graphics library refactoring and bugfixes

graphics/elements/indicators/hbar.lua

@@ -0,0 +1,97 @@
+-- Horizontal Bar Graphics Element
+
+local util    = require("scada-common.util")
+
+local element = require("graphics.element")
+
+---@class hbar_args
+---@field show_percent? boolean whether or not to show the percent
+---@field bar_fg_bg? cpair bar foreground/background colors if showing percent
+---@field parent graphics_element
+---@field x? integer 1 if omitted
+---@field y? integer 1 if omitted
+---@field width? integer parent width if omitted
+---@field height? integer parent height if omitted
+---@field gframe? graphics_frame frame instead of x/y/width/height
+---@field fg_bg? cpair foreground/background colors
+
+-- new horizontal bar
+---@param args hbar_args
+local function hbar(args)
+    -- properties/state
+    local last_num_bars = -1
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- bar width is width - 5 characters for " 100%" if showing percent
+    local bar_width = util.trinary(args.show_percent, e.frame.w - 5, e.frame.w)
+
+    assert(bar_width > 0, "graphics.elements.hbar: too small for bar")
+
+    -- determine bar colors
+    ---@fixme this doesnt work as intended
+    local bar_bkg = util.trinary(args.bar_fg_bg == nil, e.fg_bg.blit_bkg, args.bar_fg_bg.blit_bkg)
+    local bar_fgd = util.trinary(args.bar_fg_bg == nil, e.fg_bg.blit_fgd, args.bar_fg_bg.blit_fgd)
+
+    -- handle data changes
+    function e.on_update(fraction)
+        -- enforce minimum and maximum
+        if fraction < 0 then
+            fraction = 0.0
+        elseif fraction > 1 then
+            fraction = 1.0
+        end
+
+        -- compute number of bars
+        local num_bars = util.round(fraction * (bar_width * 2))
+        util.print(num_bars)
+
+        -- redraw bar if changed
+        if num_bars ~= last_num_bars then
+            last_num_bars = num_bars
+
+            local fgd = ""
+            local bkg = ""
+            local spaces = ""
+
+            -- fill percentage
+            for _ = 1, num_bars / 2 do
+                spaces = spaces .. " "
+                fgd = fgd .. bar_fgd
+                bkg = bkg .. bar_bkg
+            end
+
+            -- add fractional bar if needed
+            if num_bars % 2 == 1 then
+                spaces = spaces .. "\x95"
+                fgd = fgd .. bar_bkg
+                bkg = bkg .. bar_fgd
+            end
+
+            -- pad background
+            for _ = 1, ((bar_width * 2) - num_bars) / 2 do
+                spaces = spaces .. " "
+                fgd = fgd .. bar_bkg
+                bkg = bkg .. bar_bkg
+            end
+
+            -- draw bar
+            for y = 1, e.frame.h do
+                e.window.setCursorPos(1, y)
+                -- intentionally swapped fgd/bkg since we use spaces as fill, but they are the opposite
+                e.window.blit(spaces, bkg, fgd)
+            end
+        end
+
+        -- update percentage
+        if args.show_percent then
+            e.window.setCursorPos(bar_width + 1, math.max(1, math.ceil(e.frame.h / 2)))
+            e.window.write(util.sprintf("%3.0f%%", fraction * 100))
+        end
+    end
+
+    return e.get()
+end
+
+return hbar