update PicoCalc SD

Bin/PicoCalc SD/cc/internal/menu.lua

@@ -0,0 +1,104 @@
+-- SPDX-FileCopyrightText: 2017 Daniel Ratcliffe
+--
+-- SPDX-License-Identifier: LicenseRef-CCPL
+
+--[[- A simple menu bar.
+
+> [!DANGER]
+> This is an internal module and SHOULD NOT be used in your own code. It may
+> be removed or changed at any time.
+
+This provides a shared implementation of the menu bar used by the `edit` and
+`paint` programs. This draws a menu bar at the bottom of the string, with a list
+of options.
+
+@local
+]]
+
+
+--[[- Create a new menu bar.
+
+This should be called every time the menu is displayed.
+
+@tparam { string... } items The menu items to display.
+@return The menu.
+]]
+local function create(items)
+    return {
+        items = items,
+        selected = 1,
+    }
+end
+
+--[[- Draw the menu bar at the bottom of the screen.
+
+This should be called when first displaying the menu, and if the whole screen is
+redrawn (e.g. after a [`term_resize`]).
+
+@param menu The menu bar to draw.
+]]
+local function draw(menu)
+
+    local _, height = term.getSize()
+    term.setCursorPos(1, height)
+
+    term.clearLine()
+
+    local active_color = colors.yellow
+    term.setTextColor(colors.white)
+    for k, v in pairs(menu.items) do
+        if menu.selected == k then
+            term.setTextColor(active_color)
+            term.write("[")
+            term.setTextColor(colors.white)
+            term.write(v)
+            term.setTextColor(active_color)
+            term.write("]")
+            term.setTextColor(colors.white)
+        else
+            term.write(" " .. v .. " ")
+        end
+    end
+end
+
+--[[- Process an event.
+
+@param menu The menu bar to update.
+@tparam string The event name.
+@param ... Additional arguments to the event.
+@treturn nil|boolean|string Either:
+
+  - If no action was taken, return `nil`.
+  - If the menu was closed, return `false`.
+  - If an item was selected, return the item as a string.
+]]
+local function handle_event(menu, key)
+		if key == keys.right then
+				-- Move right
+				menu.selected = menu.selected + 1
+				if menu.selected > #menu.items then menu.selected = 1 end
+				draw(menu)
+		elseif key == keys.left and menu.selected > 1 then
+				-- Move left
+				menu.selected = menu.selected - 1
+				if menu.selected < 1 then menu.selected = #menu.items end
+				draw(menu)
+		elseif key == keys.enter or key == keys.numPadEnter then
+				-- Select an option
+				return menu.items[menu.selected]
+		elseif key == keys.control or keys == keys.alt then
+				-- Cancel the menu
+				return false
+    elseif key:lower() >= "a" and key:lower() <= "z" then
+			-- Select menu items
+			local char = key:lower()
+			for _, item in pairs(menu.items) do
+					if item:sub(1, 1):lower() == char then return item end
+			end
+    end
+
+    return nil
+end
+
+
+return { create = create, draw = draw, handle_event = handle_event }