support vertical progress

example/main.lua

@@ -13,6 +13,7 @@ end)
 layout.flowToggle:onChange(function (event)
     layout.flowTest.flow = event.value and 'x' or 'y'
     layout.slidey.flow = event.value and 'y' or 'x'
+    layout.progressBar.flow = event.value and 'y' or 'x'
 end)
 
 layout.newButton:onPress(function (event)

luigi/widget/progress.lua

@@ -9,11 +9,12 @@ between 0 and 1 (inclusive) to change the width of the bar.
 
 return function (self)
     self.value = 0
-    self.flow = 'x' -- TODO: support vertical progress?
 
+    local pad = self:addChild {
+        width = 0,
+    }
     local bar = self:addChild {
         type = 'progress.bar',
-        width = 0,
     }
 
     self:onChange(function ()
@@ -23,8 +24,18 @@ return function (self)
     self:onReshape(function ()
         local x1, y1, w, h = self:getRectangle(true, true)
         local x2, y2 = x1 + w, y1 + h
-        local min = bar.minwidth
-        x1 = x1 + min
-        bar.width = self.value * (x2 - x1) + min
+        if self.flow == 'x' then
+            local min = bar.minwidth or 0
+            x1 = x1 + min
+            bar.width = self.value * (x2 - x1) + min
+            bar.height = false
+            pad.height = 0
+        else
+            local min = bar.minheight or 0
+            y1 = y1 + min
+            bar.width = false
+            bar.height = false
+            pad.height = h - (self.value * (y2 - y1) + min)
+        end
     end)
 end