Provided by: tklib_0.7+20210111-1_all 
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::classicAnchor
• 0 - (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::classicExtras
• 0 - (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::classicMouseSelect
• 0 - (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::classicParagraphs
• 0 - (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::classicSelection
• 0 - (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::overwrite
• 0 - (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::useBlockCursor
• 0 - 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