Support for radio menu items

v2/internal/ffenestri/ffenestri_darwin.go

@@ -17,7 +17,11 @@ extern void SetWindowBackgroundIsTranslucent(void *);
 extern void SetMenu(void *, const char *);
 */
 import "C"
-import "encoding/json"
+import (
+	"encoding/json"
+
+	"github.com/wailsapp/wails/v2/pkg/menu"
+)
 
 func (a *Application) processPlatformSettings() error {
 
@@ -69,12 +73,113 @@ func (a *Application) processPlatformSettings() error {
 
 	// Process menu
 	if mac.Menu != nil {
-		menuJson, err := json.Marshal(mac.Menu)
+
+		/*
+			As radio groups need to be manually managed on OSX,
+			we preprocess the menu to determine the radio groups.
+			This is defined as any adjacent menu item of type "RadioType".
+			We keep a record of every radio group member we discover by saving
+			a list of all members of the group and the number of members
+			in the group (this last one is for optimisation at the C layer).
+
+			Example:
+			{
+				"RadioGroups": [
+					{
+						"Members": [
+							"option-1",
+							"option-2",
+							"option-3"
+						],
+						"Length": 3
+					}
+				]
+			}
+		*/
+		processedMenu := NewProcessedMenu(mac.Menu)
+		menuJSON, err := json.Marshal(processedMenu)
 		if err != nil {
 			return err
 		}
-		C.SetMenu(a.app, a.string2CString(string(menuJson)))
+		C.SetMenu(a.app, a.string2CString(string(menuJSON)))
 	}
 
 	return nil
 }
+
+// ProcessedMenu is the original menu with the addition
+// of radio groups extracted from the menu data
+type ProcessedMenu struct {
+	Menu              *menu.Menu
+	RadioGroups       []*RadioGroup
+	currentRadioGroup []string
+}
+
+// RadioGroup holds all the members of the same radio group
+type RadioGroup struct {
+	Members []string
+	Length  int
+}
+
+// NewProcessedMenu processed the given menu and returns
+// the original menu with the extracted radio groups
+func NewProcessedMenu(menu *menu.Menu) *ProcessedMenu {
+	result := &ProcessedMenu{
+		Menu:              menu,
+		RadioGroups:       []*RadioGroup{},
+		currentRadioGroup: []string{},
+	}
+
+	result.processMenu()
+
+	return result
+}
+
+func (p *ProcessedMenu) processMenu() {
+	// Loop over top level menus
+	for _, item := range p.Menu.Items {
+		// Process MenuItem
+		p.processMenuItem(item)
+	}
+
+	p.finaliseRadioGroup()
+}
+
+func (p *ProcessedMenu) processMenuItem(item *menu.MenuItem) {
+
+	switch item.Type {
+
+	// We need to recurse submenus
+	case menu.SubmenuType:
+
+		// Finalise any current radio groups as they don't trickle down to submenus
+		p.finaliseRadioGroup()
+
+		// Process each submenu item
+		for _, subitem := range item.SubMenu {
+			p.processMenuItem(subitem)
+		}
+	case menu.RadioType:
+		// Add the item to the radio group
+		p.currentRadioGroup = append(p.currentRadioGroup, item.ID)
+	default:
+		p.finaliseRadioGroup()
+	}
+}
+
+func (p *ProcessedMenu) finaliseRadioGroup() {
+
+	// If we were processing a radio group, fix up the references
+	if len(p.currentRadioGroup) > 0 {
+
+		// Create new radiogroup
+		group := &RadioGroup{
+			Members: p.currentRadioGroup,
+			Length:  len(p.currentRadioGroup),
+		}
+		p.RadioGroups = append(p.RadioGroups, group)
+
+		// Empty the radio group
+		p.currentRadioGroup = []string{}
+	}
+}