add multi select list

src/mechanize/form/multi_select_list.cr

@@ -0,0 +1,57 @@
+require "./option"
+
+class MechanizeCr::FormContent::MultiSelectList
+  getter node       : Myhtml::Node
+  property values   : Array(String)
+  getter name       : String
+  getter type       : String
+  property options  : Array(FormContent::Option)
+
+  def initialize(node : Myhtml::Node)
+    @node = node
+    @name = node.fetch("name", "")
+    @type = node.fetch("type", "")
+    @values = Array(String).new
+    @options = Array(FormContent::Option).new
+    node.css("option").each { |n|
+      @options << FormContent::Option.new(n, self)
+    }
+  end
+
+  def select_none
+    @value = Array(String).new
+    options.each &.unclick
+  end
+
+  def select_all
+    @value = Array(String).new
+    options.each &.click
+  end
+
+  def selected_options
+    options.find_all(&:selected?)
+  end
+
+  def values=(raw_values)
+    select_none
+    raw_values.each do |value|
+      option = options.find { |o| o.value == value }
+      if option.nil?
+        @value.push(value)
+      else
+        option.select
+      end
+    end
+  end
+
+  def values
+    @values + selected_options.map(&:value)
+  end
+
+  #def inspect # :nodoc:
+  #  "[%s:0x%x type: %s name: %s value: %s]" % [
+  #    self.class.name.sub(/MechanizeCr::FormContent::/, "").downcase,
+  #    object_id, type, name, value
+  #  ]
+  #end
+end