Added generic layout class and HBox.

src/ui/hbox.lua

@@ -0,0 +1,62 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local make_class = require 'src.utils.classes'
+local Layout     = require 'src.ui.layout'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local HBox = make_class(Layout)
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function HBox:_init(x, y, w, h, spacing)
+    Layout._init(self, x, y, w, h, spacing)
+end
+
+
+function HBox:load()
+    Layout.load(self)
+
+    local _x = self.x
+
+    -- Load required assets if needed and then compute the coordinates of each button.
+    for _, v in pairs(self.elements) do
+        v.y = self.y
+
+        v.x = _x
+        _x = _x + v.w + self.s
+    end
+end
+
+
+function HBox:set_dimensions()
+    if self.w == nil then
+        self.w = 0
+        for i, v in pairs(self.elements) do
+            self.w = self.w + v.w
+            if i < #self.elements then self.w = self.w + self.s end
+        end
+    end
+
+    if self.h == nil then
+        self.h = 0
+        for _, v in pairs(self.elements) do
+            if v.h > self.h then self.h = v.h end
+        end
+    end
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return HBox