tray: Better lifecycle handling

2022-09-11 21:47:50 +02:00 · 2022-09-11 21:47:50 +02:00 · 60173e5042
commit 60173e5042
parent ea5ffdd6b1
3 changed files with 138 additions and 79 deletions
--- a/include/x11/tray_client.hpp
+++ b/include/x11/tray_client.hpp
@ -6,6 +6,12 @@
 #include "utils/concurrency.hpp"
 #include "x11/xembed.hpp"

+/*
+ * Manages the lifecycle of a tray client according to the XEMBED protocol
+ *
+ * Ref: https://specifications.freedesktop.org/xembed-spec/xembed-spec-latest.html
+ */
+
 POLYBAR_NS

 // fwd declarations
--- a/include/x11/tray_manager.hpp
+++ b/include/x11/tray_manager.hpp
@ -69,14 +69,18 @@ class tray_manager : public xpp::event::sink<evt::expose, evt::visibility_notify

  ~tray_manager();

-  bool running() const;
  int get_width() const;

  void setup(const config& conf, const string& module_section_name);
  void activate();
-  void deactivate(bool clear_selection = true);
+  void wait_for_selection(xcb_window_t other);
+  void deactivate();
  void reconfigure();

+  bool is_active() const;
+  bool is_inactive() const;
+  bool is_waiting() const;
+
 protected:
  void reconfigure_window();
  void reconfigure_clients();
@ -86,7 +90,7 @@ class tray_manager : public xpp::event::sink<evt::expose, evt::visibility_notify
  void query_atom();
  void set_tray_colors();

-  void acquire_selection();
+  bool acquire_selection(xcb_window_t& other_owner);
  void notify_clients();
  void notify_clients_delayed();

@ -142,6 +146,27 @@ class tray_manager : public xpp::event::sink<evt::expose, evt::visibility_notify

  const on_update m_on_update;

+  enum class state {
+    /**
+     * The tray manager is completely deactivated and doesn't own any resources.
+     */
+    INACTIVE = 0,
+    /**
+     * There is currently another application owning the systray selection and the tray manager waits until the
+     * selection becomes available again.
+     *
+     * The signal receiver is detached in m_othermanager is set
+     */
+    WAITING,
+    /**
+     * The tray manager owns the systray selection.
+     *
+     * The signal receiver is attached
+     */
+    ACTIVE,
+  };
+  atomic<state> m_state{state::INACTIVE};
+
  /**
   * Systray selection atom _NET_SYSTEM_TRAY_Sn
   */
@ -165,11 +190,9 @@ class tray_manager : public xpp::event::sink<evt::expose, evt::visibility_notify
  unsigned m_tray_width{0};

  /**
-   * Whether the tray is running
+   * Whether the tray is visible
   */
-  atomic<bool> m_activated{false};
  atomic<bool> m_hidden{false};
-  atomic<bool> m_acquired_selection{false};

  thread m_delaythread;

--- a/src/x11/tray_manager.cpp
+++ b/src/x11/tray_manager.cpp
@ -31,10 +31,6 @@
 *
 * The tray manager needs to trigger bar updates only when the size of the entire tray changes (e.g. when tray icons are
 * added/removed). EVerything else can be handled without an update.
- *
- * TODO
- *  * Better handling of state:
- *    * Differentiate between, inactive, active, and waiting for selection
 */

 // ====================================================================================================
@ -103,45 +99,56 @@ void tray_manager::setup(const config& conf, const string& section_name) {
  activate();
 }

-bool tray_manager::running() const {
-  return m_activated;
-}
-
 int tray_manager::get_width() const {
  return m_tray_width;
 }

+bool tray_manager::is_active() const {
+  return m_state == state::ACTIVE;
+}
+
+bool tray_manager::is_inactive() const {
+  return m_state == state::INACTIVE;
+}
+
+bool tray_manager::is_waiting() const {
+  return m_state == state::WAITING;
+}
+
 /**
 * Activate systray management
 */
 void tray_manager::activate() {
-  if (m_activated) {
+  if (is_active()) {
    return;
  }

  m_log.info("Activating tray manager");
-  m_activated = true;
-
-  m_sig.attach(this);

  try {
    set_tray_colors();
  } catch (const exception& err) {
    m_log.err(err.what());
    m_log.err("Cannot activate tray manager... failed to setup window");
-    m_activated = false;
-    return;
-  }
-
-  // Attempt to get control of the systray selection then
-  // notify clients waiting for a manager.
-  acquire_selection();
-
-  if (!m_acquired_selection) {
    deactivate();
    return;
  }

+  xcb_window_t other_owner = XCB_NONE;
+
+  // Attempt to get control of the systray selection
+  if (!acquire_selection(other_owner)) {
+    // Transition to WAITING state
+    wait_for_selection(other_owner);
+    return;
+  }
+
+  m_sig.attach(this);
+
+  m_othermanager = XCB_NONE;
+
+  m_state = state::ACTIVE;
+
  // Send delayed notification
  if (!m_firstactivation) {
    notify_clients();
@ -152,20 +159,47 @@ void tray_manager::activate() {
  m_firstactivation = false;
 }

+/**
+ * Transitions tray manager to WAITING state
+ *
+ * @param other window id for current selection owner
+ */
+void tray_manager::wait_for_selection(xcb_window_t other) {
+  if (is_waiting() || other == XCB_NONE) {
+    return;
+  }
+
+  m_log.info("tray: Waiting for systray selection (current owner: %s)", m_connection.id(other));
+
+  m_sig.detach(this);
+
+  m_othermanager = other;
+  track_selection_owner(other);
+
+  m_log.trace("tray: Unembed clients");
+  m_clients.clear();
+
+  m_connection.flush();
+
+  m_state = state::WAITING;
+
+  reconfigure_window();
+}
+
 /**
 * Deactivate systray management
 */
-void tray_manager::deactivate(bool clear_selection) {
-  if (!m_activated) {
+void tray_manager::deactivate() {
+  if (is_inactive()) {
    return;
  }

  m_log.info("Deactivating tray manager");
-  m_activated = false;

  m_sig.detach(this);

-  if (!m_connection.connection_has_error() && clear_selection && m_acquired_selection) {
+  // Unset selection owner if we currently own the atom
+  if (!m_connection.connection_has_error() && is_active()) {
    m_log.trace("tray: Unset selection owner");
    m_connection.set_selection_owner(XCB_NONE, m_atom, XCB_CURRENT_TIME);
  }
@ -173,10 +207,12 @@ void tray_manager::deactivate(bool clear_selection) {
  m_log.trace("tray: Unembed clients");
  m_clients.clear();

-  m_acquired_selection = false;
-
  m_connection.flush();

+  m_othermanager = XCB_NONE;
+
+  m_state = state::INACTIVE;
+
  reconfigure_window();
 }

@ -246,7 +282,7 @@ void tray_manager::reconfigure_clients() {
 * Refresh the bar window by clearing it along with each client window
 */
 void tray_manager::refresh_window() {
-  if (!m_activated || m_hidden) {
+  if (!is_active() || m_hidden) {
    return;
  }

@ -311,30 +347,28 @@ void tray_manager::set_tray_colors() {

 /**
 * Acquire the systray selection
+ *
+ * @param other_owner is set to the current owner if the function fails
+ * @returns Whether we acquired the selection
 */
-void tray_manager::acquire_selection() {
-  m_othermanager = XCB_NONE;
-  xcb_window_t owner;
-
-  try {
-    owner = m_connection.get_selection_owner(m_atom).owner<xcb_window_t>();
-  } catch (const exception& err) {
-    return;
-  }
+bool tray_manager::acquire_selection(xcb_window_t& other_owner) {
+  other_owner = XCB_NONE;
+  xcb_window_t owner = m_connection.get_selection_owner(m_atom).owner();

  if (owner == m_opts.selection_owner) {
    m_log.trace("tray: Already managing the systray selection");
-    m_acquired_selection = true;
-  } else if ((m_othermanager = owner) != XCB_NONE) {
-    m_log.warn("Systray selection already managed (window=%s)", m_connection.id(owner));
-    track_selection_owner(m_othermanager);
-  } else {
+    return true;
+  } else if (owner == XCB_NONE) {
    m_log.trace("tray: Change selection owner to %s", m_connection.id(m_opts.selection_owner));
    m_connection.set_selection_owner_checked(m_opts.selection_owner, m_atom, XCB_CURRENT_TIME);
    if (m_connection.get_selection_owner_unchecked(m_atom)->owner != m_opts.selection_owner) {
      throw application_error("Failed to get control of the systray selection");
    }
-    m_acquired_selection = true;
+    return true;
+  } else {
+    other_owner = owner;
+    m_log.warn("Systray selection already managed (window=%s)", m_connection.id(owner));
+    return false;
  }
 }

@ -342,7 +376,7 @@ void tray_manager::acquire_selection() {
 * Notify pending clients about the new systray MANAGER
 */
 void tray_manager::notify_clients() {
-  if (m_activated) {
+  if (is_active()) {
    m_log.info("Notifying pending tray clients");
    auto message = m_connection.make_client_message(MANAGER, m_connection.root());
    message.data.data32[0] = XCB_CURRENT_TIME;
@ -491,11 +525,11 @@ void tray_manager::remove_client(xcb_window_t win, bool reconfigure) {
 }

 bool tray_manager::change_visibility(bool visible) {
-  if (!m_activated || m_hidden == !visible) {
+  if (!is_active() || m_hidden == !visible) {
    return false;
  }

-  m_log.trace("tray: visibility_change (state=%i, activated=%i, hidden=%i)", visible, static_cast<bool>(m_activated),
+  m_log.trace("tray: visibility_change (state=%i, activated=%i, hidden=%i)", visible, static_cast<bool>(is_active()),
      static_cast<bool>(m_hidden));

  m_hidden = !visible;
@ -518,7 +552,7 @@ bool tray_manager::change_visibility(bool visible) {
 * Event callback : XCB_EXPOSE
 */
 void tray_manager::handle(const evt::expose& evt) {
-  if (m_activated && !m_clients.empty() && evt->count == 0) {
+  if (is_active() && !m_clients.empty() && evt->count == 0) {
    redraw_window();
  }
 }
@ -527,7 +561,7 @@ void tray_manager::handle(const evt::expose& evt) {
 * Event callback : XCB_VISIBILITY_NOTIFY
 */
 void tray_manager::handle(const evt::visibility_notify& evt) {
-  if (m_activated && !m_clients.empty()) {
+  if (is_active() && !m_clients.empty()) {
    m_log.trace("tray: Received visibility_notify for %s", m_connection.id(evt->window));
    reconfigure_window();
  }
@ -537,21 +571,24 @@ void tray_manager::handle(const evt::visibility_notify& evt) {
 * Event callback : XCB_CLIENT_MESSAGE
 */
 void tray_manager::handle(const evt::client_message& evt) {
-  if (!m_activated) {
+  if (!is_active()) {
    return;
-  } else if (evt->type == WM_PROTOCOLS && evt->data.data32[0] == WM_DELETE_WINDOW &&
-             evt->window == m_opts.selection_owner) {
+  }
+
+  // Our selection owner window was deleted
+  if (evt->type == WM_PROTOCOLS && evt->data.data32[0] == WM_DELETE_WINDOW && evt->window == m_opts.selection_owner) {
    m_log.notice("Received WM_DELETE");
    deactivate();
  } else if (evt->type == _NET_SYSTEM_TRAY_OPCODE && evt->format == 32) {
    m_log.trace("tray: Received client_message");

+    // Docking request
    if (SYSTEM_TRAY_REQUEST_DOCK == evt->data.data32[1]) {
      xcb_window_t win = evt->data.data32[2];
-      if (!is_embedded(win)) {
-        process_docking_request(win);
-      } else {
+      if (is_embedded(win)) {
        m_log.warn("Tray client %s already embedded, ignoring request...", m_connection.id(win));
+      } else {
+        process_docking_request(win);
      }
    }
  }
@ -565,7 +602,7 @@ void tray_manager::handle(const evt::client_message& evt) {
 * so we return an answer that'll put him in place.
 */
 void tray_manager::handle(const evt::configure_request& evt) {
-  if (m_activated && is_embedded(evt->window)) {
+  if (is_active() && is_embedded(evt->window)) {
    try {
      m_log.trace("tray: Client configure request %s", m_connection.id(evt->window));
      find_client(evt->window)->configure_notify();
@ -580,7 +617,7 @@ void tray_manager::handle(const evt::configure_request& evt) {
 * @see tray_manager::handle(const evt::configure_request&);
 */
 void tray_manager::handle(const evt::resize_request& evt) {
-  if (m_activated && is_embedded(evt->window)) {
+  if (is_active() && is_embedded(evt->window)) {
    try {
      m_log.trace("tray: Received resize_request for client %s", m_connection.id(evt->window));
      find_client(evt->window)->configure_notify();
@ -595,7 +632,7 @@ void tray_manager::handle(const evt::resize_request& evt) {
 * Event callback : XCB_SELECTION_CLEAR
 */
 void tray_manager::handle(const evt::selection_clear& evt) {
-  if (!m_activated) {
+  if (is_inactive()) {
    return;
  } else if (evt->selection != m_atom) {
    return;
@ -603,23 +640,15 @@ void tray_manager::handle(const evt::selection_clear& evt) {
    return;
  }

-  try {
-    m_log.warn("Lost systray selection, deactivating...");
-    m_othermanager = m_connection.get_selection_owner(m_atom).owner<xcb_window_t>();
-    track_selection_owner(m_othermanager);
-  } catch (const exception& err) {
-    m_log.err("Failed to get systray selection owner");
-    m_othermanager = XCB_NONE;
-  }
-
-  deactivate(false);
+  m_log.warn("Lost systray selection, deactivating...");
+  wait_for_selection(m_connection.get_selection_owner(m_atom).owner());
 }

 /**
 * Event callback : XCB_PROPERTY_NOTIFY
 */
 void tray_manager::handle(const evt::property_notify& evt) {
-  if (!m_activated) {
+  if (!is_active()) {
    return;
  }

@ -659,7 +688,7 @@ void tray_manager::handle(const evt::property_notify& evt) {
 * Event callback : XCB_REPARENT_NOTIFY
 */
 void tray_manager::handle(const evt::reparent_notify& evt) {
-  if (!m_activated) {
+  if (!is_active()) {
    return;
  }

@ -669,6 +698,7 @@ void tray_manager::handle(const evt::reparent_notify& evt) {
    return;
  }

+  // Tray client was reparented to another window
  if (evt->parent != client->embedder()) {
    m_log.info("tray: Received reparent_notify for client, remove...");
    remove_client(*client);
@ -679,10 +709,10 @@ void tray_manager::handle(const evt::reparent_notify& evt) {
 * Event callback : XCB_DESTROY_NOTIFY
 */
 void tray_manager::handle(const evt::destroy_notify& evt) {
-  if (!m_activated && evt->window == m_othermanager) {
+  if (is_waiting() && evt->window == m_othermanager) {
    m_log.info("Systray selection unmanaged... re-activating");
    activate();
-  } else if (m_activated && is_embedded(evt->window)) {
+  } else if (is_active() && is_embedded(evt->window)) {
    m_log.info("tray: Received destroy_notify for client, remove...");
    remove_client(evt->window);
    redraw_window();
@ -693,7 +723,7 @@ void tray_manager::handle(const evt::destroy_notify& evt) {
 * Event callback : XCB_MAP_NOTIFY
 */
 void tray_manager::handle(const evt::map_notify& evt) {
-  if (m_activated && evt->window == m_opts.selection_owner) {
+  if (is_active() && evt->window == m_opts.selection_owner) {
    m_log.trace("tray: Received map_notify");
    m_log.trace("tray: Update container mapped flag");
    redraw_window();
@ -713,7 +743,7 @@ void tray_manager::handle(const evt::map_notify& evt) {
 * Event callback : XCB_UNMAP_NOTIFY
 */
 void tray_manager::handle(const evt::unmap_notify& evt) {
-  if (m_activated && is_embedded(evt->window)) {
+  if (is_active() && is_embedded(evt->window)) {
    m_log.trace("tray: Received unmap_notify");
    m_log.trace("tray: Set client unmapped");
    auto client = find_client(evt->window);