Merge pull request #4249 from uberhacker/add-flutter-package

Add flutter package

packages/flutter.rb

+require 'package'
+
+class Flutter < Package
+  description "Flutter is Google's UI toolkit for building beautiful, natively compiled applications for mobile, web, and desktop from a single codebase."
+  homepage 'https://flutter.dev/'
+  version '1.20.2'
+  compatibility 'all'
+  source_url 'https://github.com/flutter/flutter/archive/1.20.2.tar.gz'
+  source_sha256 'b4086649d29f85d035ec38c27e383f8989382241331d2e352f12cc00a6b8c96b'
+
+  depends_on 'libglu'
+
+  def self.install
+    system "git clone https://github.com/flutter/flutter.git -b #{version} --depth 1"
+    FileUtils.mkdir_p CREW_DEST_HOME
+    FileUtils.mkdir_p "#{CREW_DEST_PREFIX}/bin"
+    FileUtils.mkdir_p "#{CREW_DEST_PREFIX}/share"
+    FileUtils.cp_r 'flutter/', "#{CREW_DEST_PREFIX}/share"
+    FileUtils.touch "#{CREW_DEST_HOME}/.flutter_tool_state"
+    FileUtils.ln_sf "#{CREW_PREFIX}/share/flutter/bin/dart", "#{CREW_DEST_PREFIX}/bin/dart"
+    FileUtils.ln_sf "#{CREW_PREFIX}/share/flutter/bin/flutter", "#{CREW_DEST_PREFIX}/bin/flutter"
+  end
+
+  def self.postinstall
+    puts
+    puts "Type 'flutter' to get started.".lightblue
+    puts
+    puts "To uninstall, execute the following:".lightblue
+    puts "crew remove flutter".lightblue
+    puts "rm -rf #{CREW_PREFIX}/share/flutter".lightblue
+    puts
+  end
+end