From df85a6492e907735d7335108a8fdb74d14240006 Mon Sep 17 00:00:00 2001
From: Michael Carlberg <c@rlberg.se>
Date: Sat, 3 Dec 2016 22:54:58 +0100
Subject: [PATCH] refactor(eventloop): Typed events

---
 include/components/controller.hpp |  2 +-
 include/components/eventloop.hpp  | 35 ++++++++++++++++++++----
 src/components/controller.cpp     | 44 ++++++++++++-------------------
 src/components/eventloop.cpp      | 20 +++++++-------
 src/components/screen.cpp         | 13 +++++----
 5 files changed, 64 insertions(+), 50 deletions(-)

diff --git a/include/components/controller.hpp b/include/components/controller.hpp
index f55a9b93..7981571a 100644
--- a/include/components/controller.hpp
+++ b/include/components/controller.hpp
@@ -56,7 +56,7 @@ class controller {
   void on_ipc_action(const ipc_action& message);
   void on_mouse_event(const string& input);
   void on_unrecognized_action(string input);
-  void on_update();
+  void on_update(bool force);
 
  private:
   enum class thread_role {
diff --git a/include/components/eventloop.hpp b/include/components/eventloop.hpp
index db2bb8c0..aa442fd7 100644
--- a/include/components/eventloop.hpp
+++ b/include/components/eventloop.hpp
@@ -30,6 +30,16 @@ struct quit_event {
   bool reload{false};
 };
 
+struct update_event {
+  const uint8_t type{static_cast<uint8_t>(event_type::UPDATE)};
+  bool force{false};
+};
+
+struct input_event {
+  const uint8_t type{static_cast<uint8_t>(event_type::INPUT)};
+  char data[256]{'\0'};
+};
+
 class eventloop {
  public:
   /**
@@ -49,13 +59,28 @@ class eventloop {
   bool enqueue(const entry_t& entry);
   bool enqueue_delayed(const entry_t& entry);
 
-  void set_update_cb(callback<>&& cb);
+  void set_update_cb(callback<bool>&& cb);
   void set_input_db(callback<string>&& cb);
 
   void add_module(const alignment pos, module_t&& module);
   const modulemap_t& modules() const;
   size_t module_count() const;
 
+  static const eventloop::entry_t& make(update_event&& event, bool force = false) {
+    event.force = force;
+    return reinterpret_cast<const eventloop::entry_t&>(event);
+  }
+
+  static const eventloop::entry_t& make(quit_event&& event, bool reload = false) {
+    event.reload = reload;
+    return reinterpret_cast<const eventloop::entry_t&>(event);
+  }
+
+  static const eventloop::entry_t& make(input_event&& event, const string& data) {
+    snprintf(event.data, sizeof(event.data), "%s", data.c_str());
+    return reinterpret_cast<const eventloop::entry_t&>(event);
+  }
+
  protected:
   void dispatch_modules();
   void dispatch_queue_worker();
@@ -65,10 +90,10 @@ class eventloop {
   inline bool compare_events(entry_t evt, entry_t evt2);
   void forward_event(entry_t evt);
 
-  void on_update();
-  void on_input(char* input);
+  void on_update(const update_event& evt);
+  void on_input(const input_event& evt);
   void on_check();
-  void on_quit(const quit_event& quit);
+  void on_quit(const quit_event& evt);
 
  private:
   const logger& m_log;
@@ -92,7 +117,7 @@ class eventloop {
   /**
    * @brief Callback fired when receiving UPDATE events
    */
-  callback<> m_update_cb;
+  callback<bool> m_update_cb;
 
   /**
    * @brief Callback fired for unprocessed INPUT events
diff --git a/src/components/controller.cpp b/src/components/controller.cpp
index 72b9131d..5539addf 100644
--- a/src/components/controller.cpp
+++ b/src/components/controller.cpp
@@ -163,7 +163,7 @@ void controller::bootstrap(bool writeback, bool dump_wmname) {
   }
 
   m_log.trace("controller: Attach eventloop update callback");
-  m_eventloop->set_update_cb(bind(&controller::on_update, this));
+  m_eventloop->set_update_cb(bind(&controller::on_update, this, placeholders::_1));
 
   if (!m_writeback) {
     m_log.trace("controller: Attach eventloop input callback");
@@ -418,16 +418,14 @@ void controller::on_ipc_action(const ipc_action& message) {
 
   string action = message.payload.substr(strlen(ipc_action::prefix));
 
-  if (action.empty()) {
+  if (action.size() >= sizeof(input_event::data)) {
+    m_log.warn("Ignoring input event (size)");
+  } else if (action.empty()) {
     m_log.err("Cannot enqueue empty IPC action");
-    return;
+  } else {
+    m_log.info("Enqueuing IPC action: %s", action);
+    m_eventloop->enqueue(eventloop::make(input_event{}, action));
   }
-
-  eventloop::entry_t evt{static_cast<uint8_t>(event_type::INPUT)};
-  snprintf(evt.data, sizeof(evt.data), "%s", action.c_str());
-
-  m_log.info("Enqueuing IPC action: %s", action);
-  m_eventloop->enqueue(evt);
 }
 
 /**
@@ -436,17 +434,9 @@ void controller::on_ipc_action(const ipc_action& message) {
 void controller::on_mouse_event(const string& input) {
   if (!m_eventloop) {
     return;
-  }
-
-  eventloop::entry_t evt{static_cast<uint8_t>(event_type::INPUT)};
-
-  if (input.length() > sizeof(evt.data)) {
-    return m_log.warn("Ignoring input event (size)");
-  }
-
-  snprintf(evt.data, sizeof(evt.data), "%s", input.c_str());
-
-  if (!m_eventloop->enqueue_delayed(evt)) {
+  } else if (input.length() >= sizeof(input_event::data)) {
+    m_log.warn("Ignoring input event (size)");
+  } else if (!m_eventloop->enqueue_delayed(eventloop::make(input_event{}, input))) {
     m_log.trace_x("controller: Dispatcher busy");
   }
 }
@@ -474,7 +464,7 @@ void controller::on_unrecognized_action(string input) {
 /**
  * Callback for module content update
  */
-void controller::on_update() {
+void controller::on_update(bool force) {
   if (!m_bar) {
     return;
   }
@@ -557,12 +547,6 @@ void controller::on_update() {
     return;
   }
 
-  try {
-    m_bar->parse(contents);
-  } catch (const exception& err) {
-    m_log.err("Failed to update bar contents (reason: %s)", err.what());
-  }
-
   try {
     if (!m_trayactivated) {
       m_trayactivated = true;
@@ -571,6 +555,12 @@ void controller::on_update() {
   } catch (const exception& err) {
     m_log.err("Failed to active tray manager (reason: %s)", err.what());
   }
+
+  try {
+    m_bar->parse(contents, force);
+  } catch (const exception& err) {
+    m_log.err("Failed to update bar contents (reason: %s)", err.what());
+  }
 }
 
 POLYBAR_NS_END
diff --git a/src/components/eventloop.cpp b/src/components/eventloop.cpp
index d7e1e87e..59b693b3 100644
--- a/src/components/eventloop.cpp
+++ b/src/components/eventloop.cpp
@@ -124,7 +124,7 @@ bool eventloop::enqueue_delayed(const entry_t& entry) {
 /**
  * Set callback handler for UPDATE events
  */
-void eventloop::set_update_cb(callback<>&& cb) {
+void eventloop::set_update_cb(callback<bool>&& cb) {
   m_update_cb = forward<decltype(cb)>(cb);
 }
 
@@ -267,9 +267,9 @@ inline bool eventloop::compare_events(entry_t evt, entry_t evt2) {
  */
 void eventloop::forward_event(entry_t evt) {
   if (evt.type == static_cast<uint8_t>(event_type::UPDATE)) {
-    on_update();
+    on_update(reinterpret_cast<const update_event&>(evt));
   } else if (evt.type == static_cast<uint8_t>(event_type::INPUT)) {
-    on_input(evt.data);
+    on_input(reinterpret_cast<const input_event&>(evt));
   } else if (evt.type == static_cast<uint8_t>(event_type::CHECK)) {
     on_check();
   } else if (evt.type == static_cast<uint8_t>(event_type::QUIT)) {
@@ -282,11 +282,11 @@ void eventloop::forward_event(entry_t evt) {
 /**
  * Handler for enqueued UPDATE events
  */
-void eventloop::on_update() {
+void eventloop::on_update(const update_event& evt) {
   m_log.trace("eventloop: Received UPDATE event");
 
   if (m_update_cb) {
-    m_update_cb();
+    m_update_cb(evt.force);
   } else {
     m_log.warn("No callback to handle update");
   }
@@ -295,7 +295,7 @@ void eventloop::on_update() {
 /**
  * Handler for enqueued INPUT events
  */
-void eventloop::on_input(char* input) {
+void eventloop::on_input(const input_event& evt) {
   m_log.trace("eventloop: Received INPUT event");
 
   for (auto&& block : m_modules) {
@@ -303,14 +303,14 @@ void eventloop::on_input(char* input) {
       if (!module->receive_events()) {
         continue;
       }
-      if (module->handle_event(input)) {
+      if (module->handle_event(evt.data)) {
         return;
       }
     }
   }
 
   if (m_unrecognized_input_cb) {
-    m_unrecognized_input_cb(input);
+    m_unrecognized_input_cb(evt.data);
   } else {
     m_log.warn("No callback to handle unrecognized input");
   }
@@ -336,11 +336,11 @@ void eventloop::on_check() {
 /**
  * Handler for enqueued QUIT events
  */
-void eventloop::on_quit(const quit_event& quit) {
+void eventloop::on_quit(const quit_event& evt) {
   m_log.trace("eventloop: Received QUIT event");
   m_running = false;
 
-  if (quit.reload) {
+  if (evt.reload) {
     kill(getpid(), SIGUSR1);
   }
 }
diff --git a/src/components/screen.cpp b/src/components/screen.cpp
index 53c36cce..abd32426 100644
--- a/src/components/screen.cpp
+++ b/src/components/screen.cpp
@@ -100,14 +100,13 @@ void screen::handle(const evt::randr_screen_change_notify& evt) {
     }
   }
 
-  if (changed) {
-    m_log.warn("randr_screen_change_notify (%ux%u)... reloading", evt->width, evt->height);
-    m_sigraised = true;
-
-    quit_event quit{};
-    quit.reload = true;
-    g_signals::event::enqueue(reinterpret_cast<const eventloop::entry_t&>(quit));
+  if (!changed) {
+    return;
   }
+
+  m_log.warn("randr_screen_change_notify (%ux%u)... reloading", evt->width, evt->height);
+  m_sigraised = true;
+  g_signals::event::enqueue(eventloop::make(quit_event{}, true));
 }
 
 POLYBAR_NS_END