Implement tray-reversed option (#3182)

* implement tray-reversed option

* update changelog

* Update src/x11/tray_manager.cpp

Co-authored-by: Patrick Ziegler <p.ziegler96@gmail.com>

* Update CHANGELOG.md

---------

Co-authored-by: Patrick Ziegler <p.ziegler96@gmail.com>

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `internal/battery`: Added `ramp-charging` tag.
 ([`#3172`](https://github.com/polybar/polybar/pull/3172))
 by [@stringlapse](https://github.com/stringlapse).
+- Added tray-reversed = false option to tray module. Makes tray icons order reversed. ([`#3181`](https://github.com/polybar/polybar/discussions/3181))
 
 ### Changed
 - `internal/pulseaudio`: Volume adjustments now preserve balance instead of volume ratios ([`#3123`](https://github.com/polybar/polybar/issues/3123), [`#3169`](https://github.com/polybar/polybar/pull/3169)) by [`@parmort`](https://github.com/parmort)

include/x11/tray_manager.hpp

@@ -66,6 +66,11 @@ struct tray_settings {
    */
   rgba foreground{};
 
+  /**
+   * Reverse the order of tray icons
+   */
+  bool reversed{false};
+
   /**
    * Window ID of tray selection owner.
    *

src/x11/tray_manager.cpp

@@ -75,6 +75,7 @@ void manager::setup(const config& conf, const string& section_name) {
   m_opts.foreground = conf.get(section_name, "tray-foreground", m_bar_opts.foreground);
 
   m_opts.selection_owner = m_bar_opts.x_data.window;
+  m_opts.reversed = conf.get(section_name, "tray-reversed", m_opts.reversed);
 
   m_log.info("tray: spacing=%upx padding=%upx size=%upx", m_opts.spacing, m_opts.padding, client_height);
 
@@ -250,7 +251,7 @@ void manager::reconfigure_clients() {
 
   unsigned count = 0;
 
-  for (auto& client : m_clients) {
+  auto reconfigure_client = [&] (auto& client) {
     try {
       client->ensure_state();
 
@@ -267,6 +268,16 @@ void manager::reconfigure_clients() {
       client.reset();
       has_error = true;
     }
+  };
+
+  if (m_opts.reversed) {
+    for (auto it = m_clients.rbegin(); it != m_clients.rend(); ++it) {
+      reconfigure_client(*it);
+    }
+  } else {
+    for (auto it = m_clients.begin(); it != m_clients.end(); ++it) {
+      reconfigure_client(*it);
+    }
   }
 
   if (has_error) {