Number

A KontrastNumber holds a numeric value. In the simplest case the value is directly taken from a numeric JavaScript value. However, you can also assign mathematical expression as a string. The expression is parsed, evaluated, and the result is stored in the KontrastNumber object.

Assignment

• You can assign a JavaScript number.

• You can assign a string which is interpreted as a mathematical expression, such as 'e^2', 'sin(pi / 2))'. All available functions are detailed here.

Context menu

In the context menu, the number can be entered as a string in the string format described above. Underlines are shown to clarify the grouping of the mathematical expression. There are some keyboard shortcuts:

• Arrow up / Arrow down
  Increase or decrease the number by a certain step size that is determined based on the typical range of the numbers.
• Ctrl + Arrow up / Ctrl + Arrow down
  Increase or decrease the number (with half the original step size)
• Ctrl + Shift + Arrow up / Ctrl + Shift + Arrow down
  Increase or decrease the number (with one tenth the original step size)

Interface

Functions

• assign(value: string | number)
  Assign a new value.
• increase(amount: number)
  Increase value by amount.
• decrease(amount: number)
  Decrease value by amount.
• assignInstantly(value: string | number)
  Assign a new value (without a smooth transition from the old value).
• addEventListener(eventName: string, callback: function)
  Registers the callback function as an event listener for the specified event name.
• clearEventListener(eventName: string)
  Remove all event listener callbacks associated with the event name.

Properties

• type: string

  The read-only string 'KontrastNumber'.

• defaultValue: number

  A read-only number that contains the default number of the specific property.

• value: number

  The current value (as a JavaScript number).

Events

• change, callback: function () { … }
  Event that fires whenever the value is changed.

See Events in Kontrast for more details of events.