layout_parser.rb in squib-0.16.0.pre.preview1

- old
+ new

@@ -1,14 +1,17 @@
 require 'yaml'
+require_relative 'args/xywh_shorthands'
 
 module Squib
   # Internal class for handling layouts
   # @api private
   class LayoutParser
+    include Args::XYWHShorthands
 
-    def initialize(dpi = 300)
+    def initialize(dpi = 300, cell_px = 37.5)
       @dpi = dpi
+      @cell_px = cell_px
     end
 
     # Load the layout file(s), if exists
     # @api private
     def load_layout(files, initial = {})
@@ -65,10 +68,13 @@
       end
       return h
     end
 
     def handle_relative_operators(parent_val, child_val)
+      if uses_operator?(child_val) && !has_digits?(parent_val) && !has_digits?(child_val)
+        raise "Layout parse error: can't combine #{parent_val} and #{child_val}"
+      end
       if child_val.to_s.strip.start_with?('+=')
         add_parent_child(parent_val, child_val)
       elsif child_val.to_s.strip.start_with?('-=')
         sub_parent_child(parent_val, child_val)
       elsif child_val.to_s.strip.start_with?('*=')
@@ -79,30 +85,41 @@
         child_val # child overrides parent when merging, no +=
       end
     end
 
     def add_parent_child(parent, child)
-      parent_pixels = Args::UnitConversion.parse(parent, @dpi).to_f
-      child_pixels = Args::UnitConversion.parse(child.sub('+=', ''), @dpi).to_f
+      parent_pixels = Args::UnitConversion.parse(parent, @dpi, @cell_px).to_f
+      child_pixels = Args::UnitConversion.parse(child.sub('+=', ''), @dpi, @cell_px).to_f
       parent_pixels + child_pixels
     end
 
     def sub_parent_child(parent, child)
-      parent_pixels = Args::UnitConversion.parse(parent, @dpi).to_f
-      child_pixels = Args::UnitConversion.parse(child.sub('-=', ''), @dpi).to_f
+      parent_pixels = Args::UnitConversion.parse(parent, @dpi, @cell_px).to_f
+      child_pixels = Args::UnitConversion.parse(child.sub('-=', ''), @dpi, @cell_px).to_f
       parent_pixels - child_pixels
     end
 
     def mul_parent_child(parent, child)
-      parent_pixels = Args::UnitConversion.parse(parent, @dpi).to_f
+      parent_pixels = Args::UnitConversion.parse(parent, @dpi, @cell_px).to_f
       child_float = child.sub('*=', '').to_f
       parent_pixels * child_float
     end
 
     def div_parent_child(parent, child)
-      parent_pixels = Args::UnitConversion.parse(parent, @dpi).to_f
+      parent_pixels = Args::UnitConversion.parse(parent, @dpi, @cell_px).to_f
       child_float = child.sub('/=', '').to_f
       parent_pixels / child_float
+    end
+
+    # For relative operators, it's difficult for us to handle
+    # some of the shorthands - so let's just freak out if you're trying to use
+    # relative operators with words, e.g. "middle += 0.5in"
+    def has_digits?(arg)
+      /.*\d.*/ === arg.to_s
+    end
+
+    def uses_operator?(arg)
+      /^[+=|\-=|\/=|*=].*/ === arg.to_s
     end
 
     # Does this layout entry have an extends field?
     # i.e. is it a base-case or will it need recursion?
     # :nodoc: