From b25fa46ac29499c2136592b6c40489c1e26d1bd6 Mon Sep 17 00:00:00 2001
From: Michael Carlberg <c@rlberg.se>
Date: Sat, 26 Nov 2016 06:14:58 +0100
Subject: [PATCH] wip(xworkspaces): EWMH desktops

Ref #84
---
 include/modules/xworkspaces.hpp |  68 ++++++++++++
 include/x11/ewmh.hpp            |  18 ++-
 src/components/controller.cpp   |   3 +
 src/modules/xworkspaces.cpp     | 191 ++++++++++++++++++++++++++++++++
 src/x11/ewmh.cpp                |  63 +++++++++--
 5 files changed, 328 insertions(+), 15 deletions(-)
 create mode 100644 include/modules/xworkspaces.hpp
 create mode 100644 src/modules/xworkspaces.cpp

diff --git a/include/modules/xworkspaces.hpp b/include/modules/xworkspaces.hpp
new file mode 100644
index 00000000..e76ed350
--- /dev/null
+++ b/include/modules/xworkspaces.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <bitset>
+
+#include "components/config.hpp"
+#include "modules/meta/static_module.hpp"
+#include "x11/events.hpp"
+#include "x11/ewmh.hpp"
+#include "x11/icccm.hpp"
+#include "x11/window.hpp"
+
+POLYBAR_NS
+
+class connection;
+
+namespace modules {
+  enum class desktop_state {
+    NONE,
+    ACTIVE,
+    URGENT,
+    EMPTY,
+    OCCUPIED,
+  };
+
+  struct desktop {
+    explicit desktop(string&& name, desktop_state state) : name(name), state(state) {}
+    string name;
+    desktop_state state{desktop_state::NONE};
+    label_t label;
+  };
+
+  /**
+   * Module used to display EWMH desktops
+   */
+  class xworkspaces_module : public static_module<xworkspaces_module>, public xpp::event::sink<evt::property_notify> {
+   public:
+    xworkspaces_module(const bar_settings& bar, const logger& logger, const config& config, string name);
+
+    void setup();
+    void teardown();
+    void handle(const evt::property_notify& evt);
+    void update();
+    string get_output();
+    bool build(builder* builder, const string& tag) const;
+
+   protected:
+    void rebuild_desktops();
+    void set_current_desktop();
+
+   private:
+    static constexpr const char* DEFAULT_ICON{"icon-default"};
+    static constexpr const char* DEFAULT_LABEL{"%icon% %name%"};
+
+    static constexpr const char* TAG_LABEL{"<label>"};
+
+    connection& m_connection;
+    ewmh_connection_t m_ewmh;
+    event_timer m_throttle{0, 0};
+
+    vector<unique_ptr<desktop>> m_desktops;
+    map<desktop_state, label_t> m_labels;
+    iconset_t m_icons;
+
+    size_t m_index{0};
+  };
+}
+
+POLYBAR_NS_END
diff --git a/include/x11/ewmh.hpp b/include/x11/ewmh.hpp
index d7ebc8eb..fe0d13a8 100644
--- a/include/x11/ewmh.hpp
+++ b/include/x11/ewmh.hpp
@@ -3,19 +3,27 @@
 #include <xcb/xcb_ewmh.h>
 
 #include "common.hpp"
-#include "x11/connection.hpp"
+#include "utils/memory.hpp"
 
 POLYBAR_NS
 
-namespace ewmh_util {
-  bool setup(connection& conn, xcb_ewmh_connection_t* dst);
-  bool supports(xcb_ewmh_connection_t* ewmh, xcb_atom_t atom);
+using ewmh_connection_t = memory_util::malloc_ptr_t<xcb_ewmh_connection_t>;
 
-  xcb_window_t get_active_window(xcb_ewmh_connection_t* conn);
+namespace ewmh_util {
+  extern ewmh_connection_t g_ewmh_connection;
+
+  ewmh_connection_t initialize();
+  void dealloc();
+
+  bool supports(xcb_ewmh_connection_t* ewmh, xcb_atom_t atom, int screen = 0);
 
   string get_visible_name(xcb_ewmh_connection_t* conn, xcb_window_t win);
   string get_icon_name(xcb_ewmh_connection_t* conn, xcb_window_t win);
   string get_reply_string(xcb_ewmh_get_utf8_strings_reply_t* reply);
+
+  vector<string> get_desktop_names(xcb_ewmh_connection_t* conn, int screen = 0);
+  uint32_t get_current_desktop(xcb_ewmh_connection_t* conn, int screen = 0);
+  xcb_window_t get_active_window(xcb_ewmh_connection_t* conn, int screen = 0);
 }
 
 POLYBAR_NS_END
diff --git a/src/components/controller.cpp b/src/components/controller.cpp
index 815f3820..b89d91c9 100644
--- a/src/components/controller.cpp
+++ b/src/components/controller.cpp
@@ -24,6 +24,7 @@
 #include "modules/text.hpp"
 #include "modules/xbacklight.hpp"
 #include "modules/xwindow.hpp"
+#include "modules/xworkspaces.hpp"
 #include "utils/process.hpp"
 #include "utils/string.hpp"
 
@@ -401,6 +402,8 @@ void controller::bootstrap_modules() {
           module.reset(new xbacklight_module(bar, m_log, m_conf, module_name));
         } else if (type == "internal/xwindow") {
           module.reset(new xwindow_module(bar, m_log, m_conf, module_name));
+        } else if (type == "internal/xworkspaces") {
+          module.reset(new xworkspaces_module(bar, m_log, m_conf, module_name));
         } else if (type == "custom/text") {
           module.reset(new text_module(bar, m_log, m_conf, module_name));
         } else if (type == "custom/script") {
diff --git a/src/modules/xworkspaces.cpp b/src/modules/xworkspaces.cpp
new file mode 100644
index 00000000..eca17f24
--- /dev/null
+++ b/src/modules/xworkspaces.cpp
@@ -0,0 +1,191 @@
+#include "modules/xworkspaces.hpp"
+#include "drawtypes/iconset.hpp"
+#include "drawtypes/label.hpp"
+#include "x11/atoms.hpp"
+#include "x11/connection.hpp"
+
+#include "modules/meta/base.inl"
+#include "modules/meta/static_module.inl"
+
+POLYBAR_NS
+
+namespace modules {
+  template class module<xworkspaces_module>;
+  template class static_module<xworkspaces_module>;
+
+  /**
+   * Construct module
+   */
+  xworkspaces_module::xworkspaces_module(
+      const bar_settings& bar, const logger& logger, const config& config, string name)
+      : static_module<xworkspaces_module>(bar, logger, config, name)
+      , m_connection(configure_connection().create<connection&>()) {}
+
+  /**
+   * Bootstrap the module
+   */
+  void xworkspaces_module::setup() {
+    connection& conn{configure_connection().create<decltype(conn)>()};
+
+    // Initialize ewmh atoms
+    if ((m_ewmh = ewmh_util::initialize()) == nullptr) {
+      throw module_error("Failed to initialize ewmh atoms");
+    }
+
+    // Check if the WM supports _NET_CURRENT_DESKTOP
+    if (!ewmh_util::supports(m_ewmh.get(), _NET_CURRENT_DESKTOP)) {
+      throw module_error("The WM does not list _NET_CURRENT_DESKTOP as a supported hint");
+    }
+
+    // Add formats and elements
+    m_formatter->add(DEFAULT_FORMAT, TAG_LABEL, {TAG_LABEL});
+
+    if (m_formatter->has(TAG_LABEL)) {
+      m_labels.insert(
+          make_pair(desktop_state::ACTIVE, load_optional_label(m_conf, name(), "label-active", DEFAULT_LABEL)));
+      m_labels.insert(
+          make_pair(desktop_state::OCCUPIED, load_optional_label(m_conf, name(), "label-occupied", DEFAULT_LABEL)));
+      m_labels.insert(
+          make_pair(desktop_state::URGENT, load_optional_label(m_conf, name(), "label-urgent", DEFAULT_LABEL)));
+      m_labels.insert(
+          make_pair(desktop_state::EMPTY, load_optional_label(m_conf, name(), "label-empty", DEFAULT_LABEL)));
+    }
+
+    m_icons = make_shared<iconset>();
+    m_icons->add(DEFAULT_ICON, make_shared<label>(m_conf.get<string>(name(), DEFAULT_ICON, "")));
+
+    for (const auto& workspace : m_conf.get_list<string>(name(), "icon", {})) {
+      auto vec = string_util::split(workspace, ';');
+      if (vec.size() == 2) {
+        m_icons->add(vec[0], make_shared<label>(vec[1]));
+      }
+    }
+
+    // Make sure we get notified when root properties change
+    window{conn, conn.root()}.ensure_event_mask(XCB_EVENT_MASK_PROPERTY_CHANGE);
+
+    // Connect with the event registry
+    conn.attach_sink(this, 1);
+
+    // Get desktops
+    rebuild_desktops();
+    set_current_desktop();
+
+    // Trigger the initial draw event
+    update();
+  }
+
+  /**
+   * Disconnect from the event registry
+   */
+  void xworkspaces_module::teardown() {
+    connection& conn{configure_connection().create<decltype(conn)>()};
+    conn.detach_sink(this, 1);
+  }
+
+  /**
+   * Handler for XCB_PROPERTY_NOTIFY events
+   */
+  void xworkspaces_module::handle(const evt::property_notify& evt) {
+    if (evt->atom == m_ewmh->_NET_DESKTOP_NAMES && !m_throttle.throttle(evt->time)) {
+      rebuild_desktops();
+    } else if (evt->atom == m_ewmh->_NET_CURRENT_DESKTOP && !m_throttle.throttle(evt->time)) {
+      set_current_desktop();
+    } else {
+      return;
+    }
+
+    update();
+
+    // m_log.err("%lu %s", evt->time, m_connection.get_atom_name(evt->atom).name());
+  }
+
+  /**
+   * Update the currently active window and query its title
+   */
+  void xworkspaces_module::update() {
+    size_t desktop_index{0};
+
+    for (const auto& desktop : m_desktops) {
+      switch (desktop->state) {
+        case desktop_state::ACTIVE:
+          desktop->label = m_labels[desktop_state::ACTIVE]->clone();
+          break;
+        case desktop_state::EMPTY:
+          desktop->label = m_labels[desktop_state::EMPTY]->clone();
+          break;
+        case desktop_state::URGENT:
+          desktop->label = m_labels[desktop_state::URGENT]->clone();
+          break;
+        case desktop_state::OCCUPIED:
+          desktop->label = m_labels[desktop_state::URGENT]->clone();
+          break;
+        case desktop_state::NONE:
+          continue;
+          break;
+      }
+
+      desktop->label->reset_tokens();
+      desktop->label->replace_token("%name%", desktop->name);
+      desktop->label->replace_token("%icon%", m_icons->get(desktop->name, DEFAULT_ICON)->get());
+      desktop->label->replace_token("%index%", to_string(++desktop_index));
+    }
+
+    // Emit notification to trigger redraw
+    broadcast();
+  }
+
+  /**
+   * Generate module output
+   */
+  string xworkspaces_module::get_output() {
+    string output;
+    for (m_index = 0; m_index < m_desktops.size(); m_index++) {
+      if (m_index > 0) {
+        m_builder->space(m_formatter->get(DEFAULT_FORMAT)->spacing);
+      }
+      output += static_module::get_output();
+    }
+    return output;
+  }
+
+  /**
+   * Output content as defined in the config
+   */
+  bool xworkspaces_module::build(builder* builder, const string& tag) const {
+    if (tag == TAG_LABEL && m_desktops[m_index]->state != desktop_state::NONE) {
+      builder->node(m_desktops[m_index]->label);
+    } else {
+      return false;
+    }
+    return true;
+  }
+
+  /**
+   * Rebuild the list of desktops
+   */
+  void xworkspaces_module::rebuild_desktops() {
+    m_desktops.clear();
+
+    for (auto&& name : ewmh_util::get_desktop_names(m_ewmh.get())) {
+      m_desktops.emplace_back(make_unique<desktop>(move(name), desktop_state::EMPTY));
+    }
+  }
+
+  /**
+   * Flag the desktop that is currently active
+   */
+  void xworkspaces_module::set_current_desktop() {
+    auto current = ewmh_util::get_current_desktop(m_ewmh.get());
+
+    for (auto&& desktop : m_desktops) {
+      desktop->state = desktop_state::EMPTY;
+    }
+
+    if (m_desktops.size() > current) {
+      m_desktops[current]->state = desktop_state::ACTIVE;
+    }
+  }
+}
+
+POLYBAR_NS_END
diff --git a/src/x11/ewmh.cpp b/src/x11/ewmh.cpp
index 56a8ef93..91301755 100644
--- a/src/x11/ewmh.cpp
+++ b/src/x11/ewmh.cpp
@@ -1,19 +1,35 @@
 #include "x11/ewmh.hpp"
+#include "x11/xutils.hpp"
 
 POLYBAR_NS
 
 namespace ewmh_util {
-  bool setup(connection& conn, xcb_ewmh_connection_t* dst) {
-    return xcb_ewmh_init_atoms_replies(dst, xcb_ewmh_init_atoms(conn, dst), nullptr);
+  ewmh_connection_t g_ewmh_connection{nullptr};
+
+  ewmh_connection_t initialize() {
+    if (!g_ewmh_connection) {
+      g_ewmh_connection = memory_util::make_malloc_ptr<xcb_ewmh_connection_t>();
+      auto* xconn = xutils::get_connection();
+      auto* conn = g_ewmh_connection.get();
+      xcb_ewmh_init_atoms_replies(conn, xcb_ewmh_init_atoms(xconn, conn), nullptr);
+    }
+    return g_ewmh_connection;
   }
 
-  bool supports(xcb_ewmh_connection_t* ewmh, xcb_atom_t atom) {
+  void dealloc() {
+    if (g_ewmh_connection) {
+      xcb_ewmh_connection_wipe(g_ewmh_connection.get());
+      g_ewmh_connection.reset();
+    }
+  }
+
+  bool supports(xcb_ewmh_connection_t* ewmh, xcb_atom_t atom, int screen) {
     bool supports{false};
 
     xcb_ewmh_get_atoms_reply_t reply;
     reply.atoms = nullptr;
 
-    if (!xcb_ewmh_get_supported_reply(ewmh, xcb_ewmh_get_supported(ewmh, 0), &reply, nullptr)) {
+    if (!xcb_ewmh_get_supported_reply(ewmh, xcb_ewmh_get_supported(ewmh, screen), &reply, nullptr)) {
       return false;
     }
 
@@ -31,12 +47,6 @@ namespace ewmh_util {
     return supports;
   }
 
-  xcb_window_t get_active_window(xcb_ewmh_connection_t* conn) {
-    xcb_window_t win{XCB_NONE};
-    xcb_ewmh_get_active_window_reply(conn, xcb_ewmh_get_active_window(conn, 0), &win, nullptr);
-    return win;
-  }
-
   string get_visible_name(xcb_ewmh_connection_t* conn, xcb_window_t win) {
     xcb_ewmh_get_utf8_strings_reply_t utf8_reply;
     if (!xcb_ewmh_get_wm_visible_name_reply(conn, xcb_ewmh_get_wm_visible_name(conn, win), &utf8_reply, nullptr)) {
@@ -62,6 +72,39 @@ namespace ewmh_util {
     xcb_ewmh_get_utf8_strings_reply_wipe(reply);
     return buffer;
   }
+
+  uint32_t get_current_desktop(xcb_ewmh_connection_t* conn, int screen) {
+    uint32_t desktop{0};
+    if (xcb_ewmh_get_current_desktop_reply(conn, xcb_ewmh_get_current_desktop(conn, screen), &desktop, nullptr)) {
+      return desktop;
+    }
+    return XCB_NONE;
+  }
+
+  vector<string> get_desktop_names(xcb_ewmh_connection_t* conn, int screen) {
+    xcb_ewmh_get_utf8_strings_reply_t reply;
+    xcb_ewmh_get_desktop_names_reply(conn, xcb_ewmh_get_desktop_names(conn, screen), &reply, nullptr);
+
+    vector<string> names;
+    char buffer[BUFSIZ];
+
+    for (size_t n = 0, len = 0; n < reply.strings_len; n++) {
+      if (reply.strings[n] == '\0') {
+        names.emplace_back(buffer, len);
+        len = 0;
+      } else {
+        buffer[len++] = reply.strings[n];
+      }
+    }
+
+    return names;
+  }
+
+  xcb_window_t get_active_window(xcb_ewmh_connection_t* conn, int screen) {
+    xcb_window_t win{XCB_NONE};
+    xcb_ewmh_get_active_window_reply(conn, xcb_ewmh_get_active_window(conn, screen), &win, nullptr);
+    return win;
+  }
 }
 
 POLYBAR_NS_END