Class: EditorCore::Cursor

Inherits:
Object
  • Object
show all
Defined in:
lib/editor_core/cursor.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(row = 0, col = 0) ⇒ Cursor

Returns a new instance of Cursor.



6
7
8
9
10
 
# File 'lib/editor_core/cursor.rb', line 6

def initialize(row = 0, col = 0)
  @row = row
  @col = col
  freeze
end

Instance Attribute Details

#col ⇒ Object (readonly)

Returns the value of attribute col.



4
5
6
 
# File 'lib/editor_core/cursor.rb', line 4

def col
  @col
end

#row ⇒ Object (readonly)

Returns the value of attribute row.



4
5
6
 
# File 'lib/editor_core/cursor.rb', line 4

def row
  @row
end

Instance Method Details

#beginning_of_file? ⇒ Boolean

Returns:

  • (Boolean) 


68
69
70
 
# File 'lib/editor_core/cursor.rb', line 68

def beginning_of_file?
  row == 0 && col == 0
end

#clamp(buffer) ⇒ Object 



29
30
31
32
33
34
35
36
37
38
 
# File 'lib/editor_core/cursor.rb', line 29

def clamp(buffer)
  row = @row.clamp(0, buffer.lines_count - 1)
  # FIXME: Is this `buffer.lines` check needed? It ought not to be.
  if !buffer.lines(row)
    col = 0
  else
    col = @col.clamp(0, buffer.line_length(row))
  end
  Cursor.new(row,col)
end

#down(buffer, offset = 1) ⇒ Object 



14
 
# File 'lib/editor_core/cursor.rb', line 14

def down(buffer, offset = 1); move(buffer, row+offset,col); end

#end_of_file?(buffer) ⇒ Boolean

Returns:

  • (Boolean) 


64
65
66
 
# File 'lib/editor_core/cursor.rb', line 64

def end_of_file?(buffer)
  final_line?(buffer) && end_of_line?(buffer)
end

#end_of_line?(buffer) ⇒ Boolean

Returns:

  • (Boolean) 


52
53
54
55
56
57
58
 
# File 'lib/editor_core/cursor.rb', line 52

def end_of_line?(buffer)
  if buffer.lines(row)
    col == buffer.line_length(row)
  else
    true
  end
end

#enter(buffer) ⇒ Object 



40
41
42
 
# File 'lib/editor_core/cursor.rb', line 40

def enter(buffer)
  down(buffer).line_home
end

#final_line?(buffer) ⇒ Boolean

Returns:

  • (Boolean) 


60
61
62
 
# File 'lib/editor_core/cursor.rb', line 60

def final_line?(buffer)
  row == buffer.lines_count - 1
end

#left(buffer, offset = 1) ⇒ Object 



16
17
18
19
20
 
# File 'lib/editor_core/cursor.rb', line 16

def left(buffer, offset = 1)
  return Cursor.new(row, col - offset) if offset <= col
  return self if beginning_of_file?
  return move(buffer,row-1,buffer.line_length(row-1))
end

#line_end(buffer) ⇒ Object 



48
49
50
 
# File 'lib/editor_core/cursor.rb', line 48

def line_end(buffer)
  Cursor.new(row, buffer.line_length(row))
end

#line_home ⇒ Object 



44
45
46
 
# File 'lib/editor_core/cursor.rb', line 44

def line_home
  Cursor.new(row, 0)
end

#move(buffer, row, col) ⇒ Object 



12
 
# File 'lib/editor_core/cursor.rb', line 12

def move(buffer,row,col); self.class.new(row,col).clamp(buffer); end

#right(buffer, offset = 1) ⇒ Object 



22
23
24
25
26
27
 
# File 'lib/editor_core/cursor.rb', line 22

def right(buffer, offset = 1)
  #buffer.right(self,offset)
  return Cursor.new(row, col + offset).clamp(buffer) unless end_of_line?(buffer)
  return self if final_line?(buffer)
  Cursor.new(row + 1, 0)
end

#up(buffer, offset = 1) ⇒ Object 



13
 
# File 'lib/editor_core/cursor.rb', line 13

def up(buffer,   offset = 1); move(buffer, row-offset,col); end