stocks: make the overlay's collapse hotkey a toggle

docs/changelog.txt

@@ -60,6 +60,7 @@ Template for new versions:
 
 ## New Features
 - `autodump`: new ``undestroy`` option reverts pending item destruction while the game is still paused
+- `stocks`: the overlay's ``collapse all`` hotkey now toggles, expanding all categories again when everything is collapsed
 
 ## Fixes
 - Fix broken weather lookup in ``World::ReadCurrentWeather``
@@ -69,6 +70,7 @@ Template for new versions:
 - `aquifer`: make ``--skip-top`` and top-relative ``--levels`` take effect for the ``drain``, ``convert``, and ``add`` actions instead of being silently ignored
 - `autodump`: ``destroy`` no longer leaves the contents of destroyed containers in limbo or crashes when destroying unit-held items
 - `timestream`: deal properly with units who have breathing difficulties
+- `stocks`: overlay now resets scroll position when collapsing categories so the item list is no longer left blank and unscrollable
 
 ## Misc Improvements
 - Added ``Coord2d`` and ``Coord3d`` C++ templates, providing a standard set operations for 2-tuples and 3-tuples of any numeric type

plugins/lua/stocks.lua

@@ -6,24 +6,45 @@ local widgets = require('gui.widgets')
 
 local stocks = df.global.game.main_interface.stocks
 
+-- these are only safe to call while the stocks page is open; guard against
+-- stray activations as the page closes
 local function collapse_all()
+    if not stocks.open then return end
     local num_sections = #stocks.current_type_a_expanded
     for idx=0,num_sections-1 do
         stocks.current_type_a_expanded[idx] = false
     end
     stocks.i_height = num_sections * 3
+    -- the collapsed list is much shorter; reset the scroll position so the
+    -- view isn't left pointing past the end of the list
+    stocks.scroll_position_item = 0
 end
 
 local function expand_all()
+    if not stocks.open then return end
     local num_sections = #stocks.current_type_a_expanded
     for idx=0,num_sections-1 do
         stocks.current_type_a_expanded[idx] = true
     end
-    num_items = #stocks.current_type_i_list
+    local num_items = #stocks.current_type_i_list
     stocks.i_height = (num_items + num_sections) * 3
 end
 
+local function all_collapsed()
+    if not stocks.open then return true end
+    for idx=0,#stocks.current_type_a_expanded-1 do
+        if stocks.current_type_a_expanded[idx] then return false end
+    end
+    return true
+end
+
+local function toggle_all()
+    if not stocks.open then return end
+    if all_collapsed() then expand_all() else collapse_all() end
+end
+
 local function remove_empty()
+    if not stocks.open then return end
     local empties = {}
     for itype,v in ipairs(stocks.storeamount) do
         if v == 0 and stocks.badamount[itype] == 0 then
@@ -36,6 +57,10 @@ local function remove_empty()
     for idx=#stocks.filtered_type_list-1,0,-1 do
         if empties[stocks.filtered_type_list[idx]] then stocks.filtered_type_list:erase(idx) end
     end
+    -- removing types shortens the type list; keep the scroll position in bounds
+    if stocks.scroll_position_type >= #stocks.filtered_type_list then
+        stocks.scroll_position_type = math.max(0, #stocks.filtered_type_list - 1)
+    end
 end
 
 -- -------------------
@@ -57,9 +82,11 @@ function StocksOverlay:init()
     self:addviews{
         widgets.HotkeyLabel{
             frame={t=0, l=0},
-            label='collapse all',
+            label=function()
+                return all_collapsed() and 'expand all' or 'collapse all'
+            end,
             key='CUSTOM_CTRL_X',
-            on_activate=collapse_all,
+            on_activate=toggle_all,
         },
         widgets.HotkeyLabel{
             frame={t=1, l=0},

test/plugins/stocks.lua

@@ -0,0 +1,87 @@
+config.mode = 'fortress'
+config.target = 'overlay'
+
+local gui = require('gui')
+local overlay = require('plugins.overlay')
+
+local stocks = df.global.game.main_interface.stocks
+
+-- feed a key to the stocks overlay widget's input handler. This is the same
+-- code path the viewscreen's interposed feed() takes; we invoke it directly
+-- because the focus string cache only refreshes on game frames, which tests
+-- cannot wait for.
+local function send_key(key)
+    overlay.get_state().db['stocks.overlay'].widget:onInput({[key]=true})
+end
+
+local function set_stocks_open(open)
+    if stocks.open ~= open then
+        gui.simulateInput(dfhack.gui.getDFViewscreen(true), 'D_STOCKS')
+    end
+end
+
+local function expanded_count()
+    local n = 0
+    for i=0,#stocks.current_type_a_expanded-1 do
+        if stocks.current_type_a_expanded[i] then n = n + 1 end
+    end
+    return n
+end
+
+local saved_open
+
+config.wrapper = function(test_fn)
+    saved_open = stocks.open
+    -- the widget db can be empty if a rescan is still in progress
+    overlay.rescan()
+    return dfhack.with_finalize(function()
+        -- close and reopen so the game repopulates any lists the test mutated
+        set_stocks_open(false)
+        set_stocks_open(saved_open)
+    end, test_fn)
+end
+
+function test.toggle_collapses_then_expands()
+    set_stocks_open(true)
+    local num_sections = #stocks.current_type_a_expanded
+    expect.true_(num_sections > 0)
+    for i=0,num_sections-1 do
+        stocks.current_type_a_expanded[i] = true
+    end
+    stocks.scroll_position_item = 5
+    send_key('CUSTOM_CTRL_X')
+    expect.eq(0, expanded_count())
+    -- collapsing resets the item scroll position so it stays in bounds
+    expect.eq(0, stocks.scroll_position_item)
+    -- with everything collapsed, the same hotkey expands
+    send_key('CUSTOM_CTRL_X')
+    expect.eq(num_sections, expanded_count())
+end
+
+function test.expand_hotkey_expands_all()
+    set_stocks_open(true)
+    for i=0,#stocks.current_type_a_expanded-1 do
+        stocks.current_type_a_expanded[i] = false
+    end
+    send_key('CUSTOM_CTRL_Z')
+    expect.eq(#stocks.current_type_a_expanded, expanded_count())
+end
+
+function test.remove_empty_keeps_type_scroll_in_bounds()
+    set_stocks_open(true)
+    stocks.scroll_position_type = #stocks.filtered_type_list + 10
+    send_key('CUSTOM_CTRL_E')
+    expect.true_(stocks.scroll_position_type >= 0)
+    expect.true_(stocks.scroll_position_type < #stocks.filtered_type_list)
+end
+
+function test.closed_stocks_ignores_overlay_keys()
+    set_stocks_open(false)
+    -- the stocks.open guard must make every hotkey a no-op while the page is
+    -- closed, even if an activation slips through as the page closes
+    local n = expanded_count()
+    send_key('CUSTOM_CTRL_X')
+    send_key('CUSTOM_CTRL_Z')
+    send_key('CUSTOM_CTRL_E')
+    expect.eq(n, expanded_count())
+end