I just accidentally stumbled on how to make cascading popup menus -- you nest the items passed to popup_menu() in the (now) obvious way:
local LrBinding = import 'LrBinding'
local LrDialogs = import 'LrDialogs'
local LrFunctionContext = import 'LrFunctionContext'
local LrView = import 'LrView'
local bind = LrView.bind
local f = LrView.osFactory()
local items = {
{title = "Item 0", value = "0"},
{title = "Item 1",
{title = "Item 1.a", value = "1.a"},
{title = "Item 1.b", value = "1.b"}},
{title = "Item 2",
{title = "Item 2.a", value = "2.a"},
{title = "Item 2.b", value = "2.b"}}}
LrFunctionContext.callWithContext ("", function (context)
local prop = LrBinding.makePropertyTable (context)
LrDialogs.presentModalDialog {title = "Nested Menu",
contents = f:popup_menu {items = items, value = bind ("v"),
bind_to_object = prop}}
LrDialogs.message ("Selected item", prop.v)
end)
Here's what it looks like:
This is undocumented, so who knows whether it will remain "supported" in future versions (as much as anything in the SDK is "supported" these days).
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