listbox improvements, tabbing while staying in frame (autoscroll)

graphics/core.lua

@@ -7,7 +7,7 @@ local flasher = require("graphics.flasher")
 
 local core = {}
 
-core.version = "2.0.3"
+core.version = "2.0.4"
 
 core.flasher = flasher
 core.events = events

graphics/element.lua

@@ -105,6 +105,7 @@ function element.new(args, child_offset_x, child_offset_y)
         value = nil,            ---@type any
         window = nil,           ---@type table
         content_window = nil,   ---@type table|nil
+        mouse_window_shift = { x = 0, y = 0 },
         fg_bg = core.cpair(colors.white, colors.black),
         frame = core.gframe(1, 1, 1, 1),
         children = {},
@@ -344,6 +345,10 @@ function element.new(args, child_offset_x, child_offset_y)
     -- handle this element having been unfocused
     function protected.on_unfocused() end
 
+    -- handle this element having had a child focused
+    ---@param child graphics_element
+    function protected.on_child_focused(child) end
+
     -- handle this element having been shown
     function protected.on_shown() end
 
@@ -520,6 +525,13 @@ function element.new(args, child_offset_x, child_offset_y)
         else args.parent.__focus_child(child) end
     end
 
+    -- a child was focused, used to make sure it is actually visible to the user in the content frame
+    ---@param child graphics_element
+    function public.__child_focused(child)
+        protected.on_child_focused(child)
+        if not self.is_root then args.parent.__child_focused(public) end
+    end
+
     -- get a child element
     ---@nodiscard
     ---@param id element_id
@@ -652,6 +664,7 @@ function element.new(args, child_offset_x, child_offset_y)
         if args.can_focus and protected.enabled and not self.focused then
             self.focused = true
             protected.on_focused()
+            if not self.is_root then args.parent.__child_focused(public) end
         end
     end
 
@@ -704,10 +717,11 @@ function element.new(args, child_offset_x, child_offset_y)
                 end
 
                 local event_T = events.mouse_transposed(event, self.position.x, self.position.y)
-
-                -- handle the mouse event then pass to children
                 protected.handle_mouse(event_T)
-                for _, child in pairs(protected.children) do child.get().handle_mouse(event_T) end
+
+                -- shift child event if the content window has moved then pass to children
+                local c_event_T = events.mouse_transposed(event_T, protected.mouse_window_shift.x + 1, protected.mouse_window_shift.y + 1)
+                for _, child in pairs(protected.children) do child.get().handle_mouse(c_event_T) end
             elseif event.type == events.MOUSE_CLICK.DOWN or event.type == events.MOUSE_CLICK.TAP then
                 -- clicked out, unfocus this element and children
                 public.unfocus_all()

graphics/elements/listbox.lua

@@ -158,6 +158,9 @@ local function listbox(args)
         scroll_frame.reposition(1, 1 + scroll_offset)
         scroll_frame.setVisible(true)
 
+        -- shift mouse events
+        e.mouse_window_shift.y = scroll_offset
+
         draw_bar()
     end
 
@@ -219,6 +222,28 @@ local function listbox(args)
         end
     end
 
+    -- handle a child in the list being focused, make sure it is visible
+    function e.on_child_focused(child)
+        for i = 1, #list do
+            local item = list[i]    ---@type listbox_item
+            if item.e == child then
+                if (item.y + scroll_offset) <= 0 then
+                    scroll_offset = 1 - item.y
+                    update_positions()
+                    draw_bar()
+                elseif (item.y + scroll_offset) == 1 then
+                    -- do nothing, it's right at the top (if the bottom doesn't fit we can't easily fix that)
+                elseif ((item.h + item.y - 1) + scroll_offset) > e.frame.h then
+                    scroll_offset = 1 - ((item.h + item.y) - e.frame.h)
+                    update_positions()
+                    draw_bar()
+                end
+
+                return
+            end
+        end
+    end
+
     -- handle mouse interaction
     ---@param event mouse_interaction mouse event
     function e.handle_mouse(event)
@@ -226,23 +251,27 @@ local function listbox(args)
             if event.type == MOUSE_CLICK.TAP then
                 if event.current.x == e.frame.w then
                     if event.current.y == 1 or event.current.y < bar_bounds[1] then
-                        draw_arrows(1)
                         scroll_up()
+                        if event.current.y == 1 then
+                            draw_arrows(1)
                             if args.nav_active ~= nil then tcd.dispatch(0.25, function () draw_arrows(0) end) end
+                        end
                     elseif event.current.y == e.frame.h or event.current.y > bar_bounds[2] then
-                        draw_arrows(-1)
                         scroll_down()
+                        if event.current.y == e.frame.h then
+                            draw_arrows(-1)
                             if args.nav_active ~= nil then tcd.dispatch(0.25, function () draw_arrows(0) end) end
                         end
                     end
+                end
             elseif event.type == MOUSE_CLICK.DOWN then
                 if event.current.x == e.frame.w then
                     if event.current.y == 1 or event.current.y < bar_bounds[1] then
-                        draw_arrows(1)
                         scroll_up()
+                        if event.current.y == 1 then draw_arrows(1) end
                     elseif event.current.y == e.frame.h or event.current.y > bar_bounds[2] then
-                        draw_arrows(-1)
                         scroll_down()
+                        if event.current.y == e.frame.h then draw_arrows(-1) end
                     else
                         -- clicked on bar
                         holding_bar = true