Provided by: tklib_0.8~20230222-1_all bug

NAME

       ntextBindings - Alternative Bindings for the Text Widget

SYNOPSIS

       package require Tcl  8.5

       package require Tk  8.5

       package require ntext  ?1.0?

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DESCRIPTION

       The  ntext  package provides a binding tag named Ntext for use by text widgets in place of
       the default Text binding tag.

       The Text binding tag provides around one hundred bindings to the text  widget  (the  exact
       number is platform-dependent).  A few of these behave in a way that is different from most
       contemporary text-editing applications.  Ntext aims to provide more familiar behaviour.

       Features of the Ntext bindings that differ from the default Text bindings:

       •      Clicking near the end of a (logical) line moves the cursor to the end of that  line
              (not  the  start  of the next line).  If the widget is in -wrap word mode, the same
              rule applies to display lines.

       •      Double-clicking or dragging near the end of a (logical) line will  highlight/select
              characters  from  the end of that line (not the next line, or the region at the end
              of the line where there are no characters).  If the widget is in -wrap  word  mode,
              the same rule applies to display lines.

       •      On  windowing  systems  other than macOS Aqua, the Home key implements "Smart Home"
              (successive keypresses move the cursor to the start of the display  line,  then  to
              the  first  non-whitespace character at the start of the logical line, then toggles
              between the beginning and end of leading whitespace); the End key implements "Smart
              End"  (which  is  similar  to  "Smart Home").  On macOS Aqua, this functionality is
              provided by the operations <Command-Left> and <Command-Right>.

       •      When a selection exists, a "Paste"  operation  (e.g.  <Control-v>)  overwrites  the
              selection (as most editors do), and does so on all platforms.

       •      On windowing systems other than macOS Aqua, the Insert key toggles between "Insert"
              and "Overwrite" modes for keyboard input.  (In contrast, the Text binding tag  uses
              Insert  as  a  method  to  paste  the  "primary  selection",  a  task  that  can be
              accomplished instead by mouse middle-click.)

       •      The Escape key clears the selection.

       •      On the macOS Aqua windowing system, Ntext follows  Aqua  conventions  for  keyboard
              navigation.  Certain bindings related to vertical scrolling can be forced to behave
              in the same  way  as  for  the  Windows  and  X11  windowing  systems,  by  setting
              ::ntext::classicParagraphs to 1 (see Section CONFIGURATION OPTIONS).

       •      On the macOS Aqua windowing system, Ntext follows Aqua conventions for placement of
              the insert mark when keyboard navigation cancels a selection.  This behavior can be
              switched  off  by setting ::ntext::classicSelection to 1 (see Section CONFIGURATION
              OPTIONS).

       •      Selecting with <Shift-Button1> selects from the previous position of the  insertion
              cursor.  (In  the Text binding tag, the selection anchor may be the position of the
              previous mouse click.)

       •      <Shift-Button1> operations do not alter the selection anchor. (In the Text  binding
              tag, they do.)

       •      By  default,  the  Ntext  binding  tag  does not provide several of the Control-key
              bindings supplied by the Text binding tag.  Modern  keyboards  offer  alternatives,
              such  as  cursor keys for navigation; modern applications often use the Control-key
              bindings for other purposes (e.g. <Control-p> for "print").

       In the last three cases, the behavior of Text is often useful,  so  Ntext  gives  you  the
       option  of  retaining  it,  by  setting  variables  defined  in the ::ntext namespace to 1
       (instead of their default 0).  Explaining these features in more detail:

       •      If the mouse is clicked at position A, then the keyboard is used to move the cursor
              to  B, then shift is held down, and the mouse is clicked at C: the Text binding tag
              gives a selection from A to C; the Ntext gives a selection from B  to  C.   If  you
              want  Ntext to behave like Text in this respect, set ::ntext::classicMouseSelect to
              1.

       •      The Text binding tag allows successive <Shift-Button-1> events to change both  ends
              of  the  selection,  by  moving  the  selection  anchor to the end of the selection
              furthest from the mouse click.  Instead, the Ntext binding tag  fixes  the  anchor,
              and  multiple  Shift-Button-1  events  can  only  move  the non-anchored end of the
              selection.   If  you  want  Ntext  to  behave  like  Text  in  this  respect,   set
              ::ntext::classicAnchor  to 1.  In both Text and Ntext, keyboard navigation with the
              Shift key held down alters the selection and keeps the selection anchor fixed.

       •      The following "extra" Text bindings  are  switched  off  by  default,  but  can  be
              activated  in  Ntext by setting ::ntext::classicExtras to 1: <Control-a>, <Control-
              b>, <Control-d>, <Control-e>, <Control-f>, <Control-h>,  <Control-i>,  <Control-k>,
              <Control-n>,  <Control-o>,  <Control-p>,  <Control-t>,  <Control-space>,  <Control-
              Shift-space>.

CONFIGURATION OPTIONS

       Ntext provides alternatives to a number of behaviours of the  classic  Text  binding  tag.
       Where  there  is  an  option,  the  Ntext  behaviour is switched on by default, except for
       display-line indentation which is discussed on a separate page at ntextIndent.

       The behaviour of Ntext may be configured application-wide  by  setting  the  values  of  a
       number of namespace variables:

       ::ntext::classicAnchor0 - (default value) selects Ntext behaviour, i.e. the anchor point is fixed

       •      1 - selects classic Text behaviour, i.e. the anchor point is variable

       ::ntext::classicExtras0 - (default value) selects Ntext behaviour, i.e. several "extra" Text bindings are
              de-activated

       •      1 - selects classic Text behaviour, i.e. the "extra" Text bindings are activated

       ::ntext::classicMouseSelect0 - (default value) selects Ntext  behaviour,  i.e.  the  anchor  point  for  mouse
              selection operations is moved by keyboard navigation

       •      1 - selects classic Text behaviour

       ::ntext::classicParagraphs0  - (default value) on macOS Aqua, certain keyboard bindings are made to behave in
              the same way as the  Mac  application  TextEdit.   The  bindings  involve  vertical
              scrolling of the screen and are <?Shift-?Option-(Up|Down)>.

       •      1  - on macOS Aqua, certain keyboard bindings are made to behave in the same way as
              for the Windows and X11 windowing  systems  and  the  classic  Text,  ignoring  the
              conventions of Aqua.  The bindings involve vertical scrolling of the screen and are
              <?Shift-?Option-(Up|Down)>.

       ::ntext::classicSelection0 - (default  value  on  macOS  Aqua)  selects  Mac-like  behaviour,  i.e.  when  a
              navigation keystroke cancels a selection, the insert mark first moves to the end of
              the selection determined by the navigation direction of the keystroke, and then the
              keystroke is applied.

       •      1  -  (default  value  except on macOS Aqua) selects PC-like behaviour (the same as
              classic Text), i.e. when a navigation keystroke cancels  a  selection,  the  insert
              mark is not moved before the keystroke is applied.

       ::ntext::overwrite0 - (initial value) text typed at the keyboard is inserted into the widget

       •      1 - text typed at the keyboard overwrites text already in the widget

       •      The value is toggled by the Insert key.

       ::ntext::useBlockCursor0  -  the block cursor will not be used.  When the widget is in overwrite mode (see
              ::ntext::overwrite), the ordinary cursor will change color instead.

       •      1 - the block cursor will be used  when  the  widget  is  in  overwrite  mode  (see
              ::ntext::overwrite).

       •      The  default  value  depends  on the version of Tk.  In versions of Tk earlier than
              8.5.12, the sizing of the block  cursor  had  a  bug,  and  ::ntext::useBlockCursor
              defaults  to  0.  From 8.5.12 onwards the bug is fixed, and ::ntext::useBlockCursor
              defaults to 1.

INTERNALS

       In order to remain independent of the version of Tk (8.5 or 8.6), ntext  defines  its  own
       virtual  events.   These  new  virtual  events are used only in the Ntext binding tag, and
       therefore do not interfere with the real or virtual events used in other code.

       These events include <<NtextCut>>, <<NtextCopy>>, <<NtextPaste>> which are used  in  place
       of <<Cut>>, <<Copy>>, <<Paste>> respectively.

       The definition of the virtual event <<NtextCut>> (etc) is similar to that of <<Cut>> (etc)
       in Tk 8.6.

BUGS

       This version of ntext is intended to be compatible with all releases of Tk  8.5  and  8.6,
       and  with  the  branches  core-8-5-branch,  core-8-6-branch,  and trunk in the source code
       repository for Tk.  Any incompatibility with any of these versions, for any  Tk  windowing
       system, should be reported as a bug. Please report such in the category ntext of the Tklib
       Trackers [http://core.tcl.tk/tklib/reportlist].

EXAMPLE

       To use Ntext but keep classic Text 's variable-anchor feature:

              package require ntext
              text .t
              set ::ntext::classicAnchor 1
              bindtags .t {.t Ntext . all}

SEE ALSO

       bindtags, ntext, ntextIndent, text

KEYWORDS

       bindtags, text