ntext - Alternative Bindings for the Text Widget
package require Tcl 8.5
package require Tk 8.5
package require ntext ?1.0?
::ntext::new_textCopy pathName
::ntext::new_textCut pathName
::ntext::new_textPaste pathName
::ntext::syncIndentColor pathName
The purpose of the ntext package is to make the text widget
behave more like other text-editing applications. It makes the text widget
more useful for implementing a text editor, and makes it behave in a way
that will be more familiar to most users.
The package provides a binding tag named Ntext for use by
text widgets in place of the default Text binding tag.
Package ntext 's functions and variables are contained
entirely in the ::ntext namespace; its other code is contained in the
binding tag Ntext. ntext has no exports to the global or other
namespaces, and no new widget commands. It uses modified copies of the
Tk code, leaving the original code, and the Text binding tag,
unchanged.
The differences between the Ntext binding tag and the
default Text binding tag are in three categories:
- Some Text bindings behave differently from most text-editing
applications. Ntext gives these bindings more familiar behaviour.
For details see ntextBindings.
- When a logical line with leading whitespace is word-wrapped onto more than
one display line, the wrapped display lines begin further to the left than
the first display line, which can make the text layout untidy and
difficult to read. Ntext can indent the wrapped lines to match the
leading whitespace of the first display line (this facility is switched
off by default). For details see ntextIndent.
- When the user navigates or selects text, Tcl/Tk sometimes needs to
detect word boundaries. Ntext provides improved rules for word
boundary detection. For details see ntextWordBreak.
The remainder of this page describes the basic use and
configuration of all three aspects of Ntext. For more detailed
information on the different facilities of Ntext, see the pages
ntextBindings, ntextIndent, and ntextWordBreak.
See Section EXAMPLE for how to apply the Ntext
binding tag in place of the Text binding tag.
- ::ntext::new_textCopy pathName
- Replacement for ::tk_textCopy.
- ::ntext::new_textCut pathName
- Replacement for ::tk_textCut that also maintains Ntext indentation
(see ntextIndent).
- ::ntext::new_textPaste pathName
- Replacement for ::tk_textPaste that also maintains Ntext
indentation (see ntextIndent).
- ::ntext::syncIndentColor pathName
- Command to apply the current value of the variable
::ntext::indentColor to existing lines in a text widget. This
command is useful if a text widget has been created, text has been
inserted in the widget, and then the value of
::ntext::indentColor is changed (see ntextIndent).
Ntext provides alternatives to a number of behaviours of
the classic Text binding tag. Where there is an option, the
Ntext behaviour (except for display-line indentation) is switched on
by default.
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
- For more information see ntextBindings
::ntext::classicExtras
- 0 - (default value) selects Ntext behaviour, i.e. several
traditional Text bindings are de-activated
- 1 - selects classic Text behaviour, i.e. all Text
bindings are activated
- For more information see ntextBindings
::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
- For more information see ntextBindings
::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 classic Text, ignoring the conventions of Aqua. The
bindings involve vertical scrolling of the screen and are
<?Shift-?Option-(Up|Down)>.
- For more information see ntextBindings
::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.
- For more information see ntextBindings
::ntext::classicWordBreak
- 0 - (default value) selects Ntext behaviour, i.e.
platform-independent, two classes of word characters and one class of
non-word characters.
- 1 - selects classic Text behaviour, i.e. platform-dependent,
one class of word characters and one class of non-word characters
- After changing this value, the matching patterns should be recalculated.
See ntextWordBreak for details and advanced configuration
options.
::ntext::classicWrap
- 0 - selects Ntext behaviour, i.e. display lines of text
widgets in -wrap word mode are indented to match the initial
whitespace of the first display line of a logical line. If the widget
already holds text when this value is set, a function call may be
necessary. See ntextIndent for detailed instructions on the use of
Ntext 's indentation.
- 1 - (default value) selects classic Text behaviour, i.e. no
indentation
- For more information see ntextIndent
::ntext::indentColor
- {} - if the value is the empty string, then the indent of wrapped
display lines has the same color as the widget background.
- color - a valid Tk color to use for the indent of wrapped
display lines (default value #d9d9d9).
Coloring is implemented with the text widget tag option
-lmargincolor, which is available from Tk 8.6.6 onwards.
Ntext indent coloring has no effect in earlier versions of
Tk.
The value of ::ntext::indentColor will often be set at
startup. If the value is changed when text widgets already exist and
contain text, those widgets can be updated by calling command
::ntext::syncIndentColor.
- For more information see ntextIndent
::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 (except on macOS Aqua where
there is no such key).
- For more information see ntextBindings
::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.
- For more information see ntextBindings
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].
To create a text widget .t and use the Ntext bindings:
package require ntext
text .t
bindtags .t {.t Ntext . all}
See bindtags for more information.
bindtags, ntextBindings, ntextIndent, ntextWordBreak, re_syntax,
regexp, text
bindtags, re_syntax, regexp, text