randr: Add separate key for exact monitor matching

This adds `monitor-exact = true` in the bar section

This also properly does best-match instead of first-match if multiple
matches exists. For example if there are two monitors HDMI2 and HDMI-2
and we try to match HDMI-2 with monitor-exact = false, until now HDMI2
would be matched. Now exact matches are always preferred.

Fixes #1532

include/components/types.hpp

@@ -123,6 +123,7 @@ struct bar_settings {
 
   xcb_window_t window{XCB_NONE};
   monitor_t monitor{};
+  bool monitor_exact{true};
   edge origin{edge::TOP};
   struct size size {
     1U, 1U

include/x11/extensions/randr.hpp

@@ -37,7 +37,7 @@ struct randr_output {
   xcb_randr_output_t output;
   backlight_values backlight;
 
-  bool match(const string& o, bool strict = false) const;
+  bool match(const string& o, bool exact = true) const;
   bool match(const position& p) const;
 };
 
@@ -50,6 +50,7 @@ namespace randr_util {
 
   monitor_t make_monitor(xcb_randr_output_t randr, string name, unsigned short int w, unsigned short int h, short int x, short int y);
   vector<monitor_t> get_monitors(connection& conn, xcb_window_t root, bool connected_only = false, bool realloc = false);
+  monitor_t match_monitor(vector<monitor_t> monitors, const string& name, bool exact_match);
 
   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

@@ -73,6 +73,7 @@ bar::bar(connection& conn, signal_emitter& emitter, const config& config, const
   auto monitor_name = m_conf.get(bs, "monitor", ""s);
   auto monitor_name_fallback = m_conf.get(bs, "monitor-fallback", ""s);
   auto monitor_strictmode = m_conf.get(bs, "monitor-strict", false);
+  m_opts.monitor_exact = m_conf.get(bs, "monitor-exact", m_opts.monitor_exact);
   auto monitors = randr_util::get_monitors(m_connection, m_connection.screen()->root, monitor_strictmode);
 
   if (monitors.empty()) {
@@ -92,26 +93,17 @@ bar::bar(connection& conn, signal_emitter& emitter, const config& config, const
     m_log.warn("No monitor specified, using \"%s\"", monitor_name);
   }
 
-  bool name_found{false};
-  bool fallback_found{monitor_name_fallback.empty()};
+  m_opts.monitor = randr_util::match_monitor(monitors, monitor_name, m_opts.monitor_exact);
   monitor_t fallback{};
 
-  for (auto&& monitor : monitors) {
-    if (!name_found && (name_found = monitor->match(monitor_name, monitor_strictmode))) {
-      m_opts.monitor = move(monitor);
-    } else if (!fallback_found && (fallback_found = monitor->match(monitor_name_fallback, monitor_strictmode))) {
-      fallback = move(monitor);
-    }
-
-    if (name_found && fallback_found) {
-      break;
-    }
+  if(!monitor_name_fallback.empty()) {
+    fallback = randr_util::match_monitor(monitors, monitor_name_fallback, m_opts.monitor_exact);
   }
 
   if (!m_opts.monitor) {
     if (fallback) {
       m_opts.monitor = move(fallback);
-      m_log.warn("Monitor \"%s\" not found, reverting to fallback \"%s\"", monitor_name, monitor_name_fallback);
+      m_log.warn("Monitor \"%s\" not found, reverting to fallback \"%s\"", monitor_name, m_opts.monitor->name);
     } else {
       throw application_error("Monitor \"" + monitor_name + "\" not found or disconnected");
     }

src/modules/xbacklight.cpp

@@ -21,13 +21,9 @@ namespace modules {
     auto output = m_conf.get(name(), "output", m_bar.monitor->name);
     auto strict = m_conf.get(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(), strict)) {
-      if (mon->match(output, strict)) {
-        m_output.swap(mon);
-        break;
-      }
-    }
+    auto monitors = randr_util::get_monitors(m_connection, m_connection.root(), strict);
+
+    m_output = randr_util::match_monitor(monitors, output, bar.monitor_exact);
 
     // If we didn't get a match we stop the module
     if (!m_output) {
@@ -44,7 +40,7 @@ namespace modules {
       randr_util::get_backlight_value(m_connection, m_output, backlight);
     } catch (const exception& err) {
       m_log.err("%s: Could not get data (err: %s)", name(), err.what());
-      throw module_error("Not supported for \"" + output + "\"");
+      throw module_error("Not supported for \"" + m_output->name + "\"");
     }
 
     // Create window that will proxy all RandR notify events

src/x11/extensions/randr.cpp

@@ -12,15 +12,17 @@
 POLYBAR_NS
 
 /**
- * Workaround for the inconsistent naming
- * of outputs between my intel and nvidia
+ * Workaround for the inconsistent naming of outputs between intel and nvidia
  * drivers (xf86-video-intel drops the dash)
+ *
+ * If exact == false, dashes will be ignored while matching
  */
-bool randr_output::match(const string& o, bool strict) const {
-  if (strict && name != o) {
-    return false;
+bool randr_output::match(const string& o, bool exact) const {
+  if (exact) {
+    return name == o;
+  } else {
+    return string_util::replace(name, "-", "") == string_util::replace(o, "-", "");
   }
-  return name == o || name == string_util::replace(o, "-", "");
 }
 
 /**
@@ -172,6 +174,34 @@ namespace randr_util {
     return monitors;
   }
 
+  /**
+   * Searches for a monitor with name in monitors
+   *
+   * Does best-fit matching (if exact_match == true, this is also first-fit)
+   */
+  monitor_t match_monitor(vector<monitor_t> monitors, const string& name, bool exact_match) {
+    monitor_t result{};
+    for(auto&& monitor : monitors) {
+      // If we can do an exact match, we have found our result
+      if(monitor->match(name, true)) {
+        result = move(monitor);
+        break;
+      }
+
+      /*
+       * Non-exact matches are moved into the result but we continue searching
+       * through the list, maybe we can find an exact match
+       * Note: If exact_match == true, we don't need to run this because it
+       * would be the exact same check as above
+       */
+      if(!exact_match && monitor->match(name, false)) {
+        result = move(monitor);
+      }
+    }
+
+    return result;
+  }
+
   /**
    * Get backlight value range for given output
    */