Preliminary Tray support

v2/internal/subsystem/tray.go

@@ -0,0 +1,186 @@
+package subsystem
+
+import (
+	"strings"
+	"sync"
+
+	"github.com/wailsapp/wails/v2/internal/logger"
+	"github.com/wailsapp/wails/v2/internal/messagedispatcher/message"
+	"github.com/wailsapp/wails/v2/internal/servicebus"
+	"github.com/wailsapp/wails/v2/pkg/menu"
+)
+
+// Tray is the subsystem that handles the operation of the tray menu.
+// It manages all service bus messages starting with "tray".
+type Tray struct {
+	quitChannel <-chan *servicebus.Message
+	trayChannel <-chan *servicebus.Message
+	running     bool
+
+	// Event listeners
+	listeners  map[string][]func(*menu.MenuItem)
+	menuItems  map[string]*menu.MenuItem
+	notifyLock sync.RWMutex
+
+	// logger
+	logger logger.CustomLogger
+
+	// The tray menu
+	trayMenu *menu.Menu
+
+	// Service Bus
+	bus *servicebus.ServiceBus
+}
+
+// NewTray creates a new menu subsystem
+func NewTray(trayMenu *menu.Menu, bus *servicebus.ServiceBus,
+	logger *logger.Logger) (*Tray, error) {
+
+	// Register quit channel
+	quitChannel, err := bus.Subscribe("quit")
+	if err != nil {
+		return nil, err
+	}
+
+	// Subscribe to menu messages
+	trayChannel, err := bus.Subscribe("tray:")
+	if err != nil {
+		return nil, err
+	}
+
+	result := &Tray{
+		quitChannel: quitChannel,
+		trayChannel: trayChannel,
+		logger:      logger.CustomLogger("Tray Subsystem"),
+		listeners:   make(map[string][]func(*menu.MenuItem)),
+		menuItems:   make(map[string]*menu.MenuItem),
+		trayMenu:    trayMenu,
+		bus:         bus,
+	}
+
+	// Build up list of item/id pairs
+	result.processMenu(trayMenu)
+
+	return result, nil
+}
+
+// Start the subsystem
+func (t *Tray) Start() error {
+
+	t.logger.Trace("Starting")
+
+	t.running = true
+
+	// Spin off a go routine
+	go func() {
+		for t.running {
+			select {
+			case <-t.quitChannel:
+				t.running = false
+				break
+			case menuMessage := <-t.trayChannel:
+				splitTopic := strings.Split(menuMessage.Topic(), ":")
+				menuMessageType := splitTopic[1]
+				switch menuMessageType {
+				case "clicked":
+					if len(splitTopic) != 2 {
+						t.logger.Error("Received clicked message with invalid topic format. Expected 2 sections in topic, got %s", splitTopic)
+						continue
+					}
+					t.logger.Trace("Got Menu clicked Message: %s %+v", menuMessage.Topic(), menuMessage.Data())
+					menuid := menuMessage.Data().(string)
+
+					// Get the menu item
+					menuItem := t.menuItems[menuid]
+					if menuItem == nil {
+						t.logger.Trace("Cannot process menuid %s - unknown", menuid)
+						return
+					}
+
+					// Is the menu item a checkbox?
+					if menuItem.Type == menu.CheckboxType {
+						// Toggle state
+						menuItem.Checked = !menuItem.Checked
+					}
+
+					// Notify listeners
+					t.notifyListeners(menuid, menuItem)
+				case "on":
+					listenerDetails := menuMessage.Data().(*message.MenuOnMessage)
+					id := listenerDetails.MenuID
+					t.listeners[id] = append(t.listeners[id], listenerDetails.Callback)
+
+				// Make sure we catch any menu updates
+				case "update":
+					updatedMenu := menuMessage.Data().(*menu.Menu)
+					t.processMenu(updatedMenu)
+
+					// Notify frontend of menu change
+					t.bus.Publish("trayfrontend:update", updatedMenu)
+
+				default:
+					t.logger.Error("unknown tray message: %+v", menuMessage)
+				}
+			}
+		}
+
+		// Call shutdown
+		t.shutdown()
+	}()
+
+	return nil
+}
+
+func (t *Tray) processMenu(trayMenu *menu.Menu) {
+	// Initialise the variables
+	t.menuItems = make(map[string]*menu.MenuItem)
+	t.trayMenu = trayMenu
+
+	for _, item := range trayMenu.Items {
+		t.processMenuItem(item)
+	}
+}
+
+func (t *Tray) processMenuItem(item *menu.MenuItem) {
+
+	if item.SubMenu != nil {
+		for _, submenuitem := range item.SubMenu {
+			t.processMenuItem(submenuitem)
+		}
+		return
+	}
+
+	if item.ID != "" {
+		if t.menuItems[item.ID] != nil {
+			t.logger.Error("Menu id '%s' is used by multiple menu items: %s %s", t.menuItems[item.ID].Label, item.Label)
+			return
+		}
+		t.menuItems[item.ID] = item
+	}
+}
+
+// Notifies listeners that the given menu was clicked
+func (t *Tray) notifyListeners(menuid string, menuItem *menu.MenuItem) {
+
+	// Get list of menu listeners
+	listeners := t.listeners[menuid]
+	if listeners == nil {
+		t.logger.Trace("No listeners for MenuItem with ID '%s'", menuid)
+		return
+	}
+
+	// Lock the listeners
+	t.notifyLock.Lock()
+
+	// Callback in goroutine
+	for _, listener := range listeners {
+		go listener(menuItem)
+	}
+
+	// Unlock
+	t.notifyLock.Unlock()
+}
+
+func (t *Tray) shutdown() {
+	t.logger.Trace("Shutdown")
+}