: slider {
action alignment big_increment fixed_height 
fixed_width height key label layout 
max_value min_value mnemonic small_increment 
value width
}
A slider obtains a numeric value. The user can drag the slider's indicator to the left or right (or up or down) to obtain a value whose meaning depends on the application. This value is returned as a string containing a signed integer within a specified range (the integer is a 16-bit value, so the maximum range is -32,768 to 32,767). The application can scale this value as required.
A quoted string that contains the current (integer) value of the slider (default: min_value).