add test.ListBox_with_multi_select_and_visual_indicator

this test also demonstrates actual (minimal) example usage

test/library/gui/dialogs.lua

@@ -9,8 +9,8 @@ local function send_keys(...)
 end
 
 local xtest = {} -- use to temporarily disable tests (change `function test.somename` to `function xtest.somename`)
-local wait = function()
-    --delay(30) -- enable for debugging the tests
+local wait = function(n)
+    --delay(n or 30) -- enable for debugging the tests
 end
 
 local dialogs = require('gui.dialogs')
@@ -170,3 +170,94 @@ function test.ListBox_with_multi_select()
     send_keys('LEAVESCREEN')
     expect.eq(before_scr, dfhack.gui.getCurViewscreen(true), "Pressing LEAVESCREEN should still return us to previous screen")
 end
+
+-- this test also demonstrates actual (minimal) example usage
+function test.ListBox_with_multi_select_and_visual_indicator()
+    local before_scr = dfhack.gui.getCurViewscreen(true)
+
+    -- configure colors
+    local pen_active = COLOR_LIGHTCYAN
+    local dpen_active = COLOR_CYAN
+    local pen_not_active = COLOR_LIGHTRED
+    local dpen_not_active = COLOR_RED
+    local pen_cb = function(args, fnc)
+        if not (args and fnc) then return COLOR_YELLOW end
+        return fnc(args) and pen_active or pen_not_active
+    end
+    local pen_d_cb = function(args, fnc)
+        if not (args and fnc) then return COLOR_YELLOW end
+        return fnc(args) and dpen_active or dpen_not_active
+    end
+    
+    local args = {}
+    local choices = {}
+    args.choices = choices
+    local mock_cb = mock.func()
+    local mock_cb2 = mock.func()
+    args.on_select = function(ix, choice)
+        mock_cb()
+        local item = choice.item
+        item.active = not item.active
+    end
+    args.on_select2 = mock_cb2
+    args.dismiss_on_select = false
+    
+    local mock_is_active_cb_counter = mock.func()
+    local is_active = function (args)
+        mock_is_active_cb_counter()
+        return args.item.active
+    end
+    local items = {
+        {text = 'ListBox_with_multi_select', active = true},
+        {text = 'and_visual_indicator', active = true},
+        {text = 'item3', active = false}
+    }
+    for _, item in pairs(items) do
+        local args = {item=item}
+        table.insert(choices, {
+            text = {{text = item.text,
+                    pen = curry(pen_cb, args, is_active),
+                    dpen = curry(pen_d_cb, args, is_active),
+            }},
+            item = item
+        })
+    end
+
+    local lb = dialogs.ListBox(args)
+    lb:show()
+    local lb_scr = dfhack.gui.getCurViewscreen(true)
+    
+    expect.eq(pen_active, choices[1].text[1].pen(), "Pen of the first item should be the pen_active")
+    expect.eq(pen_not_active, choices[3].text[1].pen(), "Pen of the third item should be the pen_not_active")
+    
+    wait()
+    send_keys('SELECT')
+    send_keys('STANDARDSCROLL_DOWN')
+    wait()
+    send_keys('SELECT')
+    send_keys('STANDARDSCROLL_DOWN')
+    wait()
+    send_keys('SELECT')
+    wait(100)
+    expect.eq(3, mock_cb.call_count)
+    expect.eq(0, mock_cb2.call_count)
+    
+    expect.lt(0, mock_is_active_cb_counter.call_count, "is_active should be called at least once")
+    
+    expect.table_eq(
+        {
+            {text = 'ListBox_with_multi_select', active = false},
+            {text = 'and_visual_indicator', active = false},
+            {text = 'item3', active = true}
+        },
+        items,
+        "the active status should've been toggled"
+    )
+    expect.eq(pen_not_active, choices[1].text[1].pen(), "Pen of the first now not active item should be the pen_not_active")
+    expect.eq(pen_active, choices[3].text[1].pen(), "Pen of the third now active item should be the pen_active")
+    
+    expect.eq(lb_scr, dfhack.gui.getCurViewscreen(true), "With both dismiss_on_select and dismiss_on_select2 false the ListBox should stay open")
+    
+    send_keys('LEAVESCREEN')
+    expect.eq(before_scr, dfhack.gui.getCurViewscreen(true), "Pressing LEAVESCREEN should still return us to previous screen")
+end