Merge pull request #1027 from alebastr/output-fixes

Fix more issues with duplicated bars

src/client.cpp

@@ -120,17 +120,26 @@ void waybar::Client::handleOutputDone(void *data, struct zxdg_output_v1 * /*xdg_
   auto client = waybar::Client::inst();
   try {
     auto &output = client->getOutput(data);
+    /**
+     * Multiple .done events may arrive in batch. In this case libwayland would queue
+     * xdg_output.destroy and dispatch all pending events, triggering this callback several times
+     * for the same output. .done events can also arrive after that for a scale or position changes.
+     * We wouldn't want to draw a duplicate bar for each such event either.
+     *
+     * All the properties we care about are immutable so it's safe to delete the xdg_output object
+     * on the first event and use the ptr value to check that the callback was already invoked.
+     */
+    if (output.xdg_output) {
+      output.xdg_output.reset();
       spdlog::debug("Output detection done: {} ({})", output.name, output.identifier);
 
       auto configs = client->getOutputConfigs(output);
       if (!configs.empty()) {
-      wl_display_roundtrip(client->wl_display);
         for (const auto &config : configs) {
           client->bars.emplace_back(std::make_unique<Bar>(&output, config));
         }
       }
-    // unsubscribe
-    output.xdg_output.reset();
+    }
   } catch (const std::exception &e) {
     std::cerr << e.what() << std::endl;
   }