_util {
    */
   void get_backlight_range(connection& conn, const monitor_t& mon, backlight_values& dst) {
     auto atom = Backlight;
-    auto reply = conn.query_output_property(mon->randr_output, atom);
+    auto reply = conn.query_output_property(mon->output, atom);
 
     dst.min = 0;
     dst.max = 0;
 
     if (!reply->range || reply->length != 2) {
       atom = BACKLIGHT;
-      reply = conn.query_output_property(mon->randr_output, atom);
+      reply = conn.query_output_property(mon->output, atom);
     }
 
     if (!reply->range || reply->length != 2) {
@@ -84,7 +84,7 @@ namespace randr_util {
       return;
     }
 
-    auto reply = conn.get_output_property(mon->randr_output, dst.atom, XCB_ATOM_NONE, 0, 4, 0, 0);
+    auto reply = conn.get_output_property(mon->output, dst.atom, XCB_ATOM_NONE, 0, 4, 0, 0);
 
     if (reply->num_items == 1 && reply->format == 32 && reply->type == XCB_ATOM_INTEGER)
       dst.val = *reinterpret_cast<uint32_t*>(xcb_randr_get_output_property_data(reply.get().get()));