pager.rb in tty-pager-0.13.0

- old
+ new
@@ -1,103 +1,101 @@
 # frozen_string_literal: true
 
-require 'tty-screen'
+require_relative "pager/basic"
+require_relative "pager/null"
+require_relative "pager/system"
+require_relative "pager/version"
 
-require_relative 'pager/basic'
-require_relative 'pager/null'
-require_relative 'pager/system'
-require_relative 'pager/version'
-
 module TTY
-  class Pager
+  module Pager
     Error = Class.new(StandardError)
 
-    # Select an appriopriate pager
-    #
-    # If the user disabled paging then a NullPager is returned,
-    # otherwise a check is performed to find native system
-    # command to perform pagination with SystemPager. Finally,
-    # if no system command is found, a BasicPager is used which
-    # is a pure Ruby implementation known to work on any platform.
-    #
-    # @api private
-    def self.select_pager(enabled, commands)
-      if !enabled
-        NullPager
-      elsif SystemPager.exec_available?(*commands)
-        SystemPager
-      else
-        BasicPager
-      end
-    end
+    # Raised when pager is closed
+    PagerClosed = Class.new(Error)
 
-    # Create a pager
-    #
-    # @param [Hash] options
-    # @option options [Proc] :prompt
-    #   a proc object that accepts page number
-    # @option options [IO] :input
-    #   the object to send input to
-    # @option options [IO] :output
-    #   the object to send output to
-    # @option options [Boolean] :enabled
-    #   disable/enable text paging
-    #
-    # @api public
-    def initialize(**options)
-      @input   = options.fetch(:input)  { $stdin }
-      @output  = options.fetch(:output) { $stdout }
-      @enabled = options.fetch(:enabled) { true }
-      commands = Array(options[:command])
+    # Raised when user provides unnexpected argument
+    InvalidArgument = Class.new(Error)
 
-      if self.class == TTY::Pager
-        @pager = self.class.select_pager(@enabled, commands).new(options)
+    module ClassMethods
+      # Create a pager
+      #
+      # @param [Boolean] :enabled
+      #   disable/enable text paging
+      # @param [String] :command
+      #   the paging command
+      # @param [IO] :input
+      #   the object to send input to
+      # @param [IO] :output
+      #   the object to send output to
+      # @param [Proc] :prompt
+      #   a proc object that accepts page number
+      # @param [Integer] :width
+      #   the terminal width
+      # @param [Integer] :height
+      #   the terminal height
+      #
+      # @api public
+      def new(enabled: true, command: nil, **options)
+        select_pager(enabled: enabled, command: command).new(
+          enabled: enabled, command: command, **options)
       end
-    end
 
-    # Check if pager is enabled
-    #
-    # @return [Boolean]
-    #
-    # @api public
-    def enabled?
-      !!@enabled
-    end
+      # Paginate content through null, basic or system pager.
+      #
+      # @example
+      #   TTY::Pager.page do |pager|
+      #     pager.write "some text"
+      #   end
+      #
+      # @param [String] :text
+      #   an optional blob of content
+      # @param [String] :path
+      #   a path to a file
+      # @param [Boolean] :enabled
+      #   whether or not to use null pager
+      # @param [String] :command
+      #   the paging command
+      # @param [IO] :input
+      #   the object to send input to
+      # @param [IO] :output
+      #   the object to send output to
+      #
+      # @api public
+      def page(text = nil, path: nil, enabled: true, command: nil,
+               **options, &block)
+        select_pager(enabled: enabled, command: command).
+          page(text, path: path, enabled: enabled, command: command,
+               **options, &block)
+      end
 
-    # Page the given text through the available pager
-    #
-    # @param [String] text
-    #   the text to run through a pager
-    #
-    # @yield [Integer] page number
-    #
-    # @return [TTY::Pager]
-    #
-    # @api public
-    def page(text, &callback)
-      pager.page(text, &callback)
-      self
-    end
+      # Select an appriopriate pager
+      #
+      # If the user disabled paging then a NullPager is returned,
+      # otherwise a check is performed to find native system
+      # command to perform pagination with SystemPager. Finally,
+      # if no system command is found, a BasicPager is used which
+      # is a pure Ruby implementation known to work on any platform.
+      #
+      # @param [Boolean] enabled
+      #   whether or not to allow paging
+      # @param [String] command
+      #   the command to run if available
+      #
+      # @api private
+      def select_pager(enabled: true, command: nil)
+        commands = Array(command)
 
-    # The terminal height
-    #
-    # @api public
-    def page_height
-      TTY::Screen.height
+        if !enabled
+          NullPager
+        elsif SystemPager.exec_available?(*commands)
+          SystemPager
+        else
+          BasicPager
+        end
+      end
     end
 
-    # The terminal width
-    #
-    # @api public
-    def page_width
-      TTY::Screen.width
-    end
+    extend ClassMethods
 
-    protected
-
-    attr_reader :output
-
-    attr_reader :input
-
-    attr_reader :pager
+    private_class_method :select_pager
   end # Pager
 end # TTY