Module: SpinningCursor::ConsoleHelpers

Included in:
Cursor
Defined in:
lib/spinning_cursor/console_helpers.rb

Constant Summary collapse

CLR =

Unix Contains a string to clear the line in the shell

"\e[0K"
ESC_CURS_INVIS =

ANSI escape sequence for hiding terminal cursor

"\e[?25l"
ESC_CURS_VIS =

ANSI escape sequence for showing terminal cursor

"\e[?25h"
ESC_R_AND_CLR =

ANSI escape sequence for clearing line in terminal

"\r#{CLR}"
ESC_UP_A_LINE =

ANSI escape sequence for going up a line in terminal

"\e[1A"
@@prev = 
0

Instance Method Summary collapse

Instance Method Details

#capture_console ⇒ Object

Sets $stdout global variable to a StringIO object to buffer output



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# File 'lib/spinning_cursor/console_helpers.rb', line 77

def capture_console
  $stdout = StringIO.new
end

#captured_console_empty? ⇒ Boolean

Returns true if the output buffer is currently empty

Returns:

  • (Boolean) 


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# File 'lib/spinning_cursor/console_helpers.rb', line 98

def captured_console_empty?
  console_captured? and $stdout.string.empty?
end

#console_captured? ⇒ Boolean

Returns true if $stdout is a StringIO object

Returns:

  • (Boolean) 


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# File 'lib/spinning_cursor/console_helpers.rb', line 91

def console_captured?
  $stdout.is_a?(StringIO)
end

#console_columns ⇒ Object

Returns the width of the terminal window



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# File 'lib/spinning_cursor/console_helpers.rb', line 119

def console_columns
  HighLine::SystemExtensions.terminal_size.first
end

#hide_cursor ⇒ Object

Hides the terminal cursor



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# File 'lib/spinning_cursor/console_helpers.rb', line 105

def hide_cursor
  $console.print ESC_CURS_INVIS
end

#release_console ⇒ Object

Resets $stdout global variable to STDOUT



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# File 'lib/spinning_cursor/console_helpers.rb', line 84

def release_console
  $stdout = $console
end

#reset_line(text = "") ⇒ Object

Manages line reset in the console



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# File 'lib/spinning_cursor/console_helpers.rb', line 32

def reset_line(text = "")
  # Initialise ANSI escape string
  escape = ""

  # Get terminal window width
  cols = console_columns

  # The number of lines the previous message spanned
  lines = @@prev / cols

  # If cols == 80 and @@prev == 80, @@prev / cols == 1 but we don't want to
  # go up an extra line since it fits exactly
  lines -= 1 if @@prev % cols == 0

  # Clear and go up a line
  lines.times { escape += "#{ESC_R_AND_CLR}#{ESC_UP_A_LINE}" }

  # Clear the line that is to be printed on
  escape += "#{ESC_R_AND_CLR}"

  # Console is clear, we can print!
  $console.print "#{escape}#{text}"

  # Store the current message so we know how many lines it spans
  @@prev = text.to_s.length
end

#restore_stdout_sync_status ⇒ Object

Restores the previously stored STDOUT.sync value



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# File 'lib/spinning_cursor/console_helpers.rb', line 70

def restore_stdout_sync_status
  STDOUT.sync = @stdout_sync_saved_status
end

#save_stdout_sync_status ⇒ Object

Stores current STDOUT.sync value and sets it to true



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# File 'lib/spinning_cursor/console_helpers.rb', line 62

def save_stdout_sync_status
  @stdout_sync_saved_status = STDOUT.sync
  STDOUT.sync = true
end

#show_cursor ⇒ Object

Shows the terminal cursor



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# File 'lib/spinning_cursor/console_helpers.rb', line 112

def show_cursor
  $console.print ESC_CURS_VIS
end