graphics library refactoring and bugfixes

graphics/elements/indicators/light.lua

@@ -0,0 +1,54 @@
+-- Indicator Light Graphics Element
+
+local util    = require("scada-common.util")
+
+local element = require("graphics.element")
+
+---@class indicator_light_args
+---@field label string indicator label
+---@field colors cpair on/off colors (a/b respectively)
+---@field min_label_width? integer label length if omitted
+---@field parent graphics_element
+---@field x? integer 1 if omitted
+---@field y? integer 1 if omitted
+---@field fg_bg? cpair foreground/background colors
+
+-- new indicator light
+---@param args indicator_light_args
+local function indicator_light(args)
+    assert(type(args.label) == "string", "graphics.elements.indicators.light: label is a required field")
+    assert(type(args.colors) == "table", "graphics.elements.indicators.light: colors is a required field")
+
+    -- single line
+    args.height = 1
+
+    -- determine width
+    args.width = math.max(args.min_label_width or 1, string.len(args.label)) + 3
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- on/off blit strings
+    local on_blit = util.strrep(args.colors.blit_a, 2)
+    local off_blit = util.strrep(args.colors.blit_b, 2)
+
+    -- write label and initial indicator light
+    e.window.setCursorPos(1, 1)
+    e.window.blit("   ", "000", off_blit .. e.fg_bg.blit_bkg)
+    e.window.write(args.label)
+
+    -- on state change
+    ---@param new_state boolean indicator state
+    function e.on_update(new_state)
+        e.window.setCursorPos(1, 1)
+        if new_state then
+            e.window.blit("  ", "00", on_blit)
+        else
+            e.window.blit("  ", "00", off_blit)
+        end
+    end
+
+    return e.get()
+end
+
+return indicator_light