NAME¶
ntextBindings - Alternative Bindings for the Text Widget
SYNOPSIS¶
package require
Tcl 8.5
package require
Tk 8.5
package require
ntext ?0.81?
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.
- •
- The End key implements "Smart End"
(successive keypresses move the cursor to the end of the display line,
then to the end of the logical line); the Home key implements
"Smart Home" (which is similar to "Smart End", but
also toggles between the beginning and end of leading whitespace).
- •
- When a selection exists, a <<Paste>> operation
(e.g. <Control-v>) overwrites the selection (as most editors do),
and does so on all platforms.
- •
- 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.
- •
- 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").
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::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.
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