feat: Module Visibility (#2320)

Modules can now also be shown and hidden using ipc commands:

    $ polybar-msg [-p PID] cmd hide.mymodule # Hides module mymodule
    $ polybar-msg [-p PID] cmd show.mymodule # Shows module mymodule
    $ polybar-msg [-p PID] cmd toggle.mymodule # Toggles visibility of mymodule

* Hopefully implement visibility checking

* Implement hide command

* Implement `show` and `toggle` commands

* Refactor and add some logging

* Run style checks and update CHANGELOG

* Get around unused parameter warnings

* Change `set_visible` to return nothing

* Make errors more informative

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

* Update bar when changing module visibility

- Called in the module to maintain dependence on the signal emitter
- Update CHANGELOG to make changes more verbose

* wrong var

* Update include/modules/unsupported.hpp

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

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

CHANGELOG.md

@@ -59,6 +59,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([`#316`](https://github.com/polybar/polybar/issues/316))
 - Added .ini extension check to the default config search.
   ([`#2323`](https://github.com/polybar/polybar/issues/2323))
+- IPC commands to change visibility of modules
+  (`hide.<name>`, `show.<name>`, and `toggle.<name>`)
+  ([`#2108`](https://github.com/polybar/polybar/issues/2108))
 
 ### Changed
 - Slight changes to the value ranges the different ramp levels are responsible

config/config.cmake

@@ -77,6 +77,8 @@ tray-padding = 2
 cursor-click = pointer
 cursor-scroll = ns-resize
 
+enable-ipc = true
+
 [module/xwindow]
 type = internal/xwindow
 label = %title:0:30:...%

include/components/controller.hpp

@@ -76,6 +76,8 @@ class controller
   bool forward_action(const actions_util::action& cmd);
   bool try_forward_legacy_action(const string& cmd);
 
+  void switch_module_visibility(string module_name_raw, int visible);
+
   connection& m_connection;
   signal_emitter& m_sig;
   const logger& m_log;

include/modules/meta/base.hpp

@@ -114,6 +114,8 @@ namespace modules {
     virtual string name_raw() const = 0;
     virtual string name() const = 0;
     virtual bool running() const = 0;
+    virtual bool visible() const = 0;
+    virtual void set_visible(bool value) = 0;
 
     /**
      * Handle action, possibly with data attached
@@ -145,6 +147,10 @@ namespace modules {
     string name_raw() const;
     string name() const;
     bool running() const;
+
+    bool visible() const;
+    void set_visible(bool value);
+
     void stop();
     void halt(string error_message);
     void teardown();
@@ -184,6 +190,7 @@ namespace modules {
 
    private:
     atomic<bool> m_enabled{true};
+    atomic<bool> m_visible{true};
     atomic<bool> m_changed{true};
     string m_cache;
   };

include/modules/meta/base.inl

@@ -56,6 +56,18 @@ namespace modules {
     return static_cast<bool>(m_enabled);
   }
 
+  template <typename Impl>
+  bool module<Impl>::visible() const {
+    return static_cast<bool>(m_visible);
+  }
+
+  template <typename Impl>
+  void module<Impl>::set_visible(bool value) {
+    m_log.info("%s: Visibility changed (state=%s)", m_name, value ? "shown" : "hidden");
+    m_visible = value;
+    broadcast();
+  }
+
   template <typename Impl>
   void module<Impl>::stop() {
     if (!static_cast<bool>(m_enabled)) {

include/modules/unsupported.hpp

@@ -27,6 +27,10 @@ namespace modules {
     bool running() const {                                                              \
       return false;                                                                     \
     }                                                                                   \
+    bool visible() const {                                                              \
+      return false;                                                                     \
+    }                                                                                   \
+    void set_visible(bool) {}                                                           \
     void start() {}                                                                     \
     void stop() {}                                                                      \
     void halt(string) {}                                                                \

src/components/controller.cpp

@@ -530,6 +530,25 @@ bool controller::forward_action(const actions_util::action& action_triple) {
   return true;
 }
 
+void controller::switch_module_visibility(string module_name_raw, int visible) {
+  for (auto&& mod : m_modules) {
+    if (mod->name_raw() != module_name_raw)
+      continue;
+
+    if (visible == 0) {
+      mod->set_visible(false);
+    } else if (visible == 1) {
+      mod->set_visible(true);
+    } else if (visible == 2) {
+      mod->set_visible(!mod->visible());
+    }
+
+    return;
+  }
+
+  m_log.err("controller: Module '%s' not found for visibility change (state=%s)", module_name_raw, visible ? "shown" : "hidden");
+}
+
 /**
  * Process stored input data
  */
@@ -600,7 +619,7 @@ bool controller::process_update(bool force) {
     }
 
     for (const auto& module : block.second) {
-      if (!module->running()) {
+      if (!module->running() || !module->visible()) {
         continue;
       }
 
@@ -833,6 +852,10 @@ bool controller::on(const signals::ipc::command& evt) {
     return false;
   }
 
+  string hide_module{"hide."};
+  string show_module{"show."};
+  string toggle_module{"toggle."};
+
   if (command == "quit") {
     enqueue(make_quit_evt(false));
   } else if (command == "restart") {
@@ -843,6 +866,12 @@ bool controller::on(const signals::ipc::command& evt) {
     m_bar->show();
   } else if (command == "toggle") {
     m_bar->toggle();
+  } else if (command.find(hide_module) == 0) {
+    switch_module_visibility(command.substr(hide_module.length()), 0);
+  } else if (command.find(show_module) == 0) {
+    switch_module_visibility(command.substr(show_module.length()), 1);
+  } else if (command.find(toggle_module) == 0) {
+    switch_module_visibility(command.substr(toggle_module.length()), 2);
   } else {
     m_log.warn("\"%s\" is not a valid ipc command", command);
   }