add Cmd+, shortcut for settings dialog on Mac

ui/mainwindow.go

@@ -126,11 +126,7 @@ func NewMainWindow(fyneApp fyne.App, appName, displayAppName, appVersion string,
 			}
 		}()
 	})
-	m.BrowsingPane.AddSettingsMenuItem("Settings...", func() {
-		m.Controller.ShowSettingsDialog(func() {
-			fyneApp.Settings().SetTheme(m.theme)
-		}, m.theme.ListThemeFiles())
-	})
+	m.BrowsingPane.AddSettingsMenuItem("Settings...", m.showSettingsDialog)
 	m.BrowsingPane.AddSettingsMenuItem("About...", m.Controller.ShowAboutDialog)
 	m.addNavigationButtons()
 	m.BrowsingPane.DisableNavigationButtons()
@@ -240,6 +236,11 @@ func (m *MainWindow) addShortcuts() {
 			m.Canvas().Focus(nil)
 		})
 	}
+	if os.SettingsShortcut != nil {
+		m.Canvas().AddShortcut(os.SettingsShortcut, func(_ fyne.Shortcut) {
+			m.showSettingsDialog()
+		})
+	}
 
 	m.Canvas().AddShortcut(&ShortcutReload, func(_ fyne.Shortcut) {
 		m.BrowsingPane.Reload()
@@ -276,6 +277,12 @@ func (m *MainWindow) addShortcuts() {
 	})
 }
 
+func (m *MainWindow) showSettingsDialog() {
+	m.Controller.ShowSettingsDialog(func() {
+		fyne.CurrentApp().Settings().SetTheme(m.theme)
+	}, m.theme.ListThemeFiles())
+}
+
 func (m *MainWindow) Show() {
 	m.Window.Show()
 }

ui/os/shortcuts_darwin.go

@@ -21,4 +21,5 @@ var (
 		{Modifier: fyne.KeyModifierSuper, KeyName: fyne.KeyRight},
 		{Modifier: fyne.KeyModifierSuper, KeyName: fyne.KeyRightBracket},
 	}
+	SettingsShortcut = &desktop.CustomShortcut{Modifier: fyne.KeyModifierSuper, KeyName: fyne.KeyComma}
 )

ui/os/shortcuts_default.go

@@ -19,4 +19,5 @@ var (
 	ForwardShortcuts = []desktop.CustomShortcut{
 		{Modifier: fyne.KeyModifierAlt, KeyName: fyne.KeyRight},
 	}
+	SettingsShortcut *desktop.CustomShortcut = nil // TODO: is there a platform standard for Win/Linux?
 )