#63 vertical fill bar indicator

graphics/element.lua

@@ -32,6 +32,7 @@ function element.new(args)
     -- get the parent window
     self.p_window = args.window or args.parent.window()
 
+    -- check window
     assert(self.p_window, "graphics.element: no parent window provided")
 
     -- get frame coordinates/size
@@ -48,6 +49,12 @@ function element.new(args)
         protected.frame.h = args.height or h
     end
 
+    -- check frame
+    assert(protected.frame.x >= 1, "graphics.element: frame x not >= 1")
+    assert(protected.frame.y >= 1, "graphics.element: frame y not >= 1")
+    assert(protected.frame.w >= 1, "graphics.element: frame width not >= 1")
+    assert(protected.frame.h >= 1, "graphics.element: frame height not >= 1")
+
     -- create window
     local f = protected.frame
     protected.window = window.create(self.p_window, f.x, f.y, f.w, f.h, true)

graphics/elements/hbar.lua

@@ -6,7 +6,6 @@ local element = require("graphics.element")
 
 ---@class hbar_args
 ---@field bar_fg_bg cpair bar foreground/background colors
----@field border? graphics_border
 ---@field parent graphics_element
 ---@field x? integer 1 if omitted
 ---@field y? integer 1 if omitted

graphics/elements/vbar.lua

@@ -0,0 +1,82 @@
+-- Horizontal Bar Graphics Element
+
+local util    = require("scada-common.util")
+
+local element = require("graphics.element")
+
+---@class vbar_args
+---@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 vertical bar
+---@param args vbar_args
+local function vbar(args)
+    -- last state
+    local last_num_bars = -1
+
+    -- create new graphics element base object
+    local e = element.new(args)
+
+    -- blit strings
+    local fgd = util.strrep(e.fg_bg.blit_fgd, e.frame.w)
+    local bkg = util.strrep(e.fg_bg.blit_bkg, e.frame.w)
+    local spaces = util.strrep(" ", e.frame.w)
+    local one_third = util.strrep("\x8f", e.frame.w)
+    local two_thirds = util.strrep("\x83", e.frame.w)
+
+    -- 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 * 100) / (e.frame.h * 3))
+
+        -- redraw only if number of bars has changed
+        if num_bars ~= last_num_bars then
+            last_num_bars = num_bars
+
+            -- start bottom up
+            local y = e.window.h
+
+            -- start at base of vertical bar
+            e.window.setCursorPos(1, y)
+
+            -- fill percentage
+            for _ = 1, num_bars / 3 do
+                e.window.blit(spaces, bkg, fgd)
+                y = y - 1
+                e.window.setCursorPos(1, y)
+            end
+
+            -- add fractional bar if needed
+            if num_bars % 3 == 1 then
+                e.window.blit(one_third, bkg, fgd)
+                y = y - 1
+            elseif num_bars % 3 == 2 then
+                e.window.blit(two_thirds, bkg, fgd)
+                y = y - 1
+            end
+
+            -- fill the rest blank
+            while y > 0 do
+                e.window.setCursorPos(1, y)
+                e.window.blit(spaces, fgd, bkg)
+                y = y - 1
+            end
+        end
+    end
+
+    return e.get()
+end
+
+return vbar