def define_ui_tasks
      @ui_files.each do | ui_file |
        ui_header = ui_header_path( ui_file )
        file ui_header => [ @objects_path, ui_file ] do |t|
          command = "uic #{ ui_file } -o #{ ui_header }"
          shell command
        end
      end
    end
def define_ui_tasks
      @ui_files.each do | ui_file |
        ui_header = ui_header_path( ui_file )
        file ui_header => [ @objects_path, ui_file ] do |t|
          command = "uic #{ ui_file } -o #{ ui_header }"
          shell command
        end
      end
    end
UI
 /Developer/Tools/Qt/uic ../scanner_cpp/mainwindow.ui -o ui_mainwindow.h