From e47e4399549659c80a706a43e0790d9961f75e54 Mon Sep 17 00:00:00 2001
From: Michael Carlberg <c@rlberg.se>
Date: Thu, 22 Dec 2016 22:11:03 +0100
Subject: [PATCH] refactor(modules): Replace callbacks with signals

Refs #265
---
 include/components/controller.hpp |  7 ++++---
 include/events/signal.hpp         |  1 +
 include/events/signal_fwd.hpp     |  1 +
 include/modules/meta/base.hpp     | 14 +++++---------
 include/modules/meta/base.inl     | 27 ++++++++-------------------
 src/components/controller.cpp     | 14 ++++++++------
 6 files changed, 27 insertions(+), 37 deletions(-)

diff --git a/include/components/controller.hpp b/include/components/controller.hpp
index d071ce6e..72899761 100644
--- a/include/components/controller.hpp
+++ b/include/components/controller.hpp
@@ -39,9 +39,9 @@ namespace sig_ev = signals::eventqueue;
 namespace sig_ui = signals::ui;
 namespace sig_ipc = signals::ipc;
 
-class controller : public signal_receiver<SIGN_PRIORITY_CONTROLLER, sig_ev::process_update, sig_ev::process_input,
-                       sig_ev::process_quit, sig_ev::process_check, sig_ipc::process_action, sig_ipc::process_command,
-                       sig_ipc::process_hook, sig_ui::button_press> {
+class controller : public signal_receiver<SIGN_PRIORITY_CONTROLLER, sig_ev::process_broadcast, sig_ev::process_update,
+                       sig_ev::process_input, sig_ev::process_quit, sig_ev::process_check, sig_ipc::process_action,
+                       sig_ipc::process_command, sig_ipc::process_hook, sig_ui::button_press> {
  public:
   using make_type = unique_ptr<controller>;
   static make_type make(unique_ptr<ipc>&& ipc, unique_ptr<inotify_watch>&& config_watch);
@@ -60,6 +60,7 @@ class controller : public signal_receiver<SIGN_PRIORITY_CONTROLLER, sig_ev::proc
   void process_eventqueue();
   void process_inputdata();
 
+  bool on(const sig_ev::process_broadcast& evt);
   bool on(const sig_ev::process_update& evt);
   bool on(const sig_ev::process_input& evt);
   bool on(const sig_ev::process_quit& evt);
diff --git a/include/events/signal.hpp b/include/events/signal.hpp
index c6661212..3f3e758f 100644
--- a/include/events/signal.hpp
+++ b/include/events/signal.hpp
@@ -96,6 +96,7 @@ namespace signals {
     DEFINE_VALUE_SIGNAL(2, process_update, event);
     DEFINE_VALUE_SIGNAL(3, process_input, string);
     DEFINE_SIGNAL(4, process_check);
+    DEFINE_SIGNAL(5, process_broadcast);
   }
 
   namespace ipc {
diff --git a/include/events/signal_fwd.hpp b/include/events/signal_fwd.hpp
index 39d3835b..c438501b 100644
--- a/include/events/signal_fwd.hpp
+++ b/include/events/signal_fwd.hpp
@@ -10,6 +10,7 @@ namespace signals {
     struct process_update;
     struct process_input;
     struct process_check;
+    struct process_broadcast;
   }
   namespace ipc {
     struct process_command;
diff --git a/include/modules/meta/base.hpp b/include/modules/meta/base.hpp
index ad8f1f61..aa708f1f 100644
--- a/include/modules/meta/base.hpp
+++ b/include/modules/meta/base.hpp
@@ -3,12 +3,10 @@
 #include <algorithm>
 #include <chrono>
 #include <condition_variable>
-#include <mutex>
 #include <map>
+#include <mutex>
 
 #include "common.hpp"
-#include "components/config.hpp"
-#include "components/logger.hpp"
 #include "components/types.hpp"
 #include "errors.hpp"
 #include "utils/concurrency.hpp"
@@ -46,6 +44,9 @@ namespace drawtypes {
 }
 
 class builder;
+class config;
+class logger;
+class signal_emitter;
 
 // }}}
 
@@ -108,9 +109,6 @@ namespace modules {
     virtual void stop() = 0;
     virtual void halt(string error_message) = 0;
     virtual string contents() = 0;
-
-    virtual void set_update_cb(callback<>&& cb) = 0;
-    virtual void set_stop_cb(callback<>&& cb) = 0;
   };
 
   // }}}
@@ -141,9 +139,7 @@ namespace modules {
     string get_output();
 
    protected:
-    callback<> m_update_callback;
-    callback<> m_stop_callback;
-
+    signal_emitter& m_sig;
     const bar_settings m_bar;
     const logger& m_log;
     const config& m_conf;
diff --git a/include/modules/meta/base.inl b/include/modules/meta/base.inl
index 9cc7ccfc..e291026a 100644
--- a/include/modules/meta/base.inl
+++ b/include/modules/meta/base.inl
@@ -1,15 +1,20 @@
 #include "components/builder.hpp"
 #include "components/logger.hpp"
 #include "components/config.hpp"
+#include "events/signal.hpp"
+#include "events/signal_emitter.hpp"
 
 POLYBAR_NS
 
+namespace sig_ev = signals::eventqueue;
+
 namespace modules {
   // module<Impl> public {{{
 
   template <typename Impl>
   module<Impl>::module(const bar_settings bar, string name)
-        : m_bar(bar)
+        : m_sig(signal_emitter::make())
+        , m_bar(bar)
         , m_log(logger::make())
         , m_conf(config::make())
         , m_name("module/" + name)
@@ -30,16 +35,6 @@ namespace modules {
     }
   }
 
-  template <typename Impl>
-  void module<Impl>::set_update_cb(callback<>&& cb) {
-    m_update_callback = forward<decltype(cb)>(cb);
-  }
-
-  template <typename Impl>
-  void module<Impl>::set_stop_cb(callback<>&& cb) {
-    m_stop_callback = forward<decltype(cb)>(cb);
-  }
-
   template <typename Impl>
   string module<Impl>::name() const {
     return m_name;
@@ -66,9 +61,7 @@ namespace modules {
       CAST_MOD(Impl)->wakeup();
       CAST_MOD(Impl)->teardown();
 
-      if (m_stop_callback) {
-        m_stop_callback();
-      }
+      m_sig.emit(sig_ev::process_check{});
     }
   }
 
@@ -97,11 +90,7 @@ namespace modules {
     }
 
     m_cache = CAST_MOD(Impl)->get_output();
-
-    if (m_update_callback)
-      m_update_callback();
-    else
-      m_log.info("%s: No handler, ignoring broadcast...", name());
+    m_sig.emit(sig_ev::process_broadcast{});
   }
 
   template <typename Impl>
diff --git a/src/components/controller.cpp b/src/components/controller.cpp
index 234174c8..0a7fdd24 100644
--- a/src/components/controller.cpp
+++ b/src/components/controller.cpp
@@ -162,8 +162,6 @@ bool controller::run(bool writeback) {
       try {
         m_log.info("Starting %s", module->name());
         module->start();
-        module->set_update_cb([&] { enqueue(make_update_evt(false)); });
-        module->set_stop_cb([&] { enqueue(make_check_evt()); });
         started_modules++;
       } catch (const application_error& err) {
         m_log.err("Failed to start '%s' (reason: %s)", module->name(), err.what());
@@ -352,16 +350,20 @@ void controller::process_inputdata() {
   }
 }
 
+/**
+ * Process broadcast events
+ */
+bool controller::on(const sig_ev::process_broadcast&) {
+  enqueue(make_update_evt(false));
+  return true;
+}
+
 /**
  * Process eventqueue update event
  */
 bool controller::on(const sig_ev::process_update& evt) {
   bool force{evt.data()->flag};
 
-  if (!m_bar) {
-    return false;
-  }
-
   const bar_settings& bar{m_bar->settings()};
   string contents;
   string separator{bar.separator};