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scale(3tk) Tk Built-In Commands scale(3tk) 





NAME


scale - Create and manipulate 'scale' value-controlled slider
    widgets






SYNOPSIS


scale pathName ?options?






STANDARD OPTIONS


-activebackground	-foreground	-relief
-background	-highlightbackground	-repeatdelay
-borderwidth	-highlightcolor	-repeatinterval
-cursor	-highlightthickness	-takefocus
-font	-orient	-troughcolor


See the options manual entry for details on the standard
    options.






WIDGET-SPECIFIC OPTIONS


Command-Line Name:	-bigincrement
Database Name:	bigIncrement
Database Class:	BigIncrement



  

  
Some interactions with the scale cause its value to change by
      “large” increments; this option specifies the size of the
      large increments. If specified as 0, the large increments default to 1/10
      the range of the scale.






Command-Line Name:	-command
Database Name:	command
Database Class:	Command



  

  
Specifies the prefix of a Tcl command to invoke whenever the scale's value
      is changed via a widget command. The actual command consists of this
      option followed by a space and a real number indicating the new value of
      the scale.






Command-Line Name:	-digits
Database Name:	digits
Database Class:	Digits



  

  
An integer specifying how many significant digits should be retained when
      converting the value of the scale to a string. If the number is less than
      or equal to zero, then the scale picks the smallest value that guarantees
      that every possible slider position prints as a different string.






Command-Line Name:	-from
Database Name:	from
Database Class:	From



  

  
A real value corresponding to the left or top end of the scale.






Command-Line Name:	-label
Database Name:	label
Database Class:	Label



  

  
A string to display 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. If the option is specified as an empty string, no label is
      displayed.






Command-Line Name:	-length
Database Name:	length
Database Class:	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.






Command-Line Name:	-resolution
Database Name:	resolution
Database Class:	Resolution



  

  
A real value specifying the resolution for the scale. If this value is
      greater than zero then the scale's value will always be rounded to an even
      multiple of this value, as will the endpoints of the scale. If the value
      is less than zero then no rounding occurs. Defaults to 1 (i.e., the value
      will be integral).






Command-Line Name:	-showvalue
Database Name:	showValue
Database Class:	ShowValue



  

  
Specifies a boolean value indicating whether or not the current value of
      the scale is to be displayed.






Command-Line Name:	-sliderlength
Database Name:	sliderLength
Database Class:	SliderLength



  

  
Specifies 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.






Command-Line Name:	-sliderrelief
Database Name:	sliderRelief
Database Class:	SliderRelief



  

  
Specifies the relief to use when drawing the slider, such as raised
      or sunken.






Command-Line Name:	-state
Database Name:	state
Database Class:	State



  

  
Specifies one of three states for the scale: normal, active,
      or disabled. If the scale is disabled then the value may not be
      changed and the scale will not activate. If the scale is active, the
      slider is displayed using the color specified by the
      -activebackground option.






Command-Line Name:	-tickinterval
Database Name:	tickInterval
Database Class:	TickInterval



  

  
Must be a real value. Determines the spacing between numerical tick marks
      displayed below or to the left of the slider. The values will all be
      displayed with the same number of decimal places, which will be enough to
      ensure they are all accurate to within 20% of a tick interval. If 0, no
      tick marks will be displayed.






Command-Line Name:	-to
Database Name:	to
Database Class:	To



  

  
Specifies a real value corresponding to the right or bottom end of the
      scale. This value may be either less than or greater than the -from
      option.






Command-Line Name:	-variable
Database Name:	variable
Database Class:	Variable



  

  
Specifies the name of a global variable to link to the scale. Whenever the
      value of the variable changes, the scale will update to reflect this
      value. Whenever the scale is manipulated interactively, the variable will
      be modified to reflect the scale's new value.






Command-Line Name:	-width
Database Name:	width
Database Class:	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 trough and
    a small slider. The trough corresponds to a range of real values
    (determined by the -from, -to, and -resolution
    options), and the position of the slider selects a particular real value.
    The slider's position (and hence the scale's value) may be adjusted with the
    mouse or keyboard 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. In
    addition, the value of the scale can be linked to a Tcl variable (using the
    -variable option), so that changes in either are reflected in the
    other.


Three annotations may be displayed in a scale widget: a label
    appearing at the top right of the widget (top left for horizontal scales), a
    number displayed just to the left of the slider (just above the slider for
    horizontal scales), and a collection of numerical tick marks just to the
    left of the current value (just below the trough for horizontal scales).
    Each of these three annotations may be 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:


  

  
Returns the current value of the configuration option given by
      option. Option may have any of the values accepted by the
      scale command.

  

  
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.

  

  
Returns a list whose elements are the x and y coordinates of the point
      along the centerline of the trough that corresponds to value. If
      value is omitted then the scale's current value is used.

  

  
If x and y are omitted, returns the current value of the
      scale. If x and y are specified, they give pixel coordinates
      within the widget; the command returns the scale value corresponding to
      the given pixel. Only one of x or y is used: for horizontal
      scales y is ignored, and for vertical scales x is
    ignored.

  

  
Returns a string indicating what part of the scale lies under the
      coordinates given by x and y. A return value of
      slider means that the point is over the slider; trough1
      means that the point is over the portion of the slider above or to the
      left of the slider; and trough2 means that the point is over the
      portion of the slider below or to the right of the slider. If the point is
      not over one of these elements, an empty string is returned.

  

  
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. The command has no effect if the scale is
      disabled.








BINDINGS


Tk automatically creates class bindings for scales that give them
    the following default behavior. Where the behavior is different for vertical
    and horizontal scales, the horizontal behavior is described in
  parentheses.



  
[1]

  
If button 1 is pressed in the trough, the scale's value will be
      incremented or decremented by the value of the -resolution option
      so that the slider moves in the direction of the cursor. If the button is
      held down, the action auto-repeats.

  
[2]

  
If button 1 is pressed over the slider, the slider can be dragged with the
      mouse.

  
[3]

  
If button 1 is pressed in the trough with the Control key down, the slider
      moves all the way to the end of its range, in the direction towards the
      mouse cursor.

  
[4]

  
If button 2 is pressed, the scale's value is set to the mouse position. If
      the mouse is dragged with button 2 down, the scale's value changes with
      the drag.

  
[5]

  
The Up and Left keys move the slider up (left) by the value of the
      -resolution option.

  
[6]

  
The Down and Right keys move the slider down (right) by the value of the
      -resolution option.

  
[7]

  
Control-Up and Control-Left move the slider up (left) by the value of the
      -bigincrement option.

  
[8]

  
Control-Down and Control-Right move the slider down (right) by the value
      of the -bigincrement option.

  
[9]

  
Home moves the slider to the top (left) end of its range.

  
[10]

  
End moves the slider to the bottom (right) end of its range.




If the scale is disabled using the -state option then none
    of the above bindings have any effect.


The behavior of scales can be changed by defining new bindings for
    individual widgets or by redefining the class bindings.






SEE ALSO


ttk::scale(3tk)






KEYWORDS


scale, slider, trough, widget







  

    4.1
    Tk