1 files changed, 149 insertions, 0 deletions
diff --git a/sample/curses/view2.rb b/sample/curses/view2.rb
new file mode 100644
index 0000000000..037771a226
--- /dev/null
+++ b/sample/curses/view2.rb
@@ -0,0 +1,149 @@
+#!/usr/local/bin/ruby
+
+require "curses"
+
+
+# A curses based file viewer
+class FileViewer
+
+  # Create a new fileviewer, and view the file.
+  def initialize(filename)
+    @data_lines = []
+    @screen = nil
+    @top = nil
+    init_curses
+    load_file(filename)
+    interact
+  end
+
+  # Perform the curses setup
+  def init_curses
+    # signal(SIGINT, finish)
+
+    Curses.init_screen
+    Curses.nonl
+    Curses.cbreak
+    Curses.noecho
+
+    @screen = Curses.stdscr
+
+    @screen.scrollok(true)
+    #$screen.keypad(true)
+  end
+
+  # Load the file into memory, and put
+  # the first part on the curses display.
+  def load_file(filename)
+    fp = open(filename, "r") do |fp|
+    # slurp the file
+    fp.each_line { |l|
+      @data_lines.push(l.chop)
+    }
+    end
+    @top = 0
+    @data_lines[0..@screen.maxy-1].each_with_index{|line, idx|
+      @screen.setpos(idx, 0)
+      @screen.addstr(line)
+    }
+    @screen.setpos(0,0)
+    @screen.refresh
+  rescue
+    raise "cannot open file '#{filename}' for reading"
+  end
+
+
+  # Scroll the display up by one line
+  def scroll_up
+    if( @top > 0 )
+      @screen.scrl(-1)
+      @top -= 1
+      str = @data_lines[@top]
+      if( str )
+        @screen.setpos(0, 0)
+        @screen.addstr(str)
+      end
+      return true
+    else
+      return false
+    end
+  end
+
+  # Scroll the display down by one line
+  def scroll_down
+    if( @top + @screen.maxy < @data_lines.length )
+      @screen.scrl(1)
+      @top += 1
+      str = @data_lines[@top + @screen.maxy - 1]
+      if( str )
+        @screen.setpos(@screen.maxy - 1, 0)
+        @screen.addstr(str)
+      end
+      return true
+    else
+      return false
+    end
+  end
+
+  # Allow the user to interact with the display.
+  # This uses EMACS-like keybindings, and also
+  # vi-like keybindings as well, except that left
+  # and right move to the beginning and end of the
+  # file, respectively.
+  def interact
+    while true
+      result = true
+      c = Curses.getch
+      case c
+      when Curses::KEY_DOWN, Curses::KEY_CTRL_N, ?j
+        result = scroll_down
+      when Curses::KEY_UP, Curses::KEY_CTRL_P, ?k
+        result = scroll_up
+      when Curses::KEY_NPAGE, ?\s  # white space
+        for i in 0..(@screen.maxy - 2)
+          if( ! scroll_down )
+            if( i == 0 )
+              result = false
+            end
+            break
+          end
+        end
+      when Curses::KEY_PPAGE
+        for i in 0..(@screen.maxy - 2)
+          if( ! scroll_up )
+            if( i == 0 )
+              result = false
+            end
+            break
+          end
+        end
+      when Curses::KEY_LEFT, Curses::KEY_CTRL_T, ?h
+        while( scroll_up )
+        end
+      when Curses::KEY_RIGHT, Curses::KEY_CTRL_B, ?l
+        while( scroll_down )
+        end
+      when ?q
+        break
+      else
+        @screen.setpos(0,0)
+        @screen.addstr("[unknown key `#{Curses.keyname(c)}'=#{c}] ")
+      end
+      if( !result )
+        Curses.beep
+      end
+      @screen.setpos(0,0)
+    end
+    Curses.close_screen
+  end
+end
+
+
+# If we are being run as a main program...
+if __FILE__ == $0
+  if ARGV.size != 1 then
+    printf("usage: #{$0} file\n");
+    exit
+  end
+
+  viewer = FileViewer.new(ARGV[0])
+end