Autostart option added

src/trayicon.h

@@ -0,0 +1,109 @@
+// gKeyMapper - the tray icon, spoken as a StatusNotifierItem.
+#ifndef GKEYMAPPER_TRAYICON_H
+#define GKEYMAPPER_TRAYICON_H
+
+#include <functional>
+#include <string>
+#include <vector>
+
+#include <gio/gio.h>
+
+namespace gkeymapper {
+
+// The tray icon. GTK4 has no tray widget (GtkStatusIcon was GTK3 and is gone), so
+// the icon is exported on the session bus as a StatusNotifierItem plus a
+// com.canonical.dbusmenu menu - exactly the protocol libxapp and libappindicator
+// wrap, only without their GTK3 dependency (a GTK4 process must not load GTK3).
+// The panel hosts it: Cinnamon's xapp-status applet, KDE, Unity, or the GNOME
+// AppIndicator extension.
+//
+// The panel is a different process, so the icon travels as a pixmap: it cannot
+// read the icons compiled into this binary.
+class TrayIcon {
+public:
+    using Callback = std::function<void()>;
+
+    TrayIcon() = default;
+    ~TrayIcon();
+    TrayIcon(const TrayIcon&) = delete;
+    TrayIcon& operator=(const TrayIcon&) = delete;
+
+    // Owns the item's bus name, exports the item and its menu and registers with
+    // the panel's watcher - and again whenever the panel restarts (the watcher
+    // owns the icon list, a restart loses it). `icon` is ARGB32 in network byte
+    // order, which is the layout the protocol asks for.
+    void start(std::vector<unsigned char> icon, int width, int height, Callback onShow,
+               Callback onQuit);
+
+    // True once a panel hosts the icon, i.e. the icon is really on screen. Only
+    // then hiding the window is safe: without a tray there is no way back.
+    bool ready() const { return registered_; }
+
+    // The panel mirrors the menu once, so it has to be told when the texts in it
+    // changed - a language switch. Nothing else about the icon changes.
+    void refresh_labels();
+private:
+    static void on_bus_acquired(GDBusConnection* connection, const gchar* name, gpointer userData);
+    static void on_name_lost(GDBusConnection* connection, const gchar* name, gpointer userData);
+    static void on_watcher_appeared(GDBusConnection* connection, const gchar* name,
+                                    const gchar* nameOwner, gpointer userData);
+    static void on_watcher_vanished(GDBusConnection* connection, const gchar* name,
+                                    gpointer userData);
+    static void on_register_reply(GObject* source, GAsyncResult* result, gpointer userData);
+
+    static void on_item_method_call(GDBusConnection* connection, const gchar* sender,
+                                    const gchar* objectPath, const gchar* interfaceName,
+                                    const gchar* methodName, GVariant* parameters,
+                                    GDBusMethodInvocation* invocation, gpointer userData);
+    static GVariant* on_item_get_property(GDBusConnection* connection, const gchar* sender,
+                                          const gchar* objectPath, const gchar* interfaceName,
+                                          const gchar* propertyName, GError** error,
+                                          gpointer userData);
+    static void on_menu_method_call(GDBusConnection* connection, const gchar* sender,
+                                    const gchar* objectPath, const gchar* interfaceName,
+                                    const gchar* methodName, GVariant* parameters,
+                                    GDBusMethodInvocation* invocation, gpointer userData);
+    static GVariant* on_menu_get_property(GDBusConnection* connection, const gchar* sender,
+                                          const gchar* objectPath, const gchar* interfaceName,
+                                          const gchar* propertyName, GError** error,
+                                          gpointer userData);
+
+    void export_objects(GDBusConnection* connection);
+    // Runs what a click on a menu entry means ("clicked" on Show or Close).
+    void handle_event(int id, const char* eventId);
+    // Notes which of the two watcher names is on the bus and registers there.
+    void set_watcher_available(const char* name, bool available);
+    void register_with_watcher();
+    GVariant* icon_pixmaps() const;
+    GVariant* tooltip() const;
+    GVariant* layout(int parentId, int depth) const;
+    GVariant* node(int id, int depth) const;
+    GVariant* group_properties(GVariant* ids) const;
+    GVariant* menu_property(int id, const char* name) const;
+
+    GDBusConnection* connection_ = nullptr;
+    guint itemRegistration_ = 0;
+    guint menuRegistration_ = 0;
+    guint ownerId_ = 0;
+    guint watcherId_ = 0;
+    guint watcherIdX_ = 0;
+    std::string serviceName_;
+    std::vector<unsigned char> icon_;
+    int iconWidth_ = 0;
+    int iconHeight_ = 0;
+    bool watcher_ = false;
+    bool watcherAlias_ = false;
+    bool registering_ = false;
+    bool registered_ = false;
+    const char* registeringWith_ = nullptr;
+    std::string registeredWith_;
+    // Bumped whenever the menu texts change; the panel compares it to know that
+    // what it mirrored is stale.
+    guint menuRevision_ = 1;
+    Callback onShow_;
+    Callback onQuit_;
+};
+
+} // namespace gkeymapper
+
+#endif // GKEYMAPPER_TRAYICON_H