scale - Create and manipulate scale widgets
SYNOPSIS
scale pathName ?options?
STANDARD OPTIONS
activeForeground borderWidth font orient
background cursor foreground relief
See the options manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
Name: command
Class: Command
Command-Line Switch: -command
Specifies the prefix of a Tcl command to invoke whenever the value of
the scale is changed interactively. The actual command consists
of this option followed by
a space and a number. The number indicates the new value of the
scale.
Name: from
Class: From
Command-Line Switch: -from
Specifies the value corresponding to the left or top end of the
scale. Must be an integer.
Name: label
Class: Label
Command-Line Switch: -label
Specifies a string to displayed as a label for the scale. For
vertical scales the label is displayed just to the right of the
top end of the scale. For horizontal scales the label is displayed
just above the left end of the scale.
Name: length
Class: Length
Command-Line Switch: -length
Specifies the desired long dimension of the scale in screen units
(i.e. any of the forms acceptable to Tk_GetPixels).
For vertical scales this is the scale's height; for horizontal scales
it is the scale's width.
Name: showValue
Class: ShowValue
Command-Line Switch: -showvalue
Specifies a boolean value indicating whether or not the current
value of the scale is to be displayed.
Name: sliderForeground
Class: sliderForeground
Command-Line Switch: -sliderforeground
Specifies the color to use for drawing the slider under normal conditions.
When the mouse is in the slider window then the slider's color is
determined by the activeForeground option.
Name: sliderLength
Class: SliderLength
Command-Line Switch: -sliderlength
Specfies the size of the slider, measured in screen units along the slider's
long dimension. The value may be specified in any of the forms acceptable
to Tk_GetPixels.
Name: state
Class: State
Command-Line Switch: -state
Specifies one of two states for the scale: normal or disabled.
If the scale is disabled then the value may not be changed and the scale
won't activate when the mouse enters it.
Name: tickInterval
Class: TickInterval
Command-Line Switch: -tickinterval
Must be an integer value. Determines the spacing between numerical
tick-marks displayed below or to the left of the slider. If specified
as 0, then no tick-marks will be displayed.
Name: to
Class: To
Command-Line Switch: -to
Specifies the value corresponding to the right or bottom end of the
scale. Must be an integer. This value may be either less than or
greater than the from option.
Name: width
Class: Width
Command-Line Switch: -width
Specifies the desired narrow dimension of the scale in screen units
(i.e. any of the forms acceptable to Tk_GetPixels).
For vertical scales this is the scale's width; for horizontal scales
this is the scale's height.
DESCRIPTION
The scale command creates a new window (given by the
pathName argument) and makes it into a scale widget.
Additional
options, described above, may be specified on the command line
or in the option database
to configure aspects of the scale such as its colors, orientation,
and relief. The scale command returns its
pathName argument. At the time this command is invoked,
there must not exist a window named pathName, but
pathName's parent must exist.
A scale is a widget that displays a rectangular region and a
small slider. The rectangular region corresponds to a range
of integer values (determined by the from and to options),
and the position of the slider selects a particular integer value.
The slider's position (and hence the scale's value) may be adjusted
by clicking or dragging with the mouse as described in the BINDINGS
section below. Whenever the scale's value is changed, a Tcl
command is invoked (using the command option) to notify
other interested widgets of the change.
Three annotations may be displayed in a scale widget: a label
appearing at the top-left of the widget (top-right for vertical
scales), a number displayed just underneath the slider
(just to the left of the slider for vertical scales), and a collection
of numerical tick-marks just underneath the current value (just to the left of
the current value for vertical scales). Each of these three
annotations may be selectively enabled or disabled using the
configuration options.
WIDGET COMMAND
The scale command creates a new Tcl command whose
name is pathName. This
command may be used to invoke various
operations on the widget. It has the following general form:
pathName option ?arg arg ...?
Option and the args
determine the exact behavior of the command. The following
commands are possible for scale widgets:
- pathName configure ?option? ?value option value ...?
- Query or modify the configuration options of the widget.
If no option is specified, returns a list describing all of
the available options for pathName (see Tk_ConfigureInfo for
information on the format of this list). If option is specified
with no value, then the command returns a list describing the
one named option (this list will be identical to the corresponding
sublist of the value returned if no option is specified). If
one or more option-value pairs are specified, then the command
modifies the given widget option(s) to have the given value(s); in
this case the command returns an empty string.
Option may have any of the values accepted by the scale
command.
- pathName get
- Returns a decimal string giving the current value of the scale.
- pathName set value
- This command is invoked to change the current value of the scale,
and hence the position at which the slider is displayed. Value
gives the new value for the scale.
BINDINGS
When a new scale is created, it is given the following initial
behavior by default:
- <Enter>
- Change the slider display to use activeForeground instead of
sliderForeground.
- <Leave>
- Reset the slider display to use sliderForeground instead of
activeForeground.
- <ButtonPress-1>
- Change the slider display so that the slider appears sunken rather
than raised. Move the slider (and adjust the scale's value)
to correspond to the current mouse position.
- <Button1-Motion>
- Move the slider (and adjust the scale's value) to correspond to
the current mouse position.
- <ButtonRelease-1>
- Reset the slider display so that the slider appears raised again.
KEYWORDS
scale, widget