Class: QDA::GUI::TrueSelectionTextCtrl

Inherits:
Wx::TextCtrl
  • Object
show all
Defined in:
lib/weft/wxgui/controls/textcontrols.rb

Overview

a text control that is able to relate the selection back to the source text - addresses issues with the cross-platform representation of newlines in multiline text controls.

Direct Known Subclasses

HighlightingTextCtrl

Constant Summary collapse

NEWLINE_CORRECTION_FACTOR =

GTK and Mac OS X

0

Instance Method Summary collapse

Instance Method Details

#save_position ⇒ Object

call this with a block that alters the appearance or content of the text control - this includes call to set_style(), highlight() as well as changing text content. It reduces flicker and keeps the viewable area positioned correctly.



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# File 'lib/weft/wxgui/controls/textcontrols.rb', line 72

def save_position()
  freeze()
  saved_pos = get_scroll_pos(Wx::VERTICAL)
  # calculate how many pixels it moves when we nudge the scrollbar
  # down a 'line'
  scroll_lines(1)
  pos_down = saved_pos - get_scroll_pos(Wx::VERTICAL)
  # calculate how many pixels it moves when we nudge the scrollbar
  # up a 'line'
  scroll_lines(-1)
  pos_up = saved_pos - get_scroll_pos(Wx::VERTICAL)

  # how long is a 'line'
  movement = 0 - pos_down + pos_up
  yield
  show_position(0)
  if movement > 0
    scroll_lines(saved_pos / movement)
  end
  thaw()
end

#true_index_to_pos(index) ⇒ Object

given an index within the underlying string, returns the corresponding position within the TextCtrl



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# File 'lib/weft/wxgui/controls/textcontrols.rb', line 62

def true_index_to_pos(index)
  str = get_value()[0, index]
  adjustment = str.count("\n") * NEWLINE_CORRECTION_FACTOR
  index + adjustment
end

#true_insertion_point ⇒ Object Also known as: get_true_insertion_point

returns the current insertion point as an index within the underlying string



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# File 'lib/weft/wxgui/controls/textcontrols.rb', line 55

def true_insertion_point()
  true_point( insertion_point )
end

#true_point(point) ⇒ Object

a no-op



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# File 'lib/weft/wxgui/controls/textcontrols.rb', line 28

def true_point(point)
  point - get_range(0, point).count("\n")
end

#true_selection ⇒ Object

returns the start and end of the selection as indexes within the underlying string. This is handled differently on each platform, but the end result is the same.



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# File 'lib/weft/wxgui/controls/textcontrols.rb', line 17

def true_selection()
  # On windows, we have to correct for the way WxWidgets returns
  # newlines in TextCtrls as two characters.
  lines = get_range(0, get_insertion_point()).count("\n")
  [ get_insertion_point() - lines,
    get_insertion_point() + get_string_selection().length - lines ]
end