1 files changed, 47 insertions, 0 deletions
diff --git a/Library/Homebrew/requirements/x11_requirement.rb b/Library/Homebrew/requirements/x11_requirement.rb
new file mode 100644
index 000000000..890ef4d4f
--- /dev/null
+++ b/Library/Homebrew/requirements/x11_requirement.rb
@@ -0,0 +1,47 @@
+require "requirement"
+
+class X11Requirement < Requirement
+  include Comparable
+  attr_reader :min_version
+
+  fatal true
+  cask "xquartz"
+  download "https://xquartz.macosforge.org"
+
+  env { ENV.x11 }
+
+  def initialize(name="x11", tags=[])
+    @name = name
+    if /(\d\.)+\d/ === tags.first
+      @min_version = Version.new(tags.shift)
+      @min_version_string = " #{@min_version}"
+    else
+      @min_version = Version.new("0.0.0")
+      @min_version_string = ""
+    end
+    super(tags)
+  end
+
+  satisfy :build_env => false do
+    MacOS::XQuartz.installed? && min_version <= Version.new(MacOS::XQuartz.version)
+  end
+
+  def message
+    s = "XQuartz#{@min_version_string} is required to install this formula."
+    s += super
+    s
+  end
+
+  def <=> other
+    return unless X11Requirement === other
+    min_version <=> other.min_version
+  end
+
+  def eql?(other)
+    super && min_version == other.min_version
+  end
+
+  def inspect
+    "#<#{self.class.name}: #{name.inspect} #{tags.inspect} min_version=#{min_version}>"
+  end
+end